KNOWLEDGE y 0 L . I y . MAGAZINE OF SGIENCI PLAINLY WORDED -EXACTLY DESCRIBED =^ CONDUCTED BY RICHARD A. PROCTOR. Let KNOwr.EDGE fiROw from moke to more." — Tennyson YOLUME IV. JULY TO DECEMBER, 1883. LONDON: WYMAN & SONS, 7 4-7G, Cx R E A T QUEEN STREET, LINCOLN'S-INN FIELDS, W.C. 1883. K7 INDEX TO VOLUME lY. GENERAL. Accident to Mr. Eichard A. Piocjlor, reference to au, ill AckroyJ, William, the coloured curtain of the eye, 165 Ally, iolin Ernest, the fisheries exhibition, natural history department (illustrated), 8, id, 87, 12:!, 179, 253 AKriculturo and geology, 4, 19 Allen, Grant, a naturaUst's year, about variation, 1 ; crabs and lobsters, 33 ; wasps and flowers, tio ; a robin's skull, 97 ; wild peas, 129 ; the barn owl flies, 161 ; blackberries are ripe, 193; the shrews die, 22 1 ; chestnuts fall, 251 ; under false colours, 297 ; the reign of evergreens, 327 ; the robin eumes for crumbs, 355 Allinson, T. R., L.E.C.P., cheap and good food, 371 Alps, the, and the Himalayas, 210, 270 Amateur electrician, the (batteries, illustrated) , 6, 1U2, 133, 271, 333, 375 American manners in travelling, 131 Amerit-au trains, puzzle concerning, 318 Amphioxus laneoolatus, the (illustrated) , 348 Ancient comet, an, 392 Anonymous critiiism, remarks on, 5!) Antiquity of man, the, 195 Anthropologist and savage, 7 Anthropometric oommiftee, observations of the, 209 Arizona territory, the, 237 Arnold, Mr. Matthew, as a lecturer in America, 292 Association, the British, 200, for details Bee British Association Astronomical collisions, 388 Astronomical experiments at high elevations, 237 Audiences, how and when they should applaud, 59 Australian Ants. 21 1Uli„ Professor 1!. S., LL.D., the sun's distance, 197, S->''. 2.".7. -^ I. 3111 ; on the sun and the Times, 21s He(H.iit FilitiiiM i, [irinters and punctuation, 140 Bei-l. -,'ni,.ilmp. ■■■liimt the, 28, « Birlh :, ,.\ r... I myth (illustrated), 37, 50, 82, 114, I ■.,, : ■, J il, J ;'i, 269,299 Bi,h..; , Ml , , assumptions, 12 Uri , W i. , I'i ills' comet, 331 Bill 1! , etlecl on haiuhvriting, 223 Br,. I, I , . , unit from, 313 Brill. ' wiriitod), 5, 38,74, 106, 133 Ucii. || \ , -iii;; observations of the A;ii bi .J. IN I M I ,,;ii: 1 1, -i^tho elements, meteoric dust from the Himalayas, molten metals, the origin and development of tlie rhinoceros, cats with an abnormal number of toes, Mr. Adam Sedgwick on tlje periodatus. Dr. Schuster on motion of Swiss Iglacicrs, 209; mathematics in our schools, 220 ; the efl'ect of brain disturbance on handwriting. Mr. Q. i'. Culverwell on the elfect of .h1 in siillin!.' iho waves in a storm. Dr. Stone on li I-..iii.,il ii. I I, til,. e of the human body, I'l,, I I I. Ill photography, 223; .Ml I; I i I. (..| '.III tin astronomical oxperimcnl t ::( livli ,.|t..,,tii..ii . Mr. Litton Forbes on the Arizona territory, Mr. B. H. Inglis Palgrave on the old age of working men, Professor Janssen on the solar corona, Mr. Coutts Trotter on Now niil.i,-ii ■ii7, --'lis lirowiiini;, ,l,,lti ntt.tlt m 1883 (small wheels t>. Iiir^'c). 1: I. I. I, i i , I wo-speed tricycles, 212, ;ii;u, L'; t .1 I I ' , wrinkles, lubricants antl brakes, .;iiti. int,:,. iiu:; inaelunes from weather, inonding tyres, and riding in winter, 332; the Rover, the new Rtickcr, the Cobweb, the Coventry Tandem, and the llarsman, 387; weather fore- casts ami li'wv (" nrikc them, the rainband Bpectrii.1,...],.. liNii-ii Ij, 229 lirnsh dyiuni I t 1 1 :, t , it imie, the (illustrated), 21 liiirgiu djuii I iiuliine (illustrated) , .the, 390 Duller, E. A., B.A., ladybirds, 370 Cables, submarine, 31.t Cat upon a Roman tile, a, 380 Cats, heredity in, 209 Cats with an abnormal number of toes, 209 Caverns in earth and moon, 371 Caylev, Professor A., the Philosophy of Mathematics, 2111, 279 Census, the, occupations of the people compiled from, 330 Cereals, chemistry of the, 18, 52, 03, 119, 131, 201 Challenge, a, from the earth-flattening society, 36, 362 Cheap and good food, 374 Chemistry of cookery, 2, 33, 67, 98 ; frying m oil, 135, 105, 194, 223, 253, 235, 313, 342, 385 Chemistry of the cereals, 18, 52,93; bread-making, 119, 151, 201 Chess Column :— useful end game, 32 ; the interna- tional tournament at Nuremberg, 03, 79 ; game between Messrs. Bird and Rieiuami, 60 ; game between Herr Tarasch and another at the second Kuremberg international tournament, 128; problem by Graz J. Berger, 160; position in a game between Steinitz and an amateur, 176 ; one hundred chess problems (review), 325 ; remarks on various methods of chess-plaving, 235; the influence of mind on chess-playing, 236, 266 ; problem tourna- ment of the South duatralian CAroiiic/c (Adelaide), 266 ; ladies as chess players, 281 ; analysis of a game, 282 ; game played in the London international chess tournament, 334; book of the tournament, 367 ; notes of a game played by Mr. Blackburne, 368 ■ our Christmas bit, 398 ; see also 16, 48, 96, 112, 141, 191, 192, 208, 222, 250, 296, 311, 340 Cliicai/o Tribune, the, and Mr. Richard A. Proctor, 203 Chisholm, G. Geo., M.A., curiosities of the sub- tropical garden, 273 Cholera preventive, 60 Christmas works, review, 307 Clodd, Edward, the birth and growth of myth (illus- trated), 37, 50, 81, 113, 148, 182, 210, 239, 269, 299; evolution and natural theology (review), 331 Coincidences, strange, 298 Collisions, astronomical, 383 Colons and commas, 205 Coloured curtain of the eye, the, 153 Comma, the, 118 Commas and colons, 203 Conduct, the evolution of, 215 Constitution, remarks on the British. 228 Cook, Robert B., evidences of the glacial period, 37.3 Cookery, the chemistry of, 2, 35, 67, 98; frying in oil, 135, 165, 194, 225, 253, 285, 313, 342, 385 Cope, E D., the evolution of human physiognomy (illustrated), 136, 163 Copeland, Mr. Ralph, on astronomical experiments at high elevations, 237 Copernicus, a new theory of (paradox), 77 Copper salts, are tliev poisonous ? 39 CorminI ph.iiiiTiiphv' without an eclipse, 223 Co,;,!,,: ;,. , , he new series of, 13 Con III • tti ,1 , Niagara (illustrated), 1.32 Cuhn". . . M. I. I'., un the ofl'ect of oil in stilling Miwo ..I .. „i_..iii, 223 Curiosities of the subtropical garden, 273 I Mr. Proctor's lectures, 318 iig, 171 Daru ',..i.:i.-.7 Daw . W 11,1 I i.issiblo suspension of old age, 393 Day 111. ., I't It. (illustrated), 230 Dc'alli .1 Ciili.iu Webb, 108 Death of Professor Tobin, 157 Delineation, on lunar, 302 Distance of the sun, 197, 226, 257, 234, 301 Divided skirt, the, 28 Dress reform, principles of, 51, 91 Babth-elatieniso Society, a challenge from the, S36, 362 Earth, pretty proofs of the rotundity of (illustrated), 08, 84, 100, 116, 139, 117, 171, 276, 303 Earth, sim-views of the (illustrated), 57, 121, 183, ilo, 321, 377 EcHpse of last May, the (illustrated), 3(3 Klectrieal resistance of the human body, the, 223 Electrician, the amateur, batteries, «, 102, (illus. tratod), 132, 271, 333, 375 Elements, the, 211 Elsden,J. Vincent, B.Sc.F.C.S., geology and agricul- ture, 4, 19 Employers, inuniQcent, 276 l!iierg,y of nature (review), 359 Kpliciiiera, or day flies (illustrated), 230 Ephemera, view "of, 231 Evidences of the glacial period, 373 Evcdulion and natural theology (review), 331 Evolution of human physiognomy (illustrated), li% 168 Evolulioa of conduct, 105, 138, 166, 199, 215, 251 Extraordinary sunsets, the, 311 Eye, the coloured curtain of the, 155 F.1.CE of the Slty, July 6 to July 7, 13; July 20 to August 3, 43 ; August 3 to August 17, 77 ; August 17 to August 31, 109; August 31 to September 11, l-Jl ; September 14 to September 28, 172; Septem- ber 28 to October 12, 205; October 12 to October 26, 232; October 26 to November 9, 261 ; Novem- ber 9 to November 23, 293 ; November 23 to Dec. ember?, 318; December 7 to December 21,350; December 21 to January 4, 379 Figure conjuring, 28 Fish and phosphorus, 246 Fisheries Exhibition, the, the natural history depart- ments, (illustrated), 8, 40, 87, 123, 149, 179, 255, 305, 329. Fish, the lancelet, (illustrated), 318 Fiske, John, the evolution of conduct, 215 Fixed stars, the, and Mr. Proctor, 43 Flames, 242 Flight of a vertical missile (illustrated), 10, 11, 58 Polly and courage at Niagara (illustrated), 132 Food, cheap and good, 371 Forbes, Mr. Litton, on the Arizona territory, '237 Foster,Thomas, the morality of happiness, 36; conduct and duty, 66 • the evolution of conduct, 103, 138, 166 ; right and wrong, 199, 231, 283 Geology and Agriculture, 4, 19 Glacial period, evidences of the, 373 God, the ivill of, 11 Government, Mr. Herbert Spencer on the scientiflc aspects of, 228 Government of God, remarks on, 12 Great Britain, sun-views of (illustrated), 131 Green sun in India, the, 271 Hanbwbiting, brain-disturbances on the, 223 Happiness, the moraUty of, introductory, 36 ; conduct and duty, 66; the evolution of conduct, 105, 138, 166 ; right aud wrong, 199, 251, 2S3 Harvest moon, the (illustrated), 156, 161 Hastings, Dr., and the corona, 27 Henrici, Professor, mathematics in our schools, 320 Hersohel, Sir Wilham, analysis of papers of, by Messrs. Holden and Hastings, 94 Herschel, Sir William, the study of, 59 Himalayas and the Alps, the, 240, 270 How is a life-assurance society worked ? 333 How to get strong, reducing fat, 31, 4:), 70, 99, 117, 143, 252 ; in middle and advanced lite, 345 How to see (review), 359 Human body. Dr. Stone on the electrical resistance of the, 2>3 Human physiognomy, the evolution of (illustrated), 136 IcELilfD and New Zealand, hot springs of, 247 Imaginary, mathematics of the, *237 Indian insects, beasts, and birds, ways of (review), 300 India, the green sun in, 271 Infant, mind in the, 386 Infants, the senses in, 311, 313 Insects, a neglected variety of, 316 Instinct, Darwin on, 357 Irving, Mr. Henry, and New York newspaper criticism. Ischii id Vesuvius, 81 Jack Kbtch, 188 Jngo William, F.C.S., the chemistry of the cereals, 19, 53, 93 (oread-making), 119, 151, 201 Janssen, Professor, on the solar corona, 233 ElUDEil, Thomas, SI. A., sea anemones, Ac. (illus- trated). 22, 89, 115, 187, 211, 2M, 259, 305, 329 King, E. M., i>riuciples of dress reform, 51, 91 Knowlsdos, annouucjinenls for ISM, 319 Krao, 213 Labour, produce of, divided in various countries, 27 Ladybirds, 370 Lancelet Ush, the (illustrated), 3 IS Laws of brightness, 5, 33, 71, 106 (illustrated), 133 Lectures, holiday, ty Mr. Richard A. Proctor, 42, 303 Life, and its criticism of Mr. Proctor, 173 Life Assurance Society, working of a, 353 Locusts, 217 VI ♦ KNOWLEDGE ♦ General — continued. Luminosity of plants and animalSj 303 Lunar delineation, 302 Lunar theory, a point in the, 180 MlCKAY, Mr. Charles, on the word *' Masher," 22S Man, the antiquity of, 195 Marine monster, a, 332 Masher, alleged derivation of the word, 229; origin of the word, 31S Mathematical Column : Geometrical problems (illus- trated), li, 31, ■!«, 62, 78, 95, HI, 127, 1«, 220; easy lessons in geometrical problems, 175; the pliilosophy of mathematics, 279; see also ItiO Mathematics of the imai,'inary, 287; in our schools, 220 Mathematics, the philosophy of, 201 Meteoric dust from the Himalayas, 209 Microscope, pleasant hours with the (illustrateil) , 17, 71, 103, 1311, Vil, ilH, 212, 287, 316, 383 Mind in the infant, :«rt Miracles (review), 307 Missile, flight of a (illustrated), 10, 41, 68 Missing link, th^ alleged (Krao), 213 Molten metals, Professor Chandler Roberts on, 239 Monster, a marine, 332 Moon, the harvest (illustrated), 156, 161 gh a three-inch telescope (illustrated) , 5tl. , 132 Moralitv of happiness, the, introductory, 36; conduct and duty, 66; the evolution of conduct, 105, 13-1. 168 ; right and wrong, 199, 251, 283 Munificent employers, 276 Musical critics, remarks on, 59 .Myth, the birth and growth of, 37, 30, 82, 111, 116 (illustrated), 132, 210, 239, 269, 299 NiTURiL theology and evolution (review), 331 Naturalist, year of a, about variation, 1 ; crabs and lobsters, 33 ; wasps and flowers, 65 ; a robin's Bkull, 97 ; wild peas, 139 ; the barn owl flies, 161 ; blackberries are ripe, 193 ; the shrews die. 231 ; chestnuts fall, 251 ; under false colours, 397 ; the reign of evergreens, 327; the robin comes for crumbs, 355 Jfature, energy of (review), 35'J Neglected insects, 316 New Guinea, Mr. Coutts Trotter, F.R.G.S., on, 338 Newspaper science, value of, 217 Niagara (iUustrated), 73 Niagara, folly and courage at (illustrated), 152 Niagara whirlpool, safe passage of a steamer through, 90 Nights with a three-inob telescope (illustrated), 35a Notes on punctuation, 188 OcocpiTrows of the people in England and Wales, the, 3311 Oil, its effect in calming the waves, during a storm, 233 Old age, the possible suspension of, 393 Orbit of the great cumet of 18S2, Knowledgb on the, Orthocynodon the. the supposed origin of the rhino- ceros group, 209 Our American cousins (review), 190 Our boys at school. 177 Outrages on the underground railway and evolution, 293 Paobt. Sir James, recreation through uncertainty, 375 Palgrave, Mr. B. II. Inglis on the old age of working Parcels post, greatest content with, 76 Peard Miss, and the Spectator, 37 Peek, Mr. T. K. Cuthbert, on the hot springs of Iceland and New Zealand, 247 Pengelly, W., the antiquity of man, 195 People, occupations of the, 330 Periodatus, Mr. Adam Sedgwick on the, 209 Philosophy of mathematics, the, 201 Phosphorus and fish. 343 Physiognomy, the evolution of human (iUustrated), 136. les' Pleasant hours with the microscope, 17 (illustrated) 71, 103, 130, 162, 216, 212, 267, 316, 333 Poker and Tralh, 215 Poker principles, 203 Pons-Brooks, the comet of, 331 Possible suspension of old age, the, 393 Pretty proofs of the earth's rotunditv (illustrated), 68, 84, 100. 116, 139, 147, 171, 275, 303 Principles of dress reform, 54, 91 Printers and punctuation, 110 Proctor, Richard A., the laws of brightness (illus- trated), 5. 33. 74, 106, 133; flight of a vertical missile (illustrated), 10, 41, 53; geometrical problems (illustrated), 14, 31, 48. 62, 78, 95, 111, 1-7,143; easv lessons in, 175; figure conjuring, 26; spots in the sun, 51; Niagara (illustrated), 72; the greatest content with the parcel post 76- Vesuvius and Ischia (illustrated), 81; pretty proofs of the earth's rotundity (illustrated). 63 81. 100, 116, 139. 147, 171,275.303; the comma] 111; sun-views of the earth (illustrated), 57. 121, 185, 315. 321.377; American manners in travelling, 154; the harvest moon (illustrated), 156, 161; notes on punctuation. 196; strange creatures 283 • the green sun in India. 274 ; milhematics of the' imaginary, 287 : ring of small planets (illustrated), 290; strange coincidences, 2 '3; the zjne of small planets, 328, 356; a marine monster, 332; a '■hslleiige from the earth-flattening society, 336, .T;J; neglected insects, 316; how to see (review), :i/l : the universe of suns, 389, 381; caverns in the earth and in the moon, 371 ; science and safety at sea. 373 Projectiles, winds as, 170 Physical problems, U Psychical Society, the, and thought-reading phenomena, 13 Punctuation and printers. 140 Punctuation, notes on. 138 Pyramid, the great, Miss A. B. Edwards and Mr. K. A. Proctor, 53 QutNCRY, de, version of Richter's dream by, 288 Raynard, A. C, the extraordinary sunsets, 341 Recreation by wonder, 339 Recreation through uncertainty, 375 Keddie, Mr., controversy withj 189 Relief of sea-sickness, 215 Rhinoceros group, the origin and development of, 209 Rirhter, dream of, 388 Ring of small planets, the (illustrated) , 390 Rotundity of the earth, pretty proofs of (illustrated), 08. SI, 100, 118, 139, 147, 171, 275, 303 Russell, Percy, the occupations of the people in England and Wales in 1331, from the last census, 330 SATURy, the discovery of the chief division in the ring of, 75 ; in a three-inch telescope (illustrated), 319 Savage and anthropologist, 7 School, our boys at, 177 .Schuster, Dr., on the motion of Swiss glaciers, 209 Science and safety at sea. 378 Sea anemones (illustrated) 32 ; the white carnation, 89. 115; the daisy, 137, 314; the cave dweller, 2H ; the parasite, 350 : the dahlia, 305, 339 Sea-bathing, dangers of. 171 Sea creatures, strange, 363 Sea, science and safety at, 378 Sea-sickness, the relief of. 315 Sedgwick, Mr. Adam, on the periodatus, 309 Seiss, C. Few, the star-nosod mole (illustrated), 348 Sensesininfants, 314, 313 Shoebill,the (illustrated), 105 Sky, the face of the, July 6 to July 7, 13 ; July 30 to August 3, 43 ; August 3 to August 17, 77 ; August 17 to .\ugust 31, 109 ; August 31 to September 14, 111; September 14 to September 28, 173; Septem- ber 28 to October 12.205 ; October 13 to October 28, 232 ; October 20 to November 9, 281 ; November 9 to November 23, 292 ; November 33 to Decem- ber 7, 318; December 7 to December 21, 350; December 21 to .January 4, 379 Slack, Henry J., F.G.S., pleasant hours with the microscope (illustrated), 17, 71, 103, 130, 162, 216, 2^12. 287, 316, 333 Slingo, W., submarine cables, 345 Small planets, the ring of (illustrated) , 390, 328. 356 Spencer, Mr. Herbert, on the scientific aspect of systems of government, 228 I the Star-nosed mole, the (illustrated), 343 Stephen, Mr. Leslie, on the influence of science. 23 Stokes. Professor, on coronal photography without an eclipse, 323 Stone, Dr., on the electrical resistance of the human body, 223 ; on the eft'ect of brain-disturbances on the handwriting, 233 Strange coincidences, 298 Strange sea creatures, 268 Strong, how to get (reducing fat), 31.49, 70, 99, 117- in middle and advanced life, 145, 253 Submarine cables. 345 Subtropical garden, curiosities of the. 273 Sun, the distance of, 197, 226, 257, 231. 301 Sun, the. in a three-inch telescope (illustrated) 177 Sun, spots on the. 51 (illustrated), 2(10 Suns, the universe of, 389, 331 Suns, voices of the (a poem) , 229 Sunsets, the extraordinarv, 311 Sun views of the earth (illustrated), 57, 121. 185, 215, 331, 377 ; sun views of Great Britain, 181 Sii-fingered animal, alleged descent of man from a, 309 Swiss glaciers. Dr. Schuster on the motion of, 309 Thought reading. 9 Three-inch telescope, the moon through a (illustra- ted) , 66, 86, 123 ; the sun in a, 177 ; nights with a, 253 Time turned back, 363 Times, the, and newsp.iper science, 218 Tobin, Professor, death of, 157 Toes, abnormal nmnber of in cats, 209 Tricycles in 1883, small i>. large wheels, 113, 131, 169, 181; two-speed, 212, 280, 274: mud-guards, wrinkles, lubricants, and brakes, 300; protecting machines from weather, mending tyres, and riding in winter. 332 Tricycles in 1933. the Rover, the new Rucker, the Cobweb, the Coventry Tandem, and the Oarsman. 337 Trotter, A. P.. time turned back, 363 Trotter, Mr. Coutts. F.R.G.S., on New Guinea, 233 ' Truth and Mr. Richard A. Proctor, on poker principles, 206 Trii'h and poker, 215 Two-speed tricycles, 312 Tyndall, John,' remarks o LTnceb of genii through, 375 Vaot sun-spots (illustrated), '200 Vertical missile, flight of a (illustrated), 10, 41, 63 Vesuvius and Ischia, 81 Vibrato, the, 392 Voices of the suns, a poem, 229 Wats of some Indian insects, beasts, and birds (reriew), 360 Weather forecasts and how to make them, the rain- band spectroscope (illustrated), 229 Weather wisdom, 397 Webb, Captain, and his attempt to swim Niagara, 27, 108 Webb, the Rev. T. W., on lunar deUneation, 302 Which, and the use of the comma. 59 Whirlpool rapids, the, Niagara (illustrated), 152 Whist column: Taking a partner's trick, 143; long weak suits, 175 ; returning a partner's suits, 175 ; whist questions, 175 ; the Australasian and the Knowlbdgb whist column, 285 ; Signalling at Whist, 295, 335 ; a whist study, 311 ; conventional rules at whist, 334 ; notes by Mr. Lewis, 325 ; notes and criticisms, 353; see also 15, 47, 339 Wiggins, Mr., criticism of, 171 Williams, W. Mattieu. the chemistry of cookery, 2, 35, 67, 93 ; frying in oil, 135, 165. 194, 325 ; flames, 213; fish and phosphorus, 216, 253, 285, 313, 385 Wilson, Dr. Andrew, lectures by, on anatomy and physiology, 349 Winds as projectiles, 170 Wonder, recreation by, 339 Working men, the old age of, 237 Year of a naturalist, about variation. 1 ; crabs and lobsters, 33 ; wasps and flowers, 65 ; a rabbit's skull, 97 ; wild peas, 139 ; the barn owl flies, 161 ; lilaekberries are ripe, 193; the shrews die, 224 ; chestnuts fall, 251 ; under false colours, 297 ; the reign of evergreens, 337; the robin comes for crumbs, 355 Young, Prof. C. A., astronomical collisions, 388 Zauoisei and his mesmeric powers, 11 Zetetic society, the, 336 Zone of small planets, the, 323. 356 Zukertort and his defeat by Sellman and Mortimer, 27 CORRESPONDENCE. Alahmixg incident, an, 396 Alteration in coast line, 30 America, discovery of, 309 American English, 95 American warts, 142 Ancient Egyptians, height of the, 112 Animals, luminosity of, 381 Anthropometry, 262, 277, 322 Ant, intelligence of an, 45 Astronomy of the Times, 219 Audiphone, the, 363 Auditory fans, 110 Auditory fans (the audiphone), 263 Balloos, moonhght ascent in a, 323 Barn owl, the, 361, 278 Barometers, heavy fall in, 263 Battery, the Bennett, 173 Bee^'limast and chestnuts, 291 Beetle, a luminous, 367 Beluga, the. in the Brighton Aquarium, Bennett battery, the, 173 Bi. icula ,44 Birth and growth of Mvth, 333 Blackfriars, a find at, 397 Brilliiint rainbc a, 293 Capital, the doubling of, 351 Chamieleons, the feeding of, 367 Chestnuts and beechmast, 291 Cholera, 94 ; prescribing for the, 109 Coalfield men, 386 Coast line, alteration in, 30 Coffee, 174 Coincidences, strange, 351, 330 Colours of flowers, 159, 190 Comma, the. 174 Common earthenware, is it luminous ? 263 Complete magic square, a, 231 Contracted multiplication, 309 Convertible sociables, 388 Coral deposits at Blackfriars, 397 Crime and insanity, 378 Curious multipUcation, 263. 331 Curious phenomenon, a (illustrated), 173, 207, 219. 293 Day or week, 293 Deaf cats, 191 Different degrees of illumination, 153 Discovery of America. 309 ♦ KNO\VLEDGE ♦ Vll Correspondence — continued. Doubling of population, capital, &c., 263, 309, 351 Dress reform, 30, 61, 77 Drowning, obscure causes of death by, 309 Dull hearing and the microphone, 339 " EittLT Man in Britain," 201 Earth-shine, 61 Earth-worm, the common, is it luminous? 263 Egyptians, height of the ancient, 112 Enigma, an, 45 Eruption in the Sunda Straits, the, 365 Extracts from " Early Man in Britain," 261 Extraordinary sunsets, the, 364 Fekdiko chamEclcons, 367 Fiction, truth stranger than, 352 Figure-conjuring, 61, 169 Figure-magic, 262, 381 Find at Blackfriars, a, 397 Flat earth theory, the, 295 Flight of missiles, 44, 141 Floating docks and iron ships, 142 Flowers, colours of, 158, 190 Flowers, light from, 123, 174 Franklin, Dr., magic square of squares, 233 GALLEY-head light, the height of the, 158 Geuealoftical puzzle, 13 ; answer to, 29 Geometrical and real perspertive, 60 Ginger-beer plant, 45, 142, 174 Girth and the parcel post, 109 Glass, the storm, 263 Gnat poison, 125 Greatest content of a parcel which can be sent bvpost, 159 Great sea wave, 365 Green sun in India, the, 293, 247, 323 Growth of nail, the, 397 Hangman, the, 278 Heavy fall in barometers, 283 Height of the ancient Egyptians, 142 Uerschell, Sir William, alleged loss of an eye by, 219 ; see also 233, 277 Uigh-wheeled tricycles r. low wheels, 206 Hull-down ship, a (illustrated), 219, 232 •• Humble soldiers," the, 208 iLLUKiNATiorr, different degrees of, 158 India, perforated stones in, 322, 367 India, the green sun in, 293 Insanity and crime, 278 Internal parasites, 294 Iron ships and floating docks, 142 Is the Bun green ? 351 Jack Keich, 262 Jupiter, the satelHtes of, 337 Jupiter without satellites, 323 KKTcn, Jack, 262 Krakatoa, sound waves from, 323 Lake wave, a strange, 395 Lancashire, strange sunrise and sunset effects in, 363 Large and small wheels for tricycles, 277 Large meteor, a, 368, 396 Large sun-spot, 29, 60, 9 1, 278 Large p. small wheels, 339 Light from flowers, 125, 174 Lightning, silent, 381 Luminosity in plants and animals, 263, 3S1 Luminous bettle, a, 367 Luminous ring, 141 Lunar photography for small telescopes, 396 Lunar shadows, 365 Magic square, a complete, 61, 125, 234 Man, palKolithii-, 261 ■' Masner," origin of the word, 366 Mechanical puzzle, a, 61 Meteor, a large, 366, 397 Meteorites, organic matter in, 263 Mirrophone, the, and dull hearing, 339 Missiles, flight of, 44 Moon, surface of tlie, 248 Moon, sunset on the, 159 IMoon, the motions of the, 365 Moonlight ascent in a balloon, 322 Mud.guards for tricycles, 294 Myth, birth and growth of, 333 NAit, the growth of the, 397 Naked-eye spot, 207 New moon on Saturday, 293 Numbers, property of,' 263 OnsciHE causes of death bv drowning, 309 Oldest historical tree, tile, '78 Omnicvcle, the, 397 Owl, the barn, 261, 278 Optical phenomenon, 174 Ordnance nmp mensurements, 30M, 337 Organic matter in meteorites, 263 1'al.*;olithic man, 261 Parcel post problem, 126 I'orch, showers of, 396 Perforated stones in India, 322 367 erved in, 141 19: the kilt, 61 Phenomenon, a curious (iUustrated) , 173, 207, 219, 293, 3 i2, 337, 338, 396: observed in railway travelling, 141 Plants and animals, luminosity in, 263, 308 Pons, the comet of, 232 Population and capital, &c., doubling of, 262 Postage stamp forgeries, 337 Prescribing for cholera, 109 Printers and punctuation, 157 Probabilities, a problem in, 61 Problem in probabiUties, a, 61 Property of numbers, 263 Punctuation and printers, 158 Rabbit, skull of a, 174 Railway travelling, phe Rainbow, a brilliant, 293 Rational dress, 13 ; for n Reducing fat, 168 Ring, a luminous, 1 H SiTELiiTBs of Jupiter, the, 337 Saturday, a new moon on, 293 Saturn (illustrated) , 366 Sea wave, a great, 365 Severe weather in November, 1883, 323, 352 Shakespearean insects, 366 Ship, hull-down, 233 Ship struck by lightning, a, 396 Showers of perch, 396 Silent lightning, 308, 381 Singular numerical property, 142 Singular phenomenon, a, 60, 32i, 337, 338, 396 Skull of a rabbit, 174 Skyers (cricket) 61 Small telescopes, lunar, photography for, 396 Small wheels for tricycles, 248 Small wheels r. large wheels, 158, 173, 233 Sociables, convertible, 366 Softening water, 232, 310 Sound waves from Krakatoa, 323 Squirrel, curious structure of the, 126 Storm glass, the, 263, 310, 338 Stormy petrel, 173 Strange coincidences, 351 Strange lake wave, 395 Strange sea creatures, 322 Strange sunrise and sunset effects in Lancashire, 385 Sun and planet bicyi-Ie, the, 207, 219 Sun, the, is it green ? 351 Sunda Straits, the eruption in the, 365 Sunset on the moon, 159 Sunsets, extraordinary, the, 364, 395, 396 ; and blue moon, 380 Sunspot, a large, 29, 60, 94 (illustrated), 248, 278; green and blue, 247 ; and comets, 380 Surface of the eyes, how to see the, 30 Surface of the moon, 248 Theee times greater than, 309 Totemism, 219 Total abstinence, 294 Tree, the oldest historical, 78 Tricycle wheels, 218 Tric'ycles, 352, 397 Tricycles, mud-guards for, 291 Tricycles, small wheels for, 173 ; large and small wheels for, 276 TricycUng in winter, 366 Truth stranger than Action, 352 Vketicai, missile, flight of a, 141 Visual phenomenon, 19t> Vortex-atom theory, the, 110 Waet charming, 125, 142, 190, 263 ■\Varts, 45 Water, the softening of, 232 Weather forecasts, 338; how to make them, 366 Wheels, large c, small, 339 Winter, tricycling in, 366 REVIEWS. Book of the Tournament, the, 334, 36", 382 Chess problems, one hundred. By the Kev. A. CjTil Pearson, M.A. Civil Serrice Printing Company, 325 Christmas works, various publishers, 307 E.VEBGY in nature ; a course of six lectures upon the forces of nature and their mutual relations, delivered under the auspices of the tJilihrist educational trust. By W. L. Carpenter. Messrs. Cassell ct Co., London, 359 E\olution and natural theology. By W. F. Kirby, of the British Museum. W. Swan Sonnenschein, & Co., 334 How to use our eves. By John Browning, F.R.A.S. Messrs. Chatto i Windus, London, 359 MlEACLEs. a review of Hume and Huxley on. By Sir Edmund Beckett. London Society for Pro- moting Christian Knowledge, 307 OiTB hundred chess problems. By the Eev. A. Oyri^ Pearson, M.A. Civil Serrice Printing Company, sins : being personal impressions of the people and institutions of the United States. By W. E. Adams. Walter Scott, London, 190 Teibes on my frontier : an Indian naturalist's foreign policy. 'By E. H. A., with illustrations by F. C. MISCELLANEOUS. Accidents from lightning at Cyprus, 361 Agnosticism, Professor Huxley on, 317 Air, daily mean motion of the, 58 American telegraph system, the, 203 Ancient monuments of Egypt, the, 261 Aniline colours and their inlluence on health, 336 Anthracene and light, 203 Asking and answering, 285 Astronomical Alderman, the (Horace Smith's), 286 Atoms, the size of, 76 Aurora (illnstrated), electric light in, 359 Australasian statistics, 109 Autumn leaves, facsimile representations of, 131 Bbdfobd college, London, 317 Bcrthold, Consul, and his free railway pass, 26 Blackwood, diaries of, 370 Blake, Dr. L. J., on evaporation and electricitv, 213 Blank verse, observations on, 264 Bournemouth, thunderstorm at, 361 British Association, the, what constitutes membership of, 294 Bumham beeches, 213 Cable for Cochin China, a, 137 Caoutchouc, new source of, 154 Carbonaceous meteorite, a, 134 Cementing rubber or gutta-percha to metal, 91 Chinese telegraphing, 307 Careless crossing of railways in America, 268 Coal boring in China, 238 Cocliin China, a cable for, 157 Colours, capacity to distinguish in railway servants. 163 Critical points in magnetism, 155 Cyprus, accidents from lightning at, 361 Cyprus, lead-smelting in, 288 Cyprus snake, a, 232 Daewin, Mr., on theism and evolution, 276 Deity, observations on the, 279 Delo's, results of excavations in the island of, 157 Doctors, proportion of, to the population, 260 Dynamite struck by lightning, 165 Edison electric light, the, 60 Edison lamp, life of the, 202 Edison svstem in the House of Commons, 211 Egypt, the ancient monuments of, 261 Electricity and evaporation, 213 Electric lighting at mills, 214 Emotional truths and scientific hallucinations, 317 Evaporation and electricitv, 213 Exeter Literary Societv. 265 Extinction of tne mastodon, 330 Fiction, truth stranger than, 286 First inventor of the telephone, the, 315 Fiske, John, on Herbert Spencer, 162 Fiske, John, on inscrutable power, 167 Floating domes for telescopes, 42 Forth Bridge, the, 12 Oeemix imperial telegraph department, items in the cost of, 3 Olenisla, Forfarshire, remarkable phenomenon in, 38 Gnostics aud agnostics, remarks concerning, 310 Gold production in Russia, 55 Granite, the largest isolated piece known in the world, ISO Great sea wave, the, 393 HiMnrBo tramwav, llangeless-wheel cars on the, 74 Heated gases, the "luminosity of, 51 Heath, fern-portfolio of Mr", 317 Heath, Mr. F. O., on Bnruham Beeches, 213 Herbert .Spcni-er, 162 Highest bridge in the world, the, 20 House of Commons, the Edison system in the, 214 House, safety in the, 351 How a locomotive was raised from a river, 26 Human footprints in Nevada, 151 Uumher, Marriott, & Cooper, action against, patent llydrauhc lifts, fatal accidents from, 200 iKBiFFEBENTisM, observstions on, 311 Insulating wires, 151 Jack Ketch, observations on, 220 Japanese miners, some curious customs of. 306 Java disturbance, the phvsical results of the. 379 Java earthquake, the telephone during the, 361 KNOWLEDGE ♦ Miscellaneous — continued. Kexch, Jack, allusion to, 2^19 Lake dwellings at Suresnea, discovery of, 2-i3 Largest locomotive in the world, the, 341 Lead-smelting in Cyprus, 288 Life of the Edison lamp, iJ03 Light and anthracene, 203 Literary scheme, a novel, 92 Locomotive, the largest in the world, 344 Locomotives, average distances run by, in different parts of Europe, 26 Lon-est bridge in the world, the, 20 Luminosity of heated gases, 51 Mags^tism, critical points in, 155 Manchester ship canal, the, 157 Mastodon, the extinction of the, 330 Meteorite, a carbonaceous, 134 Mills, electrin lighting in, 314 Mitchell library, Glasgow, statistics of the, 218 Monolith, a monster one at Tiahuanaco, Bolivia, 331 Moimtaiu railway, a new, 203 National Health Society, the, 35i, 376 Navvies, North American Indians as railway, 205 New selenium cell, a. 300 Newspaper science, 76 Nevada, the human footprints in, 154 Nickel, improved preparation of, 138 North American Vidians as railway navvies, 205 Novel literary scheme, 92 OcrDBS, Utah, electric light in, 359 Oregon, a railroad in, 4-1 Organic compounds in the sun, 248 Overhead wires in the United States, 26 PArEB, cross-ties, 24 Paper trade, statistics of the, 141 Piunic parties, electricity for, 241 Pictorial World, purchase of the, by Messrs. H. Clay, Sons, & Tavlor, 124 Pilsen Joel and general Electric Light Company, Limited, 174 Pilsen lamp, reference to the, 92 Pittsburgh, tunnel under the city of, 364 Pleiad, the lost, remarks on, 2^4 Plumian professorship of astronomy, Cambridge, note on the, 381 Poetry, observations on, 231 Powder magazine fired by lightning, 12 Psychical research, the society for, 353 Punctuation and compositors, 235 Raixwat servants and their capacity to distinguisli colours, 165 Rheostat, M. Trouv^^'s invention, 236 Risin'' of the heavenly bodies, remarks on the, 367 Roman tUe, a cat upon a, 389 Safety in the house, 354 Scientific hallucinations and emotional truths, 317 Selenium cell, a new, 300 Shakespeare, blank verse of, 264 Ship assurance, alleged unfair dealing in, 108 Small-wheeled tricycles, 241 Snake, a Cyprus, 253 Soap-bubble colours on glass, how produced, 103 Society for psychical research, the, 353 Speed of worlang on submarine cables, 298 Spencer, Herbert, 163 Sport and science, 150 Startling scientific statement, a, 276 Students of science and the religious question, 279 Submarine cables, speed of working on, 293 Son and tire, fallacy regarding the, 294 Sun, organic compounds in the, 346 Sun-spots, 70 Sunday Lecture Society, the, 257 Tay Bridge, the ruins of the, 108 Telegraphing Chinese, 307 Telephone during the Java earthquake, the, 361 Telephone, the lirst inventor of, 315 Telephone wires and the pubUc, 124 Telephones of the worid, the, 285 Telescope, a cheap and good kind, 12 Theism and evolution, Mr. Darwin on, 276 Thunderstorm at Bournemouth, 361 Thunderstorm in the Jura, 124 Tires, proportion of breakage of on German railways 155 Tobacco smoke, analysis of, 43 Tricycle saddle, a new, 74 Truth stranger than fiction, 236 Tunnel under the city of Pittsburgh, the, 364 Victor Emmanuel gallery, the, 361 "Washington boulder, dimensions of, 150 "Washington monument, the, 150 Watch-spring, dissolving a, 367 "Water, organic impurity in metropolitan, 76 "Westinghouse brake, good services of the, 273 "Wetting coal, effect of, 246 "White glass under the inllueuce of luminous rays, 7 Whitman, Walt, science and poetry, 167 World, the telephones of the, 285 ILLUSTRATIONS. Abdomen of a bee, sketch of an, 267 Actinia bellis (sea daisy), 2; figures of, 187 Actinospherium Eichhornii, figure of (Fisheries Exhibition), 41 Agglomerate, the (electric battery) , 132 Alyasum hair, white (under the microscope), 104 Amateur electrician, the, diagram of batteries, 333 Aristarchus and Herodotus (formations in the moon), 122 Armatui'e, the, of the Brush dynamo-electric machine, 24 Ascones and Leucones, diagrams, showing the structures of, 119 Asteroids, paths of the, 291 Bee, abdomen of a, 267; fore-leg ol a, 267 Bee, tip of the tongue of a, 217 " Bottle," bichromate battery, figure of the, 273 British Isles, France, &c., as seen from the sun in Avinter, 376 Biirgin dynamo-electric machine, four figures of the, 390, 391 Cahxation, the white (sea anemone), figures of, 89 " Carrier," the (tricycle), 274 Commercial sponge, the, 88 Copernicus (ring-plain, with peaks in the moon), 86 Curious phenomenon in the sky, sketch of a, 173 Dahlia anemone, natural size, 305 Dahlia, the sea (sea anemone), 22 Drosera rotundifolia (under the microscope) , 104 Earth, pretty proofs of the rotundity of the, 148 Earth, sun-views of the, 57, 121, 185,'245, 321, 377 Eclipse of last May, the, 363 Eratosthenes (one of the lunar Apennines) , 56 Esequibo Indian women, showing deficient bridge of nose, want of waist, &c., 169 Facvl.t: on limb of the sun, 179 Filtre rapide (Maignen's), sectional views of, 179 Flight of a vertical missile, diagram illustrative of, 10 Fuller cell, diagram showing the construction of a, 376 Gassendi (mountain in the moon), 87 Girl, portraits of, at different a; the facial and cerebral regions, 137 Globigerina ooze, figure of (the Fisheries Exhibition), 8 Grantia compressa (a calcareous sponge), 124 " Gravity" Leclauch6 battery, 132 Harvest moon, the, 156, KM Uedychium Gardnerianum, sketches showing the growth of pollen tubes in, lti3 Heritiera, minor (under the microscope), 104 Herodotus and Aristarchus (formations in the moon), 123 Heteromita, figures illustrating the spores and the young of the (pleasant hours with the microscope) , 18 Honey-bee, mouth organs of, 217 House-flies under the microscope, 71 Hull-down ship, view of a, 219 lyniAK charm, sketch of, 183 Lancelbt fish, the, 343 Luehatze negro woman, profile of, showing deficient nose and chin, 16S Nbgho, face of. showing flat nose, 168 Niagara, the whirlpool rapids, 153 Niagara falls, rapids and whirlpool, 72, 73 Nights ^vith a three-inch telescope, diagrams illus- trative of, 258 Obang-octang, sections of the skulls of, 136 Pahasftic anemone, the, 259 Paths of the asteroids, 291 Polycy3tina(*'Barbadoes earth, "Fisheries Exhibition), 40 Pons-Brooks, diagram of the comet of, 334 Pretty proofs of the earth's rottmdity, diagrams iflustrating, 275, 304 Eadiolabia, drawings from living specimens of (the Fisheries Exhibition), 8 Rain-band spectroscope, figures illustrative of, 229,230 Rhabdoliths, figures of (the Fisheries Exhibition), 9 Rotundity of the earth, diagrams showing the, 68, 69, 84, 85, 100,116, 117 Satanta, portrait of late chief of the Kiowas (Texas), 169 Saturn, view of, through a three-inch telescope, 319 ; diagram showing motion of satellites of, 320 ; view of, on November 23, 18S3, 366 Saw-fly, the outer saw of a, 317 Sea anemones, figures of, 89 ShoebiU, the, 105 Sponge, outer surface of, 88 ; diagram showing the de- velopment of a, 123 Spongiila fluriatilis, diagram of, 149 Spongilla, hypothetical section ofa, 149 Star-nosed mole, the, 343 Sting of a bee, 317 Stinging-nettle hair, under the microscope, 104 Stm, spots on the, 178 ; diagram, 248 Sun-views of Great Britain, three figures of, 184 Sun-views of the earth, 57, 121, 185, 245, 321, 377 Sweet-briar root, under the microscope, 104 Thaites water at Richmond, diagrams of animal and vegetable productions contained in, 180 Three-inch telescope, nights with a, diagrams illus- trative of, 258 Totem, sketch of one from Western Indian tribes, U.S.A., 183 "Traveller," the (tricycle), 274 Troglodytes, two figures of (sea anemones), 244 Tubular live-box, parts of a (to show the actions of insects), 368 Tycho (crater in the moon), 56 Vast sun-spots, photographs of, 200, 201 Venus 's flower-basket, siliceous skeleton of, 83 Wasp, tongue of, 217 Water from cistern, diagrams of diagnosis in, 180 Whirlpool rapids, the Niagara (illustrated), 153 Zinc plate for a Leclanchc cell, 132 July 0, 1883. o KNOWLEDGE ♦ AH ti.0S^^T try . ^MAGi^ZlNEOF^ENCE PlAIKlXfORHED -EXACTLfDESCRIBED LONDON: FRIDAY, JULY 6, 1883. Contents op No. 88. PAGE A Naturalist's Year. XVI. About Variatiou. ByGrant Allen 1 The Chemistry of Cookery. XIII. By W. Mattieu WiUiama 2 Geolojjy and A^jriculture. By J. Vincent Elsdeti, F.C.S., &c 4 Laws of BriRhtness. (/«/«.) By M. A. Proctor 5 The Amateur Electrician 6 Savage and Anthropolofiist 7 The Fisheries Exhibition. (/«««). By John Ernest Ady 8 PAGB Thousbt-Headinj; 0 Flight of a Vertical Missile. By H. A. Proctor '.. lu God's Will n Editorial Gossip 11 The Face of the Sky l:! Correspondence: Rational Dress — Genealogical Puzzle — Letters Re- ceived and Short Answers U Our Mathematical Column 14 Our ■RTiist Column 1.5 Our Chess Column 16 A NATURALIST'S YEAR. .r By Grant Allen. XVI.— ABOUT VARIATION. STROLLING along the lane by the mill-stream this afternoon, I see with a shudder that the epilobes and the St. John's worts are coming out in blossom again for the season, and I feel dimly conscious in my own heart tliat the annual task of trying to sort them out decently into well-marked divisions will recur once more in full tediousness. They are a hopeless set of interlacing species, these weedy, wayside summer flowers ; a perfect chaos of gradually-merging characteiistics, eacli supposed kind shading off imperceptibly into the next through infini- tesimal and imperceptible gradations. Of course, I am personally quite convinced that the effort to introduce an artificial separation where Nature still keeps up an un- broken series is really as aVisurd as it is futile : but the superstitions of the systematists die hard, and I feel in duty bound to settle in my ov;n mind tu which particular bundle of his arbitrary groups a conscientious technical botanist would consider himself at liberty to refer this, that, or the other particular epilobe, or hypericum, or hawkwecd. The thing doesn't really matter in the least, being only a question of human naming, not a question of genuine natural distinctness ; but if one leaves it undone, one has an unpleasant sense of a social duty unperformed, and an important dogma in the Athanasian creed of con- servative science imperfectly understood. It is in great part the general want of knowledge as to the clost! way in which uiany large groups of species thus interosculato that makes most people hesitate so much about accepting the simple truths of evolutionism. The animals with which they arc best acquainted — und most people look at the matter from the standpoint of animal lift! alone — are a few big mammals, all readily distinguish- able from one another, at least here and now, and with few remaining intermediate links to bridge over the gaps between them. Nobody is in any danger of mistaking a cow for a sheep, or even a horse for a donkey ; and the various tarpans, and onagers, and quaggas, and zebras, which span the gulf in the last instance and do really merge into one another very indefinitely, are only to be seen in the Zoological Gardens, or else in Tartary, Central Africa, and other reasonably inaccessible parts. But when we come to examine all the known species of any gieat group, especially among plants, the real difficulty is often not to find intermediate links, but to discover any well demarcated lines of division, or any constant assemblage of characters marking tlieartificial bundlesinto which we choose to distribute them. Our English flora is a small and frag- mentary one, so that this difficulty is not felt within its narrow limits so greatly as when we examine wider areas ; but whenever one comes to compare together a large number of specimens from all parts of the world, it is wonderful how extremely elusive is the task of species- making. True species do often undoubtedly exist : that is to say, there are certainly many groups in which the various existing individuals fall naturally into well-marked divisions, all the intervening types having been killed out by the competition of the better-adapted specific forms, as Mr. Darwin has pointed out. Still, many other groups, perhaps almost as numerous (among plants, at least), do also exist, in which there is no such distinct demarcation of species : the various typical forms merge on either side into one another by every possible intermediate variation. Perhaps these are instances of species in the making ; perhaps they show us that primitive plastic state during which variations have not yet become fixed and definite ; but, in any case, there they are, and even the most rigo- rously orthodox botanists can hardly deny their existence. The local British interest of the epilobes, the St. John's worts and the liawkweeds, consists in the fact that they display just this close interosculation of species even within the range of our own narrow English flora. On the one hand, nobody could fail to recognise the difference between some of the most distinct types — for example, the great purple willow herb, or the pretty pink rose-bay, as com- pared with the hoary epilobe and the square epilobe of our wayside ditches ; or again, the great St. .John's wort of our gardens, bearing flowers three or four inches in diameter, as compared with the scrubby, small-flowered Jli/jH-ricum duhiuin and Hyiirricuiii qundnuigulnm, that line our dusty country roads. But, on the other hand, if one attempts to divide them all up into distinct species, one finds oneself hampered by all kinds of intermediates, which make the definite classification of the text-books practically im- possible in actual practice. Indeed, the text-l)Ooks them- selves all difl't-r as to the number of species they admit ; and though some botanists will at once decide off- hand by what name they would call a particular specimen, there are other wiser and more cautious authorities who will not thus commit themselves to a fixed and dogmatic nomenclature. I turn to Dr. Bentham on these very epilobes, and I find he truly remarks : " The numerous forms the species assume in every variety of climate make it exceedingly difficult to define them upon any certain principle, and botanists seldom agree as to the number they should admit. Those here adopted are the most marked among our British forms : but it must be con- fessed that in some instances intermediates are to be met with which will be found very puzzling." He then goes on to say that in all cases the style should be carefully observed when fresh, in order to see whether it is entire or four-lobed ; but even this distinction, upon which he bases his table of species, is a very unim- portant one ; for in most epilobes the four lobes of the style are joined in a club-shaped head at an earlj' stage in the bud, and only open as tlie flower matures ; while even in those species where tliey never open, the marks of the four cohering lobes may be easily seen with 2 ♦ KNOV\ALEDGE ♦ [Jdlt 6, 1883. a small pocket lens. The opening is, in fact, merely one of the ordinary devices to prevent self-fertilisation ; it is found in all the larger and handsomer British species, which specially lay themselves out to attract in&oet visi- tors, while it is wanting in the smaller and less conspicuous varieties. Nor is this all, for in the little intermedixte type, known as Epilobium roseum, the lobes sometimes open t^hortly, and sometimes remain closed in a club-shaped stigma : and I have found flowers in both states growing together on the same plant. A rapid glance at the various forms assumed by British representatives of this Protean genus will help better than any amount of generalised talk to explain exactly how closely the different groups resemble one another. Omit- ting the naturalised French willow or rose-bay (which I do not believe to be truly indigenous anywhere in Britain), we have four fairly distinct central types of native epilobes, as it seems to me, usually distributed into from seven to eleven or more recognised species. Of these the largest, handsomest, and, on the whole, most marked type, is the great purple-red willow-herb (Epilobium liirsutuini), with a bunch of very big and showy flowers. This is the great insect-fertilised form, laying itself out most for attractive display, and having the stigma deeply four-lobed. Below it comes the so-called broad epilobe {E. ntontanum), differ- ing from it, in good typical specimens, by its stalked and rounded leaves, while those of the willow-herb are longer, narrower, and more sessile on the stem, as well as by its much smaller and pinker flowers, still, however, with a four-lobed stigma. This is a less luxuriant form of the same general type, growing in dry situations, while the willow-herb affects moist ditches ; and it shows some signs of incipient degeneration in its short petals, sometimes twice as long as the calyx, but often only of about the same length. These two forms are universally admitted as distinct. But intermediate between them come the specimens known as E. parvifloricin, some of which closely resemble the willow-herb in leaves and flowers, while others approach very near to E. montamun. So far as my observation goes, in very wet situations, they verge in the direction of the larger type, and in very dry ones of the smaller. I may add that dwarfed specimens of E. montanum, growing on the top of walls or other water- less spots, carry the characteristics of the small type to an extreme. But between these intermediates, even, it is possiljle to find yet other intermediates, approximating still more closely to the upper or lower forms. So much for the two main large -flowered types with four-lobed stigmas ; next as to the two main small-flowered types, with a club-shaped style. One of these is a lowland form {E. tetragonum) ; the other is a low, tufty mountain plant (E. alpimim). But E. tetragonum, once more, which in very typical specimens is known by its square stem, marked with four decurrent lines, is linked to the four- lobed species by the intermediates known as E. roseum, some of M'hich have the style club-shaped, while others have it slightly opened into four short lobes. This E. roseum itself merges into E. montmuim, on the one hand, by the small-flowered dry-soil specimens mentioned above, through the shortly four-lobed form called E. lanceolatum, and into the regular E. tetragonum, on the other hand, by specimens with entire stigmas and marked decurrent lines. Other small diflerences, which I need not note here, have made some divergent plants of E. tetrngomi m be considered as specifically distinct, under the name of E. virgatum. Finally, the dwarf mountain type, E. alpinum, when growing under exceptionally favourable circum- stances, by the banks of Highland streams, assumes longer and broader leaves, toothed on the edges, and recurs somewhat towards the lowland type, in which state it is known as E. alsincefolium ; while in boggy places on lower ground, it reverts towards the square-stemmed form, and 1 ^ceives the name of E. jialustre. " It sometimes, also, oc-nes very near the narrow-leaved forms of E. roseuia and E. tetragonum," says Mr. Bentham, " but has the buds much more nodding, and the decurrent lines on the stem are either very faint or entirely wanting." For my own part, I have seen intermediate specimens between almost all these carefully-distinguished species or varieties which it would be mere juggling, in my opinion, dogmatically to refer to either or any type. But if ever the various inter- mediate forms are weeded out by the action of natural selection, there will probably remain four " good species," as systematists call them : — E. hirsutum, E. montanum, E. tetrago^ium, and E. aljjinmn. This is rather a long, dull, and technical exposition, I am aware ; but it will serve better than anything else to show how impossible is the attempt to draw definite lines in such very mixed and elastic families. Is or are these families by any means exceptional. To anybody who wishes for an insight into the variety and modifiability of plant forms even within the limits of a single small country, the careful comparative study of the following common English genera and species may be confidently recommended : the reses [Rosa canina, R. arvensis, kc. Mr. Bentham makes five species, and Mr. Babington, seventeen) ; the brambles {Rubus, from four to forty-five species recognised) ; the potentillas (including TormentiUa and the strawberry) ; the St. John's worts (Hypericum) ; the sow-thistles [Sonchus) and the hawkweeds {Hieracium). How any one can rise from a close comparison of the endless forms of hawkweed alone, a believer in strictly defined natural species, is one of those psychic mysteries only adequately to be explained by Mr. Bishop, or by Messrs. Maskelyne & Cooke. THE CHEMISTRY OF COOKERY. XIII. By W. Mattieu Williams. THE process of frying follows next in natural order to those of roasting and grilling. A little reflection will show that in frying the heat is not communicated to the food by radiation from a heated surface at some distance, but by direct contact with the heating medium, which is the hot fat commonly, but erroneously, described as " boiling fat." As these papers are intended for intelligent readers who desire to understand the philosophy of the common pro- cesses of cookery, so far as they are understandable, this fallacy concerning boiling fat should be pushed aside at once. Generally speaking, ordinary animal fats are not boilable under the pressure of our atmosjjhere (one of the con- stituent fatty acids of butter, butyric acid, is an exception; it boils at 2>\i° Fah.). Before their boiling-point, i.e., the temperature at which they pass completely into the state of vapour, is reached, their constituents are more or less dissociated or separated by the repulsive agency of the heat, new compounds being in many cases formed by re- combinations of their elements. When water is heated to 212° it is converted completely into a gas which gas returns to the fluid state without any loss on cooling below 212°. In like manner if we raise an essential oil, such as turpentine, to 320°, or oil of peppermint to 340°, or orange peel oil to 34.5°, or patchouli to 489°, and other such oils to various other temperatures, July 6, 188?.] ♦ KNOWLEDGE ♦ they pass into a state of vapour, and these vapours when cooled, recondense into their original form of liquid oil without alteration. Hence they are called "volatile oils," while the greasy oils which cannot thus be distilled (in which animal fats are included), are called " fixed oils." A very simple practical means of distinguishing these is the following : — Make a spot of the oil to be tested on clean blotting-paper. Heat this by holding it above a spirit lamp flame, or by toasting before a fire. If the oil is volatile, the spot disappears ; if fixed, it remains as a spot of grease until the heat is raised high enough to char the paper, of which charring (a result of the dissociation above-named) the oil partakes. But the practical cook may say " this is wrong, for the fat in my frying-pan does boil, I see it boil, and I hear it boU." The reply to this is, that the lard, or dripping, or butter that you put into your frying-pan is oil mixed with water, and that it is not the oil but the water that you see boiling. To prove this, take some fresh lard, as usually supplied, and heat it in any convenient vessel, raising the temperature gradually. Presently, it will begin to splutter. If you try it with a thermometer you will find that this spluttering point agrees with the boiling point of water, and if you use a retort you may condense and collect the splutter-matter, and prove it to be water. So long as the spluttering continues the temperature of the melted fat, i.e., the oil, remains about the same, the water vapour carrying away the heat. When all the water is driven oif the liquid becomes quiescent, in spite of its temperature, rising from 212° to near 400°, then a smoky vapour comes off and the oil becomes darker ; this vapour is not vapour of lard, but vapour of separated and reoombined con- stituents of the lard, which is now sufiering dissociation, the volatile products passing off while the non-volatile carbon (i.f., lard-charcoal) remains behind, colouring the liquid. If the heating be continued, a residuum of this carbon, in the form of soft coke or charcoal, will be all that remains in the heated vessel. We may now understand what happens when something humid — say a sole — is put into a frying-pan which contains fat heated above 212°. Water, when suddenly heated above its boiling point is a powerful explosive, and may be very dangerous, simply because it expands to 1,728 times its original bulk when converted into steam. Steam-engine boilers and the boilers of kitchen stoves sometimes explode simply by becoming red-hot while dry, and then receiving a little water which suddenly expands to steam. The noise and spluttering that is started immediately the sole is immersed in the hot fat is due to the explosions of a multitude of small bubbles formed by the confinement of the suddenly expanding steam in the viscous fat from which it releases itself with a certain degree of violence. It is evident that to effect this amount of eruptive violence, the temperature must be considerably above the boiling- point of the exploding water. If it were only just at the boiling-point, the water would boil quietly. As we all know, the flavour and appearance of a boiled sole or mackerel are decidedly ditTerent from those of a fried sole or mackerel, and it is easy to understand that the diiler(!nt results of these cooking processes are to some extent due to the difference of temperature to which the fish is subjected. The surface of the fried fish, like that of the roasted or grilled meat, is "browned." What is the nature, the chemistry of this browning 1 I have endeavoured to find some answer to this question, that I might (juote with authority, but no technological or purely chemical work within my reaih supplies such answer. Rumford refers to it as essential to roasting, and provides for it in the manner already described, but he goes no further into the philosophy of it than admitting its flavouring effect I must therefore struggle with the problem in my own way as I best can. Has the gentle reader ever attempted the manufacture of " hard-bake," or " toffy," or " butter- scotch," by mixing sugar with butter, fusing the mixture, and heating further imtil the weU-known hard, brown con- fection is produced. I venture to call this fried sugar. If heated simply without the butter it may be called baked sugar. The scientific name for this baked sugar is caramel. The chemical changes that take place in the browning of sugar have been more systematically studied than those which occur in the constituents of flesh when browned in the course of ordinary cookery. Believing them to be nearly analogous, I will state, as briefly as possible, the leading facts concerning the sugar. Ordinary sugar is crystalline, i.e., when it passes from the liquid to the solid state it assumes regular geometrical forms. If the solidification takes place undisturbed and slowly, the geometric crystals are large, as in sugar- candy ; if the water is rapidly evaporated with agitation, the crystals are small, and the whole mass is a granular aggre- gation of crystals, such as we see in loaf sugar. If this crystalline sugar be heated to about 320° F. it fuses, and without any change of chemical composition undergoes some sort of internal physical alteration that makes it cohere in a different fashion. (The learned name for this is allotropisiii, and the substance is said to be aUulrojnc, other conditioned; or (^i7rto?y)Aic, two-shaped.) Instead of V^eing crystalline the sugar now becomes vitreous, it solidifies as a transparent amber-coloured glass-like substance, the well- known barley sugar, which differs from crystalline sugar not only in this respect, but has a much lower melting- point ; it liquefies between 190^ and 212°, while loaf-sugar does not fuse below 320". Left to itself, vitreous sugar returns gradually to its original condition, loses trans- parency, and breaks up into small crystals. In doing this, it gives out the heat which during its vitreous condition had been doing the work of breaking up its crystalline structure, and therefore was not manifested as temperature. This return to the crystalline condition is retarded by adding vinegar or mucilaginous matter to the heated sugar, hence the confectioners' name of " barley sugar," which, in one of its old-fashioned forms, was prepared by boiling down ordinary sugar in a decoction of pearl barley. The French cooks and confectioners carry on the heating of sugar through various stages bearing different technical names, one of the most remarkable of which is a splendid crimson variety, largely used in fancy sweetmeats, and containing no foreign colouring matter, as commonly sup- posed. Though nothing is added, something is taken away, and this is some of the chemically-combined water of the original sugar, in the parting with which not only a change of colour occurs, but also a modification of flavour, as anybody may prove by experiment. When the temperature is gradually raised to 420°, the sugar loses two e(jui\alents of water, and becomes caramel — a dark-brown substance, no longer sweet, but ha\nng a new flavour of its own. It further diflers from sugar by being incapable of fermentation. Its analogies to tlie crust of bread and the " brown " of cooked animal food will be further discussed in my next. According to Mr. Kolb, one of tlie secretaries of the German Imperial Telegraph Department, the 127,166 galvanic cells in use cost .£12,3.")0, of which .£2,727, or about 22 per cent., were recovered by the sale of the battery residues, consisting of copper, zinc, and lead salts. ♦ KNOWLEDGE ♦ [July G, 1883. GEOLOGY AND AGRICULTURE. By J. Vincent Elsden, B.Sc. (Lond.), F.C.S. IN a couutry like England, in which a day's journey is sufficient to traverse rocks of every geological age, even the most careless observer cannot tai^ tc lie struck by the diversity of appearance presented by the difterent strata over -which he travels. The stifl" soils of the eastern boulder-clays, the sheep-farming of the chalk downs, the pasture-land on the cold clays of the Midland Courties, the rich land on the Old Red Sandstone, and the ban r. aspect of the rugged Silurian rocks of Wales all point to the fact that each of the great geological systems is characterised by peculiar agi-icultural features. But, in England, much of the contrast Ijetween the various formations is lost owing to the great extent to which the underlying rocks are covered up by superficial accumulations, which entirely change the character of the soO. In Belgium similar differences are to be observed between the desolate plateau formed by the Palfeozoic rocks of the Condroz and Ardennes, the fertile Hesbayan loam of the central parts, the barren Campine sands, producing only heather and pines, and the rich alluvial soil of the Polders. In Norway, the fjelds, or elevated plateaux, which occupy more than half its area, are perfectly barren ; and, ill Sweden, the cultivated tracts coincide with the deposits •of glacial clay and marl, which cover up the gneiss and granite. From the alluvial deposits forming the two immense plains of Hungary, one of the richest soils of Europe has been formed, and the chief source of the agricultural wealth of Russia is the recent deposit, known as the Tchornoi-zem, or black earth, which occupies the valleys of the Don, Dnieper, and Volga. In America, the connection between geology and agri- culture is still more marked. The sudden transition from the fertile alluvium of Virginia to the barren sands, clothed with pine forests, which characterise the Tertiary beds ; the dry chalk downs and treeless prairies, famous for Georgian wheat, which mark the Secondary deposits, and tlie general hu.sbandry and fertile soils of the Primary rocks, forming the lower parts of the Alleghanies, show the geological features of the country almost as perfectly as would a careful survey of the underlying rocks. It is not to be supposed, however, that these differences ill agricultural features are due to the character of the soil alone, for climate has as much influence as soil in modi- fying agricultural operations ; but since climate is regu- lated mainly by contour, and contour depends chiefly upon geological structure, there is the same primary cause for variations in both cases. Nor must it be forgotten that it i.5 the tendency of improved systems of agriculture to over- come all obstacles to the growth of crops, even in soils which are naturally unsuited to them ; and thus the natural diversity of character which formerly existed is, to a great extent, destroyed. This is especially noticeable in the impro\ement of large tracts formerly regarded as V astes, and in the breaking-up of permanent pasture. For ii'.stance, the agricultural features of the chalk districts of England are by no means so marked, now that they have V..:-en invaded by the plough, as they were when in rolling downs and sheep pastures only. But in these cases the improvement is artificial, and the natural conditions would reappear if constant attention were not paid to the mainte- nance of the soil in an improved state. To the ordinary oViserver the appearance of a naturally fertile soil, and of a barren soil, rendered artificially jjroductive, may be very much the same ; but to the farmer the difference is ex- treme, for while the former is worked with ease, the latter can only be made to yield good results by endless trouble and expense. Hence it is seen that not only do the natural agricultural capabilities of the soil vary with the geological structure of the rocks from which it is derived ; but also that facilities for improvement and the amount of attention necessary to pre\ent deterioration are similarly influenced. The natural vegetation of any locality is so entirely de- pendent upon the nature of the soil, that the geologist often receives great assistance, in mapping the boundary-lines between different strata, from careful observations of the plants which grow there. For instance, it is most inte- resting to note how that beautiful heath, Erica Vagans, which grows upon the serpentine of the Lizard district, in Cornwall, marks out the boundary of the barren serpentine from the fertile soils of the adjoining rocks. Buckland, writing in 1S40, describes a moor in Dumfries, in which a band of bright green herbage marked the course of a trap dyke traversing slate rocks. Similarly, in Staffordshire the line of junction of carboniferous limestone and mill- stone grit is very clearly drawn on the surface by the sudden change in the quality of the grass, and four plants in particular mark the exact spot where soil changes — the furze, the heath, the whortleberry and the sorrel. In Hertfordshire, the Ijoundary-line of the London clay is frequently defined by a verge of grass-land, which termi- nates with the out-crop of the chalk ; while in the New Forest, the presence of the taller furze is a certain indi- cation to the farmer that the land below is worth reclaiming. In many cases, also, particular formations are characterised by the trees which grow upon them. In Surrey, the Gault is distinguished by the luxuriant growth of oak and elm ; while the Weald clay has long been noted for the perfection of its oaks. Beech trees abound on the chalk formation, and elms flourish on London clay, while the famous oaks of Bugot's Park, in Staflbrdshire, mark the position of an out- lying patch of Lias. It is well-known that the districts most celebrated for their cider are situated on the corn- stones and marls of the Old and New Red Sandstone formations, and, in Scotland, the Carse of Gowrie, so famous for its apples, stretches over the Old Red strata. To such an extent, indeed, is vegetation influenced by soil and climate, that the experienced farmer can form an opinion as to the fertility of the land from the species of plant growing upon it. For this reason many parts of the British Isles have remained to this day untUled, forming the moorlands and heath-covered wastes so characteristic of many geological strata. But even a naturally fertile soil is frequently rendered unproductive by deficient water- supply or defective drainage. The scarcity of water in chalk districts is a source of continual trouble and expense to the farmer, who is obliged to sink deep wells, at a very great cost, or to depend upon the supply afforded by arti- ficially constructed dew-ponds. In Alabama, the dryness of the chalk soils is a great hindrance to agriculture, for only farmers of large means can afford to undertake the deep boring necessary to obtain a supply of water. A similar scarcity of water is experienced on account of the extreme porosity of the Oolitic soils of the Cotteswolds. On the other hand, a farmer who is located upon imperious clays is put to no less an expense in getting rid of superfluous water by draining his land. Even upon porous rocks like the Old Red Sandstone, liogs are frequent on account of the sand becoming cemented into a hard mass, by means of oxide of iron, thus forming an impermeable pan. (To be continued.') July 6, 1883.] ♦ KNOWLEDGE ♦ LAWS OF BRIGHTNESS. y. By Richard A. Proctor. THE law obtained at page 372 relates to smooth spheres, or spheres having a mat surface (German, matt, dfiiul, as applied to surfaces), unpolished. It is useful to know the law, as it affords a means of determining how far the observed changes of brightness of those planets which pre- sent phases accord with the changes which would result if the surfaces of the planets were smooth. To begin with the moon : — Now here, before proceeding to consider the moon's total brightness at her phases, we find ourselves confronted by a circumstance which in no sen.se accords with what was shown in the preceding part of this paper, as to the brightness of a smooth sphere illuminated directly. We see that the disc of the full moon does not present that shading off" towards the edge or limb which theory re- quires in the case of a smooth sphere. Setting aside the remarkable variety of brightness seen in different parts of the moon's disc, we find no perceptible tendency to diminution of brightness towards the moon's limb. ]f we look at the moon through a tinted glass suitably graduated, we find that the outline remains distinctly visible as long as any part of the moon (except, of course, the exceptionally bright spots) can be seen. It is obvious that we must look for the explanation of this circumstance in the unevenness of the moon's surface. We can easily see, for instance, that if the moon's surface were covered all over with steep conical hills, something like the observed result would follow. For let ", b, c, Fig. II, be steep conical hills on a globe, supposed to be illuminated from above ; the light rays meet the surface at Fig. 11. a small angle, and the illumination is therefore small ; hence, supposing these hills in the centre of the disc (that is, the globe " full "), they would appear as three dark spots, as ii', V, c! ; and if the whole surface of the globe were covered with such hills the whole of the middle part of the disc would be dark, comparing its light with that from the middle of a smooth sphere of the same substance and under equal illumination. Such hills on the edge of the disc, as at d, c, /"(and supposed to be illuminated in the same direction that the globe is viewed) would not appear uniformly bright, for at their edges they would be under very oblicjuc illumination, while along a central streak the illumination would be nearly square (the hills being steep) ; but it is easily seen that the total illumination of a hill- covered region so placed might be (according to the slope of the hills) rather greater than, or very little less than, the illumination of the spots, «', h\ c . It appears to me, however, that it is on the whole more satisfactory ta regard the general unevenness of the moon's surface as due rather to crateriform elevations than to conical hills. (It must be noticed that we are not con- cerned here with the features revealed by the telescope ; since the nature of the illumination of difl'erent parts of the full moon must be mainly due to irregularities not discernible by the telescope.) Now, if we take a crater having such a section as is shown in Fig. 12, we see that under vertical illumination we should have the base C D fully illuminated, and the slopes B A, E V somewhat Fig. 12. obliquely illuminated ; while under the oblique illumina- tion from the right, indicated by the transverse lines, we have B C and E F (the only parts under illumination), Ijoth illuminated nearly squarely. Of course, the latter remarks only relate to one cross-section of the crater ; but it is easily seen that the oblique illumination may give the same apparent illumination for the crater (regarded as a whole, and viewed in the same direction that the light falls) that direct illumination gives. If C D be of less reflective power than ABC and D E F, of course the oblique illumination would have a further advantage, the direction of the line of light being such that the dark bottom of the crater would be concealed behind the wall D E F. I forbear from entering further, however, into such considerations as these, simply because the varieties and combinations of slope, position, tint, itc, are endless. It suffices here that the brightness of the moon's disc near the edge is explicable in a general way by the circumstance that the moon's surface is uneven. It will be obvious that the total light received from the moon must necessarily be affected by a condition of her surface which renders the seeming illumination of difl'erent parts of her disc so different from that which would result were she smooth.* It is not easy to determine to what * Some very strange assertions are made in a section of the " Encyc. Brit." devoted to the question of the moon's brightness. They illu.strate what I liave said respecting the errors cnmmonly made on the subject of brightness, and I therefore quote the passage at leiigtli. The writer of the passage lias given certain arguments (based on Bouguer's and Leslie's inexact estimates of the moon's total brightness) which appear to show that the moon is self-Iurai- nons. He proceeds as follows; — "Although these arguments go far to support the ancient opinion of the native light of the moon, they are not entirely conclusive, and indeed cannot bo easily recon- ciled with some of the phenomena. If the nioou shines in virtue of her native light, rays will be emitted in all directions from every point of lier surface; whence, since a visual angle of a given mag- nitude includes a much larger portion of a spherical surface near the extremities of its apparent disc than towards iho centre, and as the number of rays is proportional to the suiface from which they ])rocecd, it follows that the intensity of the moon's light ought to be greater near the border than at the centre of her disc." (The writer was clearly unacquainted with the experimental law of the emission of light from self-luminous bodies). " Tlie reason why this is not the case with regard to the sun" (ho should have said, the reason why a variation of the opposite kind exists) " is that a greater proportion of the rays are ai)sorbed in passing through a greater extent of the solar atmo- sphere; but the moon, having no atmosphere, ought to be sensibly most brilliant near the circumference of her orb. The contrary is, however, the case ; her light is greatest at the centre and less intense towards the circumference (I), exactly as it rught to be on 6 * KNOV^^LEDGK ♦ [July 6, 1883. degree the total quantity of light would thus be aftected. Zollner considers that the full moon shines nearly as brightly as though she were a flat disc under full solar illumination. (To he continued.) THE AMATEUE ELECTRICIAN. BATTERIES.— II. THE Bunsen cell is one which may be regarded as a " typical " cell, and accordingly it is proposed to deal with it in this article. It must not, however, be supposed that all has been said that we intended to say on the Daniell cell. There are certain modifications of it which only require to be more extensively known, in order for tliem to receive a much larger share of patronage. Our purpose in first dealing with typical cells is to afford, sub- sequently, ready means of comparison, as well as to save time and space, which would otherwise be occupied with repetitions which our present plan renders unnecessary. The Bunsen cell consists of an earthenware jar, generally cylindrical, into which is placed a cylinder of zinc, made by rolling a piece of flat zinc into the required cylindrical form, but not allowing the two approaching edges to quite meet. The object sought is to facilitate the movement of the solu- tion in which the metal is immersed. Within the cylinder is a round porous pot containing a rod of gas carbon. Brass terminals orbinding screws are fitted on to the zinc and carbon, for purposes of connection. Concentrated nitric acid (spe- cific gravity 1 420) is put into the porous pot or the division of the cell containing the carbon rod or plate. In the outer or zinc division is poured dilute sulphuric acid, or rather acidulated water. When the highest efliciency of the cell is required, the solution contains one of acid to seven of water, but this is a proportion not to be recommended, as it causes an extravagant waste of zinc by local action, of which more will be said below. A very fair proportion is one of acid to twelve or fifteen of water. Hydrochloric (or muriatic) acid (HCl) may be substituted for the sulphuric, but it is a little more expensive. The action in the cell approaches, to some extent, the action in a Daniell cell. The zinc is dissolved and con- verted into sulphate of zinc (SOjZn), the hydrogen of the sulphuric acid (SOjH^) being set free. This, entering the porous pot, decomposes the nitric acid (ISTO^H), forming water (OH^) and nitric peroxide (N._,Oj). Expressed chemi- cally, we get Zn + SOiHo + 2X03H=S04Zn + 2OH2 -f NPi Here it will be seen that when one volume of zinc is dis- solved, two volumes of nitric acid are decomposed, and that for each double volume of nitric acid decomposed, a double volume of water is formed which dilutes the remaining acid, a volume of nitric peroxide being also produced. Thus the quantity of the nitric acid is being constantly the supposition of its being occasioned by the reflection of the solar light." I do not know the author of the passage. I may take this opportunity of noticing thac in a passage of an article on the " Indications by Phenomena of Atmospheres to the Sun, Moon, and Planets," in the Monthly Notices of the Astronomical Society for 1862-3, page 237, Prof. Challis, while correctly stating the law for the case of a self-luminous body, falls into an eiror (which the above writer avoids) when speaking of opaque illuminated bodies. He says "a distant spherical body, whether self-luminous or shining by reflected light, would, according to the law that the intensity of the radiation varies as the sine of the angle which the direction of emanation makes with the surface, appear equally bright at all points of the disc." Those correspondents, therefore, who have addressed letters to me asking whether an opaque body under full illumination should not so appear, will see that their mistake is one easily fallen into. reduced by the decomposing action, while that which re" mains is subjected to the weakening eflect of water. At the same time the acid is further impaired by impregna- tion with nitric peroxide, which, also getting into the pores of the carbon, doubtless tends to produce a polarising effect by coating the particles of carbon. A large quantity of the nitric peroxide escapes into the air, and has a highly deleterious eflect upon the human or any other animal system. It is apparent, therefore, that the Bunsen cell differs from the Daniell cell in one of the most important features. In the cell last mentioned, the strength of the cupric sulphate (SO4CU) solution remains constant, being maintained by a reservoir of bluestone crystals, but a similar reservoir of nitric acid is impossible. Even were it otherwise, the production of water produces a weakening effect, which can only be obviated by withdrawing both acid and water. The Bunsen cell is, therefore, inconstant, the strength of the current diminishing with the time. Presuming the porous pot to be well saturated, the diminution of the current theoreticallj' commences the moment the circuit is completed, and in a few minutes it may make itself perceptible. A Bunsen cell, consequently, cannot be relied upon for more than three or at the outside four hours. At the end of that time, the nitric acid requires to be replaced by fresh acid ; but the old acid may be used again twice or perhaps three times if it is allowed to stand aside for awhile to clarify it. In the outer division the zinc is rapidly dissolved, and requires to be occasionally carefully amalgamated, other- wise, however good the zinc may be, local action — that is to say, action between two points on the zinc — will set in. Wherever the metal has two different structures or mole- cular arrangements, or has a chemically impure surface, there will local action be seen. One has only to place an unamalgamated zinc in a cell for an hour or so to see this. On taking the metal out it wUl be found to be eaten away very unevenly — sometimes in holes, sometimes in longi- tudinal striations. Amalgamation is a process which homogenises the structure of the metal, and covers up all superficial impurities. The process may be carried out in a variety of ways. The metal surface is first cleaned by immersion in acidulated water. When the violent fizzing that accompanies the action of the water upon a bar or dirty piece of zinc has nearly subsided, the plate is coated with mercury. This is sometimes accomplished by placing the zinc in a solution of a mercury salt ; but the readiest method is to coat the metal with the mercury either by rubbing it in with a piece of tow or cotton-wool, or by rolling the zinc in it. In the latter case the zinc shotild be allowed to stand a short time in a dish, ifec, to drain off' superfluous mercury. A pound of mercury is suffi- cient to roll a six-inch cylinder in, and will last a very long time. Zinc so treated infallibly works more econo- mically than unamalgamated zinc, providing the entire surface of the metal is so treated. The reason assigned is, that the mercury associates itself with the zinc and presents to the solution a surface which is absolutely homogeneous, and which, therefore, does not favour local action. When the metal becomes dull, reamalgamation is necessary. The cost of making a Bunsen cell is small. One of about a quart capacity is the most generally useful. The outer jar would cost a few pence, as would also the porous pot. The carbon rob, which may be about an inch square and seven inches, or thereabouts, in length, can generally be obtained at the rate of a penny an inch. The cost of the carbon is almost exclusively due to the hard nature of July 6, 1883.] ♦ KNOWLEDGE ♦ the substance, which can, generally speaking, be obtained gratis from a gas company's works. It is one of the waste products in gas manufacture, and has no other marketable value. Anent the zinc, our remarks in the preceding article are applicable, but a little word may be added here. If the amateur has a small pocket, and is unable to get ^-inch zinc bent, he may use g-inch, and by raising it to a fairly high temperature, he will find it capable of being easily bent. The retail price foi- a cylinder weighing a little over a pound is Is. 9d., or about three times the price of the metal. Amateurs often complain that the zincs get dirty, and covered with a white salt when put away after using them. They will experience no such trouble if they will remove the zinc from the solution when the battery is done with, and, after carefully and thoroughly rinsing it with water, wipe it dry with a piece of common calico, and then place it in a cupboard or other receptacle apart from the porous pot (which may be advantageously left in the acidulated water) and the carbon block. The resistance of a Bunsen cell is practically nil, being less than the tenth of an ohm. The electro-motive force is, on the other hand, high, being 1-9 or 2-0 volts. The cell is useful for laboratory or other experimental work, on account of the intense current yielded by it ; but, on account of its rapid polarisation, it is useless where constancy is required. The Grove cell is similar to the Bunsen, the difference being that the former contains a platinum foil in the place of carbon. Its efficiency is about the same as the Bunsen, but it is cleaner, and, being generally made in the flat form, takes up less room. Its cost is about 50 per cent. more than that of the Bunsen. SAVAGE AND ANTHROPOLOGIST. WHEN the " Special Extra Meeting of the Anthropo- logical Institute " was held at the Piccadilly Hall last week, the Botocudos must have been intensely amused. It must not be imagined that the interviewing in this matter is all on the side of the European. Mr. H. M. Stanley has recorded how, in his South African wanderings, he was persistently humiliated by the consciousness that while he thought he was discovering the savages, the savages would insist upon discovering him. When he visited one of their encampments, they surrounded him as an unusually tame specimen of a peculiar pale-coloured variety of human being. They took off liis clothes to look at his skin, and noted with satisfaction that he would eat the ordinary viands of life. Thus it fre- quently happened that Stanley departed from one of their " towns " with the sorrowful knowledge that the antliropologically-nunded Africans had picked up more infuriiuition about him than he had about them. The same fate befell the Man among the Monkeys. They regarded him as a large and hitherto unknown species of monkey, which " resembled an onion " in so far that it had seveial skins which peeled off easily. In both these cases, how- ever, the European was one among many, whereas at the Piccadilly Hall the odds are all the other way. Neverthe- less, the four Botocudos there evidently consider themselves numerous enough to form a scientific quorum for the dis- cussion between theni.sclves of any more than usually peculiar anthropological curiosity in a tall hat that may chance to enter the hall, with the idea that he is the sight- seer and the Botocudo the sight — and not a very inspirit- ing one at that. But when the special extra meeting of tlie Antliropological Institute appeared on the scene, the Botocudos must have been really thankful for the treat provided them. When some Fijian .savages, under the guidance of a missionary, for the first time visited an English man-of-war, they could hardly express their grati- tude sufficiently. " We beheld the men in great numbers, and very industrious at their work," they said, and " we respected them greatly. We beheld the chiefs of the ship, and reverenced them greatly. We young men of this generation were born in blessed times to see such a ship as this. Our fathers saw no such sight." So doubtless the anthropologists and the Botocudos last week equally congratulated themselves upon their good luck. Never before had the anthropologists seen four Botocudos together, one of tliem with a large piece of wood stuck in hei* lip ; and never before had four Botocudos seen so uniformly vener- able an assortment of white men, the majority with oval pieces of glass fixed by wires in front of their eyes, and some of them quite bald. Their fathers saw no such sight. Nor is it quite certain that in a cursory comparison the Botocudos would not be able to credit themselves with the superiority. It is true that the old lady of their party has distended her lower lip to the size of a tobacco-pouch, but she has not pinched in her waist to a 6 J, -inch diameter, nor does her husband wear a shiny black funnel, with a brim to it, upon his head. The daughter, too, has obviously no need of stays : and the son's splay feet have been allowed to tread in Nature's free and easy lines ; so that between the swarthy youth inside Piccadilly Hall and the gOded youths upon Piccadilly pavement outside, if an active cockroach were the umpire, there can be little doubt which would be pronounced the most eflective "masher." The manners and customs of the white men, too, are worth noticing. When two of them meet a third, one of the two steps forward, says a few words to each of the others, and then they take off their tall hats and wave them gently towards each other's feet ; and then they put them on again. After that they catch hold of each other's hands and shake them strongly, grinning all the time as if they were happy. Among the transactions of the Anthro- pological Institute of Botocudoland it will, no doubt, be recorded that the English are in many ways — according to the report of the Botocudo deputation that explored London in 1883 — a peculiar race of men, and that the variety known as " anthropologists " are especially remark- able for their age, their fondness for palavers, and their inquisitiveness. — Globe. Some kinds of white glass become, in the process of time, more or less deeply coloured under the influence of luminous rays. The most common tints are violet and green. The materials of ordinary glass are somewhat ferruginous and capable of tinging glass with a deep green shade by the protoxide of iron. In order to remove the colouring, peroxide of manganese is added, which changes the protoxide into a sesqui-oxide, which gives a feeble reddish-yellow tint. It is almost impossible to observe the proper proportions of manganese and iron. If there is too much oxide of manganese the glass has at first a violet shade ; if there is too much protoxide of iron the glass will be greenish ; if all the manganese is reduced to a state of protoxide the glass is colourless. The influence of light and air may gradually bring about a partial oxidation of the protoxide of manganese and a violet colouring which increases with time. The Cfironiqiie Ini/ufirielle says a shade which is due to an excess of manganese is observed in the Pinacothek, at INIunich, where the upper windows of the picture-gallery give a verj marked violet light which produces a bad effect. * KNOWLEDGE (July 6, 1883 THE FISHERIES EXHIBITION. NATUEAL UISTORY DEPARTMENTS. By Joun Ernest Ady. II. (continued). "TTTE now pass on to consider the relation of the \V minute organisms considered in our last article, to the important formations wliicli have and are still taking place in the hed of the deep sea, and on which so much light has recently been thrown by the late Sir Wyville Thomson, and his associates of the Chalknr/fr expedition. If a piece of chalk, such as that of Graves- end, be gently powdered in a mortar, the uiass tied up in a small bag of coarse calico, and kneaded thoroughly in a large bowl of fresh water until it has been reduced to about one-fourth of its bulk, a milky fluid with an appre- ciable deposit will result ; the supernatant liquor may be poured off, and the residue thoroughly well washed in a large test-tube, and allowed to settle. This operation should be repeated several times, after which it will be found that the deposit consists almost entirely of the tests of ForaminiJ'tra mi.xed with a variety of things, such as sponge and other spicules, &c. Conspicuous amongst the Foraminifera two beautiful forms may be recognised ; these are Globigerbia and Texlidaria. Fig. 3. — Globigerixa Ooze, floor of the Atlantic Ocean, x 65. g. Glohigerina buUoides ; o. Fragments of Orhulina universa ; n. Nautiloid Foraminifera ; 7i. Haliomma, one of the Polycystina {Original). As long ago as 1865-1866 Major Owen read two papers to the Linna?an Society, descriptive of the life-habits of Glohigeriiia and other forms, which he obtained from the surface-waters of the Indian and Atlantic Oceans by the use of a tow-net Later on, Owyn Jeffreys* asserted that these were exclusively oceanic, and confined to the upper stratum of the sea, in opposition to the opinions of his associates, Wyville Thomson and Carpenter, that they were abyssal. During the voyage of the Cliallenger Murray had ample opportunities for proving the correctness of Jeflfreys' statement, and showed lieyond doubt that these creatures are indeed pelagic, and that only after death do their * Proc. Eoy. See. London, Nov. 121, p. 443. bodies subside to the bottom, where they form the basis of a whitish deposit termed " Globigerina ooze " (Fig. 3), so called from the preponderance therein of the tests of Glohigerhin. We shall have occasion in future to point out that other forms than Foramin\fera {f.g-, Radiolaria) live, die, and are in like manner deposited. Fig. 4 shows two Radio- larians drawn from living specimens. Fig. 4. — Eadiolaria ; a. Haliomma hecacanthum, one of the rolycyslina, with radiating pseudopodia ; h. Acanthomefra lanceo^ atai. ' (After J. JluUer, Abhandl. d. K. Akad., Berlin, 1S58). The shells of the fresh Gloliigerina: are pellucid, and of a. firm consistency ; they are perforated by many pores, sur- rounded externally by a kind of crest, so that the pore commences at the bottom of an hexagonal pit ; at each angle of this crest a delicate, long calcareous spine is given ofl', and these radiate from the centres of the respective chambers of the shell to which they belong. The whole system of spines produces a marvellously beautiful effect, and has been accurately figured and described by Wyville Thomson ; * he has stated that pseudopodia have not beeri discovered in these animals. After the tests sink to the bottom to produce the so- called ooze, they become opaque, lose their spines, and finally disintegrate. In Fig. 3, which represents a sample of Globigemia ooze from the floor of the Atlantic, fragments of another or- ganism may be observed. These are portions of the tests of Orhulina universa, and may be readily distinguished from those of Glohigerina by their pores, which are of two sizes, one about four times as large as the other. Orhulina is spherical in shape, and sometimes contains a series of internal chambers, which resemble a small Glohigerina. This led Max Schultze and others to suppose that it is but a reproductive phase of Glohigerina. It has been shown by the Challenger results that Globi- geriruK exist in vast numbers all over the surface of the ocean, and are especially abundant in the warmer seas ; accordingly, it would be but natural to suppose that the deposit on the sea-bed should always contain their tests ; but this is by no means the case, and was at first an enigma to the naturalists of the I'halhnger, who came to a solution of the difficulty through the following observations : — They found that with increasing depth the nature of the deposit varied — so much so that they were able to predict what it would be at a given depth. At about 2.2-50 fathoms the Globigerina ooze gradually changes into a " grey ooze," which is characteristic of 2,400 fathoms. Deeper down (2,700 fathoms), the deposit is known as "red clay." From chemical experiments superadded to observed facts, they were led to discover that the calcareous Globigerina ooze is so acted upon by the solvent action of the sea water, that it is gradually broken down into the grey ooze, and * Proc. Boy. Soe. London, 1874, No. 156, p. 35, Plate I. July C, 1883.] * KNOWLEDGE ♦ 9 thereafter into the red clay, which proved on analysis to consist of a silicate of the red oxide of iron and alumina, and which now contains but few testaceous remains (siliceous shells of Hadiolaria, sponge spicules, ic.) Sir Wyville Thomson noted the capture of numerous highly organised Invertehrata in this red clay, such as large Holothioria with only rudimentary calcareous neck-rings, and a paucity of or no spicules in their tegumentary system ; also of delicate Foli/'.oa with their zooecia almost wholly membranous, and the tubes of a tube-building annelid (Alyriocliele) still living ; and he reflects on the pos- sibility of such a formation in palaeozoic times, the vestiges of which are to be found in the Cambrian OhlJiamia, in siliceous sponges, and peculiar thin-shelled shrimps.* The Globigerina ooze is usually bound together by a very fine comminuted paste, which at first sight seems to be amorphous, but under a high power of the microscope is resolved into a variety of rounded and excessively beau- tiful forms, two of which are here given in Fig. 5. Fig. 5. — EiiABDOLiTHs from Glohigerir\a ooze. (After Sir Wyville Thomson, Proc. Roy. Soc, Vol. xxiii., PI. 3.) They have been termed " rhabdoliths," and are of the nature of similar rounded bodies called " coccoliths " by Huxley, and supposed to be A Iga- of a peculiar form. In conclusion, the formations which are now going on at the bottom of the ocean, and which are chiefly composed of these minute animal remains, point conclusively to the manner in which extensive formations, such as the chalk, Nummulitic limestones, itc, were evulved, and to the importance of the living things, which, although they are so diminutive apart, and not of any great commercial value directly, are intensely interesting to the philosophical observer. THOUGHT-READING. " "IVfONSENSE dies hard," says Mr. Labouchere, and he X 1 is perfectly right ; liut no nonsense dies harder than tbe nonsense of infatuated prejudice. Amongst lite- rary men, those who know Mr. Henry Sidgwick and Mr. Labouchere — the two who wrote to the I'hnes on the Thought-reading wager — very few, we suspect, would prefer Mr. Labouchere's judgment on a matter of evidence of this kind to Mr. Sidgwick's. Mr. Sidgwick has as cool and sceptical a temperament as Mr. Labouchere himself, but he has in addition a very much larger knowledge of the subject under investigation, and knows how absolutely childish it is to speak of such a power as some persons impute to Mr. Lishop as a miraculous and all but incredible thing. We say this without having formed any detinite opinion ourselves on the subject of Mr. ]5ishop's powers, and, indeed, with a strong prejudice against a man who mixes up connnon conjurer's tricks with the professed * L'jco citatOj p. 47. attempt to illustrate obscure psychological powers of this nature. But this we will say, that to all who have studied the subject, evidence literally ahoumls of the existence in rare cases of powers of thought-reading much more remarkable than any alleged in the case of Mr. Bishop. As we do not like to make this sort of statement without any kind of verification, we will take a modem instance from the writings of a Bristol medical man. Dr. Davey, who published a paper in the Journal of Psyoholoiilcal Medicim for April, 1881 (Part 1 of Volume VII. of the Journal), which records the case of a patient of his, investigated by him in concert with two other Bristol medical men — Dr. Andrews and Dr. Elliott. Here is Dr. Davey's description of Mrs. Croad's state : — In 1870, it is stated, "she became totally blind ; " in the follow- ing year deaf, and in 1874 speechless. The paralysis, which was limited to the lower extremities, involved, in 1879, the upper limbs ; but at this time the loss of sensation and motion is limited to the left arm, the fingers and thumb of the left hand being but partially affected. The right hand and arm have recovered their once-lost functions. She is now able to articulate, though with difficulty, from, as it appears to me, a tetanic rigidity of the temporal and masseter muscles, by which the mouth is kept, to a large extent, fixed and closed. It was in October last [i.e., October, 1880] that I was asked to see Mrs. Croad. I found her sitting on a semi- recumbeut position on a small bedstead, her head and shoulders resting on pillows. The eyelids were fast closed, and the left arm and hand resting by the side. The knees I found then, as they are still, bent at an acute angle, the heels closely pressed to the under and upper parts of the thighs Since October, and through the months of November and December, 1880, I have subjected Mrs. Croad to many and various tests with the view of satisfying myself as to the truth or otherwise of the statements given to the world of her blindness, sense of touch, and marvellous sympathies. To my near neighbours— Drs. Andrews and Elliot — I am much indebted. The various tests referred to were witnessed by them in my presence, and with the effect of assuring ns that she (Mrs. Croad) was and is enabled to perceive, through the aid only of a touch, the various objects, both large and small, on any given card or photograph. After an experience extending over some nine or ten weeks, during which the "tests" were many times repeated, and, now and then, in the presence of several medical and non-medical (ladies and gentlemen) friends, there remained (I believe) not the least doubt of this " transference of sense " from the eyes of Mrs. Croad to her fingers and the palm of her right hand. It need not to be supposed that I and others were content to believe in Mrs. Croad's blindness, and to take no specific precautious against any possible trick or deception — far from this. On solicitation, "she very kindly assented to be blindfolded, after a very decided fashion ; and so blindfolded, that neither deception on her part nor prejudice nor false judgment on ours were — either the one or the other — possible. The blindfolding was accomplished thus : a pad of cotton wool being placed on each orbit ; the face was then covered by a large and thickly-folded neckerchief ; this was tied securely at the back part of the head, and— even moi-e than this — mere cotton wool was pushed up towards the eyes, on either side of the nose. Not con- tent, however, the aid of two fingers of a bystander were called into requisition, and with these a continued pressure was kept up, during the 'testing,' outside and over the neckerchief and wool, and above the closed eyes. At this stage of the proceedings the room was, on two different occasions, very thoroughly darkened. Under such circumstances it was the testing commenced, and continued to the end ; the result being, as theretofore, in the highest degree, conclusive and satisfactory. The transference of sense from one organ to another as an acquired and spontaneous condition of being must, on the evidence here adduced, be accepted as a demonstrated and certain fact. I would state here, that on receiving a picture card or a photo' from a bystander she (Mrs. Croad) places it on and about the chin or mouth, and perhaps draws it across the forehead, but the minute examina- tion of the card is, apparently, the work of the fingers of the right hand. These several acts ai-e, for the most part, followed by a quiet and intense thought, a well-marked concentration of mind on the picture, or whatever it may be, wlien, after a short time, she writes on a slate kept near her a description — sometimes a full and detailed one— of the card, its colouring, and the several objects thereon. I have seen S'>mo forty or fifty picture-cards and photographs described by Jlrs. Crond at different tirae." with varions 10 ♦ KNOWLEDGE ♦ fJoLT 6, 1883. degrees of accuracy during the whole period I have known her. Occasionally her rapid and precise perception, or, if you prefer the word, conception, of the picture, and of the many, yet minute and trifling, objects going to form its entirety, is really startling. I have but seldom seen her wholly at fault, though she has met with her failures. Now, this seems to us a much more marvellous power than that of thought-reading ; but this is not all Mrs. CroacI appears to have had the very power which Mr. Bishop attributes to himself, in a very much higher degree : — Sitting quietly by, or near to, Mrs. Croad, my attention has been again and again rivetted on the manner in which Miss Croad holds communion with her mother. Miss Croad does very certainly move her fingers over and about the face of her mother, but few, if any letters or words are formed by her. Watching her very narrowly, on several occasions, I felt at length assured that Miss Croad's com- munications were altogether unlike those made by either visitors or friends. The latter named formed letters, and \vith these words, and so conversed — if the expression be allowed — with Mrs. Croad ; but it is not so with her daughter. Impressed with the fact as above stated, I spoke to Miss Croad of it, when she told me that as the rule it was requisite simply that she put herself in a close or per- sonal contact with her mother to convey to her what was wished, or to give her a knowledge of this or that, as the case may be. Now, so marked a mental sympathy or concordance as this is altogether without or outside the experience of most of us ; and it is therefore well worthy the attention of those present who have the cotu'age to investigate, what I may well call, unorthodox medicine As a ftirther illustration of Mrs. Croad's peculiar and clairvoyant gifts, it should be stated that at my second interview w-ith Mrs. Croad, and in the presence of Dr. Andrews and others, certain of my own personal and private convictions on a particular subject became, as it would seem, in a strange and exceptional manner, known to Mrs. Croad. She asked me if I would allow her to tell me a secret in my own life-history, and would I be offended if she wrote it oa her slate. I replied, " No." That written on the slate was and is a fact, than which nothing could or can be more truthf til and to the point. Dr. Andrews is prepared to verify this ; the others present on this occasion were but little known to me. Here we have one of the most remarkable amongst numbers of instances of thought-reading, known to all students of the more abnormal facts of psychology — an instance encountered by steady-going professional men, in the ordinary course of their profession, and never produced on platforms for the amusement of the crowd at all. Dr. Carpenter, in his remarkable work on "Mental Physiology," has admitted the probability of the existence of some such power as this, on the evidence in his own possession ; indeed, Mr. Bishop declares that Dr. Carpenter has verified the real existence of some kind and degree of this power in Mr. Bishop himself, and has stated his belief that Mr. Bishop's powers have been tested under strictly scientific conditions. Now, we do not pretend to have any specific opinion of our own upon Mr. Bishop's case, and have absolutely no right to any such opinion. iSTothing is more marvellous than the assumption of a mere man of the world like Mr. Labouchere, that because the phenomena have never come within his knowledge, they are incredible. To him, apparently, opinions like Dr. Carpenter's are not even entitled to a respectful recognition, for he does not refer to them, unless it be in the remark that " nonsense dies hard." At all events incredulity dies hard. There are plenty of facts on which eminent medical men have come without having any motive whatever for credulity, and to which they have been compelled to give their attestation, such, for instance, as those we have quoted from Dr. Davey's address to the Bath and Bristol Branch of the Medical Association, far more remarkable, and far more difficult to bring under any of the known laws of nature, than the achievements of Mr. Bishop, even if these achievements be what Colonel Statham and Colonel Trench affirm, and what Mr. Labouchere denies. — Spectator FLIGHT OF A VERTICAL MISSILE. By Richard A. Proctor. Let a b 0 be part of the earth's equator, C the earth's centre, and let a missile he projected in direction a k {ver- tical), v)ith a velocity of 1,000^1!. p«r second. Supposing the point a to he carried to c durint/ the flight of the missile, determine the point, b, where the missile will reach the ground — in other words, determine b c the westerly devia- tion of the missile. (The resistance of the air is neglected.) Let aA.h be the actual path of the missile, and part of a long ellipse AA' about C as farther focus, the portion aA.h being ap- preciably parabolic. Join Ca, Qb, Cc, and draw AM to bisection of arc ah. Then, by Kepler's second law, the missile in moving around the path aAb, sweeps out equal areas around C ; and ob\-iously the point a sweeps out equal areas around 0, as it is carried uni- formly along the arc ahc. More- over, it is clear that the missile as it starts from a and the point a in passing from its initial posi- tion a are sweeping out the same equal areas around C (for the in- crease in the missile's distance from C does not affect the mo- mentary description of areas, which depends only on the rate of motion perpendicular to the radius vector). This equality continues through- out the motion, since neither the missile nor the point a changes its rate of describing areas around C Consequently, when the mis- sile reaches b, at which time the point a has come to c, the total areas described are equal, that is, area aCbA. = sector aCc, or, re- moving common sector aGb area aAh == sector bGc, that is, since aA.h is appreciably a parabola and «M6 a straight line perpendicular to the axis AM, •2 1 ah . AM = ^ ic . ahC '. ; or, putting AM=7i, iC=r, westerly deviation=6c= 4 h ah. Compared with ah, be is so small that we may put ac for ah without appreciably affecting the result ; and obviously, if 2< is the time of flight (t for the ascent or descent), P the earth's rotation period, we have ac= — 2-r P 1. r I 2t -, /ih\ l^Trht wherefore 6c= — 2jr| — 1 = P \3/ 3P Cor. — If the place of projection is in latitude ,\, the westerly deviation is 16s-/t< cos X 3R Sotc. — I said incorrectly that Mr. Bray's result at p. 393, letter 853, was correct. It is only half the actual July G, 1883.] KNOWLEDGE - 11 deviation. For, if we substitute in the above formula his correctly stated values for I and h, we get westerly de- viation for a missOe projected vertically with a velocity of 1,000 ft. per second 16 X 3000000 X 6000 XTT ~3x 193x193x24x60x60 IOOOOOOt: :93-62 ft. (about). (193)2x9 It may interest inquirers into problems of this sort to find out why Mr. Bray's apparently correct reasoning leads to a result twice as great as it should be. If I can find time and space, I will give, shortly, in the mathematical column, an analytical solution of the problem. GOD'S WILL.* SPEAKING of the Sunderland accident, the Sjiectator makes the following pregnant remarks : — " The moment the calamity was known, every one seems have behaved admirably, and the tone of the town since has been the true one, that of sad but helpful resignation to an ine.Yplicable Will. For it is an inexplicable Will, especially to those who believe, as we do, that God governs, as well as reigns. What should we say of a man who, merely by putting a thought into Mr. Fay's head, the thought to stand at the gallery-door and see the children out in batches, could have presented that ghastly massacre, and did not put it? Yet that mu.st be true of the Almighty, if any one of our ideas about his attributes is true, if he fore- sees, if he is all-powerful, if he has free-will. Apart from the sufl'ering — suffering often to the good, for it was pro bably the kindest parents who sent their children to the show — why does lie allow all that monstrous waste of life among the innocent, that destruction of potential useful- ness 1 The only answer is the simjile and unsatisfying one that we know nothing about the matter, and never shall know all, though we may know much more than we do now. Man cannot know the policy of God, which is not shown as changed, but as always the same, in these great catastrophes. Thsy do but concentrate a process which never stops. Taking Asia and Europe together, the half of all children born die before they are two. It is certain that more children died in London in the week of the catastrophe, unnoticed, than died in Sunderland to the horror and pity of the world. It is quite probable, though there are no statistics, that more children died in the United Kingdom still-born on Saturday than died in that staircase shambles. Vast, unending, inexplicable waste of life, never utilised even for a little while, is the law of the planet, the will of its Creator, as little to be made intelligible by thought as the endless mystery of non-educative pain. Theology gives us no more light on the subject than Science does, and though it is best, or at least most comforting, to think that tlie children are the happit-r for escaping this life and its miseries, there is no proof of that — rather evidence from analogy that they lose an opportunity which would have been to their profit. Why not, if the world, and life in the world, are, as wo all suppo.se, of any use at all ? Men are not the better for escaping, but for fulfilling, duties. There is no explana- tion whatever to be found, nor is there any need of one. If man acknowledges God at all, he must acknowledge a Being whose wisdom must be so far above his own that failure to perceive it is failure in the creature, not in the Creator. It may not be an absurdity, though it seems one to us, to recognise God, and yet think that he can err ; but • From the Spectator. it is certainly a folly to think that we can detect error in Him. The theologian, like every other man, is studying the Infinite, and when he has thought himself out, he can only acknowledge that he is always at last face to face with a mystery past his solution. Thought sometimes only helps us to pile up more figures on the recurrent decimal. €UUoriaI (goeisiip. One cannot but be amused at the tone of jeering supe- riority with which the psychical problems involved in such questions as thought-reading and thought-finding are dis- missed by folk who are only not stupidly credulous because they are stupidly incredulous. With such persons there is no middle path ; they either refuse to consider evidence at all, or they swallow everything they are told. In either case it is the same defect in the unscientific mind which does the mischief. A man of this class believes or dis- believes— he does not inquire. Take such a subject as mesmerism, for example : — " Mesmerism ! my good sir," he will say ; " mesmerism is utter humbug ; nothing in it but lies and trickery ; " or, it may be (just according to the way in which he has taken up the matter), he will talk equal nonsense on the other side, and tell you that mes- merism is the most marvellous power in existence. Many years have passed since I made my first acquaint- ance with these two classes of persons — or rather with these two forms of the same class. A man named Zamoiski came to Cambridge, who professed to possess marvellous mesmeric powers. He really had a very fair amount of that particular mind-influencing power which we may con- veniently call mesmerism (as a name not suggesting any theory as to the nature of the power). But he promised all manner of performances, far outside of anything he or any man could do without the aid of confederates. He appeared on the platform, went through a number of per- formances, some interesting and curious, but by no means miraculous, on college men of various standing, others which would have been marvellous indeed if they had been genuine. But they were performed on certain boys who were no doubt paid for their parts in the display. I FOUND after the performance that those who had seen it could be divided into three classes, two nearly equal in numbers and one much less than the others. There were a number who supposed the whole series to be humbug, the collegians being in the trick like the rest ; a number more accepted the whole series as genuine because they kneiv that the collegians were not in it. The few, more scientifically minded, recognised tlie evidence for what it was worth. A certain phenomenon, partly mental, partly physical, had been observed, strange enough to explain why weak- minded persons supposed there was something uncanny in it, but not at all outside what is natural. This phenomenon, though rejected by the weak-mmded of another sort as sheer trickery, seemed yet well worth inquiring into in a scientific way, — that is, under the test of observation and experiment. I SUPPOSE I had begun, even at that time, to have scien- tific tastes — though my friends and the worthy Fellows who had dealings with me failed to recognise this charac- teristic. Any how, I determined to test Zamoiski's powers by enabling him to give a less public entertainment. My largest sitting-room (I occupied rooms intended for a Fellow) could accommodate more than forty. So I and a 12 ♦ KNOWLEDGE [July 6, 1883. few friends invited the mesmerist to try his powers on as many as could be brought together, at a day's notice, in my room. Tliere came, in all, forty-two, including seven or eight " dons " (among them the Rev. S. Parkinson, my private tutor), about a score of Wranglers, and ten or twelve first-class Classics — " in sooth a goodly company." Zamoiski came along in due time, with a galvanic apparatus to keep him lively. He wanted to go through his customary discourse; but "we would none of it." We wanted simply to test his power of influencing mind and muscle. He tried nearly all of us (all, in fact, who were not unwilling). Among the number was my friend, W. Baily (Second Wrangler that year), who had been influenced to some degree — slight, but enough to show the reality of the phenomenon at the public exhibition — and Mr. Garrett, our organist (collegian also), who had felt the influence of Dove and other mesmerists. Zamoiski failed all round at the first trial. On this Mr. Garrett said : " You ought to succeed with me ; for Dove did," or words to that effect. Zamoiski then gave his whole energies to influencing him, and at last with such success as to make Mr. Garrett forget (or rather become for a few moments unable to recall) his own name. After this he tried others with whom he had Ijefore failed, but in whom he had recognised signs of yielding to the mesmeric influence (whatever it may be). He achieved a fair measure of success. My friend Baily was so far influenced as to be unable to open his eyes except with an effort. Others were unable to strike the mesmerist's hand, though they went willingly — even rather viciously — for it. (This had happened in the public exhibition with well-known University men, some of whom, as Ingham of the 'Varsity boat, would have made M. Zamoiski remember the evening, if they had got in at his rather soft-looking hand with their clenched fists, as they tried hard to do.) One or two had to struggle to remember their names, but succeeded after afew seconds. As I had expected, nothing very wonderful was done, but every experiment was satisfactory, as the whole company were known to each other, and all anxious to put Zamoiski to the test Several who were not actually influenced said they felt they had to exert an active resisting power. I was not one of these. He tried his power on me in public and in my rooms, and I noticed only that a sort of resistance was excited which was barely noticeable, so easy it seemed to overcome the influence he was trying to exert. Even this I only noticed when, of set purpose, I sought to yield my mind to any influence which might be exerted upon it by him. A FEW days later my fencing-master, Jackson, a sixteen-stone man, of splendid muscular development and full of vitality, told me that, while showing what Zamoiski had done and tried to do, he had found that he himself possessed the same power, and in rather greater degree. Zamoiski was a fat man, but not muscular. He seemed to be full of coarse vitality ; but his lecturing (save the mark !) did not suggest the idea of superabundant mental power. The phenomena which the Pyschical Society are en- deavouring to investigate are akin to those called mesmeric in several respects. There is nothing supernatural about them, though much that is mysterious, in the same sense that (for example) gravity is mysterious (l)ut in infinitely less degree). Of course, to unscientific minds they neces- sarily appear either miraculous on the one hand, or imaginable on the other. Fortunately, it is not from either class of mind that science expects any developments in the way of progress. The most brilliant idea which has yet occurred to such minds has been that of proflering a wager ! Of Mr. Bishop personally, I may say, vidi tantum. Like his fellow-countryman, the late Dr. Beard (a thoroughly scientific inquirer, almost equally abused by the would-be keen ones), he appeared to me a man of an intensely nervous temperament. I know, from the report of trusted friends, that his powers of thought-reading and feeling- reading are very great ; and in the range of such powers in what he claims to do and to have done there is certainly nothing beyond the natural. That he should obtain money through the exercise of his gifts does not seem to me open to exception, any more than that Bishops of another sort should receive money for exercising spiritual gifts — a point about which a certain Jewish writer has made very sensiVile remarks. It is unfortunate, perhaps, that so few take interest in purely scientific research that Mr. Bishop has had (I suppose) no choice but to relieve his mind-experiments with conjuring tricks ; but in this there is nothing more objectionable than there is in the lecturer on astronomy relieving the strained attention of his hearers by an occasional anecdote or jest. The cool assumption that, because the power claimed by Mr. Bishop is beyond tJteir slow minds, dullards are free to treat him as if he were a proved swindler, would be discreditable to them in the extreme, if it were not that — presumably — they know no better. A Cheap .\sd Good Telescope. — We have received from Mr. Theobald one of his singularly cheap telescopes, which we have had excellent opportunities of testing during the last few weeks at the seaside. It is an excellent in- strument— a perfect marvel for the price. It conies sharply and cleanly into focus, has a uniform field, and gives clear and good definition. We have not yet tried it on many double stars, not having a suitable stand. But it has done well with those we have tried. This little tele- scope will be found to give very pleasing miniatures of the lunar views described by F.R.A.S. , though, of course, the young observer must not expect it to show such details as a 3-inch telescope presents. We hope soon to test the work of this capital little telescope on Jupiter and Saturn, and will report the results in due course. Powder Magazixe Fired by Lightning. — A telegram from Scutari, Albania, dated Sth ult, says: — "The powder magazine of the fortress of Scutari was struck to-day by lightning. A great explosion followed, and a portion of the bazaar was destroyed. Many persons are reported killed." Later information says that ten soldiers and seven civilians were killed, and forty soldiers and fifteen civilians injured. The Forth Bridge. — On Thursday, the 14th inst. Sir Thomas Tancred, one of the contractors for the Forth Bridge, laid, with Masonic honours, the first granite block of stone in connection with the structure. He was accom- panied by Mr. Symons, one of the Government Inspectors, Mr. Gray, manager of the works at North Queensferry, and several other gentlemen. The stone, of pure Aberdeen granite, weighing about 10 cwt, was placed at the south- west corner of pier No. 12 from the south end of the bridge, which is situated a little to the east of the church at North Queensferry. There are now at the works — north and south — nearly 100 tons of Aberdeen granite for the outer casing of the piers. Four steam stone-crushers, each capable of crushing 80 to 90 tons per day, are at work preparing the whinstone for centring of the piers, and all along the line the greatest activity prevails in getting ready the preparatory operations required for this great structure. July 6, 1883.] ♦ KNOWLEDGE ♦ 13 THE FACE OF THE SKY. From July 0 to July 20. By F.R.A.S. THE snn Tpill bo -watclied, as usual, for groups of spots and faculae, which have recently become both more numerous and interesting. The face of the night sky will be found depicted on Map VII. of " The Stars in their Seasons," but there is no real night in the United Kingdom until July 22. The heavens continue to offer a practical blank to the observer, as far as the apparition (if any of the planets is concerned. The moon is 1'9 day old at noon to-day (July 6), and quite obviously 15'9 days old at the same hour on the 20th ; hence she is favourably placed for the observer dmring the greater part of the period of which we are treating. Her south declination, however, becomes con- siderable during the latter half of it. Two occultations of stars occur during the next fourteen days. The first is that of the sixth magnitude star 28 Libra;, which will disap])ear at the moon's dark limb at 11 h. 11 m. p.m. on Jnly 14, at an angle of 119° from her vertex ; but she will have set ere it reappears. The second occul- tation occurs on July 17, and is of B. A. C. G,081 (also a star of the sixth magnitude). This will disappear at the dark limb of the moon at 11 h. 31 m. p.m., at an angle of 133° from her vertex ; and reappear at her bright limb at 12 h. 41 m. p.m. at a vertical angle of 277°. During the next twenty-four hours the moon travels from Cancer into Leo. There she remains on the 7th, passing into Sextans during the early morning of the 8th. She leaves Sextans and travels into Leo again about 3 a.m. on the 9th. She remains in Leo until about 6 a.m. on the 10th, when she moves into Virgo. She does not leave this constellation until about four o'clock in the afternoon of the 13th, when she crosses into Libra. There she continues until about 6 p.m. on the 15th. In the course of the next ten hours she travels across the northern part of Scorpio into the southern portion of Ophiuohus, where she continues until six o'clock in the evening of the 17th, when she enters Sagittarius. She remains in Sagittarius until 8 a.m. on the 19th, and by noon on the 20th has travelled into Aquarius, where we leave her. " Let Knowledge grow from more to more." — Alfred Tennyson. Only a sviall proportion of Letters received can possibly he in' verted, Correspondeiits must not he offended, therefore, should their letters not appear. All Editorial coinmunications should he addressed to the Editor op Knowledge ; all Business communications to the Publishers, at the Office, 74, Great Queen-street, W.C. If this is not attended to, DELAYS arise FOR WHICH THE EDITOR IS NOT RESPON.SIBLE. All Remittances, Cheqiies, and Post Office Orders should he made payahle to Messrs. Wyman & Sons. The Editor is not responsible for the opinions of correspondents. No communications are answered by post, even though stamped AND directed envelope BE ENCLOSED. RATIONAL DRESS. [864] — The female members of my family complain that " Pedestricnne " fails to describe the only part of her dress which they want to know how to make, viz., the " divided skirt." They would like to try the costume recommended, but ask for a detailed descrijition of what " I'edcstriennc " means by a " divided skirt." Cyclist. GENEALOGICAL PUZZLE. [865] — The following may amuse some of your younger readers : — A and B are two persons in no way related — of no consanguinity. They meet, and one asks the other : — " How is our brother Tom f " [Tom being brother to both of them.] Show how this may bo. "j.M. LETTERS RECEIVED AND SHORT ANSWERS. J. R. (Malta). — As to " Stars in their Seasons," note advcrti.iie- ments. — Moke Light. Yes ; if your facts are " firmley established," you can — as you say — "afford calmley to wait." (You seem, in- deed, to take your e's pretty freely.) I really cannot say who is " the best living authority on the subject ; " not being quite clear what subject you mean ; you only mention your " facts of the weather," which you apprehend I " may think ronsencical " (here you are clearly " half c'a over "), " and therefore worthless" (which, if nonsensical, they probably would be) ; but I don't know what they are. However, on nearly all subjects there is variety of opinion as to who is the greatest authority. As you say, " some old one man and some another." — G. Mackixl.w. Thanks. Both statements relate to cannon balls flying athwart the range of vision, though this is not expressly stated. In mid-flight, which was what I re- ferred to, a cannon ball has not a greater rate than 500 yards per second, even when its initial velocity has been as great as 900 yards per second. I have myself frequently seen cannon balls in mid-flight from behind the gun. — A. Parnell. Many thanks; an occasional article might find insertion ; but, as you may have noticed, space is crowded. The subject is full of interest.— A Learner. Six inches square = 3 in. by 1 ft.; that is what was meant. — W. B. No ; the question whether a wager is won or not is quite out of om- line. Of the wager in question, one can only say that it was vulgar to offer it, unwise to accept it. Science has nothing to do with wagering, except to say that all forms of gambling are essentiallj- immoral. — T. J. Dewar. Your manner is so rough (not to say rude) that though your matter has been in part useful, it is scarcely worth getting at through such breakers. Hereafter, I fear your handwriting (or signature, if handwriting not recognised) will cause our trusty sub-editor to "basket" yourcommunications rather sum- marily. If a passer-by flings a stone through my drawing-room window, he would probably be removed by A 21 before I had learned from him that he only wanted to give me his opinion about the kitchen chimneys. I trust I make myself understood. Yon fling "awful rubbish" at my head or that of a valued contributor — 'tis the same thing : do you suppose I go beyond that to read your de- tailed criticisms ? — E. A. Hoeson. Many thanks; the Indian obser- vatory most interesting. There is a description of it in one of the earlier volumes of the Penny Ma,jazine.—1^E. (1) The position of the earth's axis varies sensibly (to instrumental tests) from summer to winter, through the effects of precession and nutation. (2) Try " York's List of Astronomical Diagrams." (3) See ad- vertised list of lectures. (4) Algebra certainly essential. — H. Malim. Calculation given this week. — A Worthy Correspon- dent. Many thanks.— Tim J. W. Cannot answer by post. — G. Duncan." Thanks; your communication submitted to the proper persons to decide about such matters. — G. Jordan. The movements of the moon, as seen from all latitudes, north and south, have been in precise accordance with accepted theories. Why should the moon not be seen every month in the Arctic regions, seeing that every month the moon is half the time north of the celestial equator r — J. M. Thanks. Puzzle not very difiBcult. In my own family "our brother" appears in another way. Thus, if widower having a child marries a widow who also has a child, a son by this marriage is for his child and hers " onr brother," though they are in no way related by blood. — Zoologist. Have no idea. — Mary, Housem.aid. Not bad, my dear sir, not bad ; nay, " the stars and their seasonings" very good— rather too good for " Mary, Housemaid." The " combination " [of J accidents impossible". N.B, Anyone who would spell "minute" with two " n's," would spell it with two " i's," not " minnute." Both mw " i's" open so that I C through U with E's.— S. Truro. See solu- tion this week. — G. W. Really we do not know what you ought to do under the dismal circumstances you mention. When " you start a meal you scarcely know when to finish ;" no wonder tliat at night you " feel weary, and also your eyes are heavy too." The best advice we can give you about over-eating is " Don't." But we are not medical. — W. Fitzroy. We do not know how your namesake acted ; and the question is not one we should like to ventilate here. — Equites. Reallj', some readers ask curious ques- tions. You say that when riding, the sides of your knees get sore, and you ask how to avoid that trouble. Keep on and it will go off. Besides, its the best way to keep on. If this fails, try riding with the other sides of your "knees towards the horse ; you have no idea how effective that will be (and also look). But why do you ask 7116 this particular question H Now, if you were to try the editor of Nature, who compares the motion of the earth to the motion of a galloping horee on a smooth plain, of which motion the rider re- mains— he says — unconscious, you might learn how to save your knees. I have never reached this stage in riding, but still remain emphatically conscious of motion during a gallop, even over the smoothest fields. Sub-Editorial. K. L. W., Perple.\ed, J. Hawkins, M. E. W., H. N. Medlicott, K. R. and N. M., Langu.\ge, Halloween, and others. Unsuitable — T. J. Dewar (later communication). See editorial remarks. 14 ♦ KNOVS^LEDGE [JcLY 6, 1883. &UV iHattjtmatiral Column* GEOMETRICAL PKOBLEMS. By Richard A. Proctor. Part VI. LET ns next try a few problems — properly so termed — that is, propositions in whicli something is required to be done. In these, as we have said, the analytical method is nearly always to be preferred. We will begin with a simple example. Ex. 6. — On a given straight line describe an isosceles triangle, each of whose equal sides shall he double of the base. Fig. 11. Let A B (Fig. 11) be the given straight line. Suppose that what is required is done, and that on the base, A B, there has been described the triangle, A C B, in which the sides A C and C B are equal to each other, and each double of the base A B ; and let us consider what constructions are suggested. It seems hardly possible that the resemblance between this problem and Euc. I., 1, should escape the student's notice. He will inquire, then, whether the method of that problem cannot be applied to the present cue. Instead of the circle with radius equal to A B, we now require circles with radius equal to twice A B. It is clear, then, that if we produce A B to D, making B D equal to A B, and B A to E, making A E equal to A B (Euc. L, 3), then A D and B E will each be double of A B.* Therefore, if with centre A and radius A D we describe a circle D C F, and with centre B and radius B E the circle E C G, then C, the intersection of these circles, is the vertex of the required triangle. For A C and B C are severally equal to AD and E B— that is, are double of the base, A B. We will next trj' the following : — Ex. 7. — The point P, Fig. 12, is within the acute angle formed by the lines A B and A C. It is required to draiv through P a straight line which shall cut off equal parts from A B and A C. Fig. 12. Let D P E be the required line, so that A D is equal to A E.f Then D A E is an isosceles triangle, and it is an obvious cotrrse to see whether any of the properties of isosceles triangles will help us to a solution of our problem. Now, the only property of isosceles triangles explicitly contained in Euclid is that of Bk. I., prop. 5. * We have seen this problem given with the proviso that no problem beyond Euc. I., 1, shall be made use of. In this case the student will see at once that if, ■(vith centres A and B, and distance A B, he describes the circles B F E, A G D, then E B and A D, the diameters of these equal circles, are severally double of A B. t In constructing the figure, proceed thus : — Take A D equal to A E, and join D E ; then take P, a point dividing D E into unequal parts. This gives us the angle A D E equal to the angle AE D, — a property which avails us nothing. But there are other properties of isosceles triangles, not expressly mentioned by Euclid, which every geometrician ought to be ac- quainted with. We will assume that the student is familiar with them — and indeed they are nearly self-evident. They are included in the statement that the perpendicular from the vertex on the base of an isosceles triangle bisects the base and also the vertical angle. Draw A il perpendicular to the assitmed line D E ; then the angle M A D is equal to the angle MAE, and also D M is equal to M E. Now let us consider whether this construction affords us any hints : — First, we cannot see how to di-aw the line through A perpendi- cular to the real line D E, because it is this very line we seek to draw. Secondly, we cannot, for n similar reason, see how to draw the line from A to the bisection ol li K. But, thirdly, we can draw the line A M, bi-secting the angle DAE. And this clearly gives us the solution of otu- problem, since we can now draw D P E at right angles to A 31. Thus the solution runs as follows : — Draw A M bisecting the angle DAE, and through P draw D P JI E at right angles to A M ; then shall A D be equal to A E. For, in the triangles M A D, 31 A E, the angle 31 A D is equal to the angle MAE, the right angle A 31 D is equal to the right angle A M E, and A M is common to the two triangles ; therefore the triangles are equal in all respects (Euc. I., 26), and A D is equal to AE. The proof of the equality of the triangles 31 A D and MAE was not included in the prior examination of the problem, since is involved in the assumed knowledge on the student's part of the fundamental properties of isosceles triangles, proved farther on. But, of course, it is well (in a case of such simplicity) to introduce the proof into the solution of the problem. Let us next try the following problem : — Ex. 8. — The points P and Q, Fig. 13, are on the same side of the line, AB. It is required to determine a point C in AB, such that the lines P C QC may malce eqv/il angles with A B. Let C be the required point, so that the angle P C A is equal to the angle Q C B.* Let us try drawing a Une, C D, at right angles to A B. Then the angle P C D is equal to the angle Q C D. On a consideration of this relation, however, it seems unlikely to help us. For it is not easier to gather anything from the equality of P C D and Q C D, than to make use of the equality of P G A and Q C B. It seems an obvious resource, since the equality of the angles, P C A and Q C B, as they stand, is not readily applicable to our purposes, to produce either P C oi Q C, in order to see whether the vertical angle either of P C A or Q C B might be more serviceable to us. Produce P C to E. Then the angles Q C B and B C E are equal, or C B is the bisector of the angle Q C E. The only property connected with the bisector of an angle which seems likely to help us is this one, that the bisector of the vertical angle of an isosceles triangle is perpendicular to and bisects the base. Now, we can make an isosceles triangle of which C shall be the vertex and C Q a side, for we have only to take C E equal to C Q, and to join Q E, cutting C B in F. Then, by the property just mentioned, Q E is at right angles to C F, and is bisected in F. These relations obviously supply all we want. For, reversing our processes, we have only to draw Q F E perpendiculsir to A B, and * Construct as follows : Draw A B, and from any point C in A B, (\Taw tbe uneqiial lines C P, C Q equally inclined to AB. Then there is no risk that accidental relations will appear as necessary ones. July 6, 1883.] ♦ KNOAVLEDGE ♦ 15 to take FE equal to Q F ; then clrawing PE to cut AB in C, we are certain that C is the required point. In all such cases we should not be equally certain that the proof would be as simple as the analysis, since sometimes the reversal of a process involves pro- perties not so readily seen as their converse theorems. In this case, however, it is obvious (or will at least appear on a moment's inquiry), that the proof is simple. For, join C Q (we are going now through the synthetic treatment of the problem, and therefore ignore the prior constructions). Then, because Q F is equal to F E, and C F is common and at right angles to Q E, the triangles C P Q and CPE, are equal in all respects. Therefore, tlie angle Q C F is equal to the angle EOF. But E C F is equal to the vertical angle P C A. Therefore the angle Q C F is equal to the angle P C A. It is an excellent practice, when a problem has been solved, to notice results which flo'w from, or are in any way connected with, our treatment of the problem. In Ex. 8, Fig. 13, we notice that the line C Q is equal to the line C E, so that the sum of the lines P C, C Q, is equal to the line P E. It might occur to us to inquire what is the sum of lines drawn from P and Q to any other point, as G, in A B. Join P Q and Q G. Then the fact that C E is equal to C Q reminds us that if we join G E, G E will be equal to G Q. Thus P G and G Q are together equal to P G and G E together. But P G and G B are together greater than P E ; that is, P G and G Q are together greater than P C and C Q together, or P C Q is the shot-test path from P to Q, siihject to the cvnditio7i that a point of the path shall lie on A B. Erratum.— On p. 397, 1st col., lines 17 and 18 from bottom, for ' a right-angled triangle " read " an isosceles triangle." GEOMETRICAL PROOF OF THE FORMULA FOR DOUBLE ANGLES. Let AP B be a semicircle, with centre C. P C N any angle less than 90° (2.r) .•.PAN = ii!. B PN-90°-PBN = PAN = a PN Sin 2a! =- Cos 2x = rad. 2PN 2PN ~2rad AB ^PN AP "AP .AB = 2 Sin J c Cos X. CN ~rad 2CN CN-t-CN ~2 rad AB . ~ AN — rad + rad - -NB AB A N . A P. N B PB AP.AB PB.AB = Cos- .^ — Sin- a;. PN_2PN_ 2PN '■~CN 2CN~CnTcN 2 PN "AN- rad -t- rad - N B PN AN AN_NB PN AN PNAN 2 tan X 1 — tan- J). ©ur WA^i^i Column, By " Five op Clubs." The Hands. B. Spades— K, 2. Hearts— Kn, 10, ■i, 2. Clubs— Q, Kn, G, 5. Diamonds — K, 6, 5. A. Spades — A, Q, 8, 7. Hearts— Q, 9, 3. Clubs— 9, 8, 7, 3. Diamonds — Q, 3. Spades—Kn, 10, 5. Hearts— A, Q, 8, 5. Clubs— 10, 4. Diamonds— A, 10, 8, 4. * * 4. 4. B 0 o o + ift ^m «? ' should have led his own suit, notwithstanding the major tenace. He knows from liis partner's lead, himself holding Club Ten, that his Hearts are stronger than his partner's Clubs ; and apart from that, the suit is intrinsically so strong that it was liis duty to show it. But there are players who never will lead from a suit headed by Ace, Queen. The Club Two is seen now to be with Z, Eight and Seven with A\ Queen and Knave with Y. 4. Z (Mr. J. Clay) has been blamed for discontinuing here his own suit. But there were good reasons; although the event turned out unfavourably. He knew that the Diamond Queen was held by either A or B. If by A, then a Club lead from A would give i> a ruff, likely enough to suit him, as Z holds four trumps himself. If B holds the Queen, it is likeU- that, having no Clubs, he holds one or two more Diamonds, and that A holds no more. In this case there is danger of a cross ruff. On the other hand, as A led from a weak suit of Clubs, and B did not lead Hearts, it looked more than likely that both were weaker still in Hearts, and therefore that I' held groat strength in that suit- On the whole, though the question is one of probabilities only, Mr. Clay seems to us to have shown his usual judgment in leading what he thought would be his partner's suit. 5. Having made his tenace, 7> might ?io)(', at least, have en- lightened his partner as to the con- stitution of his hand. If ho had led Ace of Hearts, Z playing the Six would have showed he had no more. Another lead of Hearts •6 KNOWLEDGE ♦ [JcLY 6, 1883. would eitlicr liave forced Z, or if, as is probable, Z had refrained from ruffing, .4's King would have made. Then a Club lead from .1 would have given B a ruff ; and a final Heart lead from B would have given A a ruff. A small trump lead from A would have given B a trick ; the next trick would have been made by ^'s Ace, draw- ing the King ; then the Queen would have made ; and the game would have been won. And though it is not sufficient to point thus to results, we think there can be little room for doubt that the game should have been continued thus. But, like many other players, B, who would not lead from a long suit headed by major tenace, would not play from a suit led by an opponent, though it was clear the opponent had led from weakness. 6. B should have ruffed with the Five, Club Two being certainly with Z. 7. From this point to the end the play is very pretty. A can now place almost every card. He knows that Z has the winning trump and three Diamonds, probably headed by Knave. He knows that B holds the Heart Ace, 1' the Heart Knave (for Z can have no more), and trick 4 shows the Knave is not with B. The Knave of Clubs is with Y. 10. Leading the losing trump is the only way to win. It compels Z to lead Diamonds while the command is with the enemy ; 11. And thus, while Z cannot bring in his Diamonds, unless B and A make a double mistake (B discarding a Heart at trick 11, and A leading a Heart at trick 12), Y is forced either to discard a Heart, leaWug B the full command, or his winning trump, leaving A to make his Club Eight. 12 and 13. A and B make three by tricks and the game. Note. — The above game is from the Westminsier Papers, and is interesting as one of the latest in which Mr. James Clay took part. ^uv Cftcfis Column. By Mephisto. STEIXITZ has challenged Zukcrtort to a match for a stake of about £200 a side, for eight or ten games up. The Chess world will be highly pleased and interested if a match will result from this prompt d^Ji. Blackburne, Mason, Bird, and Gunsberg will represent England at Nuremberg. This tournament promises to be a very great sticcess, notwithstandiug (oddly enough) that the prizes are very small. The Counties Chess Association will, we believe, hold its annual gathering at Birmingham in the first week of August. The following exceptionally fine ending occurred in actual play at Purssell's, Cornhill : — ASHTEUR. Black. White to play and win. PROBLEM No. 86. By C. Pl.\nck. Black. Whiib. White to play and mate in three moves. PROBLEM No. 87 By J. C. S. Black. Whitb. White to play and mate in three moves. ANSWERS TO CORRESPONDENTS. *#* Please address Chess Editor, AMATEnR. — We do not know the book published in 1882. SPECIAL NOTICES. Part XX. (June, 1883), just ready, Volume III., comprising tfie nur will be ready in a few weeks, price 7s The Title Page and Index to Volui Binding Cases for Volume III., price 28. each (including Title, Index, and Case) for 33. each. Is., post-free, Is. 3d. published from January to June, 1883, III. will be ready shortly, price 2d., post- Subscribers' numbers bound TERMS OF SUBSCRIPTION. Th« terms of Annual Sabschptien to the weekly numbers of KirowLBoei are as follows ; — B. d. To any address in the United Kingdom 16 10 T» the Continent, Austraha, New Zealand, South Africa & Canada 13 0 To the United States of America 53.25. or 13 0 To the Eaet Indies, China, &c. (^id Brindisi) 16 2 All subscriptions are payable in advance. F. O. Orders and cheques should be made payable to the Publishers, Mbssbs. Wymak & 9oK8, London, at the High Holbom District Post-office. Agent for America — C, 8. Carter, American Literary Bureau, Tribune BaildlngBi New York, to whom subscriptions can be forwarded. OFFICE : 71-76, GREAT QUEEN STREET, LONDON, W.C. July 13, 1883.] - KNOWLEDGE ♦ 17 AN ILOLSTRATED MAGMNEof^IENCE PUmrripRDED -£XACTl|DESCRIBED LONDON: FRIDAY, JULY 13, 1883. Contents op No. 89. PAOB. Pleasant Hours with the Micro- scope. By H. J. Slack, F.G.S., F.R.M.S. iniu8.) 17 Chemistry of the Cereals. — I. By W. Jago, F.C.S IS Geology and Agriculture. — II. By J. V. Elsden.F.C.S., &c 19 Australian Ants {co»t.) 21 Sea Anemones at the Fisheries Exhibition, {Illus.) By Thonias Kimber, M.A., Lond 23 Mr. Stephen Leslie on the Influ- ence of Science The Brush Dynamo-Electric Ma- chine. (Iltits.) Fiffure Conjuring. ByR. A. Proctor Editorial Gossip The Divided Skirt Something about the Beet Correspondence Our Mathematical Column Our Chess Column PLEASANT HOURS WITH THE MICROSCOPE. By Henry J. Slack, RG.S., F.RM.S. THE figures now given illustrate the descriptions in the last paper, and show some of the principal varieties of infusoria. They will also enable some in- teresting questions concerning their movements to be con- sidered. Motion that looks more or less like voluntary is by no means confined to the animal world. Motile spores of algif, for example, are very common, and there are few objects more fascinating than the exquisite emerald-spangled globes of volvox swimming with the aid of numerous cilia. There are no sharp boundaries between the animal and vegetable worlds, but as advances from the lowest forms are examined, a positive preponderance of character is dis- covered. Speaking generally, the respiration of plants is like that of animals. They absorb oxygen and evolve carbonic acid ; but they can also digest that acid, and use its carbon to build up their structures, which thorough animals cannot do. The chlorophyl of plants is the agent for effecting this process, and a few animals which possess it — Euglenre', for example — may have a similar power. In proportion as organisms exhibit decidedly animal characteristics, we might expect their movements to appear more likt; the ir ill-directed actions of the higher orders, and this is generally true. When moving objects jostle together, go to the edge of a containing cell and stick there, or in any other way appear blundering, they probably belong to the vegetaV)le world. Mr. Saville Kent, whose opinion is entitled to great weight, finds that as a rule the animal types " make tentative, well- controlled progress in various directions, and intelligent deviations." Let us investigate this. Fig. 1 shows a minute creature {Ikleromtla lens) with a small whip ; the little group of dots are its spores. The magnification is 800 linear. Many much smaller objects swim skilfully by means of similar whips. In this group and in many others, Mr. Kent observes that the movements seem to be intelli- gently guided. It is impossible without intolerable circum- locution to speak of these things with accurate precision. In using such a word as intelligence, it does not mean the same as if it were applied to a human being, but something on a lower platform, in some respects resembling it. Fig. 2, a and A, are EiKjknoi (F. viridis). They were formerly placed by most authors amongst the plants, but Mr. Kent confirms the observations which assign to them a small mouth, and he succeeded in inducing them to swallow minute particles of carmine. On this, and on other accounts, he claims them as animals. On a sunny day, go to a quiet pond that is covered, or streaked, with a thin scum, like green-pea soup. Skim a little into a bottle, and the capture most likely consists of myriads of beautiful little fish-like things of emerald lustre, with a so called ruby eye-speck. These are Uugleua:. There are several species ; the commonest — the one figured — varies from 1-1150" to 1-240" in length. The bottle containing them should be kept in the light, to promote their development. In the dark they sink to the bottom ; the light brings them to the surface. They are furnished with a remarkably elastic integument, and can assume all sorts of odd shapes, or a globular one. Our object now is to watch their swimming. A drop of the water containing them is placed in a little glass cell, 100th of an inch deep. This gives them plenty of room for moving at different depths. A half-inch objective, with A or B eye-piece and dark-ground illumination, shows them off well. Continual watching rarely detects a collision. For hours together they swim backwards and forwards, this way and that, often with sudden changes of direction as sharp as those of a swallow or bat. If one is comparatively quiet, a little ripple amongst floating par- ticles proclaims the motion of the long, whip-like swimming organ, but the lash itself is invisilile, or very troublesome to see with any power while the creature is active ; and when it rounds itself, and lies still, it is not displayed. To see it, put a droplet of tincture of iodine, as big as a pin's head, on a glass slide ; then add a rather larger droplet of water containing the creatures ; put gently over them a thin covering glass. They all die ofl'-hand, and the whips are then so plain that we wonder they were not seen before. They are rather longer than the animal, and their arrested motion leaves them in wavy or twisted patterns. The swimming is sometimes assisted — perhaps entirely caused — by contractions and expansions of the integument ; but often the queer changes of shape must make it more dilEcuIt for the whip to move the creature, as it does, in a definite way. Fig. .5 is a Paramecium, with plentiful rows of cilia, but its motions are not so wonderful as those effected by the whip of the Euglemt. Where a cilium is highly magnified, and its motion becomes slow as the water dries up, it is seen to be much like what can be done with a long flexible cane, held in the hand, and worked by sharp turns of th(^ wrist A wave motion runs from the base to the tip. When an animalcule uses a quantity of these organs, rhythmical agreement is the chief thing necessary; but how to row a canoe with a whip-lash is quite another matter. Whips and cilia are commonly described as the same things, only difiering in stiffness. Watching the work of the whips leads tlie present writer to regard them as very diflerent things. The Etirjlnm has its whip at the mouth (red speck end), and it pulls itself forwards through the water, with rapid changes of direc- tion. It is impossible to conceive this could be done by moving the whip by an impulse from its base only, as is the case with cilia. Tlu' whole length of the whip appears highly vitalised, whil(> the cilium is only an elastic bristle of a delicate description. A curve at any part must modify the direction of the currents produced by its lash- ing, and as the motions always look skilful and purposeful, 18 ♦ KNOWLEDGE ♦ fJDLY 13, 1883. each portion must concur with the rest, just as much as the several joints do in a preliensile monkey's tail. Many infusoria have a plurality of whips at their anterior end. Fig. 4, AmpMinonas dispar, has two; Fig. 3, Cercomonas acuminata, has one at each end, and it must want some skill to prevent their motions from conflicting. Fig. 6 represents Euplotes patella in two positions. The under side is exhibited in a, and h gives a profile view. This creature swims with its cilia, or walks with its bristles. Intelligence, or a sufficient substitute for it, guides the animal to the right use of these two sets of organs, but nothing in the locomotive line done by the ciliata, or hetero- tricha, is so wonderful as the Etujlena whip work. Fig. 1 (a) Kg. 1 (6). Fig. 2 (a). Fig. 2 (6). Fig. 3. Fig. 4. Fig. 5. Fig. 6 (a). Fig. 6 (b). Fig. 1, a and 6, represents the spores and young of Heteromita lens, X 800. Fig. 2, a and h, Euglena viridis in two positions, X 250. Fig. 3, Cercomonas acuminata, x 500. Fig. 4, Amphi- monas dispar, x 300. Fig. 5, Paramecium aurelia, x 75. Fig. G, Eaptotes patella, «, underside; li, walking attitude, x 140. When any bird or insect does a skilful-looking thing, it is popularly said to be directed by iKsliitc/, but few persons endeavour to mean anything really intelligible by the term. Instinct in birds and insects, for example, is not, as often asserted, unerring ; it does not compel the creature always to do the same thing. It does not preclude experiment, and, to a certain extent, a modification of plan and use of new materials. Instincts are probably inherited aptitudes, and in their higher exhibition are associated with reason. What are we to say of the lower and of the far minuter objects that perform acts of locomo- tion, food-seeking, itc, in a way that must be called skilful, and which would be impossible unless their bit of protoplasm had molecules so arranged as to perform work analogous in character to the nerve actions of higher animals 1 They must receive impulses from without, and send forth the right sort of impulses in reply to them. To avoid an obstacle means taking some physical cogni- sance of it, and directing the motile organs accordingly. To move after prey witli aspect of skill requires some faculty of recognising where it is, of distinguishing it from other things, and of steering accordingly. Do these minute creatures think ? No one supposes that they are conscious of their existence ; that they reflect upon the sense impulses they receive ; or that they knowingly exer- cise a will force, or have such a feeling as desire ; but, after dismissing as improbable the attributes that belong to animals with an elaborate nervous organisation, there is much to be accounted for that differentiates them very strongly from inorganic matter, and that prefigures some, at least, of the mental processes of higher beings. In investigating the phenomena of living beings we soon feel that we are in the presence of an unknown something which is not like any merely physical or mechanical force. The iodine solution may be made by dissolving on"^ grain of iodine and three of iodide of potassium in one ounce of distilled water. Half the quantity is an abundant stock for the numerous experiments for which iodine is. useful. CHEMISTRY OF THE CEREALS. By William Jago, F.C.S. No. I. THE name " Cereals " is applied to the group of grasse.s cultivated for human food ; included in their number arc wheat, barley, rye, oats, maize, and rice. As a result of analysis we find these bodies to consist in great part of organic compounds, together with a small proportion of inorganic material. This latter, derived from the soil on which the plant has grown, contains potassium phosphate- magnesia, lime, silica, and minute quantities of other in- gredients. Our present purpose leads us more especially to the study of the organic constituents of the members of the great grain family ; these bodies are themselves of inestimable value to man, and further, by virtue of certaiii chemical changes, yield a number of other most useful and interesting products. Subjoined is a table giving thi- average composition of the cereal grains : — Wheat. Barley. Oats. Eve. ilaize. Rice. Water Ill 120 142 143 llo lOS Starch 623 52-7 56-1 549 548 788 Fat 1-2 2-6 4-6 20 47 01 Cellulose 83 11-5 10 G-4 149 Oi Gum and Sugar... 38 4-2 57 11-3 2-9 re- Albuminoids 10-9 13-2 IGO 8-8 8-9 7-2 Mineral matter ... I'G 28 2-2 1-8 1-6 0-J> Loss, Ac 0-8 10 0-2 Oo 07 0-4 1000 1000 1000 1000 lOOO lOO-O We see from this table that water is present to a greater or less extent in all, wheat and rice containing the least quantity. The sample of wheat was, however, an old one, and therefore will have got drier by keeping. We also see that starch is by far the most abundant constituent of these grains ; its percentage ranges from ,52 '7 in barley to 788 in rice. The first step, then, in thf- study of the chemistry of the cereals will be to make our- selves acquainted with the nature and properties of thii body. The composition of starch is represented by tht- formula C,-H]|,0-,. Its general appearance is well known, for, besides being largely used for laundry purposes, we find it occurring in a considerable number of other pre- parations; thus "violet powder" is, or should be, pure starch, scented with orris root, and the various "corn- Hours " are simply the starch of maize. Let us take a sample of starch as sold by the chemist and e.xamine it. We have a fine white powder, which, on being pressec'i between the fingers, produces a peculiar sound, known as "crepitating." An examination under the microscope shows that this powder possesses a very marked struc- July 13, 1883.] ♦ KNOWLEDGE ♦ 19 ture ; writing with that instrument before me, let me describe the observation I have just made. Having obtained a little potato starch, and, in addition, some arrowroot (also a starch), I placed a drop of water on a clean slide, then the smallest pinch of starch, and, finally, very gently iiressed down a cover glass. I then looked at each sample with an eighth objective. Taking the potato starch, it is readily seen to be composed of little granules ; some of these are spherical, others, wliich are older, are shrivelled, and have polygonal outlines ; some of the more favourably-situated corpuscles show a series of ring-like markings. This latter peculiarity points to the.se particles having a concentric structure, somewhat like that of an onion. Viewed by polarised light, with crossed nicols, a black cross is seen in each granule. Looking at the arrowroot, the first point noticed is that the granules are larger, and of a different shaped outline. Their form re- minds one of the shape of a mussel-shell, and the ring-like markings start, like those of the shell, from a point near one end ; using polarised light, the black cross is again seen distinctly, but its arms are no longer at right angles ; the centre of the cross also coincides with the point around which the markings are concentric. These little starch corpuscles of which we have been writing consist of an outer envelope of starch cellulose, a substance closely allied to starch, and of granulose, or starch proper, which constitutes the interior of the granule. Starch, as far as we know, is not dissolved without change by any known liquid. This is, in fact, exactly what we might expect, because starch possesses an organised structure ; when once that is destroyed by solution, it can never be restored liy simply driving off the liquid ; for though by evaporation we may thus obtain, of certain substances, crystals of perfectly regular shape, it is impossible, without the aid of life, to build up organised structures. Cold water is aVisolutely without action on starch ; but take a small quantity aud, having shaken it up with water, gradually heat, the starch swells up and forms a thick paste. By the action of heat, the starch granules are ruptured and the interior granulose dis- solves ; the addition of a large quantity of water renders the starch almost entirely soluble ; the little envelopes, however, remain, and may be filtered off' from the solution. It is a matter of uncertainty as to whether this soluble starch is chemically or only mechanically dis- tinct from the insoluble form. Before dealing further with the chemical constitution of starch, it will be well to inquire a little into how starch is oVitained from the dif- ferent substances containing it. If a small quantity of wheat>fiour lie taken and wrapped in a piece of muslin, and then kneaded between the fingers in a small basin of water, the water becomes milky, and there remains behind, within the muslin, a tough glutinous substance, termed gluten. Of this we shall have to say more a little later. Let now the water stand ; it gradually becomes clear, and deposits , a white powder at the bottom of the basin. If now the water is poured ofl^, and the powder allowed to stay, a fairly pure sample of starch is thus yiiOded. lu manufacturing starch on the large scale, wlieat is first coarsely ground, and then wetted with w\ater ; on being allowed to stand for some days, fermentation sets in. The wheat is then transferred to large vats, and addi- tional water added ; fermentation goes on apace, and the gluten putrefies, evolving a most offensive odour. Certain acids (acetic and lactic) are formed as a result of fermentation, and these dissolve any remaining gluten. The remaining starch is next thoroughly washed and sub- se.quently dried. During the latter operation the masses pf starcli shrink and split up into the columnar structure so well known in laundry starch. A considerable quantity of starch is also manufactured from the potato. The principle is much the same : the tubers are first washed, then i-asped into a pulp, and washed on a sieve ; the water, which runs through milky, from the presence of starch granules, is allowed to stand until it deposits its starch ; the sediment is then carefully washed and dried. As the potato contains no gluten, the process of putre- faction necessary with wheat is not required. It was before mentioned that " corn-flour " is the starch of maize ; in its preparation the disagreeable method of removing gluten liy putrefaction is avoided by using a very dilute solution of soda as a solvent for that compound. The gluten is thus first dissolved out, and the remaining starch is washed and dried. In this manner is yielded a very pure and elegant form of starch. While, as a pre- paration of starch for food-purposes, corn-flour leaves nothing to be desired, it should never be forgotten that it is, after all, starch, and starch only. That cheapest form of starch, viz., that of the potato, has recently been brought into the food market under the name of " potato fecule ; " fecule, be it remembered, is simply the French name for starch. A glance at the table given at the head of this paper shows rice to be almost entirely composed of starch. For the great majority of purposes where starch is re- quired as an article of food, there is no better substance to use than rice, either in the form of the whole grain or ground into meal by passing through a small hand-mill. The difi'erence in cost of rice compared with that of these other staich products is well known to every prudent housewife. GEOLOGY AND AGRICULTURE. By J. ViNXEN-T Elsdex, B.Sc. (Lond.), F.C.S. 11. ri^lHE quantity of water carried down Ijy rivers depends _L also upon the strata over which they flow. Thus the Medina, in the Isle of Wight, is a very narrow stream while in the chalk district, but widens otit immediately on reaching the less permeable Eocene beds. Indeed, limestone districts can frequently be traced on a map by the absence of streams and rivers. The Thames affords a striking illustration of this influence of geological structure upon the discharge of rivers. In flowing over Lias clay, it is estimated to discharge 320 cubic feet per minute, but coming to the porous Oolitic strata, its discharge suddenly falls as low as 10 cubic feet per minute. The quality of the water is also influenced by the com- position of the rocks through which the river flows ; and considering the large amount of irrigation which is carried on in many agricultural districts, the composition of river w ater is of tin; first importance to the farmer. Thus, in Surrey, the water of the ]Mole is far superior to that of the Wey for irrigation purposes, for the ilole, after traversing the Weald, flows through calcareous strata, and becomes impregnated with fertilizing mineral substances ; while the Wey flows almost entirely through barren sandy districts. Tlie water from the Lower Greensand of Surrey is also ill- adapted for irrigation on account of the very small amount of mineral nuxtter dissolved in it ; nor is it a matter of any surprise that the Lower Creensand itself sliould form here so barren a soil, considering tlie small amount of soluble material which it yields. The water from the Carboniferous limestone of Yorkshire, on the other hand, is known to be extremely useful as a fertilizing agent ; while the remark- able excellence of the water-meadows of Gloucestershire is 20 ♦ KNOAVLEDGE ♦ [Jolt 13, 1883. attributable to the fact that they are watered by streams from the higlily calcareous rocks of the Cotteswolds. Per- haps in no county in England is irrigation less practised than in ^\'ar^vickshire — a fact wliieh is easily explained by the physical features of the district, for the majority of its streams originate in the elevated plateau around Birming- ham, known as the ^vaterslied of England, and have not yet been long enough in contact with the rocks to have ac- quired enough dissolved mineral matter to make them valu- able as fertilizing agents. Just as a fertile oasis marks the position of a spring of water in the parched and barren desert, so, though in a less degree, is the fertility of our English soils influenced by the peculiar character of the water of each geological formation. The saliferous marls of Staffordshire give rise to such brackish streams, that on their banks sea-side plants are frequently to be found ; but the injurious influence on agriculture of an excessive amount of soluble matter in the underlying rocks is best seen in the immense natron plains of Hungary, between Arad and Debriczin, which are rendered unproductive by an efflorescence of soda-salts from the soil ; while in some low tracts of land on the shores of the Mediterranean, •which are too salt for cultivation, it has been found neces- sary to remove the saline matter by artificially flooding with fresh water, and afterwards draining. Perhaps no geological agency exerts so much influence upon agriculture as denudation — that slow and silent action whereby the surface of the earth has been moulded into its present form. Thus the mechanical action of running water acquires an agricultural interest almost as great as its chemical influence, which we have just considered. Not only are immense quantities of the most productive .soils carried away by this means, but by being deposited in other localities, the most fertile admixtures are often pro- duced. This accounts for the great improvement which soils usually exhibit near the outcrop of other formations. The peculiar fertility of the hop district of Farnham is due, to a great extent, to the many outcrops, in a small area, of beds of different character, and to the consequent mixing of different soils. The great value of alluvial soils, also, is to be explained V>y this natural admixture of sediment carried down by running water from strata varying in mineral composition. The Golden valley of Herefordshire owes its superiority to a fertile alluvium derived from the corn- stones of the surrounding Old Red Sandstone formation. So valuable, indeed, is the detritus carried down into the sea by rivers, that, in favourable localities, the flood-tide is made, Ijy artificial means, to overflow the fields around and to deposit its precious freight of fertile mud upon the farmer's land. The inundations of the Nile are beneficial to the soils of Egypt only in proportion to the quantity of finely-divided sediment which is thus deposited upon them, and Duponchel has even conceived the idea of fertilising the barren lancles of Gascony by artificial warping from the Pyrenees. This artificial admixture has lieen practised with great success in many parts of England, and many a barren soil has been rendered productive by the processes commonly known as claying, marling, and chalking. By judicious admixture of materials from neighbouring strata, many of the waste lands of England have been permanently improved, and have increased in value both to the owner and tenant. But if advantage is gained by the farmer who cultivates the rich alluvial tracts, the fertility of which may be traced to the nature of, perhaps, distant strata, it is far other- wise with those from who.je land the sediment has been transpoi-ted. In many districts agricultural operations are seriously impeded by the rapidity with which the soil is re- moved l>y denudation. This is nowhere so well shown as on steep slopes, such as the sides of the granite hills of Cornwall, or in incoherent soils like the Black Earth of Russia, in which huge ravines are formed with surprising rapidity, and the most fertile alluvium in Europe quickly swept away. The presence of igneous dykes seems invariablj' to exert a beneficial influence upon the soil. In some parts of Cornwall, where the general rental of the land is about thirty shillings an acre per annum, the accidental occur- rence of an igneous dyke improves the land to such an extent that the produce is nearly doubled, and the rental consequently increased. In a similar way the Carboniferous limestone soils of Derbyshire are greatly impro\'ed by the presence of those volcanic rocks which are locally known as toadstoac.s, and in some parts of South Wales, where trap- rocks occur, an otherwise barren soil is completely changed and rendered capable of producing nearly every crop. It is interesting to note how quickly the lavas and ashes of Etna are transformed into vineyards or gardens by the ceaseless industry of the husbandmen, even although they are repeatedly destroyed by fresh eruptions. It generally happens that in those localities where the nature of the rocks has resulted in the production of the most pleasing scenery, there agriculture is least developed. Of course, where the scenery is bold and mountainous, we shall expect to find great hindrances to agricultural opera- tions ; but even in districts such as the Isle of Wight or Surrey, we find a pleasing landscape accompanied by a most backward state of agriculture. Nor does it often occur that great agricultural value characterises those districts which are famous for their mineral wealth. The mining districts of England are chiefly noticeable for the general unproductiveness of the soil, which is sometimes so poor that three or four shillings an acre is the utmost rental that can be obtained. Enough has now been said to show the general con- nection between agriculture and geology. In the New World, where there is no lack of available gi-ound, colonists need cultivate only the most favourable districts — the allu's-ial plains and valleys watered by running streams ; but the crowded population of Europe necessitates a con- tinual struggle against natural agencies to improve every available spot. Thus by ceaseless toil and industry the greatest obstacles have been overcome. The natural aridity of Egypt, the deficient water-supply of Lombardy and Tuscany, are conquered by the most careful irrigation ; wastes have been reclaimed ; marshy tracts have been rendered fertile by draining ; the hills on the banks of the Moselle and the Rhine and the steep slopes of Provence, in spite of the rapidity with which the soil is washed away, are kept clothed with vines, corn, and olives by the endless toil of terracing the hill-sides, and thus overcoming the obstacles which nature has opposed to successful cultivation. The Highest Bridge in the World. — This is the railway viaduct of Garabit, in France, now being erected over a river in the department of Cantal. The total length is about 1,880 ft, and near the middle of the great centre arch, the height from the bed of the river to the rail is 413 ft. The viaduct was begun in 1881, and is to be completed next year. The longest bridge in the worM is said to be in China, at Sangang, over an arm of the Chinese Sea. It is five miles long : the roadway is 70 ft. high, and stands upon 300 arches. The parapet is a balustrade, and each of the pillars, which are 75 ft. apart, supports a pedestal on which is placed a lion 21 ft. long, made of one block of marble. July 13, 1883.] ♦ KNOWLEDGE ♦ 21 AUSTRALIAN ANTS. (Continued from page 374, Vol. III.) THE treeants are very frequently met with. Of these there would seem to be at least two species, the one contenting themselves with nestling under the loose bark, while the other bore into the trunk of the tree itself, by reason of which habit they are designated carpenters. They do not, however, use timber for building purposes : they only excavate it to provide themselves with a dwelling- place ; still, as the particles of wood lie scattered round the root of the tree, looking like heaps of regular sawdust, the designation seems by no means inappropriate. A favourite resort of both these species is dead stumps, and, singular to say, three sides only of the stump are appro- priated. These are invariably east, north, and west. These several sides, as every one will remember, are the only ones well exposed to the sunshine, necessary in winter for the comfort of the community, and in spring, summer, and autumn for the hatching of the eggs and the development of the pup;c. A sanitary expert could not have devised his plans more satisfactorily. These ants are very fierce when molested, attacking some of the larger kinds, and often come off conquerors. The little "sugar ants" are well known to most dwellers in towns, and even in central Melbourne sometimes prove a nuisance to housewives, by invading any saccharine matters that may be left uncovered. They owe their popular name to their fondness for this article of food. If a small heap of the same is placed in their way, they seldom stop to eat it on the spot, but carry the prize away, crystal by crystal, evidently for the benefit of the general population. Fond as they are of sugar, they are still more partial to honey, and will readily leave the former for the latter. This is not carried away, but eaten wherever met with. So attractive seems this ambrosia, that even the queens are tempted out to partake of it. Before depositing the honey I once or twice introduced some stranger ants, who were immediately attacked. While the fight was going on I placed the honey near the belligerents, who, as it seems, having more taste for the pleasures of a terrestrial Valhalla than the turmoil of the battle - field, let go their antagonist to feast with their already nearly gorged confreres. On one occasion two combatants fell into the honey. The stranger, owing to superior strength escaped and was followed by a little crowd of his enemies. The object of the pursuers, however, did not seem to be the further punishment of the interloper, but simply to despoil him of the dainty which he was carrying away adhering to his legs and body. If a working ant fell into the honey he was left contemptuously alone to escape as best he could. On two occasions, however, 1 noticed (lueens who had similarly come to grief. These, strange to say, were pulled out and cleaned by three or four of the adjacent workers. With respect to queens, there seems to be a good deal of gallantry displayed towards them, alto- gether independently of nation or race. I ha^e never, in fact, seen a strange que(>n molested when placed among hundreds of a thoroughly hostile tribe. I once noticed another remarkable fact with respect to the behaviour of ants towards strangers. I had placed some ants fully a <|uarter of an inch in length upon a board surrounded with water. Soon afterwards I brought home a number of tree ants, tog(>ther with some twenty or thirty (jueens and several hundred pupie, placing my second find at the opposite end of the .'ianii^ board. I fully looked forward for a fight, and so there was, but not as was expected. The tree ants at once began to seize and carry oil' the pup:e, and in the direction of the stronghold of their gigantic fellow-prisoners. Queens, as before stated, were allowed to pass unmolested, as also, in most instances, were un- laden ants, but an ant bearing a pupa or egg in its mandi- bles was at once assaulted and nipped by some assailant The pupa was, of course, dropped, the despoiled bearer thereof creeping away badly, sometimes fatally, wounded. Singular to say, the dropped pupa was never appropriated by the attacking party. His object seemed to be murder, to which he was incited for some unknown reason, and not robbery. Perhaps of all Australian ants the so-called bulldog is the most noticeable. These do not seem to exist at pre- sent in any great numbers near Melbourne, although during a walk through the more unfrequented part of woods and paddocks .some few are almost certain to be met with in the summer months. Their mandibles are very large, but do not appear to be of the shape espe- cially adapted for wounding the human skin. Their principal means of defence and attack in all probability lies in their formidable sting, a wound from which, although by no means dangerous, is often painful. Their name is most likely derived from the singular habit they have of always facing their enemy bull-dog fashion. It is very rarely that you can make them take to flight. They ratherchoose to maintain their ground, and assumeathreaten- ing attitude. Held captive under a glass, I have frequently seen them attack spiders many times their size, and armed with formidable jaws. The spider, however, is a dan- gerous adversary, his flight being often attended with mis- hap to the pursuing party, since the fugitive has a habit of playing a thoroughly Parthian trick during his retreat, not, however, shooting an arrow, but darting out a series of webs, which adhere to, and generally tlisable, the enemj-. Bulldog ants would seem to have some idea of colour, and, like the bo\ine monarch defending his seraglio, have an especial antipathy to oVijects of a bright ruddy tint. In confinement, at any rate, I have seen them fairly rash at a piece of scarlet silk, seizing it with apparent fury, and holding thereto for several seconds. Although not very numerous near town, they seem to be holding their own in some remote parts of the colony. According to Mr. Selwyn's geological reports, issued some fifteen years since, a party of his surveyors were literally driven out of a dis- trict near Cape Howe by swarms of these pugnacious little animals. A remarkable kind of ant is sometimes met with near town. It is of a metallic sap-green colour, usually of about five-eighths of an inch in length, rather lively in its uiotion.=, but not, by all accounts, given to either bite or sting. Its defence is the singular attitude which it takes up when an alarm is given or an enemy approaches. It suddenly ele- vates the abdomen so that this stands nearly perpen- dicular. In this position it may really appear very formidable to some would-be assailants, although man is not likely to be greatly intimidated thereby. This par- ticular ant seems to be especially addicted to solitary habits, and it is on very rare occasions that as many as two are seen together. It would also seem to be of the female sex, which, in this instance, is not formed accord- ing to the general rule. On the other hand, the males are capable of flight, are of much smaller size, and very sluggish in their movements. At the proper season a female is often seen followed by some five or six of lier male admirers, who, with their slow motion and the rather peculiar arrangement of their wings, remind one of a group of languid swells clad in ulsters, and with well-bred lounge dogging the footsteps of some reigning belle as the latter coquettishly " does the block " on a tine afternoon. — .1 ustrahiiian. 22 ♦ KNOWLEDGE ♦ [July 13, 18B3. SEA ANEMONES AT THE FISHEEIKS EXHIBITION. A popular accovMt of the principal Sea Anemo7ies in Tank No. 10,* and the Subsidiary Yafes. By Thomas Kimber, M.A., Lond. THIS exhibition of sea anemones as a whole is probably the largest, if not the most varied, collection tliat has ever been made. Many of the examples here displayed are of extraordinary beauty, much exceeding iti size those usually obtained, while in freshness and depth of colour they could not Ije surpassed, and have rarely been equalled. The very great difficulties invariably attending the setting up of an aquarium appear at length to have been success- fully surmounted, and the tanks, if not yet quite bright, are brightening, and are becoming increasingly attractive and more interesting, and daily drawing larger numbers of visitors to inspect and examine them. That the readers of Knowledue may take an enhanced interest in this very popular department of the Exhibition, it is proposed to give, first, a short introduction, and, afterwards, in separate articles, descriptions of the choicest anemones to Ije seen in the Exhibition, with sufficient details as to outline, colour, and dimensions, that each may he easily recognised, and also to add a few words on their hal)its and the locali- ties in which they are generally found. All living beings are endowed with organs or means of providing for nutrition and reproduction which are abso- lutely necessary for their existence and continuance. These are called organic functions, because all organic beings pos- sess them ; they have, too, been called vegetable functions, because in vegetable life these organs alone are found. Sensation and motion occur in animal life, and are called animal functions. This restriction of two living functions to plants, and its extension to ymir in animals, draws the line between plants and animals. It was for a long period held that many of the lower animals which have a manifest resemblance in external form to plants participated in the functions of both. They were supposed to be plants endowed with animal properties, and were hence called zoophi/ti-s, that is, animal plants. The name is still retained, though now their true place amongst animals is fully accorded to them. From their likeness or fancied resemblance to our most elegantly fringed and radiated flowers, the names anemone, sunflower, carnation, marigold, were respectively applied to several species by Ellis, a London merchant, who has given a very accurate account of these animals as observed by him a hundred years ago. He has been called the father of English Zoophytology. Independently of the above popular appel- lations are the names assigned by naturalists, which are generally derived from Greek or Latin roots, and have reference to the character or structure of the oViject named. Actinia (Gk. aKTti; a ray) is the scientific name of the genus sea anemones. To economise space, and to make our descriptions more exact, we premise a few definitions. The parts of an anemone — considered as an animal plant — to be described are : — 1. The root, called the base or foot. 2. The stem, called the column or body. 3. The flower, called the disk or face. •Another and, perhaps, almost the most attractive branch of the aquaria i.s that which contains the anemone.?, for the linest specimens of which the Committee are indebted to tlie Directors of the Brighton Aquarium, who have given ereiy assistance to ptocure a thorough and handsome collection. — Official Catalo'jue, page 1-18. 1. The foot (basis), by which the animal adheres to rocks or shells. 2. The body {columna), may be smooth {hrvis), warty (ver'xcosa), longitudinally furrowed {sulcata), transversely furrowed or insected (insecta), if the intersections are deep or constricted (constricta), if crossed by lines or furrows, i.e., cancellated {cancellata), if rough like the bark of a tree or corrugated {corruijata). The substance may be leathery [coriacfia), fleshy (cornosa), pulpy (jmJposa). Warts on the column are often suckers {acetabula). At its stimmit {i-frte.r) the column is cut ofi" in a transverse direc- tion, and a margin [margo) is formed. In some cases the margin rises and forms a parapet (tichium). Between the margin and the feelers or tentacles (tentacula) there may be a groove or foss {fossa). The margin may be notched {crenata), or formed of tentacles, i.e., tentaculated {tenta- culata). 3. The disk {fades) is the flat top of the column. It is either plane {plana), wavy {unduhita), lobate or frilled {sinuosa). In the centre of the disk is the mouth {os), with lips {labia). Converging lines on the disk are radii. Two radii, strongly marked, on opposite sides of the mouth are gonidal radii {radii yonidales). From the surface of the disk spring the tentacles or feelers, which are hollow cones, with a root {radix) and a tip {apex). Flower {aidfu's) is the term used to describe the anemone when the disk with its tentacles are expanded. Button {oucus) is employed to explain that the tentacles and disk are retracted or concealed. Sea anemones are the Actinic^ of Baron Cuvier, a genus of the Acalephce (nettles), which again forms his third class of Zoophytes. The internal structure of the anemone has been carefully investigated, to show which we give a vertical section for reference. The Dahlh, Actinia coriacea, Cnvier. Tegument, septum. Foot by which the animal attaches itself. Three rows of tentacles. Mouth. Stomach. Longitudinal muscles. Point in wiiich they unite. Ovaries which open into the stomach. Generally anemones can at pleasure either attach them- selves, or creep, or float. The cold weather drives them from the shore to deeper water. On changing their abode, some creep along the Ijottom, some abandon themsehes to the waves, and others, it is stated, turn themselves inside out, and use their feelers as feet. The longitudinal muscles shown in section aliove conduct to the tentacles placed round the creature's mouth, and are believed to be the tendons which move its feelers at the will of the animal. The actini.T are incommoded by a strong light, noise startles them, they are aflected by odours, and fresh water kills them. They may be cut perpendicularly or crosswise, and each cutting will usually live and become a new animal. July 13, 1883.] ♦ KNOWLEDGE ♦ 23 They also issue already formed from the mouth, and some- times a portion of the base is severed, continues to live, and in time grows into a complete actinia. Actiniie feed, in their free, natural condition, upon medus.'e and other small crustaceous and molluscous animals, which they seize with their tentacles, and afterwards disgorge what they cannot digest. In aquaria they are fed successfully upon fragments of meat. Many species are eaten as a delicacy in tropical countries, where they are much more numerous than on the British coasts. MR. LESLIE STEPHEN ON THE INFLUENCE OF SCIENCE.* " ~rF it were a qualification for his office," Mr. Stephen j_ remarked, "to be impartial in the sense of not having an opinion on the matter, it would have been hardly possible to select a less qualified chairman in all London than himself. He believed that the spread of scientific influence had not only not been bad, but that the thing of which we stand most in need is a great deal more scientific thonglit and method in every direction. He felt, how- ever, that his case was so strong that he could afford to give points to the opposite side ; and for this reason, and because, to a certain extent, he was prepared to go with the opener in his remarks, he hoped to be able to point out fairly where the various argu- ments which had been used found their proper place. The only definition, or rather description, of science which ever appeared satisfactory to him was that — Science is that body of truths which may be held to be defini- nitely established, so that no reasonable person doubts them. To speak of mischievous science is, therefore, to assert that truth is mischievous, an assertion to which no one would be likely to seriously agree, especially in such a place as University College. If it is to be supposed that science is mischievous, it must either be meant that certain false theories which call themselves science are wrongful, which may well bo the case, or that the scientific progress at the present time happens to bo exercising a mischievous influence. " No one denies that science may accidentally lead to a large number of our particular mischiefs, as in the case of the invention of dynamite ; but it cannot in any way be admitted on that account that science is mischievous. For the question arises, if science is bad, what can be substi- tuted for it 1 and in what way will these mischiefs be remedied if we are not scientific ? It is impossible to say that erroneous impressions will make us better off "than correct ones. For instance, the old belief in medicine subjected people to years of torture be- cause of supposed witchcraft. In India it is still believed in some parts that smallpox is a demon, and efforts are made to propitiate it, so that, if unnecessary torture and small-pox are evils, we are better for the light which the scientific man has thrown on these subjects. vStill it must be admitted that in particular ways the •development of science has produced new evils as well as new benefits, and for that matter no sort of progress is made without collateral evils. But the question then re- mained as to the remedy, and in his opinion that remedy * Remarks by Mr. Leslie Stephen in summinp: up a debate at ' Niversity College, London, on the motion by Mr. B. Paul Newman ; '■ That the spread of scientific thought and method has, on the whole, exercised an injurious influence on English societj-." The motion was supported by Jlr. N. Jlickloman, and opposed by tlie licv. A. Capes Tarbolton and Jlr. .1. G. Pease. could be very shortly described as more science and not less. There is no sort of conflict between a scientific and a literary education. Everybody ought to have some literary know- ledge, and everybody ought to be taught the first principles of science ; even a smattering of chemistry might be useful in a literary pursuit. He himself had found what little smattering of science he had acquired at Cambridge and elsewhere of the greatest use in every other kind of study. The habits of thought and feeling acquired by the study even of mathematics, which he took to be the most un- interesting science there is to most individuals, are very useful when one comes to need accurate thinking'any where, even in matters purely literary. " It had been urged that science prevents a man from taking the same sort of pleasure in nature as he would do without it. Wordsworth was very fond of saying this, and of denouncing generally the scientific position. But the reason of that was that Wordsworth knew nothing about science. The result was that there is no other instance of so great a poet leaving oft writing great poems so early in his career. All his finest poems were ■mitten in his early life ; and the reason is that he went mooning about the mountains by himself, and did not get any new thoughts. In contrast to him Goethe stands out as a man great in both science and poetry, and is a typical example of the way in which they react on one another. Whenever it was suggested that science is opposed to a love of nature, the speaker always thought of the greatest man of science of modern times, JNIr. Darwin, whose books are, apart from their scientific value, quite delightful in their literary style. Xo one, for instance, could read his " Voyage in the Beagle" without seeing that Darwin's love of science was only a part of his love of nature. There is, indeed, no conflict between the two, and a man cannot strengthen the one side of his nature without at the same time contributing to strengthen the other. Indeed, the reason why so many of our living poets are inferior to those who wrote at the beginning of this century, or to those of an earlier generation still, is just that they have not had the pluck to look science Ln the face, but have only taken a passing and sideway glance at it. "An important point in the argument — namely, the relation of science to morality — was suggested by the remarks that had been made on the subject of vivisection. The vivisection question, in the first place, did not seem to him to be quite fairly stated. People speak as though vivisection were a recent practice just introduced by a hard-hearted scientific generation. But in point of fact vivisection had been going on for many centuries. The thing which was new was the ol)jection to it. The stock argument in favour of vivisection — that liy it the discovery of the circulation of the blood was made — is only one of many instances. " It had been remarked by a previous speaker, with whom he was inclined to agree, that there had been a great increase in liumanity in modern times, and that this increase is to be attributed to the growth of science. It is not true, for instance, to say that the abolition of excessive and cruel punishments has been due to the action of a few energetic but unscientific individuals. They were, on the coittrary, put down by the growth of the scientific spirit of the age — a spirit closely allied to humanity, and which showed itself in the philosophy of the eightcentli contury, especially in the writings of Hume and Bentham. They gave up the idea of punishment as simply a revenge to gratify the fc^elings of the punishers, and took the Utili- tarian ground, that it must only be administered in so far as it is beneficial to society. They were thus inevitably drawn into denouncing excessive punishments. Komilly, who 24 - KNOWLEDGE ♦ [Jdly 13, 1883. had been cited by the other side, was probably a pupil of that school ; and certainly Benthaiii and Mill were, who really spread the principles which led to the abolition of excessive punishment. And those principles were only the principles of science applied to morality. " Though he admired our ancestors of the sixteenth century, he felt bound to admit that they were a brutal lot. An instance of how far we have improved in point of humanity is to be seen in Roderick Random. After having reduced his young, amiable, and beloved hero to very great straits through " dissipation," Smollett makes him go to India to purchase a lot of slaves, whom he sells in America at a large profit. This we should consider brutal and degrading conduct, and the fact that we do so consider it marks the great improvement which has taken place in our morality. It is quite true that it is not merely the growth of science, but the general intellectual development of the country which has put a stop to cruelty; but it is equally true that the growth of science is an integral part of that development, and one that cannot be separated from it. None of these things would have been possible unless the intellect had widened ; and science has helped to do this. We may hope for similar good results from the application of science to other things ; for example, to politics, where there is little enough of scientific prin- ciples at present. " On the religious question I can only say this," Mr. Stephen remarked in conclusion, " that you have got this plain dilemma to face, which cannot be avoided. In the first place, if any religion, or religious belief, is true, what can the holders of it have to fear from the growth of truth, which you call scientific truth ? If these beliefs are destroyed, is it not a conclusive proof that they may be false, or at least contain an element of untruth t The religion may, indeed, have been very useful, although not true, and not qualified to satisfy all the aspirations of a cultivated mind. You may see, when a civilised race comes in contact with a lower race, that the effect of the sudden contact may be to destroy the religion and the rule of life of the inferior race, without putting anything it its place. Evils of that kind have been caused by modern science." It is destroying inevitably many beliefs which people have lived under well and happily. It is undeniable that this causes pain, and that it may be injurious to their morality I shall not attempt to deny. But when I am asked to say that therefore science is injurious, I have to come back to my original proposition — the remedy is more science. The only way out of the difficulty is this ; We are here, and we have got to go — forward. And the only way is to apply the test of truth to all our beliefs. This effects a certain amount of pain, as every other kind of progress does ; but the only other way is to go on believing what you know to be lies. And, without saying which are true and which are false, I cannot see how any person can wish to do anything else but increase the amount of truth, the only satisfactory cure." Paper Cross -Ties. — A railway cross-tie has, says Engineering, been invented in America, made of paper or any other fibrous substance, such as straw or grass. This is reduced to a pulp, and run out into boards. Sheets or layers of this straw-board are laid one upon the other, cemented and pressed into moulds to form the cross-tie, which is practically fire and water proof, having been manufactured under a temperature of 500 deg. It is claimed that atmospheric changes have no effect upon it, that it can be made as cheaply as a wooden one, and will outlive five. It does not rot, and it deadens sound, which would be an advantage upon elevated railroads. THE BRUSH DY^^AMO-ELECTRIC MACHINE. {Concluded). IN the previous article on the Brush dynamo it was stated that its chief feature is its armature, which, in so far as it consists of a ring of iron, with projecting teeth between the coils, resembles the Pacinotti ring. It has comparisons also with the Gramme ring ; but the excep- tional feature in it is the method of connecting the coils. In the Gramme, and all the long list of closely-allied machines, each coil of wire is connected to the next succeeding coil. In the Brush, however, no two contiguous coils are so joined, each coil lieing permanently connected by one of its extremities to the coil opposite it. This arrangement is shown roughly in Fig. -"i, where R R is the iron ring, and S the shaft. The free ends of the coils are al) connected to the commutator. Fig. 6, a diagram introduced by Prof. Thompson, in his paper before the Society of Arts, will help us materially in comprehending the general principles upon which the generation of the current depends. By referring to Fig. 1 (Knowledge, No. 81) it will be seen that (as pointed out in the article) there are two pairs of lirushes, pressing on four commutator rings ( Fig. 3), which are represented in Fig. 6 by A A', B B'. The coils permanently connected are (in Fig. 6) similarly numbered, as 1,1, 2,2, (i-c. S and N represent the field- magnets, the arrows indicating the direction of the current. As the armature revolves, each pair of coils passes through the magnetic field, and is subjected, successively and oppositely, to every stage of the inductive influence- — ttiat is to say (associating ourselves with the coils 1,1), both coils are simultaneously in the neutral zone, or the region of minimum induction, this zone being at right angles to the direction of the lines of magnetic force. In this position, one of the brushes of the com- mutator presses the insulating piece (C, Fig. 3), and accordingly the circuit through coils 1,1 is disconnected. The object achieved in this arrangement is of a twofold nature. In the first place, the absence of a current in the coils during the period of disconnection allows time for the coils to get cool — an object which is also assisted by the grooved form of the iron ring, currents of air being allowed to pass through these grooves to carry ofl' a large quantity of heat. It must not be forgotten that the resistance of a metallic conductor increases with the temperature, so that there are electrical as well as mechanical objections to a heated machine. In the second place, the coils being in the neutral zone, no useful current is being produced, and if the current produced in the other coils is allowed to pass through them, uot only do they perform no good office, but they become a positive obstacle to the production of a July 13, 1883.] ♦ KNOWLEDGE ♦ 25 current of the highest efficiency by virtue of the electrical resistance offered by them. In recently-constructed machines, an insulating block similar to C is fixed on the opposite side of the commutator ring. This addition does not increase the duration of the disconnection, which, as each block, C, measuring one-eighth of the ring's circumference, passes under the brushes twice in each revolution, amounts in the aggregate to 25 per cent, of the time the machine is running. The object attained by the adoption of two insulating blocks is to pre- vent a " static " charge in the coils, and so to materially reduce the sparking, which in the Brush machine is mainly due to static effects. Reverting to Fig. 6, coils 1, 1 pass next to the positions 4, i, one going through the north field and the other through the south field. The coils for the current to split at B, part going through 2, 2, and part through 4, 4, reuniting at the brush B'. Thence the current passes through the field magnets in the direction indicated by the arrows, and, exciting them, emerges finally at +, which becomes the positive pole of the machine, the external current being con- nected to — and -I-. In Fig. 4 (Kxowledge, Xo. 81) the cvirrent is shown to enter the field magnets after leaving the brush A' and before entering the brush B, in which case B' becomes the positive pole. It is clear that " the four pairs of coils constitute in reality four separate machines, each delivering alternate currents to a commutator, which commutes them to intermittent uni- directional currents in the brushes ; and that these inde- pendent machines are ingeniously united in pairs by the thus approach the zone of greatest action, 3, 3, simul- taneously, but in opposite phases. Similarly, as they pass the position 2, 2, they both recede from the maximum and approadi the minimum zone simultaneously and in opposite phases. Regarding the armature at a moment when the various coils are in the position indicated in Fig. G, the coils 3, 3 arc in the region of maximum action, one coil being con- nected to the brush A, which becomes the negative pole of the machine, the other coil at the same time communi- cating its positive charge to the brush A', and thence by wire to the brush B. The coils 2, 2 have left the position of best action, and the coils 4, 4 are at the same time approaching that position. The induction in each case is only partial, and, accordingly, an arrangement is made device of letting one pair of brushes press against the commutators of two pairs of coils. Further, that these paired machines are then connected in series by bringing a connection round from brush A' to brush B." The Brush dynamo thus involves some of the prettiest ideas hitlierto conceived ; and multitudinous as has been the number of recently-born rivals, it remains the best where a large number of lamps are required to be worked in series. With the 40-light machine the objection to an electro-moti\e force of 2,000 volts in the conductors is, of course, a great one. !>o, also, is the objection to enormous gas-mains, as numy living in tlie region of Tottenham Court-road a year or two since have cause to remember. Wliere, therefore, such immense currents are employed, it is imperative that the engineering should be 26 • KNOW^LEDGE ♦ [July 13, 1883. of the best, and that a pennywise policy should never be resorted to. From what has been recently going the rounds, it is to be feared that too little attention is being given to these latter requirements, and that the value of employes is estimated more by their servility and energy in " touching their hats to their superiors " than by their capacity for useful and remunerative work. Overhead Wires ix the United States. — Great opposition is being made, especially in Chicago, to the prac- tice of the telephone and telegraph companies of carrying wires close to or over the roofs of houses, without the con- sent of the owners, or any compensation paid to them. In consequence of several adverse decisions, the companies in some places propose to stop communications. Consul Berthold, of Breslau, had a free pass given him as a director of the Breslau, Schweidnitz, and Freiburg Eailroad. He used it to secure free transportation for a part of the baggage of his wife and daughter when going to Marienbad. For this lie was arrested and tried by a criminal court, charged with illegally obtaining a service worth 1 -38 dols. He was found guilty, and sentenced to imprisonment for one week. He appealed, but in the higher court, his sentence was confirmed. What, says the Railroad Gazette, if this were thus in America ? In Switzerland in 1881 the average distance run per lo^comotive was 16,039 : on the German railroads it was 17,185 ; and on the Austro-Hungarian roads 16,010 miles. In this country by the last census it was 22,355 miles. Here, therefore, 100 locomotives do as much work as 131 in Germany, 139 in Switzerland, and 140 in Austro- Hungary. — Eaginner. How A Locomotive was Raised from a River. — The Ehn-ated Railroad Journal relates how the feat of raisin^ a huge freight engine from the mud in Bush River, on the Philadelphia, Wilmington, and Baltimore Railroad, below Havre de Grace, was successfully accom[)lished a few days ago. The engine fell through the drawbridge some time ago. The difficulties of the feat may be imagined when it is understood that the engine was several feet below the water's surface, and completely buried in the mud. The wreckers have been at work a week, the first thing accom- plished being the placing of heavy chains beneath the great mass of iron. Two divers, sent down for the purpose, were compelled to dig several feet under the soft mud at the bottom of the river. The chains were made taut to four heavy scows, which were filled with water at low tide. Everything being satisfactory, the water was pumped out of the scows, thus tightening the chains about the engine. When the tide began to rise, the engine was pulled a few feet from the mud. Then other scows were brought, and when the tide was again low, water was pumped in and the chains fastened to them. The tide went up again, and so did the engine, which came to the surface. After this had been repeated a number of times, the engine was swinging clear of the water, and was then placed on a large float, only slightly damaged, and wanting but few repairs to make it as good as before its tumble into the river. The railroad will now take charge of its fished-up property, and tow it to the river bank near the railroad track. To th?.t point, when the tide is high, a temporary track will be built connecting with the railroad, and when the tide has fallen sufficiently to place the wheels of the engine on a level with the temporary structure, the engine -will then bo run on the wharf and to the main track. It will be taken to Wilmington and repaired ; it cost 1,000 dols. to fish the engine out. FIGURE CONJURING. By Richard A Proctou. THE figure conjurings given by several correspondents seem to me imperfect, because before the conjuror has abstracted the numbers really added during his mystifying processes, the number attained shows three out of the four digits in their original order. For instance, in the process on p. 395, the numbers 5, 4, 3, 2 were written do\\'n, and the number finally attained by the conjuror's victim is 543,520. [ would propose some such arrangement as the following : — Take the four digits in their order, multiply by 2, add 2,460, multiply by 5, add 45, multiply by 10 ; then subtract (privately) 123,450. Thus, let the numbers be 5, 4, 3, and 2. The process, then, is as follows : — 5,432 multiply by 2 add 10,864 2,460 multiply by 13,324 5 add 66,620 45 multiply by subtract 66,665 10 666,650 123,450 giving the number 5432 00 Where the trick has to be performed several times the arrangement can easily be varied, especially as regards the sum added at the second step and subtracted at the last. It is convenient to let all the digits of this number be even. Note also that the second digit of the second number added is of no account; it is only added to help the mystification, by avoiding two cyphers at the close of the operations followed by the performer openly. If these rules be fol- lowed, the number to be secretly subtracted is always given by halving the three first digits of first addend and appending the first digit of the second. Thus, let the first be 4,280 and the second 37 ; then the number to be sub- tracted (or the only part of that number worth consider- ing), will be 2,143 (half of 428 with 3 appended). Take, for instance, the digits 7,1,9,3; then the process will be : — 7,193 + 14,386 4,280 X 18,666 5 + 9.3,330 37 X 93,367 10 subtract 93,36|70 2,143 7,193 as required. The multiplication by 10, by the way, is quite unnecessary. July 13, 1883.] ♦ KNOWLEDGE ♦ 27 etittonal (Sostsiip. Captain Webb is to swim the Lower Rapids of Niagara, for the benefit of himself first — should he survive the experiment — and of the American railway companies in any event We should be sorry to limit in any way Captain Webb's legitimate right to do what he likes with his own. But unfortunately his plan involves more than this. He is setting a most demoralising example. The railway companies are bartering a life against money, and the rascality of their course is so obvious as to need no comment. But many will feel sympathy with Captain Webb instead of that contempt which should be felt for the man who, being well able to earn an honest living in more ways than one, prefers to stake liis life for a sum large enough to keep him for several years, as a reward for a. few hours' struggle with death. It is time that the nonsense ventilated about Zukertort and his defeat by Sellman and Mortimer should be answered. We are told of the exhaustion following his protracted struggle, of his wilfully giving up the games, and so forth. Any one who plays through the two games will see that Zukertort, having no special reason for wanting to win these two games, was content to play rather for effect than on those strictly sound principles which can alone ensure success in match games. There is not the slightest trace of weakness in his game with Mortimer, the weakest of his opponents ; but there is marked evidence of rashness, or rather, of what would have been rashness if success in the tourney had depended on success in this particular game. Men are not apt when exhausted to go in for undue daring. Dr. Hastinos, finding line 1,474 longer on that side of the corona most exposed, both before and after totality, starts the theory that the outer parts of the corona are merely phenomena of diffraction. The observation really shows that the matter giving this line does not extend into or near the outer parts of the corona. We shall have Mr. Lockyer going back to his first love, tlie atmospheric glare corona, illustrated by the cork-in-a-shutter experiment, in which the sun is the sun, the cor)-: the moon, and the shutter is — nothing in particvdar. The simple facts that every solar appendage which is not hidden by the moon illuminates our air even at the time of totality, while any illumination so caused must increase witli distance from the solar disc, accord perfectly with Dr. Hastings' observation, as with all others yet made, without the absurdity to which he is said to have committed liimself, — at which I imagine those among his fellow-workers in America who are competent to form an opinion, as Professors Young, Newcomb, and Langley, will be disposed to smile. In Knowledge for April 6 we chanced to remark of the Sidereal Alesaenger for December, 1882, that it con- tained chieff)' borrowed articles and editorial notes. " ' Chiefly borrowed articles ! ' " says the Messem/er for June ; " Knowledi:e ought to know that such a statement is grossly untrue." If wo have offended against truth, oven this " lie direct " is deserved ; and whether it is or not deserved, it shall not provoke the " countercheck ([uarrel- somo." Tlie SuhreaJ J/estKiiJ/er, conducted by Professor W. W. Payne, Director of Carleton College Observatory, is a very useful publication, and of the June number it certainly cannot be said that it contains chiefly borftiwed articles. There is an admirable article on the " Effect of Flexure on the Axis of Transit Instruments with the (so- called) Broken Telescope," by Professor C. A. Young, Prince- ton, N.J. ; one article only borrowed (from the proceedings of the Appalachian Club), on " Mountain Observatories," by Prof. E. C. Pickering ; an article by the editor on " The Comet of 1882 "; one by Mr. Louis Swift on " Intra-Mer- curial Planets "; and two other original articles. As to the December number, we do not repeat our statement that it consisted chiefly of borrowed articles and editorial notes, because that would seem like giving our esteemed Trans- atlantic contemporary the lie direct, and that would not be courteous. We simply note that besides editorial notes and borrowed articles, it contained two original articles, one on " the Computation of a Para>)olic Orbit," and one on the " Great Comet of 1882,"— "only these, and nothing We further expressed our opinion that our own very early discussion of the orbit of the great comet of 1882, in which we expressly referred to the possibility that the Vienna observation of September 24, on which the discus- sion was practically based, might be incorrect, ought not to have been reprinted in December, when it was known that that observation was utterly incorrect, without some remark to that effect. The editor of the Messenger, instead of expressing regret for what was a manifest injustice to us, though doubtless only by inadvertence, dwells now on our unique haste and liold guessing. There was no haste and no bold guessing, but simply what we take to have been an instructive computation (the Jfessenger admits that it involved a simple and neat application of cycloidal geo- metry), every line of which was correct, and the result, with the proviso indicated plainly in the body of the article, correct also. We repeat now what we said then, that were the observation at Vienna on September 24 correct, the period of the comet would have been as short as we stated. The Spectator charges Miss Peard, in " Contradictions," with betraying ignorance of cricket, because she describes a player as " caught at slip from a skyer," which he considers next door to an absolute impossibility. ^Mr. H. Katenkamp, joining issue, says that, on the contrary, of all the fates that await an uncertain batsman, none, especially in the long slip, is more common. To which the Spectator makes rejoinder that a "skyer" is a ball hit or driven with the batsman's full force, but with the left shoulder not suffi- ciently forward; and that "a very late hit to leg might just conceivably send a skyer to the slips." Surely this is absurd. A "skyer" is a ball which flies skywards, whether from a drive, a hit to leg, or a cut. A misjudged late cut at a ball with plenty of spin on is as apt to .send a skyer to the slips as any stroke a cricketer can make; but a "skyer" to the slips from a late hit to leg is next to an impossibility, and how such a stroke could be regarded as made with the left shoulder in any degree forward, it would puzzle W. G. himself to imagine. Let any one try to hit a leg ball to the slips with his left shoulder forward, and he will learn that there are twisters other than twisting balls. The produce of labour has, we read, been divided between capital and labour as follows in the countries named : — Assuming the produce of labour to be 100 in Great Britain, .")G parts go to the labourer, 21 to capital, and 23 to the Government. In France, 47 parts go to labour, 3G to capital, and 17 to the Government. In the United States, 72 parts go to labour, 23 to capital, and 3 to the Govern- ment. 28 ♦ KNOV^^LEDGE ♦ [July 13, 1883. THE DIVIDED SKIRT. IN the first number of Knowledge I gave an amusing article from the Neiv York Times about pyramid theories. It was written presumably by Mr. Alden, whose occasional serio-comic articles are a most attractive feature of that leading New York paper. I suppose we owe to the same clever pen an article recently quoted in the Standard about a habit chaffingly attributed to the Missourian belles, who, according to this view, might be described as snapping turtle[dove]s. (Four Missourian ladies happened to be present in my house when that article appeared, but obser- vation has hitherto failed to confirm the statements of the Jfew York Times in their case, and I can only assume that the habit of biting is not universal among the fair Mis- sourians.) I think readers of Knowledge will read with amusement the following specimen of Mr. Alden's quaint humour : — " Mr. Richard A. Proctor, the distinguished astronomer, has recently made some new investigations as to certain heavenly bodies which show him to be a man of great fear- lessness and originality. " According to Mr. Proctor's own statement, set forth in a letter addressed to the London Times, he has of late ceased his explanations of the milky way and concentrated all his powers of observation upon corsets and skirts. Of course, his scientific attainments have given him excep- tional facilities for exploration in hi.s new field. Knowing the diameter of any given skirt, he is able to calculate its contents, and if the elements of a corset are given to him he can ascertain to the millionth part of an inch the length of arm required to encircle it, and the cubic feet of girl which it contains. Conversely, with a knowledge of the radius of any given girl, he can find the size of both the skirt and corset best adapted to her. There is no hap- hazard guesswork in Mr. i'roctor's investigations of femi- nine dress. He proceeds by strictly scientific methods, and he grasps figures with an assurance and success which no unscientific person could hope to rival. " Several interesting experiments have been made by Mr. Proctor upon ' subjects ' styled by him the ' ladies of my famUy.' These experiments began with the removal of corsets. It was found that great advantages at once followed this measure. For example, the voice ' increased markedly both in power and compass,' so that when Mrs. Proctor now remarks to Mr. Proctor, from the top of the stairs at midnight, ' Pachard, you've been sitting up with those horrid stars again,' slie can be heard by neighbours living at a distance of an eighth of a mile, whereas her voice could formerly be heard only half that distance. "At the same time Mr. Proctor found that the withdrawal of corsets left the skirts of the subjects insufficiently sup- ported. He therefore substituted ' divided skirts ' for those of the usual pattern, and thus obviated the difficulty. With the ' divided skirt,' lawn-tennis, tricycling, and other open- air exercises became much easier, and Mr. Proctor is so completely satisfied with the result which he has attained that he is now longing to deprive all his countrywomen of corsets and to put them into the 'divided skirt.' " From the tone of his letter, it is plain that the astro- nomer is more enthusiastic as to the clothing of the women of England than he has even been as to the stars. The transit of a young lady clothed in a ' divided ' skirt over a stone wall is watched by him with as much interest as if he were observing a transit of Venus across the sun, and the orbit of a tricycle rider with a divided skirt presents elements more interesting than those of the orbit of any comet. In all probability Mr. Proctor will henceforth throw aside his telescope, and devote himself exclusively to observations made through an opera-glass. " It may be quite possible that all the advantages claimed for the ' divided skirt ' by Mr. Proctor may exist, but whether they would compensate for the ugliness of the garment is a question which most women, and all men with minds uncontaminated by astronomy, will unhesitatingly answer in the negative " [only as no eye, not even the keenest astronomical eye, armed with a telescope of "ten million gas magnifying power " can recognise any change at all, this particular objection scarcely counts. — R. P.]. SOMETHING ABOUT THE BEET. AS the editer kindly allowed me to put before the readers of K.vowLEDGE a few facts ascertained by chemists with respect to the potato, I am in this going to try if I cannot give some interesting, and at the same time scientific, facts with refer- ence to the beet. In 1880 alone, there were no less than forty -three important communications to the scientific world, announcing the results of various investigations carried on in connection with this plant. And it is through this that I think it a duty for some person or other to lay before the public some, at least, of the interesting and useful parts of their (the chemists') investigations. What do most of ns know about the beet, beyond the fact that we plant it in our gardens, and in dne time eat it, either as pickle or ])lainly boiled, or prepared like cucumber, or used for salads ? I take it for granted that we all, at the same time, know all about the manufacture of this plant for sugar, also its history, and how chemistry in those early days came to the rescue of the manufac- turer, so that he might be able to manufacture a sugar in his own country (Germany and France), instead of importing the colonial cane-sugar ; how the duties were raised on foreign sugars to make it prohibitory to import them, as it raised the price to a fabidons sum per pound, I forget now how much, and should not like to guess, fur fear of underrating the amount ; but these and other interesting matters will be found in the " Chemistry of Common Life," by Johnson and Church, by those who have not read the account of it. But it is not my intention to go back to the old groimd, but to bring forward later information. In my communication about potatoes, I showed you what an influ- ence light had on the sprouting of tubers; we shall now see that light has also a very marked effect on beet. Beet, when grown in the shade, runs more to seed, and does not ripen as soon as when it is grown in the open ; and to make this more clear, I will give two results obtained by two different chemists to bear out the assertion. In one case the relation — in the shade — between the leaves and root was 66'34, and in the open the relations were nearly exactly reversed, viz., 35'66. The same chemist foand that 1,000 plants in the open yielded 32'5 kilos sugar, while the same number in the shade only yielded 13'-t kilos (a kilo = about 2 lb. 3 oz.). The other chemist planted a lot of willows, and between the willows he planted his beets with the following results : — The beets he grew in the open yielded 11'14 per cent, of sugar, 350 grammes of root to 100 of leaf, and the beet grown amongst the willows yielded only 8'8 per cent, of sugar, and only 40'3 grammes of root to 100 of leaf (a gramme is not quite 15i grains). This shows us how important it is to set our plants in the open, and the same also applies to the potato, for the two plants are very similar in their wants, as we shall see. We now come to the effect of heat on the growing beet, and we find that a mean temperatm-e of from 14° to 18° C, from May to October inclusive, and a warm and wet spring, together ivith a not too dry summer, are the best conditions under 'which beet can be grown. Heat has the same beneficial effect on the beet as on the potato. Beets require a total temperature of 117° C. before they make their appearance above ground, and as beets require to reach perfection in as short a time as possible for successful estraction of the sugar, it is easily seen that too early planting is disadvantageous to the growth and manufacture. Beet thrives best in those countries where a hot summer is followed by a very cold winter (| of the number of degrees Centigrade + Z'2 = the degrees Falirenheit, i.e., English temperature). When you cut open a beet you see two concentric rings, the one white and opaque, the other clear, transparent, and mostly coloured ; the former contains the chief part of the sugar, while the latter contains tlie albumen. Ploughing has a very favourable influence on the quantity of the crop, if the ploughing is deep, and is next in importance to planting. July 13, 1883..] ♦ KNOWLEDGE ♦ 29 which we shall see is one of the chief causes of success in beet cultivation. If the manm-es are ploughed in, the roots form regularly, only about 35 per cent, having irregularities, side roots, &c., whtreas in the other case, i.e., if the manure is not ploughed in, the percentage is about 60 per cent. In thick sowing, the produce of the beet crop is smaller in quantity, but of higher value, on account of the sugar, and in the density and purity of the juice, than in thin sowing. According to the space allotted to each plant, the yield of sugar varied, in one case, from 86 to 91 per cent., and in another case from 88 to 93 per cent. This important fact is more to be considered than the manuring or the kind of beet grown. The distance between the plants should be small on a humid and matured land, but great on a dry, high ground and poor soil. A better produce is obtained from a sandy soil than from a peat soil. Experiments give for the former 10-46 and 13-90 per cent, of sugar, and for the latter 8-35 and 8-39 per cent, as the yield. The leaves of the beet have had a good deal of attention given them by the chemist. Cows fed on the leaves of beet yield more milk a day than when pasture fed, though the milk is lower in total solids and fat ; but not only is the yield of milk more through the use of the leaf, but the food is, at the same time, more nourishing to the animal. I will give you one of the results of experiments made to confirm this : — Kilos. After feeding on leaves, weight 485 Before ,, ,, „ 450 Increase 35 kilos. So we see that there was a gain of at least 82 lb. through feeding the animal with this food. It is not, at the same time, advisable to feed them entirely on this. The leaves should be preserved in pits, according to the well- known plan, and covered with earth about a foot deep ; then, when required for use, given with a mixed diet, containing a large amount of the leaves. It will be found that this is the best kind of fat- tening fodder for sheep and cattle. The leaves of the beet contain small quantities of glucose, and those roots which have well deve- loped their leaves are the richest in sugar. The fresh leaves contain about 4 per cent, of oxalic acid, about a third of which exists in a soluble form. It will now be seen why I said it was not advisable to feed cattle entirely on the fresh leaves, as the acid induces inflammation of the mucous membrane of the stomach. Pickling the leaves mth chalk will, in all probability, prevent this, as the soluble acid would be converted into calcium oxalate, which is insoluble in the stomach. Leaves of the beet change through keeping ; in fact, no other cattle food loses so much by storing as these leaves. The mineral constituents suffer the most, especially potash-magnesia. Phosphoric and silicic acid and chlorine — the soluble oxalates — are also removed, for tlioy urc reduced from I't-I to '53 per cent. This shows why it is of sn imifli advantage to preserve the leaves, and accounts for the well-kuowu fact that beet leaves are comparatively harmless after having been allowed to decay. Aconite may be extracted from beet leaves, as well as other organic substances. The residue left liy tin' diffused method of extracting the juice is of much greater value for cattle fodder than that obtained by the hydraulic or maceration ju-ocesses. We now come to a matter on which some chemists differ — I mean iu the relation of phosphoric acid in root and leaves to the sugar in beet. I will give three different results deduced by separate chemists, and leave your readers to judge for thcn\selves if there is, or is not, a relation between the two. These are the results: — 1. There is a certain constancy in the proportion existing between the amount of sugar in beet and the amount of phosjihoric acid in the root and leaves, and between the sugar and the ash. Experiments gave the proportion of the former 100 : 1-2 and 100 : 1-15 ; and the proportion between sugar in beet and ash (root iind leaves), 100:18-3. 2. Gave for the proportion 100 : 1'15, and says that tlie relation is constant. It will be seen that his results coincide with Number 1. The higher the yield of sugar the less the soil is impoverished, wo aro informed. 3. Made experiments to prove that there is a relation between the potash absorbed in the root to the sugar produced, lie says this is constant ; viz. — about 100 : 2 ; but he could not observe any constant relation between the phosphoric acid and tho sugar. After seeing these three reports, we see that there is some doubt about tho matter, which will, we hope, soon be cleared up. It certainly looks as if there was a certain constant relation, when two chemists, working sep.arately, coincide in their results ; but we cannot be satisfied until every doubt is removed. (To he continued.) " Let Knowledge grow from more to more." — Alfeed Teknyson. Only a small proportion of Letters received can possihly he in- serted. Correspondents must not he offended, therefore, should their letters not appear. All Editorial communications should he addressed to the Editok of Knowledge; all Business communicatirms to the Publishers, at the Office, 74, Great Queen-street, W.C. . If this is not attended to, DELAYS arise FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should he made payable to Messrs. Wyman & Sons. The Editor is not resptmsihle for the opinions of correspondents. No COMMUNICATIONS ARE ANSWERED BY POST, EVEN THOUGH STAMPED AND DIRECTED ENVELOPE BE ENCLOSED. LAKGE SUN-SPOT.' [866] — Once more, and for the fourth time within the last eighi months, there is a spot on the sun so large as to be visible to tlie unaided eye. In observing the sun with my telescope on Wednesday and Thurs- day last, I saw, besides many other smaller ones, one very pretty group of fair-sized spots. After Thursday, I had not an oppor- tunity of observing tho sun with the telescope until yesterday, and I then found that in the meantime one of the spots of this group had grown into a very large one, and on procuring a piece of ordi- nai-y smoked glass to look through, I could see the spot distinctly with unaided eyes, it being situated a little north of the sun's centre, and I have again seen it in the same way this morning. Seen in the telescope, it is a remarkably pretty spot, the central black part, or umbra, being oblong in shape and crossed in several directions by the white streaks called bridges. Just to the east of this spot, and apparently almost touching it, is another good-sized one, verj' long and narrow in shape ; and in close proximity to these two are several much smaller ones, altogether forming a very pretty group. And then, in addition to all these, there are many other small ones scattered about the sun's face, principally near the western edge, so that just now the sun is a pretty sight to any one possessing the means of scrutinising it. Excelsior. Huddersfield, July 2, 1883. ANSWEK TO GENEALOGICAL PUZZLE IN OUE LAST. [867] — X marries M, and has a son, A. His wife dies (say in 1820), and, in 1822, he marries again, N; and has a son, Tom. X dies in 1824, and his widow, N, marries Z, and they have a son, B. Or— M 00 X 00 N 00 Z I I I A Tom B 865, page 13. Solution : — A's father dies. A's mother marries again, and Tom is born. A's mother dies. Tom is Irother to A. Tom's father marries again, and B is born. Tom is brother to B. A and B are in no consanguinons way related. [There are several ways in which tho puzzle may be solved. Query, How many ? — R. P.] RATIONAL DKESS FOR MEN. [868]_I think "Mr. G. C. Mesnard," in writing in favour of braces over the belt, may not know how the bolt should bo made or worn. I have woni my bolt for six years. It was made for me l>y my tailor, Mr. Davies, of South ilolton-street, Bond-street ; it is Jin. wide, made of morocco leather, has a rinij over each hip, and a special buckle. "The rings and buckles in my case are silver, as I conld not get the buckle otherwise. It should be w-orn as low over 30 ♦ KNOV\^LEDGE ♦ [July 13, 1883. the bowels as possible, and kept there by means of loops. This is essential to comfort. An old sinner I once knew, who had kept his figure well, wore a wide linen belt inside his trousers, fastened at the hips. For heavy trousers t wear a wide belt (material unknown) fastened at the hips and buckled behind. I think " A Woman " will find that trousers are cooler than knickerbockers, as socks can be worn ; they also protect the ankles, and prevent dirt getting into the shoes. After much trial I do all manual labour in knickerbockers, but far prefer trousers for walkinjf in. Still, I think knickerbockers would be far more comfortable for ladies ; there is a sense of freedom in them. JoHX Alex. Ollaed, Enfield. DRESS REFORM. [869] — Having read most of the letters and articles on " Dress Reform" appearing in Knowledge, might I inquire, if sufiiciently relevant to the subject, of some of our readers who know what thi; reason or advantage is in wearing the " scarf " round the waist, as worn b>- Frenchmen, Spaniards, Italians, &c., some of which scarves are very large (1 ft. broad by 12 ft. long) ? If this is necessary as part of their dress, it certainly seems ungainly (as 3 or 4 inches of trousers), though it may be rational. F.^JA. [870] — I am sorry I did not describe the divided skirt : there has been so much said about it, that I imagined this was unnecessary. It takes from i to 41- yards of ordinary skirting, and is in two legs, like a large pair of woman's drawers. For any one of medium height, the dimensions of the skirt proper would be as follow : — Entii-e length (front) 31 in., (back) 1 yd. ; length of leg on inside seam 24 in. ; circumference of leg at ankle 22 in., at widest part, 35 in. Each leg is trimmed with two kiltings ; the little one round the bottom is 2 in. in depth, the other 11 in. The top of the skirt is gathered into an inch band, one yard long ; this band has button-holes in it, corresponding to buttons on the -belt. The belt is the most difficult thing to describe, and I doubt if I can do it intelligibly. It fits the hip closely ; the depth in front is 7 in., at the back (where it fastens) it is 4^. The foundation is of some stiil material, and has four gores in front. These are 3 in. wide at the top and 4^ at the bottom, but I am very small over the hips. A dressmaker would fit the belt best. The buttons I have mentioned can be anywhere on the belt, mine are round the middle. I would recommend ladies living in the country not to have the skirt too long, as it catches the mud. These measurements are carefully taken from a pattern sent me by the original society. I shall be glad to give anyone more parti- culars if these are not sufficient. Pedesteiexxe. ALTERATION IN COAST-LINE, &c. [871] — Professor Geikie was my authority for saying the sea was gaining on the land on some pai-ts of the east coast of England at the rate of about three feet a centiiry ; but I did not say in my letter (768) that the Sheppey cliffs were going at rhis rate. Prom personal observations, I knew the action on the island was very rapid ; in fact, I should say it was much greater than your correspondent (820) states. As regards the submerged forest, my information was obtained some considerable time since from a scientific magazine, the name of which I forget ; but I am quite willing to believe Mr. Shrubsole — who is an authority — that after all it was drift timber which had been discovered, and which led to the notion that a " submerged forest " had been found. H'sett. THE BELUGA IN THE BRIGHTON AQUARIUM. [872] — A noble quadruped galloping through the water. Perhaps I ought to have written to Mr. Lockyer about galloping, but should much prefer your judgment, if obtainable. The first sentence appears to me a correct description of the swimming movement of the dolphin, and at the same time a new view of the motion, or one that has not previously been remarked upon. Professor Flower has shown (which I learned through Know- ledge) that whales are derived from land quadrupeds, and this being admitted, it foDows that their (the whales') progressive movements through the water are derived in the same way. Thomas Kimbek. [It is singular that when I was watching the bottle-nosed dolphin at the Brighton Aquarium, from above (Mr. Lawler kindly accom- panied me, and gave me much interesting information), the same idea occurred to me, as I (dlserved the singular contrast between his way of using his tail aiip that in which a fish uses his. That movement of the tail and fiBe resulting change in the position of the body — which one sees also in the movement of porpoises — is strongly sugtcestive of galloping, though, of course, the absence of hind legs somewhat impairs the idea. — R. P.] TO SEE THE SXJEFACE OF THE EYES. [873] — Having read the papers and letters on the eyes with much interest, I herewith give a method of seeing the surface of the eye which may be new and interesting. Make a very small pin-hole through a piece of paper, and, holding the paper about an inch from the eye, look through at a light. If the hole is small enough the sun will do, but gas or candle-light gives the best results. A small spherical or other body which gives a very small but strong reflection will give the same results. I h.ave had several "fires" on my eyeballs, and have found by this method that the marks have remained for a year or two, although they disappeared in two or three days to all outward appearance. W. Melville. LETTERS RECEITED AND SHORT ANSWERS. G. M. Many thanks. Mr. Clodd's earher books (sold by tens of thousands) published .by Macmillan. But I think the book you refer to, "Jesus of Nazareth," is published by Chatto & Windus. Being away from home (see lecture advertisements) cannot refer to my copy to see. Signalling at whist is playing an unnecessarily high card to a trick, as " five " when you hold " two ;" the fall of the lower card in the next round completes the signal. — C. W. Harding. Do not keep account of such matters. Writers send me their names and addresses in guarantee of good faith, but my memory does not retain them all. — E. H. Stutter. The word Timex, No. 87, p. 381, was written without any apostrophe at all, the apostrophe being added by the printers of the Neiccastle Weekly Chroiiicle. I meant it as written, just as one might speak of a Punch article, or an Echo remark. One would certainly not speak of the Times' views, but of the Times' s views; but as you say, where the "es" at the end of a word is sounded, then — and then only — the apostrophe alone should be used, as Moses' laws, Archimedes' theory, and so forth. — P. A. Fothergill. Have not time to look up Mr. Hamp- den's remarks on evolution ; but I agree with you that his being astray on one subject is no reason why he should be astray on all. — E. Luxmoke. Thanks. — J. B. If I missed the first of your ques- tions, it must be in not noticing that what you want me really to determine is the proper meaning of the word " level." I sub- stituted the word " horizontal." in that sense in which it is equiva- lent to the word " level." If you want to know whether water poured on a perfectly plane table, a mile square and with its plane at the centre at right angles to the direction of gravity, would be deeper in the centre than at the sides, my answer tells you. If you ask whether such a table could properbj be called " level," I answer "no." If you ask what would be meant by a level table a mile square, I answer that I don't know. Neither the scientific sense of the word " level," nor the ordinary sense, can properly be applied to a surface so large, whether plane or curved. In level- ling, distances so short are dealt with that the curvature of the earth may be neglected ; if distances much larger are dealt with, other words must be used. — J. S., S. S. L. If you want an exact answer, mine is correct. If yon think " the curvature is practically 7iil," then you can leave it out of account. I m sure I don't want to consider it. As a. matter of fact, when a cannon ball is fired with a horizontal velocity of 2,000 feet per second, from a parapet 16 feet high, over smooth water, it travels (ajiart from atmospheric resistance) 2,000 feet before it has been drawn 16 feet earthwards; and since a point on its original course, but 2,000 feet from its starting-place, is 16 feet IJ inch above the water, the cannon-ball is still li inches above the water at the end of a second, when the one let fall from the same height has just reached the water. So much if you ask for information ; but if your object in asking the question was eventually to remind me of the law that " change of motion is in the direction of the impressed force, and proportional to it," I can only say I am very much obliged to you : as I should be if you reminded me of one of the details of the multiplication table. — E. G. McG. Thauks; but quite unable to spare space for such notices. — L. McGaul. I thank you warmly for the pains yon have taken ; but the subject is not one to be dealt with so fully in these columns. There are many who are offended at the very use of the word "faith" in that connection, just as they are offended by a common use of the word " loyalty " in a sense which seems to them at once degraded and degrading. I would not needlessly offend these, even if I did not agree with them. The question amounts for most to little more than this : a certain people (not too warmly beloved by July 13, 1883.] ♦ KNO\VLEDGE ♦ 31 all) seem to have collected everything written by men of their race, as of superhuman excellence, and many outside the race accept that view ; others do not : with the farmer such matters as your father dealt with are very properly regarded as " of faith " ; with others they are not so regarded at all. These last take little interest in inquiries of the sort. It seems to them the merest accident that instead of them, such matters as the proper interpretation of the Homeric records have not come to be questions of faith. We must Consider these, who are many — even among those who are supposed to view matters otherwise. — A. Andrews. I am sorry, but it is con- trary to " our " rules to answer queries of the sort. — H. Askew, Any proof by which it is shown that the sum of the roots of an equation of the ?ith degree is equal to minus the co-efficient of x"~', will serve to show that the sum of the nth roots of unity, and the sum of their reciprocals, are each equal to zero. — H. C. Jones. Your society for correcting, detecting, and, where necessary, expos- ing slander, has my heartiest good wishes ; but my time is so fully occupied that my joining it would be useless. Many thanks for your kind words and good wishes. — W. T. Southwakd. "Most men" and " a large majority of your fellow-countrymen ! " We question each point ; but the two statements are very different. Albeit Knowledge is meant for those who take an interest in science. "Most men" and "the large majority of our fellow-countrymen ' do not take the least interest in science. More are students of science now than were so twenty years ago ; but they are not one in a hundred of the population yet. Can you imagine that in catering for these, I am likely to consider those others, even if most of them do hold, as you say they do, the ideas you mention P The only way in which those ideas can ever become matter of scientific inquiry is in the way in which they have been touched on here. Their origin, the way in which they have spread, have become modified, have died out among those who inquire, and so forth — these are matters of scientific interest, because, among the subjects of inquiry which science takes up, all relating to man and his ways must be included. If you regard as sneering every expression implying views which do not hap- pen to agree with your particular views, it is unfortunate ; but the fault is not here. Of myself personally I may say (so far as I can judge myself), what I recognise as true of Messrs. Slack, Williams, Clodd, Grant Allen, Wilson, and others whose personaliiy comes most clearly before the readers of Knowledge, that we are one and all exceptionally free from any concern or trouble of mind because others may not view matters precisely as we do. For instance, it appears you differ from me in some points on which you have touched. Very well. What can it matter ? If what I say does not commend itself to you, it does «of, and there an end. No sneer whatever is intended when I say that, while preferring my own views, I have no wish to controvert yours. — H. Malim. No : tiie velocity in the original horizontal direction is affected by gravity, which oidy acts at right angles to that part of the motion at the beginning. See analytical solution. — E. P. Toy. I am much obliged to you ; but travel about so much that fear the book might not be returned in due time. May I be permitted to mention here that your letter gives strong avouchment of tho truth of the account of Mrs. Croad's thought-reading powers ? — P. Pekcival. The statement has never, I believe, been challenged. It was discussed a few years ago before tho Astrono- mical Society, but not questioned. Dr. Warren de la Rue brought it, if I remember rightly, before the notice of tho society. Hut while, so far as I know, no one doubts or denies the occasional existence of organic matter in meteorites, what has been challenged and tho- roughly controverted is the statement made a year or two ago, that the remains of lower types of vegetable and even animal life had been detected in meteorites. — C. .1. B. Your question cannot be answered ; tho velocity of the foot varies from 0 through a maximum to 0, the average rate being 2 yds. (the actual di.stanco covered by tho moving foot in a so-called one-yard step) in 41- I5ths of a second, the time during which one foot is moving and the otlier at rest. — A Weak One. So hard to get space ; but soon. — G. M. Mr. Clodd's " Jesus of Nazareth " is published by Messrs. Kegan Paul & Co. — G. G. Hakdinoiiam. It would not be very easy to answer your (juestions about star-drift in convenient space here. Maps showing tlio star-drift for all the stars whoso proper motion has been deter- mined appear in my " Universe of the Stars." Sun-EDITOBIAl. J. S. W.— A. F. 0.— J. Habbington.— M. N. E.— A Blind One.— T. .1. R. — Perple.ked. — P. Mackay. The Editor ia not a medical man, nor am I. Errata. — In the solution at pp. 10, 11, the following errata occur: P. 10, line 19 from bottom, for \hc.ahC, read \hc.hC ; p. 11, lino 11, for "twice" read "half." ®\\x ifiattjematical Column. GEOMETEICAL PROBLEMS. By Eichakd A. Peoctok. Part VII. THE result obtained at p. 15, fitly introduces us to an important class of problems — viz., those in which we have to show that certain lines, areas, &c., are the greatest or least which can be con- structed under certain assigned conditions. There are few problems of this sort in Euclid. In fact, the seventh and eighth propositions of the third book are the only theorems in Euclid expressly dealing with geometrical maxima and minima. But many interesting de- ductions involve such relations as we are speaking of, and it is well for the student to know how to deal with them. It will be noticed that some of the problems already dealt with may be presented as examples of geometrical maxima and minima. For instance, Ex. 4 may be presented in the following form : — Ex. 9. — From a point ivithin a quadrilateral lines aredrav.-n to the angles of the quadrilateral ; shou' that the sum of these lines will be a minimttm ivhen the point is at the intersection of the diagonals. Presented in this form the problem would be solved precisely as Ex. 4. But suppose it had been given in the following form : — Determine a point mithin a quadrilateral such that the sum of the lines from the point to the angles of the quadrilateral shall he a ininimuni. Here assuming the student to have no knowledge of the property established in Ex. 4, the problem is not quite so simple. Let us see how it is to be dealt with. Fig. 14. Draw first the quadrilateral, A B C D (Fig. 14), and from sonio assumed point, P, draw P A, PB, P C, and P D. Then we have to inquire how to shift P so as to lessen the sum of the distances, PA, PB, PC, PD. A very short inquiry suffices to show that we shall not gain much information by considering the lines PA, P B, PC, and PD in adjacent pairs. The inquiry might run somewhat in this way : — If P be brought towards B A, the sum of the Unes P B, P A will diminish ; but the sum of the lines P C and P D will increase. We have no obvious signs showing whether the diminution or increase be the greater. Therefore we are not tempted to continue this mode of inquiry. Can we, then, by taking the lines in alternate pairs, diminish the sum of one pair without increasing tho sum of the other ? By bringing P towards tho line U 1) (which we draw, at tliis point of the inquiry), tho sum of the lines B P, P D, is diminished (Euc. I., 21). Now if this were done without any attention to the lines PC, P A — for instance, if P moved to Q — it would not be easy to assert that the sum of the four distances from the angles was diminishing. But if P be made to move along PA, as to P,, then — since C P is less than P C and P P, together — we are diminishing, not merely the sum of the distances from B and D, but the sum of those frrm 0 and A. So long, then, as wo continue this process, we cannot be going wrong. So that if we bring P to P.; — the intersection of P A and B D. — we have diminished the sum of the distances as much as t/u.i process allows us to do. It is now obvious that by shifting our point from P; towaids A C, along the line P.. B, we are yet farther diminishing tho sum of the ilistances, until we reach the intersection of P; B and A C (which are here drawn in). At this point of intersection, 0, the second process has done all it can do for us. We see, also, that O is a fixed point within the quadrilateral, since it is the intersection of the diagonals. Also, P being any point, our process shows that wherever our point be taken, the sum of tho distances diminishes continually as the point 3.2 ♦ KNOWLEDGE ♦ [July 13 1883. is made — by the double process above described — to approach 0. Thus we are rjuite certain that O is the required point. Instead, however, of proving this by facing through the necessary steps of the above process — which mAiId be a sufficient proof — the student should give the proof in the following form, obviously suggested by the process he had before followed : — Draw the diagonals A C, B D meeting in O ; then 0 is the required point. For, let P be any other point, and therefore not on both diagonals — say not on B D. Then B P and P D are greater than B D (Euc. I., 20), and A P and P C are not less than A C (greater than A C if P do not lie in A C) ; hence P A, P B, P C, and P D are together greater than O A, 0 B, 0 C, and O D together. We have given the process determining the solution, in the form which would most probably snggest itself. The double process is also veiy instructive and suggestive. But the practised geometri- cian would probably notice at once that the approach of P towards 0, in a straight line, diminishes at once the sum of P B, PD, and that of P A, P C. Hence we would argue — in presenting the proof — 0 must be the point we seek ; for, let any other point give a tninimum sum, then, by taking a point nearer O, we obtain a less sum — that is, said point does not give a minimum : which is absurd. (To be continued.) &nv Cljtss Column. By Mephisto. USEFUL END GAME. IN a game between Blackburne and English in the late tourna- ment, the former player effected a draw in an ingenious manner, although being at the time a Pawn behind. E.VGLISH. Black. 1 p. r^ — — - ^^ i t t 2 -J ^ \ B 1 _J .1 1 #: __ It will be seen that we were trj-ing to get a position which might give us a similar chance for a draw, and in spite of the fact of our opponent having three good parvus, we think a draw can be forced. We hope the preceding example will enable our readers to work out this very interesting position. We shall give our analysis next week. Whitb. BLACKEfP.N'E. In this position Blackburne drew by playing K to B4 R to B7 (ch) K to Q5 (If Black checks on Kt4, White also plays K to Q5) E to B6 K to BG R takes QP B to Kt8, and Black could not avoid the draw, for if K to E2 the E checks on Kt7 and Kt8. The ingenious idea of placing the K on B6 and threatening a mate or a perpetual check with the Rook, led us to ai-rive at the following position when playing an actual game : — White to play and draw. PROBLEM Xo. i By a. J. Ma.\s. Black. White to play and mate in three moves. REVIEW. Chess Blossoms. Miss F. F. Beechy, an experienced problem composer, has published a collection of her two-move problems. These composi- tions are of more than average merit, as proved by the fact of several of them having won prizes. The prize problems of English problem competitions for 1882 are appended, together with some readable (chessy) verses and poetry. This is a pleasant little book and is published by the authoress at Matlock, Bath. ANSWERS TO CORRESPONDENTS. •»* Please address Chess Editor. R. v. Tyley. — Dran-n games are sometimes counted half to each player. W. Teebili,. — Could you kindly send a copy ? G. W. Thompsox. — If P moves there is no mate. W. — Solutions of Ending and Problems No. 86 and 87 correct. SPECIAL NOTICES. Part XX. (Jane, 18S3), just ready, price Is., post-free. Is. 3d. Volume m., comprising the numbers published from Januarr to June, 1883, will be ready in a few weeks, price 7s. 6d. The Title Page and Index to Volume III. will be readv shortlv, price 2d., post- free, 2^d. Binding Cases for Volume III., price 28. each. Subscribers' numbers bound (including Title, Index, and Case) for 33. each. TERMS OF SUBSCRIPTION. The terms of Annual Subscriptien to the weekly numbers of KFOWLXrei are ae follows: — B. d. To any address in the United Kingdom 10 10 To the Continent, Australia, New Zealand, South Africa & Canada 13 0 To the United States of America ^.25. or 13 0 To the East Indies, China, &c. (itd Brindisi) 16 % All subscriptions are payable in advance. P. O. Orders and cheques should be made payable to the Publishera, Mbssbs. Wtmah & Sons, London, at the High Holbom District Post-office. Agent for America — C. S. Carter, American Literary Bureau, Tribune Buildings, New York, to whom subscriptions can be forwarded. OFFICE: 7-4-76, GREAT QUEEX STREET, LONDON, W.C. July 20, 188.3.] * KNOWLEDGE ♦ 33 AN 1UliS?RATED MAGAZINE OF S€rENCE PIAINLT^ORDED -£XACTL|gESCRIBED LONDON : FRIDAY, JULY 20, 1883. Contents of No. 90. A Naturalist's Year. XVII, Crabs and Lobsters. By Grant Allen ...33 How to Get Strong ; Reducing Fat 31 The Chemistry of Cookery. XIV. By W. Mattieu Williams 33 The Morality of Happiness : Intro- ductory. By Thomae Foster 36 The Birth and Growth of Myth. XI. By Edward Clodd 37 Laws of Briehtnesa. VI. By Uichard A. Proctor 38 Are Copper Salts Poiaonous? 39 The Fisheries E.xhibiiion. (/«»»). Bv John Ernest Ady 4C Flight of a Vertical Missile. By Biehard A. Proctor 41 Editorial Gossip 42 The Face of the Sky. By F.E.A.S. « Something about the Beet. II 43 Correspondence ; Flight of Missiles —Binocular Vision, &c 44 Our Mathematical Column : Geome- trical Problems. VIII 46 Our Whist Column 47 Our Chess Column 48 A NATURALIST'S YEAR. By Grant Allen. XVII.— CRABS AND LOBSTERS. AMONG the olive-green hanging seaweed that drops like a curtain from the landward side of this broken ledge of rock, I have just disentombed with my stick a little soft-shelled crab, who, bent on indulging his naturally retiring disposition, had taken refuge there in solitary security, when the tide began to leave his open feeding- grounds high and dry. See him scuttle hastily sideways now across the bare patch of beach, and make his way with all convenient speed towards the neighbouring pool, where he proceeds at once to bury himself, tail foremost, once more under the wet sand beneath the overhanging eaves of the ledges ! How fast and how clumsily he runs ! How quickly and yet how awkwardly he grubs his way into the yielding quicksands ! A crab always suggests to one the notion of an animal that has not quite fully adapted itself to the conditions under which it is living. It seems to have learnt the trick fairly well, so to speak, but not to be able to perform it with perfect grace and ease. This is a feeling one often has about creatures which have widely diverged in habit, and especially in attitude, from tlie rest of their kind. They always seem to be clumsy in their movements. One notices it, among birds, in the penguin, the puffins, and many other erect species, as well as in the waddling of ducks ; or among mammals, in the seals and their con- geners, as well as in the kangaroos and jcrl)oas. Nay, even man himself has something of the sanu^ awkwardness about liim, for though he can walk well enough, he can't squat or sit gracefully without the aid of an artificial nieclianism, sucli as a chair or a sofa. In all these cases, we may fairly say that the peculiar modilication of the ancestral type for a sjiccial purpose has entailed a certain newssary clumsiness in other matters, because the original limbs were fitted for difl'erent ends from those to which they are now applied. The clumsiness is due, in fact, to what one may describe as patching and altering on the part of Nature. The crab is an excellent example of such natural after- thoughts. By descent all crabs are, roughly speaking lobsters ; or, to put it more correctly, both crabs and loljsters are derived from a single common ancestral form, from which the crab has diverged a great deal, while the lobster has diverged relatively little. Crabs, in fact, may be approximately described as the kind of lobsters that has taken to walking instead of swimming and jumping. If you compare a lobster with any one of its less developed relations, such as a prawn or a shrimp, you will see that while they differ in many important points of structure (which I leave aside, as belonging rather to the province of professional biologists, like Dr. Wilson, than of mere strolling field naturalists like myself), they agree in certain general proportions of the most conspicuous external parts. They have all long, large muscular tails, wliich contain the principal fleshy part of the body, and which, in fact, we all know particularly well, because they form the portion that we ourselves use as food, and they have a cylindrical head and chest (so to say), as well as a considerable number of swimming appen- dages. But if you compare a lobster with a crab you will find that, while they agree with one another in many impor- tant points of structure far more closely than they do with their lower relations, they yet diflPer in general outward appearance far more widely than the prawn and shrimp. It is these conspicuous outward differences — merely adap- tive points to the true biologist — that most require expla- nation in the eyes of the world at large. The other matters are the really important ones — the ones on which the science of biology must be fundamentally based ; but these are the ones that interest ordinary people the most. Now, the adaptive differences between crabs and lobsters are all due to the initial fact that the crab is a walking crustacean, while the lobster is a jumping and swimming one. If you watch the lobsters in an aquarium, you will see that they hardly use their small legs for walking at all ; they employ them almost entirely for standing, or rather for poising themselves lightly upon the shelves of rock where they love to loiter. There are two large muscular tracts in the lobster's body — the two parts which we mainly use for food ; one is the big and powerful tail, which is the real organ of locomotion in the lobster ; the other is the two great claws, which, of course, are used as organs of prehension and weapons of ottence or defence. But if you look closely at a crab, you will find that though its mem- bers answer in the main, part for part, to the members of the lobster, its shape and relative development are very diflerent The tail, instead of being a large fleshy organ, capable of producing long and rapid springs through the water, is doubled up and tucked away under the crab's body ; and, as we have frequently had occasion to observe when eating cral) (the only form of dissection that most of us ever practise), it contains no meat worth the trouble of extracting. The fact is, most crabs have so long found their tails a mere incumbrance, and have consequently tucked them quietly away behind them, that they have gradually dwindled by disuse, in accordance with a well-known general law, that all parts which are seldom or never exercised tend slowly to atrophy and obsolescence. Use and disuse combine with natural selection thus to alter the forms of organs. A part which is much exercised tends to grow large and prominent ;. a part which is little exercised tends to fade imperceptibly away. The other clause of this law is equally well exemplified in the body and legs of the crab. What most people natu- rally regard as the whole creature (barring the small and inconspicuous tail) answers in fact merely to the front half or " body " of the lobster ; and as this part contains 34 ♦ KNO^VLEDGE [July 20, 1883. the only organs of locomotion now practically used by tlie adult crab — namely, the legs — it has grown to a relatively immense and inordinate size. In a crab, we have all observed (also in pursuit of our personal objects) the meatiest part after the big grasping claws consists of the network of shell and muscles in the under portion of the body. Now, this part is really the governing and moving mechanism of the small legs, or, in other words, the muscles that actually do the work of walking. Hence it is easy to see why the crab ditfers so much in externals from the lobster. But, besides this main central diflerence, there are other minor difl'erences of shape and appearance, due in like manner to adaptive modifi- cation. While the lobster's whole form is roughly cylindri- cal and pointed in front, so as to enable him to dart readily through the water with very little resistance, the crab's form is much more flattened and massive, so as to suit better with his crawling and almost terrestrial habits, as he makes his way quietly and unobtrusively along the bottom. The one type might almost be compared with that of the greyhound or the hare, the other with that of the tortoise or the armadillo. Indeed, the crabs are by far the most land-loving of all their immediate group, for most of them hug the shore, many of them live on the margin between high and low water, and not a few of them haxe actually taken to living on dry land, or even climbing con- siderable mountains. These last return annually to the sea in order to lay their eggs, and the young pass their early or larval stages as free swimming creatures in the salt water, but in their full-grown form they take at length to the land, and tliere grub away in the soil to their heart's content. Grubbing, in fact, even more than walking, might be set down as the peculiar differentia of the crab race, the one thing which, more than any other, has given the whole group its special and distinctive features. To my mind there is no more speaking lesson in evolution than just to buy a common edilile crab, and look at the curiously dwarfed and dwindled condition of its tail. If that one simple concrete argument and example does not convert a man, he must be hard wedded indeed to his own view of the cosmos and its origin. HOW TO GET STRONG. KEDUCIXG FAT. IT is hard to say whether corpulence is to be regarded as a greater nuisance in its direct or in its indirect effects — whether it is worse to be loaded constantly with the weight of two or three suits of clothes, to have the circu- lation impeded, the liver obstructed, and the lungs op- pressed, or to be rendered almost unable, and quite un- willing, to take such exercise as would open the lungs, free the liver, and stimulate the circulation. The mischief of corpulence works in a very vicious circle. It is an evil in itself, and it tends to increase its own evil effects. At the very outset, then, of any system of exercise for those who are oppressed with much fat, comes the inquiry, how that excess of adipose tissue is to be reduced. Observe, I say " fat," not " flesh." It is absurd to speak of fat men as fleshy men. Ko one is the worse for flesh, nor can there well be excess of it ; for flesh is muscle. It is excess of fat only which is obnoxious ; and because, amongst other reasons, wherever there is excess of fat there is defect or deterioration of flesh. Now, with regard to the reduction of fat, there are a dozen or so of methods which are in more or less favour with those whom Dr. Dio Lewis calls the "wobblers," though in England, at any rate, many fat men walk as steadily, in appearance, as the lean ones. I do not, for my own part, believe in any one of these methods ; but I believe in all or very nearly all of them. This sounds like a contradiction ; Ijut it is not. I think the fat man who pins his faith on this, that, or the other cure for obesity, is not only unlikely to get rid of his extra fat, but is very likely to do himself serious mischief. But I think also that the man who pins his faith on this, that, and the other cure, is very likely, if he is patient and resolute, to be successful in reducing himself to reasonable proportions. It is by applying all the proper remedies (for some are obviously bad) at the same time, and in due proportion, that fat may be reduced most safely and most eflectively. But in tlie struggle with obesity, resolution, self-restraint, and patience are all important. Unfortunately, fat is very often an evidence of impatience, weak will, and want of self-restraint. Also of want of wisdom. The pleasure of a goodly meal, swallowed hastily (that is, without due patience in mastication), washed down (hateful, but in such cases too appropriate expression) Vi)- draughts of wine, or beer, or spirits, and followed by fat-engendering repose, seems greater than the enduring pleasure of good digestion, active frame, and light spirits, with the power to limit sleep to sleep's proper hours. A quiet read in a soft arm- chair by the fire-side in winter, or in the cool, softly-lit study in summer, seems a greater good, even when taken at the expense of exercise which the body needs, than the less- noticed, but longer lasting, sweetness of health and cheer- fulness secured by a wholesome regimen. The necessary resolution, patience, and self-restraint to reduce excess of fat can be obtained in no other way that I know of than by reasoning. Let a man consider within himself what he pays for those indulgences which keep him fat, and he must be foolish, I take it, if he is unwilling to give them up or to reduce them in such degree as may be necessary. Nay, let him even consider the matter in the light of such indulgences. Does he enjoy his food as much when over-burdened with fat as he would if he were in better condition 1 Does he enjoy the rest he takes unnecessarily anything like the rest he would vajit if he were more active ? In fact, does he know the real pleasure afforded by either feeding or resting 1 One meal sauced by hunger is worth a dozen eaten when the system is already over-loaded. One rest earned by exercise is worth any amount of lounging laziness. Then again, consider the work a fat man has to do as a direct result of shirking work he ought to do. The man who has been unwilling to walk four or five miles a day when of reasonable weight, has no choice later (unless he summons resolution and patience to his aid) but to carry about with him wherever he goes a load of perhaps forty or fifty pounds of useless muscle- encumbering fat. A man who is unwil- ling to put on a suit of flannels and a " sweater," weighing, perhaps, two or three pounds more than his usual dress, to work <^ff a pound or two of his weight, carries about with him (groaningly, it may be, but still unresistingly) the weight of five or six complete suits of clothing.* A man who is unwilling to sweat for his health, sweats daily four or five times as much as leaner men, though what he so loses he replaces by heavy draughts, not always of innocuous water. So much premised, and noting also that to follow at once several fat-reducing methods is much easier, as it will be found much more effective and therefore much more encouraging than to follow one, I proceed to consider * A summer suit of clothes for a man of medium size (height and stoutness) weiglis .ibout 8 lb., including boots and hat. A fat man not only carries 40 lb. or 50 lb. more weight of hia own than he need, but has to have rather heavier clothing. July 20, 18'83.] ♦ KNOWLEDGE ♦ 35 the various methods available for attacking superabundant fat, hoping that many overweighted persons among my readers may take courage to enter systematically and patiently on the profital)le work of fat-reduction. I begin with medicinal systems as on the whole the least useful methods, and those which need to be most cautiously applied, where applied at all. (I say nothing of corset or busk wearing, partly because in a former paper I said enough of that foolish plan, only fit for those whose resolutions needs bolstering up artificially. I note only in passing that our editor must have been of most inquiring disposition to put so obviously unnatural a method to the test. ) Nearly all medical methods for the reduction of at depend in reality on the amount of mischief which may be done by medicines to the digestive system and to the appetite. If a man takes an emetic four or five times a day, and a strong aperient twice or thrice a day, he would, probably, be considerably reduced at the end of two or three weeks, supposing he survived. It is easy to devise medical systems which, without being quite so obviously pernicious, would do so much mischief that a man's weight would soon be much reduced, and also his strength. Of such systems nothing good can be said. Akin to them are such methods as depend on dosing the food with vinegar, or otherwise making it either unpalatable or unprofitable. Yet medicines may be used, especially at the beginning of a course of fat- reduction, with some advantage, if wisely administered — which should be done by medical advice. The fat man is in an unwholesome state, and though he may be able to get better without medicine, he may save some trouble by taking such medicines as a sensible doctor may consider suitable to help the action of the stomach, the liver, the kidneys, and the skin. Albeit, recourse should only be had, in my opinion, to the doctor, in very bad cases, or where, as sometimes happens, the first application of other and better methods leads to constipation, chills, headaches, and other forms of mischief. These are so apt to dis- hearten the struggler against fat, that it may often be well to give the disordered, impeded, or congested organs a little help from judiciously -selected drugs. (To be continued.) THE CHEMISTRY OF COOKERY. XIV. By W. Mattieu Williams. IN my last I described the dissociation of sugar by hea and the formation of caramel, to illustrate by simple example the " browning " of other kinds of food. I might have added, in connection with this cookery of sugar, an historical connection with one of the lost arts of the kitclien — viz., the "spinning" of sugar. Within the reach of my own recollection no evening party could pretend to be stylish unless the supper -table was decorated with a specimen of this art^ — a temple, a pagoda, or some- thing of the sort done in barley-sugar. These were made l)y raising the sugar to 320", when it fused and became amorphous, or vitreous, as already described. The cook then dipped a skewer into it, the melted vitreous sugar adhered to this and was drawn out as a thread, which speedily solidified by cooling. While in the act of solidification it was woven into the desired form, and the skilful artist did this with wonderful rapidity. I once witnessed witli childish delight the spinning of a great work of art by a French cook in St. James's Palace' It was a ship in full sail, the sails of edible wafer, the hull a basket work of spun sugar, the masts of massive sugar- sticks, and the rigging of delicate threads of the same. As nearly as I can remember, the whole was completed in about an hour. But to return from high art to chemical science. The conversion of sugar into caramel is, as already stated, attended with a change of flavour ; a kind of bitterness replaces the sweetness. This peculiar flavour, judiciously used, is a powerful adjunct to cookery, and one which is shamefully neglected in our ordinary English domestic kitchens. To test this, go to one of those Swiss restaurants originally instituted in this country by that enterprising Ticinese, the late Carlo Gatti, and which are now so numerous in London and our other large towns ; call for ■maccaroni al svgo ; notice the rich, brown gravy, the "sugo." Many an English cook would use half-apound of gravy beef to produce the like, but the basis of this is half- anounce of sugar, or even less ; the sugar is browned by heating, not quite up to the caramel state. Burnt onion may contribute, but this is only another form of caramel with more savoury properties. While engaged upon your maccaroni, look around at the other dishes served to other customers. Instead of the pale slices of meat spread out in a little puddle of pale, watery liquid, that a»e served in English restaurants of corresponding class, you will see dainty morsels, covered with rich, brown gravy, or surrounded by vegetables im- mersed in the same. This sugo is greatly varied according to the requirements, by additions of stock -broth, tarragon vinegar, ketchup, &c., &<:., but burnt sugar, or burnt onions, or burnt something is the basis of it all, sugar being the cheapest. To further test the flavouring properties of browning, take some eels cut up as usual for stewing ; divide into two portions ; stew one brutally — by this I mean simply in a little water — serving them with this water as a pale gravy or juice. Let the second portion be well fried, fully browned, then stewed, and served with brown gravy. Compare the result. Make a corresponding experiment with a beef-steak. Cut it in two portions ; stew one brutally in plain water ; fry the other, then stew it and serve brown. Take a highly-baked loaf, better one that is black out- side; scrape oft' the film of crust that is quite black, i.e., completely carbonised, and you will come to a rich brown layer, especially if you operate upon the bottom crust. Slice oft" a thin shaving of this, and eat it critically. Mark its high flavour as compared with the comparatively insipid crumb of the same loaf, and note especially the resemblance between this flavour and that of the caramel from sugar, and that of the browned eels and browned steak. A delicate way of detecting the fla\our due to the l)rowning of bread is to make two bowls of bread and milk in the same manner, one with the crust, the other with the crumb of the same loaf. I am not suggesting these as examples of better or worse flavour, but as evidence of the fact that much flavour of some sort is generated. It may be out of place, as I think it is, in the bread and milk, or it may be added with much advantage to other things, as it is by the cook who manipulates caramel and its analogues skilfully. The largest constituent of bread is starch. Excluding water, it constitutes about three-fourths of the weight of good wheaten flour. Starch diflers but little from sugar in composition. It is easily converted into sugar by simply heating it with a little sulphuric acid, and by other means of which I shall have to speak more fully hereafter when I come to the cookery of vegetables. When simply heated, it is converted into dextrin or " British gum," 36 ♦ KNOWLEDGE [July 20, 1883. largely used as a substitute for guui arable. If the heat is continued a change of colour takes place ; it grows darker and darker until it blackens just as sugar does, the final resu't being nearly the same. Water is driven off in both cases, but in carbonising sugar we start with more water, sugar being starch plus water or the elements of water. Thus the brown material of bread-crust or toast is nearly- identical with caramel. I have often amused myself by watching what occurs when toast and water is prepared, and I recommend my readers to repeat the observation. Toast a small piece of bread to blackness, and then Hoat it on water in a glass vessel. Leave the water at rest, and direct your attention to the under side of the floating toast. Little thread-like streams of brown liquid will be seen descending in the water. This is a solution of the substance which, if I mis- take not, is a sort of caramel, and which ultimately tinges all the water. Some years ago I commenced a course of experiments \vith this substance, but did not complete them. In case I should never do so, I will here communicate the results attained. I found that this starch caramel is a disinfec- tant, and that sugar caramel also has some disinfecting properties. I am not prepared to say that it is powerful enough to disinfect sewage, though at the time I had a narrow escape from the Great Seal Office, where I thought of patenting it for this purpose as a non-poisonous dis- infectant that may be poured into rivers in any quantity without danger. Though it may not be powerful enough for this, it has an appreciable efiect on water slightly tainted with decomposing organic matter. This is a very curious fact. We do not know who in- vented toast and water, nor, so far as I can learn, has any theory of its use been expounded, yet there is extant a vague popular impression that the toast has some sort of wholesome effect on the water. I suspect that this must have been originally based on experience, probably on the experience of our forefathers or foremothers living in country places where stagnant water was a common beverage, and various devices were adopted to render it potable. Gelatine, fibrine, albumen, ic. — i.e., all the materials of animal food — as already shown, are composed, like starch and sugar, of carbon, hydrogen, and oxygen, ■with, in the case of these animal substances, the addition of nitrogen ; but this does not prevent their partial carbonisation (or "caramelising," if I may invent a name to express the action which stops short of blackening). Animal fat is a hydro-carljon which may be similarly browned, and, if I am right in my generalisation of all these browning pro- cesses, an importa.nt practical conclusion follows, viz., that cheap soluble caramel made by skilfully heating common sugar is really, as well as apparently, as valuable an element in gravies, iVrc, as the far more expensive colouring matter of brown meat gravies, and that our English cooks .should use it far more liberally than they usually do. Its preparation is easy enough ; the sugar should be gradually heated till it assumes a rich brown colour and has lost its original sweetness. If carried just far enough, and not too far, the result is easily .soluble in hot water, and the solution may be kept for a long time, as it is by cooks who understand its merits. In connection with the idea of its disinfecting action, I may refer to the cookery of tainted meat or " high " game. A hare that is repulsively advanced when raw, may by much roasting and browning become quite wholesome, and such is commonly the case in the ordinary cooking of hares. If it were boiled or merely stewed (without preliminary browning) in this con- dition, it would be quite disgusting to ordinary palates. A leg of mutton for roasting should be hung until it begins to become odorous ; for boiling it should be as fresh as possible. This should be especially remembered now that we liave so much frozen meat imported from the antipodes. When duly thawed it is in splendid condition for roasting, but is not usually so satisfactory when boiled. I may here mention incidentally that such meat is some- times unjusth' condemned on account of its displaying a raw centre when cooked. This arises from imperfect thawing. The heat required to thaw a given weight of ice and bring it up to G0°, is about the same as demanded for the cookery of an equal quantity of meat, and therefore, while the thawed portion of the meat is being cooked, the frozen portion is but just thawed, and remains quite raw. A much longer time is demanded for thawing — i.e., supplying 142" of latent heat — than might be supposed. To ascertain whether the thawing is completed, drive an iron skewer through the thickest part of the joint. If there is a core of ice within it will be distinctly felt by its resistance. THE MORALITY OF HAPPINESS. By Thomas Foster. IXTRODUCTORY. IT is known to all who watch the signs of the times — ol:)vious, indeed, to them, and known to many who are less observant — that those moral restraints which claim to be of sacred origin are no longer accepted by a large and increasing number of persons. I have no wish to inquire here whether those restraints should be re- garded as of divine origin or not. I note only the fact that by many they are not so regarded. I am not con- cerned to ask whether it is well or ill that their authority should be rejected, and their controlling influence be diminishing or disappearing among many ; it suffices, so far as my present purpose is concerned, that the fact is so. The question then presents itself. Does any rule of conduct promise to have power now or soon among those who have rejected the regulative system formerly prevalent 1 We need not consider whether such a rule of conduct, neces- sarily secular in origin, is in itself better or worse than a rule based on commandments regarded as divina All we have at present to ask is whether such a regulative system is likely to replace the older one with those over whom that older law no longer has influence. Here at the outset we find that those who hold extreme views on either side of the questions I have left untouched, agree in one view which is, I think, erroneous. On the one hand, those who maintain the Divine character of the current creed insist, not only that it is sufficient for all, but that, in the nature of things, no other guide is possible. On the other hand, those who reject the authority of that creed most energetically, assert as positively that no new regulative system, no new controlling agency, is necessary. As Mr. Herbert Spencer has well put it, " both contem- plate a vacuum, which one wishes and the other fears. ' But those who take wiser and more moderate views, who, in the first place, recognise facts as they are, and, in the next, are ready to subordinate their own ideas of what is necessary or best for the ideal man to the necessities of man as he really is, perceive that for the many who no longer value a regulative system which, so far as they are concerned, is decaying, if not dead, another regula- tive system is essential. Again to use the words of the great philosopher whose teachings are to be our chief guide in this series of papers, " Few things can happen more July 20, 1883.] ♦ KNOWLEDGE . 37 disastrous than the decay and death of a regulative system no longer fit " (for those we are considering), " before another and litter regulative system has grown up to replace it." My purpose in these papers is to show how rules of con- duct may be established on a scientific basis for those who regard the so-called religious basis as unsound.* I shall follow chiefly the teachings of one who has inculcated in their best and purest form the scientific doctrines of morality, and may be regarded as head, if not founder, of that school of philosophy which, on purely scientific grounds, sets happiness as the test of duty — the measure of moral obligation. To Mr. Herbert Spencer we owe, I take it, the fullest and clearest answer to the melancholy ques- tion. Is Life Worth Living? whether asked whiningly, as in the feeble lamentations of such folk as Mr. Mallock, or gloomily and sternly, as in the Promethean groans of Carlyle. The doctrine that happiness is to be sought for oneself (but as a duty to others as well as to self), that the happiness of others is to be sought as a duty (to oneself as well as to them) — happiness as a means, happiness as the chief end — such has been the outcome of the much-maligned philosophy of Mr. Herbert Spencer, such has been the lesson resulting from his pursuance of what he himself describes as his " ultimate purpose, lying behind all proxi- mate purposes," that of " finding for the principles of I'ight and wrong in conduct at large, a scientific basis." If I can help to bring this noble and beautiful doctrine — for noble and beautiful even those must admit it to be who deny its truth — before the many who regard Herbert Spencer's teachings with fear and trembling, not knowing what they are, I shall be content. But I would advise all who have time to read the words of the master himself. Apart from the great doctrines which they convey, they are delightful reading, clear and simple in language, grace- ful and dignified in tone, almost as worthy to be studied as examples of force and clearness in exposition as for that which nevertheless constitutes their real value — the pure and beautiful moral doctrines which they offer to those over whom current creeds have lost their influence. Let me hope that none will be deterred from following this study, by the inviting aspect of the moral rules ad- vanced by the great modern teacher — even as in past times men were anxious, or even angry, when another teacher showed more consideration for human weaknesses than had seemed right to the men of older times. I will not ask here whether doctrines of repellant aspect are likely to be more desirable than those which are more benignantly advanced. It suffices that with many the former now exert no influ- ence, whether they should do so or not. So that, as far as these (for whom I am chiefly writing) are concerned, all must admit the truth of what Mr. Spencer says respecting the benefits to be derived from presenting moral rule under that attractive aspect which it has when undisturbed by superstition and asceticism. To close these introductory remarks by a quotation from the charming pages of his " Data of Ethics " : — " If a father, sternly enforcing numerous commands, some needful and some needless, adds to his severe control a beliaviour wholly unsympathetic — if his children have to take their pleasures by stealth, or, when timidly looking up from their play, ever meet a cold glance, or more frequently a frown, his government will inevitably be dis- * I Bay "BO-called," referring rntlicr to the word "religious" than to any ciuestion conceruing the (Hvino origin of current creeds. Strictly speaking, tho word religious may bo as correctly applied to moral rules based on sciontifie considerations, as to those formulated in company witli any of tho diverse creeds prevailing among men. liked, if not hated ; and the aim will be to evade it as much as possible. Contrariwise, a father who, equally firm in maintaining restraints needful for the well-being of his children or the well-being of other persons, not only avoids needless restraints, but, giving his sanction to all legiti- mate gratifications, and providing the means for them, looks on at their gambols with an approving smile, can scarcely fail to gain an influence which, no less efficient for the time being, will also be pernjanently efficient. The controls of such two fathers, symbolise the controls of morality as it is and morality as it should be." (To be continued.) THE BIRTH AND GEOWTH OF MYTH. By Edward Clodd. XI. THE belief that human beings could change themselves into animals was alluded to in my remarks on witch- craft, but, in view of its large place in the history of illusions, too incidentally, and it is proposed to give it further reference here. Superstitions which now excite a smile, or which seem beneath notice, were no sudden phenomena, appearing now and again at the beck and call of wilful deceivers of their kind. That they survive at all, like organisms, atrophied or degenerate, which have seen " better days," is evidence of remote antiquity and persistence. Every seeming vagary of the mind had serious importance, and answered to some real need of man as a sober attempt to read the riddle of the earth and get to its inmost secret. So with this belief. It is the outcome of that early thought of man which conceived a common nature and fellowship between himself and brutes, a conception based on rude analogies between his own and other forms of life, as also between himself and things without life, but having motion, be they waterspouts or rivers, trees or clouds, especially these last, when the wind, in violent surging and with howling voice, drove them across the sky. Where he blindly, timidly groped, we walk as in the light, and with love that casts out fear. Where rough resemblances suggested to him like mental states and actions in man and brute, the science of our time has, under the compara- tive method, converted the guess into a certainty ; not to the confirmation of his conclusions, but to the proof of identity of structure and function, to the demonstrating of a common origin, however now impassable the chasm that separates us from the lower animals. TJie belief in man's power to change his form and nature is obviously nearly connected with the widespread doctrine of metempsychosis, or the passing of the soul at death into one or a series of animals, generally types of the dead man's character, as where the timid enter the body of a hare, the gluttonous that of a swine or vulture. " Fills with fresh energy auother form, And towers an elephant or glides a worm ; Swims as an eagle in the eye of noon, Or wails a screech-owl to tho deaf, cold moon. Or haunts the brakes where serpents hiss and glare, Or hums, a glittering insect, in the air." But while in transmigration the soul returns not to the body which it had left, transformation was only for a time, occurring at stated periods, and eflected by the will of thi^ transformed, or by the aid of sorcery and magic, or 38 ♦ KNOWLEDGE [July 20, 1883. sometimes imposed by the gods as a punishment for impious defiance and sin. Other causes, less remote, aided the spread of a belief to which the mind was already inclined. Among these were the hallucinations of men who believed themselves changed into beasts, and who, retreating to caves and forests, issued thence howling and foaming, ravening for blood and slaughter ; hallucinations which afflicted not only single persons, as in the case of Nebuchadnezzar, whose milder monomania (he, himself, saying in the famous prize poem : — "As he ate the unaccustomed food, It may be wholesome, but it is not good,") rather resembled that of the daughters of Prsetus, who believed themselves cows, but which also spread as virulent epidemic among whole classes. It is related that, in 1600, multitudes were attacked by the disease known as lycan- thropy, or wolf-madness (from Greek, lukos, a wolf, and anthropos, a man), and that they herded and hunted in packs, destroying and eating cliildren, and keeping in their mountain fastnesses a cannibal or devil's sabbath, like the nocturnal meetings of witches and demons known as the "Witches' Sabbath. Hundreds of them were executed on their own confession, but some time elapsed before the frightful epidemic, and the panic which it caused, passed away. Besides such delusions, history down to our own time records instances where a morbid, innate craving for blood, leading sometimes to cannibalism, has shown itself. Mr. Baring-Gould, in his " Book of Werevolves," cites a case from Gall of a Dutch priest who had such a desire to kill and to see killed that he became chaplain to a regiment for the sake of witnessing the slaughter in battle. But still more ghastly are the notorious cases of Elizabeth, an Hungarian lady of title, who inveigled girls into her castle and murdered them that she might bathe her body in human blood to enhance her beauty ; and of the Marechal de Retz who, cursed with the abnormal desire to murder children, allured them with promises of dainties into his kitchen, and killed them, inhaling the odour of their blood with delight, and then burned their bodies in the huge fireplace in the one room devoted to these horrors. When the deed was done, the Marechal would lie prostrate with grief, " would toss weeping and praying on a bed, or recite fervent prayers and litanies on his knees, only to rise with irresistible craving to repeat the crime." Such instances as the foregoing, whether of delusion or morbid desire to destroy, are among secondary causes ; they may contribute, but they do not create, being inade- quate to account for the world-wide existence of trans- formation myths. The animals which are the supposed subject of these vary with the habitat, but are always those which have inspired most dread from their ferocity. In Abyssinia we find the man-hya>na ; in South Africa, the man-lion ; in India, the man-tiger ; in Northern Europe, the man-bear ; and in other parts of Europe the man-wolf, or were-wolf (from A.-S. iver, a man). Among the many survivals of primitive thought in the Greek mythology, which are the only key to its coarser features, this of belief in transformation occurs, and, indeed, along the whole line of human development it appears and re-appears in forms more or less vivid and tragic. The gods of the South, as of the North, came down in the like- ness of beasts and birds, as well as of men, and among the references to these myths in classic writers, Ovid, in the " Metamorphoses," tells the story of Zeus visiting Lykaon, king of Arcadia, who placed a dish of human flesh before the god to test therebv his omnisicence. Zeus detected the trick, and punished the king by changing him into a wolf, so that his desire might be towards the food which he had impiously offered to his god. " In vain he attempted to speak ; from that very instant His jaw9 were bespluttered with foam, and only he thirsted For blood, as he raged amongst flocks and panted for slaughter. His vesture was changed into hair, his limbs became crooked. A wolf— he retains yet large traces of his ancient expression. Hoary he is as afore, his countenance rabid, His eyes glitter savagely still, the pictui'e of fury." But we may pass from this and such-like tales of the ancients to the grim realities of the belief in mediaeval times. LAWS OF BRIGHTNESS. VI. By Richard A. Proctor. ZOLLNER, as I have said, regards the full moon as though she were a nearly flat disc under full solar illumination. He estimates the brightness of the full moon at of the sun's, and, comparing surfaces, he makes 619,600 > ' f o the sun's brightness equal to 618,000 times the moon's. Now, it is easy to determine what would be the brightness of the full moon supposing the surface perfectly reflective (not specularly) and smooth, and regarding it as a flat disc. Such a disc, placed where the moon is, would be illuminated by a sun about 32' in diameter, since the sun appears as large seen from the moon as seen from the earth. Now, such a sun would occupy a part of the whole heavenly vers . 10' sphere represented by the proportion — . — ! . or 0 0000054. But the brightness of such a disc, sup- posed to be illuminated by both halves of a com- plete enclosing sphere of solar brightness, would be the same as the sun's brightness. Now, different parts of such enclosing sphere would illuminate the disc at diflerent angles, and, therefore, we must not consider the mere area of the sphere. Thus, the portion P, Fig. 1 3, of such a sphere (the radius may be any whatever) would illuminate D obliquely, and with an eflect reduced from what would result if the illumination were direct, in the proportion of the sine of arc P K to unity. But it is obvious that the little area p, which is the orthogonal pro- jection of P on K L (the plane of D), bears just this pro- portion to P. Hence the illuminating eflect of the area P may be represented by the area p, and the total illumi- nating eflect of the hemisphere will be represented by the area of the circle K L. Thus, for the whole sphere, we get twice the area K L, instead of the area of the sphere (which is four times this circle). Thus, the actual illumi- nation of the supposed disc placed where the full moon is, bears to solar brightness the ratio of area S (representing July 20, 1883.] ♦ KNOWLEDGE ♦ 39 the space on the heavens occupied by the sun, supposed vertical) to half the area of the whole sphere, or the ratio 108 : 10,000,000 or 1 : 92,592. If we suppose the disc replaced by a smooth spherical moon, we must increase 92,592 in the ratio of 3 to 2, getting the ratio 1 : 138,888. Now, the actual quantity of light received " from the moon is about 1,618, 000th of the sun's light, or less than the 92,592nd part in the ratio 92,592 to 618,000, which would give the moon's reflective power (on the assumption of her reflecting as a flat disc, and of her disc being as large as the sun's), the value 92,592 . 618,000 ' but taking into account the smaller mean disc of the moon, we deduce the value 0-16 approximately. Taking the moon as a smooth sphere, we obtain the value 0 2 4. Now, Zollner gives the value 0-1736, which is much nearer the former than the latter value. This is what, following Lambert, he calls the idbp-do, or whiteness of the moon ; and he justly remarks that, taking her whole brightness, the moon must be regarded as more nearly black than white. But he adds that from his estimates of the illumi- nation of the moon's brighter or brightest parts, he is satisfied that their whiteness can be compared with that of the whitest of terrestrial substances — or, to use his own words, he has arrived at the result " dass der Mond an seinen helleren und liellslnH stellen aus einem Stofle besteht, der, auf die Erde gebracht, zu den weissesten der uns bekannten Ktirper geziihlt werden wiird." Zollner gives the following determination of the albedines or tvhitenesses of diflerent terrestrial substances : — By diffused reflected light — Snow just fallen 0'783 White paper O'TUO White sandstone 0'237 Clay marl O'lSG Quartz porphyry O'lOS Moist soil 0-079 Dark gray syenite 0-078 By regular reflection^— Mercui-y 0-G48 Speculum metal 0-535 Glass 0-040 Obsidian 00.32 Water 0-021 It will be noticed how closely Zollner's result accords with the statement of Sir John Herschel that the moon's average I)rightn(!ss does not exceed that of sandstone. "The actual illumination of the lunar surface is not much superior," Herschel says, " to that of weathered sandstone rock in full sunshine. I have frequently compared the moon setting behind the grey perpendicular farade of the Table Mountain, illuminated by the sun just risen in the opposite quarter of the horizon, when it has been scarcely distinguishablf! in lirightness from the rock in contact with it. The sun and moon being nearly at equal altitudes, and the atmosphcn^ pc-rfcctly free from cloud or vapour, its ellect is alike on both luminaries." It follows, of course, that since the brightest portions of the moon's surface are four or five times as bright as her average or mean illumination, the darkest portions are very much less bright tiian the average. We may assume that the floor of Plato, for instance (not absolutely the darkest part of the moon), is considerably darker even than dark grey syenite. (To be continved.) ARE COPPER SALTS POISONOUS? To most readers this will seem a foolish question, as from one generation to another people have been warned against pickles made green with copper salts, putting half- pence into the pot with peas or cabbages to ensure their coming to table with good complexions, and against cook- ing anything in copper vessels without special precautions to prevent the metal from being acted upon. It is hard to believe that all these warnings have been unnecessary, that so far from copper salts being mischievous, they can do no harm in the quantities likely to be found in food in con- sequence of the practices mentioned, and may even be of prophylactic use to the persons swallowing them. About a year ago a number of French doctors took copper-tinted peas and similar articles under their protection, and at the same time advocated the greatest care in keeping lead salts out of the way. They considered it very dangerous for tinned vessels intended to hold preserved meats or vege- tables to be soldered inside, as the lead of the solder -vv-as likely to be acted upon, and even in very small quantities the lead salts would be dangerous. Copper salts are dis- tinguished from lead salts in having no cumulative action upon the system, and symptoms of poisoning do not follow their repetition in minute doses, as they do in the case of lead. As a practical question, it is contended that the employment of copper as a food colouring agent ought not to be treated as an adulteration dangerous to health, and a decision in Belgium has been lately reported founded upon this view. M. A. Gautier has recently published a work on "Copper and Lead in Alimentation and Industry," and his state- ments regaiding the former metal coincide with those of previous "French inquirers. He speaks of the presence of copper as a normal ingredient in many articles of food, such as wheat, barley, rice, beans, cofiee, itc. The quantities in these cases are infinitesimal, but capable, in some instances, of producing a noticeable effect upon the creature swallow- ing them, as in the interesting case of the Turacous, whose fine red feathers Professor Church discovered to be coloured with a compound he named turacine, which was soluble in soft water, and contained a portion of copper derived from the fruits on which the birds feed. M. Gautier finds in the articles of food above mentioned from four to ten milligrammes per kilogramme* of copper. Preserved aliments, such as vegetables and fruits, with copper " verdure clad," contain more of that metal — froni ten to 200 milligrammes per kilogramme. Five milli- grammes a day he reckons to be about the quantity com- monly taken, and no inconvenience results from it. Choco- late is amongst the articles which, contrary to what might be expected, appear to contain a maximum of copper. The strong and repulsive flavour of copper salts limits the quantity anybody would be willing to swallow. When food is dosed with four grammes (over 61 grains) per kilo- gramme, it is too nasty to eat ; but even then Jl. Gautier affirms it would not be dangerous to take. Copper salts soon act as an emetic, unless the quantity is small, and, according to the new \-iews, poisoning by them is almost impossible. These opinions are founded upon experiments French doctors have made upon themselves and their friends. Dr. Galippe as far back as 1875 tried copper salts upon various animals, and acquired so much confidence in their innocence that he proceeded to take and give verdigris to his family and acquaintances without any mischief ensuing. * The milligramme is -0154 of a gi-ain; the kilogramme 21b- 3 oz. 5 drams, or 15-44rlO-2344 grains. 40 KNOW^LEDGE ♦ [July 20, 1883. According to these notions tinning copper vessels is not only unnecessary, but is a source of danger, as it is common to mix lead with the tin, partly because it is a much cheaper metal, and perhaps, still more, because it facili- tates the process. Many of the disasters attributed to copper are now thought more likely to have been caused by the tinning. An unclean copper vessel is pronounced less dangerous than that one tinned with an alloy contain- ing 10 per cent, of lead, and from 30 to 40 per cent, is found to be a common proportion. The chances of lead getting into the system are very great. The mischievous metal lurks in sardines, tunny, and lobster, as well as in the vegetables sold in tins. It is also to be found in shining wall-papers, certain table-cloths, the glazing of earthenware, and in a swarm of cosmetics. In India, it is customary for Europeans to have all their cooking done in copper vessels, which are retinned every few weeks. In the army some precautions are taken to prevent the employment of a lead alloy in this process, but ordinary poisons are easily checked. When some of the so-called tinning is worn ofl' the copper, the lead is more likely to be acted upon, and it is not improbable that some supposed copper poisonings have beiii ellected by the lead. We should be glad if our medical readers in India would look into this question, and let us know the result. Small doses of copper salts are supposed to e.xert a pre- servative action against typhoid fevers and some other com- plaints. Workers in copper and players upon copper and brass instruments are said to liave escaped from typhoid poisoning better than other folks. Compared with the whole population, they are a very small class ; there may be other things besides their contact with a particular metal that may help to secure their immunity. The ques- tion demands further inquiry. THE FISHERIES EXHIBITION. By John Ernest Ady. III. IN that most delightful toaside resort in the Isle of Weight called Freshwater there is a liay adjoining the little hotel village known as Scratchell's LSay. The escarpment of the chalk cliffs, which descends abruptly for several feet to the level of the sea, shows in a most remarkable manner layer after layer of chalk, alternating with linear bands of flints. We have already solved the problem of the origin of the chalk with the assistance of the microscope, but how about the flint 1 It has been supposed that the flint derived its existence from the tests of !>lUceous organisms which abounded in the Cretaceous .seas, and which have been dis- solved and redeposited in that new and obscure shape. W^e pointed out before* that the tests of Foraini)tifera undergo profound changes at great dnprhs. which ri^sult in the for- mation of a fine " red clay " (a silicate of iron and alumina) almost free from any traces of organised remains. \Vh may now draw attention to the fact that in certain localities, e.q. the Gulf of Mexico, in comparatively shallow watei (100 to 300 fathoms), the calcareous shells of the Foraminifera are subject to other changes, whereby the chambers of their tests become filled with a green material (also a silicate of iron and alumina), whilst the calcareous walls gradually disintegrate and finally dissolve, leaving behind the so-called "green sand" com- po5ed of a mass of exquisite casts or pseudomorphs of the shell chambers ; these finally break down and crumble * Vt su% ra, p. ?, away into a formless paste, the vestiges of former anima- tion. Evidences of the organic origin of vast azoic for- mations have thus been elucidated by the recent researches of the deep sea explorations, and suggested to the mind of the late Sir Wyville Thomson that many of the most ancient (Cambrian and pre Cambrian) rocks, such as the highly-metamorphosed ^slates, itc, may possibly have been derived from foraminiferal and other remains. Whilst noting these phenomena, Huxley* observes that the words of Linn;eu3 may be literally true when he says : — " Petrefacta non a calce, seel calx a petrefactis. Sio lapides ab animalibus, iiec vice versil. Sic rupes saxei non prima'vi, Bed temporis lilioe." And he adds : — "And there may be no part of the common rocka, which enter into the earth's crust, which has not passed through a living organism at one time or another." But apart from the silent flints and clays, there are large zones of the crust of the earth which testify aloud to the former existence of myriads of lovely organisms which resemble the Foraminifera in many things, but are possessed of siliceous instead of calcareous tests. These Jiadiotaria form great masses of rock in the Barbadoes. Fig. G is a Fig. 0. — PoLVLY.sTi.NA, " Barbadoea earth." Tertiary deposits, Springfield, Barbadoes. x 300 diameters. (Ori^jinal.) drawing, magnified 300 diameters, of some of these beautiful skeletons. They are called Fo/yci/stina, and may be readily obtained for examination by the following method : — Procure a small piece of the friable rock known as " Barbadoes earth," put it into a large test-tube, and add equivalent bulks, each of water and washing soda ; boil for about one hour. The upper pellicle must now be poured off, fresh water and washing aodsk added, and the boiling continued. These processes should be repeated a third, and, if necessary, a fourth, fifth, and si.xth time, until a fairly cleansed residue is left. The deposit thus obtained may he calcined by the application of a strong heat if the objects are to be examined by condensed reflected light under the micro- scope ; but this further process is unnecessary if they are to be mounted in a transparent medium, and observed with transmitted light. Thug prejjared they will be freed from adhering extraneous particles, and will present the wonderful beauty and symmetry which has been outlined in Fig. 6. * " The Anatomy of Invertebrated Animals," p. 87. July 20, 1883.] • KNOVSALEDGE ♦ 41 Now let us endeavour to show what relation these pretty shells hold to the bodies which have produced them. The reports of the Chalhnyer expedition have shown that the lladiolaria of the great oceans usually live towards the surface, and that their skeletons, like those of the Glohi- gerhm, are being continuously showered down on to the bed of the deep sea from its surface waters. Unlike the GlobiyerhuV; however, the Radiolaria prefer to live in the temperate zones of the world; at about 55 deg. on either side of the equator the Glohi- Let us try this problem another way. Put 0 Y—.v, d.v P Q,=d.c. Then time of falling through P Q= , ; and V2gx during this time the body gains a westerly deviation corre- sponding to the excess of the eastwardly motion of the 42 ♦ KNOWLEDGE ♦ [July 20, 1883. point v over that of the point G, during that interval ; or py2^Vv/-^- "^ ' :. total westwardly deflection 2- /-o / = ^^(2/1=- iicA py2 is a very obvious consideration, at this point, that if we join Ci L wo shall have Q C, h an isosceles triangle, C, Q being clearly equal to C, L (Euc. I. 4). Hence, PC, and C, L together are equal to PC, and C, Q together. But PC,, C, L together are greater than PL (Euc. I. 20). Hence PC, and C, (,) ar(3 together greater than PC, CQ together. We find, then, that our surmise is correct, for what we have proved for P C,, C, Q can be jiroved equally well wherever C, may be taken. Thus the problem is solved. It is not necessary to give the synthetical statement of our solution, since this has already been given in the scholium to Example 8. It may bo argued that such tentative processes as we began with, herr, iiic uMi mill lumatics. To this it is to be answered — first, lliat tho art i>r "ih ' ill wi'll is an important aid to the matluMnatician ; and seconilly, Ihiil \vi> deal with our gviesses by means of mathonuitical I'easoniiig, and tlius gain all tho benefit available from niathomatical processes. But further, there are no laws for applying simple geometry — that is geometry resembling Euclid's— to deductions, and therefore in many cases we have no choice but to make use of jciitativo methods. ♦ ♦ ♦ o ♦ ♦ ♦ ♦ 0^0 <;? 4- * 4. 4. 0 0 0 0 + + e and purpose of the water- 64 KNOAVLEDGE [July 1883. chamber, and of the ascending and descending passages, as tubes through which to obtain the reflection of the rays of Draconis, offers the only rational explanation of these parts of the structure with which I am acquainted ; and your exposition of the purpose of the great gallery — which, as it now exists in the heart of the structure, ending against a dead wall, is entirely without object or use — appears to me absolutely irrefragible. That the Great Pyramid was, in even a secondary sense, erected in order to obtain an astronomical platform and an observing tube, is what I cannot subscribe to ; but given that the Pharaoh built his monster tomb during his life- time, I can fully admit the likelihood of its having been made use of, during its progress, for purposes of astrono- mical or astrological observation. Amelia B. Edwards. [I think my correspondents referred chiefly to remarks by some continental Egyptologists ; but as Miss Edwards had expressed the same views in her very kindly notice of my book on the Great Pyramid, it is probable that several of them referred to her known views on the subject. It appears to me that most Egyptologists fail to estimate the significance of the astronomical relations involved in the Pyramids, and especially in the Great Pyramid. What Miss Edwards, for instance, regards as proved beyond further question, carries with it a great deal which she appears to regard as more than improbable. I will run briefly through the considerations which seem, to my own mind, logically convincing in this respect : — Either the Egyptian rulers were greatly interested in the advance of astronomical and astrological learning for its own sake, or they were not. If they were not, it would be very unlikely that merely for the sake of such astronomical purposes as the structure might subserve at certain stages of its erection, they would have gone to the enormous extra expense, labour, and care involved in the construction of the great slant gallery. If, on the other hand, they were greatly interested in the advance of astro- nomy, it would be manifest to persons as familiar as they obviously were with astronomical relations, that little of real importance could be added to their knowledge by an observing gallery only available for a few years ; they would have recrignised the absolute necessity, if they would efifectively advance their science, of an observatory so con- structed as to be available for centuries. Seeing, then, that whether the Egyptians were, or were not, greatly in- terested in the advance of astronomy, they would never, for that purpose, have given to the Great Pyramid the qualities as an observatory which were actually given it at the cost of enormous extra labour, care, and cost, it follows certainly that the astronomical and astrological relations considered by the builders were other than those merely connected with the advance of their science — were, in fact, such as made it worth their while to devote all that skill which they evidently possessed, to employ all that extra labour and to go to all that extra expense of which the building gives evidence, for astronomical and astrological relations which vmvJd, in their belief, be eflectively advanced during the few years that the great platform and gallery could be used for observing purposes. I can see no escape, for my own part, from the conclusion that these astronomical and astrological matters related solely to the king for whom the Great Pyramid was erected. In other words, it appears to me a demonstrated fact (whatever the interpretation of the fact may be) that while the ultimate purpose of the Great Pyramid was that it should serve as a tomb for Cheops, its primary purpose (not a secondary purpose at all) was that by means of it those observations of celestial bodies, which, according to the belief of his time, were essential for his success in life and (I have no doubt) for his welfare after death, should be satisfactorily and effec- tively pursued. If there is any way of escape from this conclusion, I have not seen it, nor has any Egyptologist who has ever asserted that the Great Pyramid was a tomb and a tomb only, ever indicated one. Lepsius, of all among them, took, I think, the most logical position, — in regarding astronomical evidence as not worth considering at all. In so doing, he only rejected a demonstrated fact But to accept that fact, and not to accept what it proves, is to be wanting in the logical completeness of unreasonableness which Lepsius showed in this matter. Indeed, the tomb theory taken alone proves a good deal which those who hold it seem to overlook. In concluding that the Great Pyramid was a great tomb, we are admitting that its erection was closely and intimately associated with the religious ideas prevalent among the ancient Egyptians when it was built. From all the indications which have reached us as to the nature of those ideas, it might be shown, I believe, even though nothing whatever were known of the Great Pyramid, except that it was very large and had been erected at such-and-such cost of time and labour, that during the lifetime of its future tenant it must have had some such astronomical characteristics as is actually possessed. If sun and moon and planets were the gods of the ancient Egyptians, and the star sphere the house in whose " many mansions " those gods moved — and there are abundant indications that such was the nature of the most ancient Egyptian cult — the aspects of the heavenly bodies were bound to be considered during life and after death in the case of every Egyptian " worth counting " (I suppose the " common-folk " were not considered worth counting at all), more particularly in the case of governors, generals, official rulers, and priests, still more particularly in the case of princes and members of the royal family, but most particularly of all in the case of him who was at once King, Prime Minister, Chief General, and Highest Priest. Knowing what we know, and inferring what we may safely infer, of the religion of Old Egypt, the wonder would rather have been that astronomical and astrological relations should not have been considered in the Great Pyramid — being what it was, the future resting-place of the greatest of their nation — than that we should find these relations considered so thoughtfully and so skilfully, with so much care, at such great cost, and at the expense of so much labour. — R. P.] PRINCIPLES OF DRESS REFORM. By E. M. King. MERE novelty, divorced from the ' eternal canons of loveliness,' as Ruskin calls them, can produce only oddity of various kinds, as we see in the world of fashion, where a morbid love of change is always at hand to usurp the throne of reason, and to juggle Nature out of her most comely graces and most healthy proprieties." — Professor Blackie's article in " Contemporary Bevieiv " for June, 1883. " Utility, and fitness to attain a practical end, must be as in all the useful arts ; but it is there as a basis on which the beautiful is erected, or as a stem out of which it grows." — The same. " There are two sides to the artistic view of the question (dress). On one side is nature ; on the other art. I need go no further than to remind your readers that the human frame, if in its unsullied grandeur, is, of all the Creator's works, the most artistic. Consequently, I contend that July 27, 1883.] ♦ KNOWLEDGE ♦ 55 the dress which best adapts itself to the form and require- ments of that frame has the best right to be considered artistic. The mind of man has discovered for himself a dress which, I hold, fulfils both these requisites. It remains to be seen whether the mind of woman is equal to the task of devising a similar one for herself." — Letter hy Clavnriny Mesnard, in Knowledge of June 29. " Women now will have to be content to wait before art (in dress) in any true sense of the term can be theirs. Tiiey have so distorted and disguised nature that art for the present is impossible. We must wait and gain a correct and right appreciation of nature before we can have any true art. Before we attempt to decorate, let us have some veneration for the divine temple of our bodies which now, while ignorantly seeking to adorn, we only desecrate. And while we are waiting and learning this great lesson, a truer beauty will arise compatible with use and fitness, and women become reformed not in dress only but in mind and character." — PanqMet hy E. J/. King. " Men are very near towards gaining beauty and grace in their dress, they having already secured, in a very great degree, the more essential requisites of comfort and con- venience. Women, on the contrary, having sought only beauty and grace in their dress, and neglected the essentials of comfort and convenience, have, in reality, failed to secure either. Men's dress is only negatively ugly, but women's dress is positively ugly. It is not only ugly in itself, but it insists upon making the body which it covers ugly — that is, deformed. But, unfortunately, our eyes are holden that we cannot perceive this ugliness, custom having long familiarised our sight to it, and because it has been disguised by always being decked out in beautiful colours, to which it has no claim. And so it is that, for men's dress to conform to right principles, very little alteration is required ; while, for women's dress to be made to answer to them, such a wide measure of reform is called for that it amounts almost to a revolution." — Lecture hy the same. These four passages agree on the following points : — That the foundation or basis of beauty in any useful art must be utility or fitness. That the source of beauty in art lies in the study and appreciation of Nature. That dress, being one of the useful arts, must have its basis in use and fitness ; and its beauty, growing out of this as out of a stem, must be derived from a correct appreciation of the liuman form. That the dress which answers to the requirements of the body, and best adapts itself to the form, is at once the most useful and the most beautiful dress. That men's dress, being closely adapted to the form of the body and its requirements, is the most beautiful. That women's dress, as having little regard to use or fitness, and not adapted to the form of the body, does not possess beauty. That Fashion, which in women has usurped the throne of Reason, can never give us a dress at once useful and beautiful. That if the mind of woman is ever to become equal to the task of devising for herself a dress adapted to the form of her body and its requirements, she must dethrone the usurper Fashion which has implanted in her mind a morbid desire for change and juggled her out of tlu; most comely graces of nature and of its most healthful proprieties, and must substitute for it the guidance of Reason and right principles. That the change required in womcn'.s minds, feelings, and habits, in order to substitute the guidance of reason for that of fashion, is so great as to amount almost to a revolution. I have here endeavoured to put together the opinions of two men writers with those of my own, to show how far these agree with mine, and also to show that if these are correct, nothing short of a revolution can effect the change we desire. The change from the external despotism of fashion to that of self government of reason and right principles, is a revolution. The change from unfitness and ugliness to suitableness and beauty is a revolution. To eflFect this twofold revolu- tion the inward or mental, and the outward or practical must work together hand in hand or both remain abortive. To call in the despot Fashion to introduce a change, how- ever practically beneficial, is useless. To believe in and subscribe to right principles without power or courage to carry them into practice is also useless. In order to form a basis of mental self-government in dress, I have drawn up the following principles or require- ments of a perfect dress. They may or may not be en- tirely feasible ; they may or may not be altogether correct ; they may be insufficient, or they may be redundant ; but they are an attempt to dethrone the usurper Fashion, and to raise in its stead the guidance of reason. The require- ments of a perfect dress are : 1. Freedom of movement. 2. Absence of pressure over any part of the body. 3. No more weight than is necessary for warmth, and both warmth and weight equally distributed. 4. Grace and beauty combined with comfort and convenience. But it has before been proved that dress, to be both useful and beautiful, must be adapted to the form of the body and to its requirements ; therefore, in practically carrying out the foregoing principles, clothing must follow, and drapery not contradict, the natural lines of the body. In efTecting any radical change we must be careful so to bring it about as not to put ourselves, or to induce others to put themselves, too much out of harmony with our or their surroundings. This brings me to my fifth requirement, upon which I specially desired to write, which is that it must (5) not depart from the ordinary dress of the time. I found it, however, impossible satisfactorily to discuss this point until I had clearly marked out the road we have to follow. It may be doubted whether " the mind of man " had very much to do in bringing about the change in men's dress from a highly-decorated one to an extremely and, I may say, an over-plain one. It is more likely to have been produced by men's love of comfort and a sort of can't-be-bothered feeling, rather than by any conscious mental efibrt. The task which women have before them is a far harder one than that which men had to encounter, because we have to work up through the prejudices and conventional ideas of the other sex as well as our own, and to do battle with the accumulated power and influence of various trades — an influence which seems to extend every year ; for now the tailors have got hold of us as well as dress- makers, drapers, and manufacturers, all ready to rack or wreck our bodies and souls so that they may but fill their own purses ; while the unreasoning and illogical male multitude tacitly b.ack them up, looking on us as, in a measure, fair game, as a sort of corpus: vile, which it does not much matter if fashion works its deforming and degrading experiments upon, because, forsooth, " spending is good for trade." (To be continued.) Gold Puoduction in Russi.v. — According to a report drawn up by Mr. Irvanow, the production of gold in Russia during the year 1882 amounted to 57 million roubles (SI millions sterling). Russia thus stands next to North America, which produces annually about 9 millions sterling, while Australia follows with 7 J, millions. 56 ♦ KNOWLEDGE ♦ [July 27, 1883. THE MOON IN A THREE-INCH TELESCOPE. By a Fellow of the Royal Astronomical Society. ERATOSTHENES (110), of which we spoke on p. 391 of Vol. III. as terminating the magnificent chain of the Lunar Appenines, presents a beautiful spectacle about the ninth day of the moon's age. Our drawing was made Eratosthenes. Moon's Age, 9'23 days. ■with a power of 160, when the moon's age was 9 -2 3 days. The diameter of this finely-terraced formation is about 37i miles, and its walls will be seen to be very rugged. The three central peaks, too, are conspicuously shown under this illumination. It is curious that a formation presenting such strongly-marked features when lighted obliquely by the rising or setting sun, should be by no means easy to find at full moon. South-east of Eratosthenes will be noted a deep mountain range, terminating in a ring- plain whose walls are only some 1 30 ft. or so high. Hence it is only visible during a short period of favourable illu- mination, and forms a very severe test of the defining power of a 3-in. telescope, and of the keenness of the observer's vision. The height of the connecting ridge of mountains is some 4,470 ft. As Ben Nevis is 4,406 ft., and Snowdon only 3,. 571 ft. high, this maysuffice to furnish a scale whereby the student may estimate the dimensions of the lead- ing features of this neighbourhood. Schruter (106), or rather its northern vicinity, should be carefully looked at when near to the terminator, for the strange .system of ramparts sloping ofl' on either side of a central one, which Gruithuisen believed to be artificial, but which in reality consists of a series of parallel valleys. Parry (217), Bonpland (218), and Era Mauro (219), are those more or less imperfect ring-plains which present a curious appearance when pretty near the terminator. Pitatus (186) and Hesiod (187) are a pair of huge craters, or rather ring-plains, connected by a pass. The northern wall of the former will be seen to be imperfect, while the southern wall is separated from Tycho, which we are immediately to examine, by a rugged mass of mountain peaks. The two most notable pecu- liarities in Hesiod are a central crater in the floor, and a cleft (shown in our map) running into the Sea of Clouds. And now we arrive at what has been aptly called by Mr. Webb, " the metropolitan crater of the moon," Tycho (180), reference to the system of streaks emanating from which has been once or twice previously made. This splendid formation, visible as a white spot to the naked eye at full moon, measures fifty-four and a quarter miles across, and xhibits an elaborately terraced wall, some 16,000 ft high on the east side ar.d upwards of 17,000 ft. in height in its western portion. In the subjoined sketch we have purposely abstained from any attempt to T}-cl)0. Moon's Age, 924 days. delineate the extremely disturbed and rugged region surrounding Tycho, confining ourselves strictly to drawing the crater itself. The central hill shown above is between .^jOOO and 6,000 feet high, its conical shadow being very conspicuous at the time our drawing was made. The inex- tricable mass of craters, hillocks, pits, and irregularities in the immediate neighbourhood of Tycho almost defies any attempt to draw or map it. The wonderful system of light rays radiating from this great crater extends over at least a quarter of the entire visible hemisphere of the moon. Some of them may be traced to the southern limb, and doubtless extend beyond it into that hemisphere which is always hidden from the terrestrial observer. Onetremendous ray passes through the Sea of Serenity, the craters 70 and 73 in our Map (Vol. III., p. 223), lying upon it. Another very conspicuous one connects Tycho with the interesting formation Bullialdus (213). It is a notable fact that while these rays in nearly every other instance pursue their course tlirough hill, valley, crater, and plain without deviation or interruption, the crater Saussure (196) has deflected one of them, and caused it apparently to bend round its southern wall. What these stupendous bands are can only be regarded, at present, as a mystery. Nasmy th considers them to be cracks filled up with molten lava from the Moon's interior ; but arguing from their ter- restrial analogues, trap-dykes, we should expect to find them projecting more or less above parts of the lunar surface, and, as a necessary consequence, casting shadows when on or near the terminator. As a matter of fact, we find them, everywhere, absolutely level with the regions which they traverse. Of whatever material they are composed, its re- flective power must be very high, inasmuch as the ray- system of Tycho traverses the (in many cases) huge and complicated formations, Sasserides (183), Gauricus (185), Heinsius (190), Wilhelm I. (191), Longomontanus (192), Clavius (193), Maginus (195), Orontius (197), Nasir-ed-din (198), Lexell (199), Walter (200), Moretus (262), Stofler (354), and Maurolycus (358), all which are most con- spicuous oVijects when obliquely lighted ; but which, one and all, disappear wholly at full moon, or under vertical illumination ! The late Professor Nichol, amid much which, after all, merely amounted to assertion, did point out one valuable piece of evidence furnished by these rays ; and that is, the proof afi'orded by their continuous visibility and the homogeneous character of their brightness throughout their course, that the reflective substance of which they are composed is absolutely everywhere uncovered. Did anything in the shape of vegetation, for example, exist in the moon, it must obscure portions of these light streaks. That they pass undimmed, then, from their origin to their termination, shows plainly enough that they traverse " a rocky desert, devoid of life or living thing." Here our night's work may cease. We shall turn our telescope upon Copernicus (112) as soon as it is favourably illuminated. July 27, 1883.] ♦ KNOV/LEDGE ♦ 57 Onf. Month HKKnitf: Simmer SfiT.sm k. KrMMFR Soi.STHE. Onf ^[o\TH AfTER Sl'MMER SOLSTICE. ^B.' ^^^Q iBUiaiiH^^^MHI^BilaUDiifal SUN VIEWS OF THE EAHTH; OR, "TJIE SEASONS I L L U S T K AT E D." By Richard A. Proctor. I GIVE tliis week our Sun Views of the Earth for the month, showing the aspect of the earth as supposed to be seen from the sun at six in the morninf,', noon, six in the evening, and midnight of Greenwich solar time, one mouth after the summer solstice. For comparison, I repeat the Sun Views for June and Hay. 68 ♦ KNOWLEDGE ♦ [Jtly 27, 1883. FLIGHT OF A MISSILE. By Richard A. Proctor. Prop. — To deternii7ie what westerly deviation is produced in the case of a missile fired vertically from the equator to a height li {tlie resistance of the atmosphere being neglected). The real cause of the westerly deflection is the action of gravity during the time of flight retarding the motion originally possessed by the missile at right angles to the line joining the earth's centre and the point whence the missile was projected. Let ah che part of the equator, a the point whence the missile is projected vertically, with velocity v'2 gh, so that it reaches the height h in time t^, and in time 2 l^ reaches the ground again at b, the point a having in the mean time been carried to c, so that 6 c is the westerly deviation we require to determine. Let c' be the point in a T which a body moving in the straight line a T with constant velocity r would reach in time 2 t^, V the point which it would have reached if constrained to move in the straight line a T, but with its velocity in this direction, V at starting, aflected by the action of gravity, so that 6' c' is the devia- tion we require ; for the arc a c is so small that for the purpose of this inquiry, the inclination of b c to aT may be neglected. We also may manifestly neglect the variation in the force of gravity due to the varying distance of the actual missile from the earth's surface. Suppose that in time t the body has reached the point X, put « X = .T, and join C x (0 being the earth's centre). Then the retarding action of gravity on the Viody at X is equal to ^ - (»• being the earth's radius). Hence we have — drx _ _ gx dt' M^x dt- ■ r dx _ Igx di ^ ~V and C^y- \dt) \dtf = - 5^- + C. r r But when x = 0, (-) - ^dt' = la- \dxf J dt and -- __ r rv" - gx- dx wherefore t ^ 9 J:^ _ 9 = A/!:sin-i 9 — X- or .^ = '• \A' sin 9 in time 2t^, the = V A /r sin 9 Vf (Constam =0) Hence, since ah body is \/l-2t, ' r at b', we have -'.^/l[^ r V(?)' 2.3. [approxima tely 2.3 9 ,^ But ad = 2vt^ . V < 4 vat,"- :, be = — :i-!- 3 r XT (/t- T 2;7r JNow 9i = tL_ ; and v = 2 P • b'c'=— rfli^lSrr/i^i ■■ '^ "3"' T 3P~ the same result which was obtained by the simpler method of regarding the missile after it had once left the earth as travelling in an elliptical orbit around the earth's centre, and subject, therefore, to the second law of Kepler. If the missile is projected in latitude A, it may easily be shown that the westerly deviation IGirht, cos \ 3P The mean daily motion of the air in 1882 was 306 miles, being 27 miles greater than the average. For the month of November, the mean daily motion was 4-19 miles, being 150 miles above the average. The greatest daily motion was 758 miles on Nov. 4, and the least 30 miles on Dec. 11. The greatest hourly velocity was 64 miles, and the greatest pressure — with the chain — 29 lb., on Oct. 24. Remarkable Phenomenox ix Glenisla, Forfarshire. — About two o'clock on the afternoon of Wednesday, the 11th current, the sky was very dark, and I was on the outlook for thunder, when, standing at Broomhall, in Glenisla, my attention was attracted by a peculiar noise, similar to that produced by a train crossing a bridge. This noise was very loud, and seemed at first to be distant, but latterly it came quite near, and sounded like the rapid discharge of musketry, with a booming sound. There was no rain at this time, but a few minutes before there had been a heavy fall of rain, accompanied with a thunder-peal. I looked up, and saw about a mile away a large cloud twisted in the form of a screw, and revolving round and round at a very rapid rate. It looked like a huge column of steam, and cloud, and vapour, about fifteen yards in breadth, and so high that the top of it went out of sight. It was narrow towards the earth, and spread out in its screw form as it reached its extreme height, with huge volumes of what looked like steam or smoke in its train. The efi'ect was grand. It rose above the horizon, which from my point of view was formed by a wooded hill on the south, and gi-adually descended towards the earth. It had two motions, one circular and the other forward, and the latter I guessed to be at the rate of a mile in 2i minutes. It seemed to be engulfing everything in its vortex, and was scattering branches, and what appeared to me pieces of burnt paper, but whicli turned out to be slates. The air was pervaded with a strong sulphurous smell. I followed the vision, which was that of a "rushing mighty wind," over the other line of the horizon to the north towards a mill-pond, from which it sucked up water in great quantities, which appeared to be absorbed and scattered in its weird-like dance. On further inquiry I found that this same visitant had in this immediate neighbourhood knocked down stone dykes, levelled trees, tirred a cottage, which it shook, shattered its chimney-cans in a thousand pieces, and scattered the zinc ridges for hundreds of yards. The fields in its train are strewed with limbs of trees, slates, and splintered wood, and the whole advent was so solemn as to strike with terror men, women, children, and the beasts which were in the field ; and doubtless others of your cor- respondents will recount its story and tell its name. — Dundee Advertiser. July 27, 1883.] ♦ KNOWI.EDGE ♦ >9 ajottonal (gosisiip. My lecture audiences in the Philharmonic Hall, South- ampton, very considerably exceeded the " small dozen " which an astronomical resident assigned as the total number here who take the least interest in astronomy. In fact, they were excellent audiences, both in size and quality. It was particularly pleasing to me to find that the numbers present increased as the course proceeded. I regretted the more that the third lecture was given under considerable difficulties, and, indeed, ought not to have been given at all. I was a passenger by the 7. .50 train from Portsmouth on Saturday morning, which ran into a heavily-laden excursion train, and have felt since (like Pete Jones after his encounter with Bud Means) " consid'able sliuk up." It was a somewhat singular experience to me to lecture under such conditions, and I was interested to find that for the greater part of the time the mere mechanical action of speaking went on, or seemed to go on, almost without thought. But the effort was trying, and I shall be careful how I repeat it before I have recovered my customary working powers. Good service may be done occasionally by showing the class of readers who place reliance on anonymous criti- cisms, the shallowness of average criticism, and the dis- honesty of a good deal which is below the average in one sense, but in cleverness often rather above it. A criticism of my Mysteries of Time and Space, by no means un- kindly in tone, though amusingly corrective considering the writer's manifest inexperience, has been sent me by a good- natured friend (never mind the theological participle), for notice, I suppose. It appears in the usually rather caustic pages of the Saturdny Eeviev), but I must admit that the purpose of the writer seems throughout to impart infor- mation, not to cauterise the poor author. This is kindly meant, and as I should imagine from his remarks that my friendly critic really has given an hour or two for every year that I have given to the subjects about which he wishes to set me right, he stands manifestly on higher ground than the average critic. That he has not read my book is clear enough, from his remark that the essay on " Herbert Spencer's Philosophy " — which introduces most stupendous " mysteries of time and space " — has no busi- ness in the book at all, and from his reference to Mr. Spencer's special law of the " Persistence of Force," which might be erroneous, yet his philo.'iophy sound. But it is an exceptionally honest critic who reads everything on which he comments, and my critic really is very fairly honest. Nine-tenths of his corrections present only misapprehen- sions of his own. What I wish specially to note in this criticism is the following remark on my essay, " A Survey of the Northern Heavens": — "Mr. Proctor, who has investigated the matter very carefully, maintains that at the end of his life Herschel gave up all belief in either of his two methods of ' star-gauging ; ' V)ut we could wish that he had noticed the arguments on the opposite side which have been lately put forward by Professor Holden in his short ' Life and Works of Sir William Herschel.'" I BELiEVK that I have given to the study of Sir W. Herschel's papers more time and attention than anyone else has yet bestowed on them, not excepting William Struve, wlio however is a long way ahead of all others in this respect. His conclusions and inferences are almost exactly the same as mine, neither of us, by the way, having ever suggested any sucli absurdity as that which the critic attributes to me. Herschel never "gave up all belief in either of his two methods of star gauging," but he did give up the theories he had based on them. But if I had not been content with my own and W. Struve's study of Herschel's papers, it is at least not likely that I should notice arguments respecting them put forward by Professor Edward Hoklen, formerly of Wash- ington and now of Ann Arbor, Mich., celebrated for years past as the man who has most notably surpassed the usual achievements of book-reviewers. They have sat in judg- ment sometimes on books they have not read, and it is whispered that one or two of them have sat in judgment on books they have not even seen. But Prof. Holden, aiming only at the latter achievement, unfortunately shot so far beyond his mark as (unwittingly) to pronounce judgment on a book which — though announced for early publication two years before — had not been completed, and has not been published yet ! Ilia remarks on the long and diffi- cult series of papers written by Sir W. Herschel must be worth noticing indeed ! There is a good illustration in a recent number of Nature of the risk arising from the constant custom of putting a comma before " which." In an article on cholera, a writer is made to say " that the disease has, in this country, been mainly associated with the use of water supplies, which have been subjected to the risk of receiving special infec- tion." I daresay the compositor supposed that in throwing in the comma he was correcting slipshod punctuation. As a matter of fact he made the author he was correcting teach that we should refrain from the use of water supplies (which would be awkward), and for the reason (which would be rather scaring, if true) that our water-supplies have one and all been subjected to the risk of receiving special • •ifection. I AM glad to see that our musical critics, who usually waste a good deal of their ink in writing fanciful nonsense, have begun to notice the evil habit which some of our operatic singers have of showing off their voices at the expense of their parts. Albani is a great offender in this respect. With a magnificent voice (the musical critics will smile at such a word as " voice " being used, instead of the impressive "organ"), Albani sometimes gives pain to hearers who really love music by introducing into some expressive phrasing a marvellous bit of trilling, as utterly out of place as a somersault would be towards the close of Hamlet's suicide soliloquy. If Nilsson or Patti, who, we know, can achieve all that Albani does, were to lose no opportunity of doing so, they would not hold the place they do in the hearts of all who prefer singing to musical gymnastics. By-the-way, might not something be done to teach audiences how and when to applaud. Perhaps some of our singers, especially at concerts, are more to be blamed than the'^audience, for often by their action they suggest that the right time to applaud is when their own voices cease to be heard. Be this as it may, much sweet music is lost through the stupid habit of those listeners who think only of the voice, and drown what Beethoven, Mozart, or Rossini (who perhaps knew rather better than these noisy ones) thought an essential part of the performance. One often feels that concerts and operas could only be properly enjoyed if none were admitted to hear them who did not know something and care something about music. As it is, more than half our audiences seem to be of the opinion of Lord Foppington, that listening to the music, though " pardonable in the country," is " a monstrous inattention in a polite assembly." But this is a very old trouble. 60 ^ KNOWLEDGE [July 27, 1883, CHOLERA. (Preventive.) To the Editor of Knowledge. THE progress which medical art combined with sanitary arrangements have made fince 1866, has greatly diminished the dread of this epidemic. Yet forewarned, forearmed ; for not to be watchful against danger is fool- hardy. The most important thing is not to be afraid of it, since terror, fussing, and worry destroy more than disease. Pay very strict attention to body and home cleanliness, diet, and daily exercise, with avoidance of heavy drinks, greasy substances, and fruits. In my large London parish the following proved most successful : — E^xperience has taught me that more depends upon pure water, boiled (best) or filtered, than anything else. A simple filter (costing a few pence) is made out of a common 6-in. garden pot plugged with sponge ; at the bottom a layer of 1 ?, iru of powdered wood or bone-charcoal, then 2 in. of silver sand, and on top li in. clean washed small pebbles. Renovate every eight or ten weeks. Or Atkins' (62, Fleet-street, London) splendid carbon filters, 2s. 6d. to £2. 2s. ; or Lipscombe's, 233, Strand. If diarrhcea or pains come on, the following reliable Indian remedy, which has been very successful during previous visitations in London, and which your chemist can make for 6d. to 7d. — and taken within a quarter of an hour — will prove very beneficial : — Sp. pro Mist. Crette jss. Conf. Aromat. jiss. Tinct. Catechu 5iss. Tinct. Opii , m.xx. 01. Cinnam m-^j- Aquas Ad. Jvj. Fiat Mist. Adults 3 table-spoonfuls every 3 or 4 hours. Ages 7 to 16 ... li ,, ,, ,, „ 4 to 7 3 teaspoonfuls ,, ,, „ 3 to 4 2 „ 1 to 2 1 „ Under 1... J (Beef tea, mutton broth, arrowroot, boiled rice.) Always keep some of the mixture in store, also a bottle of Dr. Collis Browne's C'hlorodyne. If any complications arise, without a moment's delay call in your doctor. I hope what formerly proved so efficacious may be again beneficial to my fellow-creatures. — A. Styleman Herrixg, Vicar of St. Paul's, Clerkenwell, London. The Edison Electric Light. — The Criterion Theatre, Piccadilly, is to be lighted throughout with about six hundred Edison incandescent lamps. The generating plant will comprise two Armington A- Sim's horizontal high-speed engines, having 13" cylinder by 13'' stroke, running at 275 revolutions per minute, and driving on to counter shafting, from which will be run four Edison L dynamos, each capable of sustaining 150 16-candle lamps. Each engine will be capable of indicating 84 h.p., at 70 lbs. pressure, and either engine will thus be able to take the whole load in the event of accident or repairs to the other. The wiring will be arranged on eight circuits, each under independent control by means of a specially designed regulator, capable of lowering or raising the brilliancy of the lamps from normal candle power to nil The contract for the work, which will be carried out by the Edison Electric Light Company, stipulates for the completion of the installation by the beginning of September. " Let Knowledge grow from more to more." — Alfred Texntson. Only a small proportion of Letters received can possibly be in- serted. Correspondents must not be offended, therefore, should their letters not appear. All Editorial co-mmunications should be addressed to the Editob op Knowledge; all Business communications to the Publishees, at the Office, 74, Great Queen-street, W.C. If this is xot attended to, DELAYS ARISE FOE WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should be made payable to Messes. Wymax & Sons. The Editor is not responsible for the opinions of correspondents. No COMUrNICATIONS ARE ANSWERED BY POST, EVEN THOUGH STAMPED AND DIRECTED ENVELOPE BE ENCLOSED. LARGE SUN-SPOT. [880] — It may interest " Excelsior " (letter 866, p. 29) to learn that I measured the fine spot — or rather group of spots — -to which he refers, on June 30, and that the total superficial area of the sun involved in that stupendous disturbance amounted to 1,837,310,200 square miles ! The superficial area of our o^vn world, it may not be unworthy to note, is only 197,000,000 square miles. A Fellow of the Eoyal Astronomical SoctEir. GEOMETRICAL AND REAL PERSPECTIVE. [881] — It is the practice of artists to exaggerate the size of distant objects. Imagine, for example, in a landscape, a distant hill with a lake in front of it, and a man walking across the fore- ground so that the observer sees the collar of his coat in a line with the top of the hill, and the end of his coat-tails with its base ; the artist will probably show the top of the hill above the man's hat, and the base coirespondingly low. TVlien the sketch is com- pared with a i:)hotograph, it looks correct, but the photograph makes the hill look too small. The following is suggested as a likely explanation : — The camera takes its picture in true geometrical perspective, except as regards slight errors due to the lenses, and differences of focus. By using a camera with a small hole, instead of lenses, these may be avoided. In the camera the man's coat takes the same height on the screen as the hill does, but still, in the photo- graph, the hill looks too small. On looking at a picture or photograph, the eye has not to alter its focus, and can see two objects supposed to be at different distances simultaneously, and sharply defined. Thus, on looking at the photograph, the coat covers the same height on the retina as the hill does ; but in the case of the picture the hUl corresponds, perhaps, to the man's coat, hat, and other kind of garment, "which, by-the-bye, the artist will have shown bright red for the sake of the blue and yellow of the picture. In looking at the real scene, the eye has to adapt itself to the different distances, as it cannot look at near and remote objects at the same time. On looking from the man's coat to the hill, it alters its focus ; and this it does, not like a lens camera, but by increasing the focal length of its lenses by flattening the crystal- line lens. A result of this is, that the image of the hill on the retina is enlarged, and occupies more height than the man's coat did when in focus, justifying the artist's practice. The effect of this action of the eye is easily seen by holding a pencil, or anything suitable, between the eye and a distant object, and looking from it to the pencil and back quickly. The object appears to change its size. By holding the pencil so as to subtend the same angle as some dimension of a distant object of striking colour, and then, having previously looked at the object till the eye is somewhat fatigued, looking at the pencil, the images on the retina may be compared, as the object will still be visible in com- plimental colours. Jas. Swixbuexe. SINGULAR PHENOMENON. [882] — A short time ago, I was pricking out some annuals on a flower-bed, on which some geraniums were already planted, when I was surprised to see flashes of light coming from a truss of gera- nium flowers. At first I thought it was imagination, but my wife July 27, 1883.] KNOWLEDGE ♦ 61 and a friend who were present also saw them. Time was about 9 p.m., and the atmosphere clear. There were other geraniums of a different colour on the same bed, but there was no effect on them. The particular geranium was a Tom Thumb. Is this at all common f I have never seen or read of it before. S. Ingham. SKYERS. [883] — With reference to your note upon the absurd statement of the " Siiectator " that a " skyer " can only result from a drive, will you allow me to point out that nothing is more common than for a batsman to hit binder the ball in hitting to leg, with the almost invariable result of sending it spinning over his shoulder towards " long slip," or, perhaps, " third man ; " and such a hit is a verit- able " skyer," both in a literal and what one may call a technical sense. A " skyer " from a laie hit to leg would be indeed a curiosity. I should be sorry to be keeping wicket when it happened. F. M. D. Uplock. [Yes ; I knew a bowler who had a favourite dodge based on the fact mentioned by Mr. Uplock. When bowling to a batsman who favoured leg-hitting, he would send an occasional leg-ball with a break from the off-side, or au-ay from the wicket. Such a ball, pitched rather forward, is very apt to be hit under, with the result of sending a " skyer " to long slip. Especially is this the case if it comes after several leg-balls sent down with the right sort of break for taking the wicket — that is, a break from leg. — R. P.] DRESS REFORM— MEN. [884] — I am in my "forties," and since myyouthhave discarded braces, belt, or buckle. I merely have my trousers made to a " nicety," to fit just over the hip. Anything more comfortable is beyond my imagination. I think my tailor has not taken my measure more than two or three times during my "career," so that this ordeal has been avoided. A. G. [Unfortunately some men, oppressed with over-much adipose tissue, have no hips worth mentioning. — R. P.] RATIONAL DRESS : THE KILT. [885] — In all the letters and papers which appeared in Knowledge on dress, I am surprised that our national dress, the hilt, has not been referred to. Those of us who are in the habit of, at times, wearing it, and at other times trousers, know how much more com- fortable and pleasant it is than the latter. Two things, however, arc indispensable to this comfortableness and pleasantness. (1) That it be made so i 0 0 i 1 '> Bird 1 i 1 0 i 1 0 5 Blackbume . . i 1 i * 1 0 5 Fritz i 0 k 1 1 1 0 0 3i Gunsberg ... 0 \ __ 0 1 0 1 0 i 1 i i i * 0 i i n i 4 0 0 1 J T n i 3* LefEmauu . . . 0 0 i ♦ 0 0 0 0 i Mason 0 1 1 * i: 1 0 4 L. Paulsen ... * * 1 0 k k it , t 4 W. Paulsen .. 0 * 0 0 1 0 1 i 3 Riemann * 1 0 i ^ 1 * 0 k 4t Schallopp ... 1 i 1 1 1 k 0 — 1 6 Schottlander * * 1 k 0 * * — 0 0 3* J. Schwarz... 0 k 0 1 i i 1 1 — k i i 1 J 0 1 i 1 3i 5 Winawer . . . 1 1 1 0 1 1 0 GAME PLAYED IN THE NUREMBERG INTERNATIONAL CHESS TOURNAMENT, JULY 16, 1883. Position after White's IGth move of Q to Kt-l :— Mason. Slack. ///m Fbitz. French Defence. 16. Q to Kt4 17. K to Q2 18. Q to KtG (ch) 19. Q to Kt7 (ch) 20. Q to KtS (ch) 21. Q takes P (ch) 22. R takes R White announced mate in four. Black. R takes R (ch) P takes P Kto K2 K to K sq K toK2 K to B sq B to B sq 23. R to RS (ch), K to Kt2. 24. R toR7(ch),KtakesR. 25. Q to B7 (ch), K to R sq. 26. Ktt» KtC mate. Ci ♦ KNOWLEDGE ♦ [July 27, 1883. FIKST PRIZE THEEE-JIOVER IN THE PROBLEM TOURNAMENT OF THE GERMAN CHESS ASSOCIATION. By Feitz, of Gejiersstaxn. Black. Whitb. WWte to play and mate in three moves. [This is a very beantifnl problem. I hare ventured to omit the key move, snppUed by Mephisto, in the belief that among our Chess readers are many who wonld prefer to contend with it unaided.— R. P.] Position in the game between Pavlsen and Guxi^beeg. W. P.U'LSEN. Whitb. The game proceeded as follows : P to K5 P takes P Kt to B4 P takes Kt Kt to K4 Castles QR Q to Kt3 R takes Q Q to B2 B to Q sq B takes B P takes P B to R3 Castles E to K sq B to B4 R takes Kt Q takes B (ch) B takes Kt R to Q sq R takes E R to Q5, and won. Position in the game between Gcnsbekg and'Winawee. Winawee. Black. 'i t s i* 1 t ■J G Guxsbeeg. The game proceeded with : — Kt to B3 K takes Kt E (B sci) to BS Kto K-1 K to B5 P takes R KtoK4 K to B4, and won. Kt takes Kt P to Kt7 K to KtG (eh) R (Kt6) takes P (ch) R (K3) takes P (ch) R to B6 (ch) E to KG (ch) Position in the game between Schallopp and Gcnsbeeg. Schallopp. , © M #t 1 t £ t i 3 W - ^ 1 "White. GUNSBEBG. In this position White played as follows : — KR to QR sq K to B sq B to Q2 E takes P R to ES (ch) R (E sq) to E7 (ch) Q to Kt sq E takes R Q to Kt4 (ch) Q takes R B to K sq P to B6 (ch) QR to KR2 B to B3 R takes P K to B2 K to K3 R takes R Q takes R K to Q3 Q to ES (ch) Q to QS, and wins. Contents or No. 90. PAGB A Naturalist's Tear. XTII. Crabs and Lobsters. By Grant Allen ...33 " to Get Strong ; Eeduci Fat The 34 Chemistry of Cookery. "SJX . jjy W. Jlattieu Williams 3: The Mcralilv of Happiness : Intro- ductorr. By Thomas Foster 31 The Birth and Growth of Myth. XI. By rdward Clodd 37 htness. TT. By Kichard A. Proctor Are Copper Salts Poisonous? PAGB The Fisheries Eiliibition. IJlhu). By John Ernest Ady 4C Flipht of a Tertical Missile. By Eichard A. Proctor 41 Editorial Gossip 42 The Face of the Skr. By F.K.A.S. 43 Something about the Beet. II 43 Correspondence : Flight of Missiles ^Binocular Vision, &c 44 Our Mathem'ical Column : Geome- trical Pro 1- -ns. Till 46 Our Whist Co'umn 47 Our Chess Column 48 SPECIAL NOTICES. Part XXI. (July, 18S3), just ready, price lOd., post-free. Is. Id. Volume III., comprising the numbers published from January to June, 1S83, will be ready in a few days, price 73. 6d. The Title Page and Indei to Volume III. is now Binding Cases for Volume III., price 2s. each, (including Title, Index, and Case) for 3s. each. The publishers have a few copies of Knowledge No. 1 at Sd. each, post-free. ady, price 2d., post-free, 2\A. Subscribers' numbers bound TERMS OF SUBSCRIPTION. The terms of Annaal Subscriptien to the weekly ntimbers of KirowuiDei are as followfl:— s. c. To anv addresa in tbe Ufiited Kingdom 10 10 Te the Continent, Australia, New Zealand, South Africa & Canada 13 0 To the United States of America ^.26. or 13 0 To the East Indies, China, kc. {via Brindisi) 16 2 AJl subscriptions are payable in advance. P. O. Orders and cheques should be made payable to the Publishers, Mkssbs. WrMAH & SoHB, London, at the High Holbom District Poet-oflSce. Agent for America — C. 8. Carter, American Literary Bureau, Tribune Buildings, New York, to whom subscriptions can be forwarded. OFFICE : 74-76, GREAT QUEEN STREET, LONDON, W.C. Aug. 3, 1883.] ♦ KNOWLEDGE ♦ 05 ^^^f^^^^?*^ AN li^miRATED MAGAZINE ofB^ENCB LONDON : FRIDAY, AUG. 3, 1883. Contents of No. 92. P\GE A Naturalist 's Year. Wasps and Flowers. By Grant Allen 63 The Moralit)- of Happiness : Con- duct and Duty. By Thos. Foster 66 The Chemistry of Cookery. XIV. BvW. Mattieu "WiUiams 67 Pretty Proof of the Earth's Botun- dity. (///««). By E. A. Proctor . 68 How to Get Strong 70 Pleasant Hours with the Microscope. (/Has.) ByH. J. Slack 71 Niagara. Illlns.) By E. A. Proctor. 72 Laws of Brirhtness. VII 71 Discovery of the Chief Division in Saturn's King. Bv Capt. Noble ... 75 The Face of the Sky. By F.E.A.S. 77 Paradox Column : A New Theory of Copernicus 77 Correspondence 77 Our Mathematical Column : Geome- trical Problems. X 78 Our Cheas Column 79 A NATURALIST'S YEAR. By Grant Allen. XVIII.— WASPS AND FLOWERS. ON the very summit of the wind-swept heath, scarcely sheltered from the north by a ragged row of straggling Scotch tirs, a colony of broom manages somehow to battle hard for life against wind and weather, while on its roots the fat tuberous stems of the greater broomrape have fastened themselves vigorously to suck out whatever little sap the poor drained plants can spare, with all the ruthless, leech-like greediness of born parasites. Broom- rape, we call the withered brown weed, in fact, in good old English, for this very reason, because it roots itself firmly on the underground stem of the broom, and violates or plunders it till almost nothing is left of it but bark and wood. It is a tall, wilted-looking thing, this broomrape, so dry, and grey, and faded, that you would hardly take it at lirst sight for a living flower at all ; you would be much more likely to pass it by unnoticed as a sere and withered stalk covered with last year's empty seed- vessels. If you look at it closely, however, you will see that, though it is almost leafless, like most other thoroughgoing plant-parasites (having only thin stem-scales instead of green foliage) it is, nevertheless, a fresh, vigorous, and succulent living spike of dingy blossoms. At this moment, the spikes are all surroundeti by belted black and yellow wasps, whom I have often seen hovering before around the dull flowers ; for greater broomrape is a wasp-fertilised plant, though the fact seems to have escaped the observant eye even of that most patient and careful of German naturalists, Hermann Midler. Everybody knows, of course, the close connection that exists between bees and flowers ; but I don't think most jicople are aware that there are a few exceptional plants which depend almost entirely upon wasps for the due conveyance of their pollen from head to liead ; so perhaps 1 can't do better than take this ding)' brown broomrape for the text of a short discourse on this very subject, and point out how far tlu! peculiar a-sthetic tastes of the omnivorous wasps have reacted upon the special ilowors on which they have concentrated their unconscious botanical efl'orta. Wasps, as we have all observed, are very promiscuous feeders. They will eat almost anything they can get, from a good piece of raw beef to a plum or a potato. Hence, like most other promiscuous feeders, they have not acquired any marked taste for beauty of form or colour. As a rule, in the animal world, love of colour is found only among those l)irds cir insects which restrict themselves entirely to honey-sucking in brilliant blossoms or to eating equally brilliant fruits. On the other hand, wasps are not wholly devoid of the flower-haunting habit ; for they are very fond of sugar and all other sweets, as we have often noted both in grocers' shops and at our own dessert. So they seek for honey in a few special and peculiar blossoms, which have thus been compelled to adapt themselves to the very low tastes of the.se uncanny insect allies. Bees are fond of flowers with long tubes, which preser\e the nectar from other thieving species; and in order to allure their fastidious eyes, such blossoms have acquired brilliant tints of purple, blue, or crimson, which are very attractive to the honey- loving aristocrats of the insect world. But the wasps care nothing for such beautiful a>sthetio displays ; they are strictly practical insects, with a decided eye to material advantages, and all they ask is that the flowers they patronise should not play at fox and stork with them, by concealing their nectar at the bottom of a long and narrow tube. Wasp blossoms, in short, must have shallow, open, cup-shaped corollas, just liig enough to lit the insect's head, and with abundant honey so disposed that it can be readily abstracted without much trouble by the vespine mouth. They need not be liright^coloured ; indeed, brightness of colour, by attracting other insects which are less adapted for fertilising them, would prove actually disadvantageous to the species ; so as a class they are the very dingiest and dullest of known flowers, being specially modified, as has been quaintly said, " to suit the wants of an insect circle possessing very uncultivated ,i>sthetic tastes." You could not have a better example of the group than that afforded us by this brown and dry-looking greater broomrape. It is inconspicuous enough to keep away all other insects ; and those few venturesome flies that do venture near it, allured by the smell of honey, are sure to be quickly driven off by the sharp jaws and deadly stings of its natural possessors, the wasps. We have not very many native wasp-flowers in England, but what few we have are quite sufficient to give us a very good general idea of the eti'ects produced by such very special and exceptional selection. The commonest among them are the two fig-worts or scrophularias, which grow abundantly by the water's side. These very odd and un canny blossoms are shaped so as just to form a hood or helmet for the wasp's head ; and when he inserts his mouth into the flower, he rubs the pollen from the stamens last visited on to the forked and bent stigma with un- erring certainty. In colour, the corolla of the fig-worts is an indescribable dirty olive brown, with a toucli of chocolate red and green in it, not at all pretty, but extremely queer and noticeable. You can't stand by the side of one for five minutes without seeing it visited by at least one wasp, and on bright, sunny mornings you are pretty sure to see half-a-dozen. Another somewhat rarer English wasp- flower is the broad-leaved epipactis, an orchid growing in shady places, and not infrequent on the outskirts of moor- land farms. In colour, it is almost the same dingy purplish- green as the fig-worts, and it is arranged so as to form a very similar hond-shaped cap, just fitting the wasp's head. So far as family goes, these two weeds are as wide apart as any two flowering plants can possibly be, for the one is a very advanced monocotyledon, while the other is a highly- moditied type of dicotyledon ; but their adaptive peculiari- 66 - KNOWLEDGE ♦ [Aug. 3, 1883. ties, developed by the selective action of the same wasps, are almost exactly similar. On the other hand, we have in England a second epipactis, confined to marshy situa- tions, and in all essential particulars practically identical with the liroad-leaved species ; but it is fertilised by the honey bee, by certain flies, and by some other colour-loving insects, and therefore, instead of being dull purple or brown, it is prettily variegated with pink and white — being, in fact, one of our daintiest and most beautiful native orchids. This case admirably exemplifies the powerful influence of the insect guests on such easily-modified points as colour and dappling. Another wasp - flower which, though not exactly British, has been planted in our shrubberies and borders till it has become practically naturalised, is the snowberry, whose small, round, bell-shaped blossoms and pulpy white fruit are familiar to everybody. By descent the snowberry is a member of the honeysuckle family ; but it has acquired the habit of being fertilised mainly by wasps, and it has adapted itself accordingly to their needs and requirements. Instead of a narrow deep tube like the true honeysuckle, be- loved by long - tongued humming - bird hawk - moths, it has got a short, shallow, goblet - shaped corolla, exactly fitted for the accommodation of a wasp's head. In colour the flower is rather pinkier and prettier than the figworts or the greater broomrape, but then it is also more dependent for occasional chances \ipon other colour-loving insects. It has not yet completely specialised itself for wasps alone, and in some places it is almost equally visited by hive-bees. Lastly, I must not forget to mention the most famous wasp-flower of all, that of the edible fig, whose fruits cannot be properly set without the intervention of a closely-correlated insect ally, known as the fig-wasp. Figs are practically what is called in the technical language of botany, ditccious — that is to say, the stamen-bearing and seed-bearing flowers grow separately on distinct trees, for the female flowers are abortive in some cases, and the male ones in others. Only the female, or fruit^producing trees, are cultivated. The wild caprifico of Italy supplies the complementary males. The fig-wasps lay their eggs in the fruit of the caprifico, and there the young hatch out. Then the peasants hang the caprifico fruits on the fig-tree, so that the wasps, on flying out covered with pollen, may at once enter the yoimg figs. The whole history of these wasps and the figs which they impregnate is a marvellously interesting one, but it is too long and far too complicated to enter into at full length here. It must suffice to note that the fig inflorescence is just as dingy green or dull purple as all the other known THE MOKALITY OF HAPPINESS.* By Thomas Foster, conduct and duty. MORALITY relates to those parts of our conduct of which it can be said that they are right or -wTong. Under the general subject conduct, then, morality is in- cluded as a part. Or regarding the word " duty " as implying all that we ought to do and all that we ought to avoid, we may say that duty is a part of conduct. All actions which are not purposeless may be regarded as included under the word " conduct," as well as some " * I remind the reader tliat in these papers, as stated in the intro- ductory one, I am followinf; the lines along which Mr. Herbert Spencer has alre.-sdy traced the general doctrine of the morality of happiness. Where his reasoning seems open to objection or too which, though purposeless at the time, result from actions originally done with purpose until a fixed habit had been acquired. But only those actions which we consider good or bad are referred to when we speak of duty ; and the principles of what we call morality relate only to these. Here, however, we have already recognised a connection between duty and conduct generally, which should show all who are familiar with scientific methods that morality cannot properly be discussed in its scientific aspect without discussing conduct at large. Every student of science knows that rightly to consider a part, he must consider the whole to which it belongs. In every department of science this general law holds, though it is not always recognised. No scientific subject has ever been properly dealt with until it has been considered in its relations to its surroundings as well as separately. Even in matters not usually considered from a scientific standpoint the same law holds. To go no farther than our own pages, the writer who is dealing with the question " How to get strong ? " would not consider how the arms are to be strengthened without duly considering that the arms are part of the body, their exercise related to the exercise of other portions, their development associated with the de- velopment of other limbs, with the action of other parts of the body, with the regimen proper for the whole frame. It may not by many be regarded as a fault of most systems of morality, that they overlook the necessarj' con- nection between conduct in general and conduct as guided by moral considerations. For, many are content to regard moral laws as existing apart from any of the results of experience — whether derived from individual conduct, the conduct of men generally, or conduct as seen among creattu"es of all orders. With many, morality is looked upon as a whole, — the wliole duty of man — not as a part of conduct. They even consider that moral obligations must be weakened when their dependence on conduct in general is insisted upon. Moral rules, with them, are right in themselves and of necessity — and whether inculcated by extra-human authority, or enjoined by law, or perceived intuitively, are open neither to inquiry nor objection. Clearly if this were so, morality would not be a fitting subject for the scientific method. Its rules would be determinable apart from the discussion of evidence based on experience whether observational or experimental. I do not here inquire whether this view is right or wrong. Later on it will fall into my plan to do so. At present I only note that we are considering our subject from the standpoint of those who desire to view morality in its scientific aspect. For them it is essential that as conduct in general includes conduct depending on duty, the discussion of questions of duty cannot be complete or satisfactory unless it is con- ducted with due reference to the whole of which this subject forms a part. If any doubt could exist in the mind of the student on this point, it should be removed when he notes that it is impossible to draw any sharply defined line between duty and the rest of conduct not depending on considerations recondite to be quite readily followed, I shall indicate such objections, and my own opinion respecting them, or endeavour to remove such difficulties, but the moral doctrine I am here dealing with is that of which he has been the chief teacher, if he may not be regarded as its only founder. Even if the scientific study of Ethics, on principles analogous to those which have made astro- nomy, geology, and more recently biology, true sciences, has been taken up by others and pursued till new truths have been recognised and perhaps some errors pointed out in his treatment of it, it remains still true that he was the first to indicate the true scientific method, and to show where hitherto it had been departed from even by the founders of the school of philosophy to which he belongs. Aug. 3, 1883.] ♦ KNOWLEDGE ♦ 67 of duty. Not only are those actions which under par- ticular circumstances seem absolutely indiii'erent ound under other circumstances to be right or wrong and not indifferent, not only do different persons form different ideas as to what part of conduct is indifferent or other- wise, but one and the same person in different parts of his life finds that he draws different distinctions between conduct in general and conduct to ,be guided by moral con- siderations. In the evolution of conduct in a nation, in a town, in a family, or in the individual man, the line separat- ing conduct regarded as indifferent from conduct regarded as right or wrong, is ever varying in position, — sometimes tending to include among actions indifferent those which had been judged bad or good, oftener tending to show right or wrong in conduct which had been judged indifferent. If moral laws, then, are to be established on a scientific basis, it is essential that conduct at large should be care- fully considered ; and not conduct only as it is seen in man, but as it is seen in animals of every grade. Thus and thus only can the evolution of conduct be rightly studied ; by the study of the evolution of conduct only can the scientific distinction between right and wrong be recognised ; from and out of this distinction only can moral laws be estab- lished for those with whom the authoritative enunciation of such laws has no longer the weight it once had, those who find no other inherent force in moral statutes than they derive as resulting from experience, and who reject as unreasonable all belief in the intuitive recognition of laws of morality. We proceed then to consider the evolution of conduct in the various types of animal life from the lowest upwards to man. THE CHEMISTRY OF COOKERY. xiv. By W. Mattieu Williams. BEFORE leaving the subject of caramel, I should say a few words about French coffee, or " Coffee as in France," of which we hear so much. There are two secrets upon which depend the excellence of our neighbours in the production of this beverage. First, economy in using the water ; second, flavouring with caramel. As regards the first, it appears that English housewives have been de- moralised by the habitual use of tea, and apply to the infusion of coffee the popular formula for that of tea, " a spoonful for each person and one for the pot." The French after-dinner coffee-cup has about one-third of the liquid capacity of a full-sized English breakfast-cup, but the quantity of solid coffee supplied to each cupfull is more than equal to that ordinarily allowed for the larger English measure of water. Besides this the coffee is commonly, though not uni- versally, flavoured with a specially and skilfully-prepared caramel, instead of the chicory so largely used in England. Much of the .so-called " French coft'ee " now sold by our grocers Ln tins is caramel flavoured with coffee rather than coffee flavoured with caramel, and many shrewd English housewives have discovered that by mixing the cheapest of these French coffees with an equal quantity of pure coftee they obtain a better result than with the common domestic mixture of three parts coffee and one of chicory. A few montlis ago a sample of " coffee-finings " was sent to me for chemical examination, that I might certify to its composition and wholesomeness. I described it in my report as " a caramel, with a peculiarly rich aroma and flavour, evidently due to the vegetable juices or ex- tractive matter naturally united with the saccharine sub- stance from which it is prepared." I had no definite information of the exact nature of this saccharine substance, but have good reason to assume that it was a bye product of sugar refining. Neither the juice of the beetroot nor the sap of the sugar-cane consists entirely of pure sugar dissolved in pure water. They both contain other constituents common to vegetable juices, and some peculiar to themselves. These mucilaginous matters, when roughly separated, carry down with them some sugar, and form a sort of coarse sweetwort, capable by skilful treatment of producing a rich caramel such as I received. I tested its practical*, merits by making an infusion of pure coffee of fine quality, dividing this into two parts, adding to one a small quantity of the caramel, and leaving the other half unmixed. I found the infusion greatly im- proved in flavour by the admixture, and recognised the peculiarity which characterises the coffee prepared by Gatti and his compatriots, whose numerous establishments are doing so much for the promotion of temperance in this country. The aroma of this particular caramel is peculiarly fine, and the greater part of it is soluble in boiling water ; thus I was able to mix it by merely adding to the coffee as we add sugar. I have used my best eloquence in trying to persuade the manufacturers to sell it separately, but have not yet suc- ceeded. They seem to have had painful experience of the gastronomic bigotry of Englishmen who refuse to eat or drink anything that is not hallowed by the sanction of their great-grandmothers, unless it is surreptitiously introduced by means of some device approaching as nearly as possible to a commercial swindle. Returning to the subject of frying, we encounter a good illustration of the practical importance of sound theory. A great deal of fish and other kinds of food are badly and wastefully cooked in consequence of the prevalence of a false theory of frying. It is evident that many domestic cooks (not hotel or restaurant cooks) have a vague idea that the metal plate forming the bottom of the frying-pan should directly convey the heat of the fire to the fried sub- stance, and that the bit of butter or lard or dripping put into the pan is used to prevent the fish from sticking to it or to add to the richness of the fish by smearing its sur- face. The theory which I have suggested (see No. 13, page 2) is that the melted fat cooks by convection of heat, just as water does in the so-called boiling of meat If that is correct, it is evident that the fish, iVrc, should be completely immersed in a bath of melted fat or oil, and that the turn- ing over demanded by the greased-plate theory is unneces- sary. Well educated cooks imderstand this distinctly, and use a deeper vessel than our common frying-pan, charge this with a quantity of fat sufficient to cover the fish, which is simply laid upon a wire support, or frying-basket, and left in the hot fat until the browning of its surface, or of the flour or bread-crumbs with which it is coated indi- cates the sufficiency of the cookery. At first sight this appears extravagant, as compai-ed \y\th. the practice of greasing the bottom of the pan with a little dab of fat, but any housewife who will apply to the frying of sprats, herrings, itc, the method of quantitative induc- tive research, described and advocated by Lord Bacon in his " Novum Organum Scientarum," she may prove the contrary. " Must I read the ' Novum Organum,' and buy another dictionary, in order to translate all this," she may exclaim in despair. "No !" is mj' reply. This Baconian inductive method, to which we arc indebted for all the triumphs of 68 ♦ KNOWLEDGE ♦ [Aug. 3, 1883. modern science, is nothing more nor less than the systematic and orderly application of common sense and definite mea- surement to practical questions. In this case it may be applied simply by frying a weighed quantity of any par- ticular kind of fish — say sprats — in a weighed quantity of fat used as a bath ; then weighing the fat that remains and subtracting the latter weight from the first, to determine the quantity consumed. If the frying be properly per- formed, and this quantity compared with that which is consumed by the method of merely greasing the pan- bottum, the bath frying will be proved to be the more economical, as well as the more efficient method. The reason of this is simply that much or all of the fat is liui'nt and wasted when only a thin film is spread on the bottom of the pan, while no such waste occurs when the bath of fat is properly used. The temperature at which the dissociation of fat commences is below that required for delicately browning the surface of the fish itself, or of the tiour or breadcrumbs, and therefore no fat is burnt away from the bath, as it is by the overheated portions of a merely greased frying-pan, and as regards the quantity ad- hering to the fish itself, this may be reduced to a minimum by withdrawing it from the bath when the whole is uni- formly at the maximum cooking temperature, and allowing the fluid fat to drain off at once. When cooked on the greased plate, one side is necessarily cooling, and the fat settling down into the fish, while the other is being heated from below. PRETTY PROOFS OF THE EARTH'S ROTUNDITY. CHIEFLY FOR THE SEASIDE. By Richard A. Proctor. ALTHOUGH I suppose none of the readers of Know- ledge entertain any manner of doubt as to the rotundity of the earth, it is not unlikely I think that some will find the illustrations or proofs of that rotundity which I propose to describe in this and a few following papers, somewhat novel. They have occurred to me during my residence at the seaside in former years and recently, and during my travels over prairie levels in North America, and so far as I know have not as yet found a place in text^tooks of astronomy. Just now when many readers of Knowledge are at the seaside these methods or some of them will be found especially interesting, since the sea-surface constantly illustrates terrestrial rotundity. Let me premise that as commonly presented in works on astronomy the proof of rotundity afibrded by the appear- ance of ships as they pass over the horizon limit and beyond, is apt to introduce a serious difiiculty, though sound enough in itself. We are shown in a picture entirely out of proportion, a roimd hill of water over the top of which a line of sight is carried from an observer as at A, Fig. 1, a departing ship being shown in several posi- tions as at 1, 2, 3, 4, fully seen at 1 and 2, hull down The bath-frying, of course, demands separate supplies of fat — one for fish, another for cutlets and other similar kinds of meat, a third for such goody-goodies as apple- fritters — a most wholesome and delicious dish, too rarely seen on English tables. I suspect that the prevalence of the greased frying-pan is the reason of its rarity. Cooked by this barbaric device, apples are scarcely eatable, but when thin slices are immersed in a bath of melted fat at a temperature of about 300° F., the water of their juice is suddenly boiled, and as this water is contained in a mul- titude of little bladder-like cells, they all burst, and the whole structure is pufted out to a most delicate lightness, far more suitable for following solid meats than soddened fruit enveloped in heavy indigestible pudding - paste. Another advantage is that with proper apparatus (wire basket, stew-pan, and store of special fat) the fritters can be prepared and cooked in about one-tenth of the time demanded for the preparation and cookery of an apple pudding or pie. A few seconds of immersion in the fat- bath is sufficient. But the fat that has been used several times requires purification. This is especially the case with that devoted to fish-frying. The purification of fat is an important and interesting process that I will endeavour to treat as simply as may be in my next. *^* There is no Editorial Gossip this week for the reason that the Editor's medical adviser recommends cessation for the present from all work not absolutely necessary. at 3, and showing upper part of mast only at 4 to the spectator at A. In such pictures the depression of the line of sight Aa touching the convexity of the water, or the angle aAt which it makes with the horizontal line At, is so considerable as to be obvious. Now the student is thus taught two things, — one true the other untrue. He learns correctly enough how and why a ship disappears beyond the convexity of the sea ; but he is also taught what is not correct, viz. that the sea horizon dips obser- vably below the true horizon, and that the depression of the sea horizon becomes obviously greater as the observer's height above the sea-level increases. When the learner is next at the sea-side and notes that there is no such visible depression, nay that when he is a good deal above the sea- level the sea horizon appears (by an optical illusion, indeed, but still very strikingly) higher than when he stood on the seashore, he is apt to think he has been wrongly taught on the other point also. It was in this way indeed that the small but lively sect of flat-earth men were deceived by the man who under the pseudonym Parallax has borne — for reasons best known to himself — three surnames of more familiar sound, and to this day the peculiarity in question is the one Ijy which his followers are deluded. It cropped up in the notorious Bedford Level experiment by which the wager respecting the rotundity of the earth was decided ; and I fancy that to this day, on the strength of this misleading peculiarity the loser of that foolish wager considers that he was most hardly dealt with. The experiment actually made on that Aug. 3, 1883.] ♦ KNOWLEDGE 69 occasion was neat and decisive enough ; and bf/ore the experiment I have not a doubt the loser thought the trial could have but one result. It may serve as one among the " pretty proofs " now to be dealt with, while the de- lusive experiment which the loser wished to substitute after the matter was settled may also be considered with advantage. On the Bedford level, where there is a water surface without bend for more than twenty miles, are two bridges as at A and C in Figs. 2 and 3, six miles apart, the water surface between them extending straight from A to C. Supposing the earth's surface plane the straight line ABC (Fig. 2) will correctly represent this water sur- face. On the other hand if the earth's surface is globular, ABC will be an arc of a large circle as in Fig. 3, the straight line A C falling as A h C. Now at A a telescope was set up as at i, At being a given length, say 10 ft. (it really matters not what the length so that the same lengths were used at all the stations). At B midway between A and C a pole of the It is clear then that the test is a very simple and ob\dous one. For supposing we have a disc 1 ft. in diameter at b, and a disc 2 ft. in diameter at c, so that seen from t both look equally large, it is obvious that the centre of the disc c will be seen 6 ft. below the centre of the disc b, or the appearance presented will be as at Fig. 4, the distance ey' being five times ody is punished. One can get rid of fat and other mischiefs without punisliing the system. I would advise those who have fallen into the evil habit of sleeping in the afternoon, to resist each day for a time the heaviness which comes over them at the hour when they are accustomed to sleep. When the effort becomes painful, let them, instead of lying on a sofa or bed, sit comfortably in an arm-chair, loosing collar, cravat, and wristbands (also if necessary the waistband). Then let them sleep for about halfan-hour. I don't mean that they should give folk instruction to waken them, but that they should mentally resolve as they yield to the influence of sleep that it shall be but for half-an-hour or so. Without being wakened they will wake within a few minutes of the time. At least it will be so before long. Then let them stroll to bedroom or lavatory and repeat the face-plunging process as in the morning performance. They will be wide awake, yet all the better for the sleep. As time progresses the sleeping time may be shortened, and probably before long the afternoon nap altogether discarded. It will be found that the change of diet both in quantity and quality suggested in our last will greatly help in giving mastery over sleep, especially over afternoon sleep. The active exercise advised in what follows may at first encourage the desire for sleep ; but not long. By helping to make sleep sounder it will rather tend to shorten the sleeping hours in the long run. We consider next, however, not exercise, but the treat- ment of the skin, on the condition of which the value of exercise in great part depends. Probably there is no surer and sounder system of fat reduction than that which is based on due encouragement of the healthy action of the skin. {To be continued.) Sun-Spots.— Mr. Slack writes that on the 22nd ult. [his letter was unfortunately forwarded to Ventnor, where, in consequence of a railway accident, the Editor was unable to go], in the afternoon, the sun's disk presented an extraordinary appearance; a succession of spots stretched nearly across it, most of them exliibiting a mul- tiplicity of nuclei. There were also three spots isolated from the groups. With such a prodigious line of disturbance, any action which the spot condition may have upon the weather might be expected to be strongly marked. Adc. 3, 1883.] ♦ KNOWLEDGE ♦ 71 PLEASANT HOURS WITH THE MICROSCOPE. By Henry J. Slack, F.G.S., F.R.M.S. IT is very common for persons unacquainted with en- tomology to suppose all the flies of somewhat similar aspect seen on a window-pane are the same sort ; the big ones being taken for the grandfathers and grandmothers, and the least for their baby grandchildren. All insects, however, that pass through transformations such as common flies and butterflies do, reach their full size when they emerge from the chrysalis, and do not grow afterwards. Another common mistake is often made towards autumn, when " the flies " are accused of biting, the words implying a belief that the common house-fly gets vicious, or goes mad about that time of the year, which is not the case. Everybody must have noticed that when a house-fly settles upon any substance to feed, it puts forth a horse's head- like proboscis. This is a most wonderful apparatus, and a good way of commencing acquaintance with it is to assist at a bluebottle's dinner. To accomplish this, tirst catch your bluebottle and keep him under a pill-box or a wine- glass till his meal is ready. To prepare it, crush a bit of loaf sugar the size of a pin's head in a droplet of water. Take a little of the syrup thus made upon the end of a bit of wood — a lucifer match is just the thing — and smear it on the inner side of the glass cover of the live-box opticians usually supply with a microscope. Put the bluebottle upon it, and quickly shut him up by pressing the live-box into the rim of its cover, leaving the fly no room to turn over, but not squeezing him. The box is then placed on the microscope stage and the fly has his under side upper- most. It will soon begin to suck the syrup. The proboscis comes ovit of a cavernous cleft, the horse's-head end of it opens like two lips, which press against the glass, and the fluid is rapidly swallowed. If it is too thick, the fly can moisten and thin it. It can only swallow fluids, and the wonderful collection of tubes kept open by series of incomplete rings of a hard material act as filters to keep solid particles out. It would take a volume to describe the details of this wonderful apparatus, and no drawings can be made efiicient substitutes for seeing the thing itself. The student should dissect such oVijects with needles set in wooden handles, fine scissors, and a fine, thin-bladed knife. It is also well to buy two slides made !)y a skilful preparer ; one with the proboscis flattened out in the common way, and another mounted in fluid, and not squeezed out of its true shape. The insects can be fed with syrup tinged with cochineal, and the motion of it better seen. No examination of the house-fly or blow-fly will detect any apparatus adapted for biting or piercing a hard substance. In the middle of the proboscis are some teeth fit for scraping a material like moistened sugar, but no saws or lancets, or even knives capable of cutting. On a hot day in the country, especially near cattle or horses, flies something like bluebottles and house-flies, but with elegantly-mottled wings and splendid green and bronze eyes, are sure to be found. These will take any opportunity of exercising their skill upon the hands or faces of human beings. They are furnished with a pro- boscis similar to that of the house-fly or bluebottle, and use it in the sam(! way, but their delight is to suck the blood of the animal th(!y torment, and to get at it they have tools to pierce a tough skin. If one of these flies is iiold in the hand by the wings, and the proboscis is gently poked with a finger-tip, some sharp tools will come out of a fold in its upper side. The males have four, and the females six implements. The latter will be found to possess a pair of Fig. 1, and another pair of Fig. 2, and one each of Figs. 3 and i, which are pressed together to form a tube. A power of about 25 linear, obtained with an inch and a-half objective, will show the bluebottle at his dinner, and be sufiicient to exhibit the form of the knives, &c.,of the breeze-fly. A much higher magnification, say 500 linear, shows that an instrument (Fig. Irt), shaped like a carving-knife, or sword-bayonet, has its edge very fine and sharp, and the back, for more than half its length, very finely serrated, with the teeth set downwards. As it is pulled back out of a wound it would both enlarge and irritate it. The next tool (Fig. 2a) has teeth much like those of a coarse rasp, such as is used upon wood. This can act quickly upon the-hides of an animal, and the great central tubular organ has teeth at the top, which a move- ment of partial rotation backwards and forwards must make a good piercer like a drill. liMmimiiliify^ m{ji},^ I §i liijijji Fig. la, X 500. Fig. 3a, X 500. All these instruments should be teased out with needles, and mounted in Canada Balsam. A fly's head, with these organs simply extended, should also be kept as an opaque object. Unfortunately the splendid eyes do not retain their colour, but while fresh are singularly beautiful when strongly illuminated. To see the bluebottle using his proboscis or trunk, it must be lit up from above. A Lieberkuhn acts well, or a side silver reflector. Beck's is an excellent pattern ; but th(! ordinary form answers well, and best if it is mounted on its own sliding stand and not made to fix on the micro- scope. Few spectacles are more astonishing than the quick nervous agitation with which the great lips open and shut, and the vigour with which they work. • KNOWLEDGE ♦ [Aug. 3, 1883. The mouths of tliese Hies exhibit remarkable departures from the most typical insect pattern, but the comparative anatomist regards their peculiar organs as modifications of simpler forms. Their mouths are called " autliate, with a fleshy proboscis (labium, or lip), and enclosing several lancet-like organs," so says Westwood of the Diptera in general, but it is only in certain genera that these lancet organs are adapted to hard work. It is instructive to compare the gnat's lancets and saws with tliose of the breeze-flies (Taoaiii), whose instruments are here figured, and their proboscis with the longer, and in every respect different one of the butterfly and moth. The most for- midable of our insect enemies belong to the diptera, as that great group embraces mosquitoes, blowflies, breeze-flies, gad-flies, etc., in this country, and also the terrible zimb, and the still more dreadful tsetse, whose bite produces a fatal disease in the horse, ox, sheep, or dog. The modifications of mouth organs in various insects suggests a great lapse of time for their formation by the slow process of descent with modification, and the action of such a fly as the tsetse affords a striking instance of the immense series of changes that may spring from the peculiarities of one small creature. Take away all the animals which the tsetse will not allow to live, and not only is a great country rendered comparatively useless to man, but its vegetation must be different in many parti- culars from that cropped by herbivora, and manured by their excrements. The poison of the tsetse is very injurious to man, but not nearly so much as to the animals he most needs. Three or four of them are said to kill an ox, and yet the weight of the poison-drops they pour into their \-ictim must lie quite infinitesimal. The breeze-flies are not poisonous, but they sometimes attack human beings after their apparatus has been dipt in decomposing filth, and then serious sores result. NIAGARA. By Richard A. Proctor. THE brave man who earned a world-wide fame by swimming Dover Straits and had earlier won an even nobler name by plunging into the Atlantic Ocean during storm to save (if so might be) a fellow creature's life, has cast himself a prey to the remorseless wa'ers of Niagara. We cannot now, in the pain and horror excited by the terrible end of his mad attempt, speak as perhaps the stern moralist might speak, of the wrong Webb did his name and fame, the false example he set, by this last use of his splendid courage. We may well believe that he overrated his powers, and underrated (it would be impossible to overrate) the tremendous forces against which he proposed to contend. He maybe did not know, what a rough estimate of the energies at work in Niagara should have shown, that amid that mass of water which descends from the basin below the Falls to the engulfing vortex of the Whirlpool, the body of the biggest and strongest living creature must be as powerless as a drop of water in mid- Atlantic. We may well hope and believe that no weariness of the work of life led him to barter life, or ninety -nine hundredths of his life - chances, against the money by which those dependent on him might live in comfort. We learn that the American railway companies were guiltless, at the last at any rate, of the foul conduct imputed to them ; and we may well hope that whatever was said of the sums Webb expected in reward of his exploit, he himself was moved only by the excitement of a contest with forces which other men deemed insuperable, but which he hoped to overcome. Let undue daring be held the only fault in the brave man we have lost. His example, so judged, though not free from blemish, will do little harm, compared at least with what it might have done had fear of life work moved him to his final exploit. Remembering that in his first and noblest achievement he was moved by no hope of gain or even of glory we may well believe that not ignoble thoughts but a lofty though unwise ambition stirred him to attempt the hopeless contest with Niagara in which his brave life was lost. Lest others, fascinated as he seems to have been by the- awful majesty of Niagara, should underrate the fearful power of the forces at work along the course hj which the waters of Erie pass to Ontario, or deem that with better luck the Whirlpool Rapids might yet Vie passed with life — I venture to say a few brief words here about this marvel of nature. Fig. 1.— THE NIAGARA FALLS, RAPIDS, ANli WlIIKLrMi IL. The map (Fig. 1) shows the position of the Falls (tlie Horse-Shoe on the left the American on the right facing directly towards the west), the Whirlpool, and the Rapids, — the Upper Rapids between Iris Island and French Landing, the Lower Rapids between the Suspension Bridge Aug. 3, 1883.] ► KNOWLEDGE ♦ 73 and the Whirlpool, the Whirlpool Rapids being those just above the Whirlpool itself. Fig. 2 shows in section, enor- mously exaggerated vertically, the descent from Lake Huron to Lake Ontario, — the River Niagara (Falls, Rapids, Whirl- pool, and the quieter parts) being all compressed in this figure in the narrow space shown between Lake Erie and Lake Ontario. Niagara is wonderful in this that here we have brought before us within a limited space the action of forces usually at work over a far wider area. In comparison with the forces of Nature actually at work in the earth, even during a single hour, the work done at Niagara in many years is almost as nothing. A small quantity of the waters gathered from the higher regions of a small portion of Northern America finds here an outlet, and passes from a level^ of no great height, by comparison with the elevation of even the smallest mountain ranges, to a height still considerably above the sea-level. Yet thence to solar forces before which tlie whole might of earth is as nothing, and onwards to the starry depths wliere every point of light is such a sun as ours, until in the black darkness which hides from our eyes the real glories of the universe we recognise the mystery of Infinite ilight unknown and unknowable : Lo ! these are but a portion of God's ways : they utter but a whisper of His glory ; the thunder of His power who can understand 'i Professor Tyndall writes as follows in the Daily ^eio» : — " The ' rapids ' proper of Niagara occur above the fall, where for a mile or so the water comes galloping and tumbling down before it.takes its final leap over the ledge of the cataract. Below the cataract the river flows through a deep gorge, which has been excavated by the river. At some distance down there is a ferry between the American and the Canadian sides. Lower still is a suspension bridge for foot passengers, while about two miles below the fall Hypotenuse of the Trian^lelSOOl^esZon^ Section froTTh Tide Waler to LaJccBicroTh Fig. 2.— WATER SLOPE FROM LAKE HURON TO THE SEA. because the range of distance within which the descent is accomplished is small, we have a display of nature's energies which impresses, even appals, the thoughtful mind, by presenting concrete e%-idence of the action of a force of whose might we have usually but abstract indications. To shallow minds Niagara is naturally disappointing, because they cannot even liegin to comprehend its significance. To a dull mind the Atlantic and the Andes, the earthquake and the hurricane, are disappointing, — impressing it little more than they would impress a horse or a dog. But the mind which knows something of the language in whicli Niagara speaks, finds awful, almost oppressive, teaching in the thought that this work which goes on amid deafening uproar and confusing tumult represents not a millionth part of the energies residing in terrestrial gravity, — the force which our mother earth ordinarily uses as if but in play. Here its grim might is seen, and all the more impressively since we know that while it is but the merest nothing of the earth's force which is at work before us, yet we are overwhelmed by its vehemence, powerless in its presence. ^^'hen the real energies of Niagara have been recognised, and the relation between these energies and the might of terrestrial gravity is understood, the mind must needs bo awed, even oppressed, by the stupendous significance of Niagara. We pass from the grandeur of the scene displayed before us to the infi- nitely mightier terrestrial energies of which it speaks. the river is spanned by the railway suspension bridge. Between the ferry and this bridge, the river Niagara flows unruffled, but below the suspension bridge the gorge narrows, and the rapidity and turbulence of the water increase. For a certain distance the width can hardly be more than three hundred feet ; and here occur what are called the ' Whirlpool Rapids,' which are not to be confounded with the rapids above the fall. It was through the Whirlpool Rapids that poor Captain Webb had to steer his way. It is impossible to describe the wild fury of the waters at this place. I send for your inspection a photograph by Bierstadt, which will give you some notion of it. The river boils and leaps in the most frantic manner, the most extraordinary effect being pro- duced when two waves so coalesce that the united forces of both run on and toss the crest of the compounded billow, shivered into liquid spherules, high in air. In the middle of the river no man could live, and we are informed that Captain Webb avoided the middle. But the tossing everywhere is terrific. Lower down the river suddenly liends nearly at a right angle, and here is formed the whirlpool from which the Lower Rapids derive their name. The river strikes the bank opposed to it with tremendous force, and is thereby thrown into gyratory motion. Here, it is said. Captain Webb lost liis life. I do not think a powerful swimmer, with his wits about him, need have come to grief in the Whirlpool itself. But how any man could have kept his senses intact amid the battering and tossing of the 74 ♦ KNOWLEDGE ♦ [Aug. 3, 1883. Whirlpool Rapids it is difficult to imagine. It was pro- bably the exhaustion of his power among the rapids that rendered the mighty swimmer unable to escape from the whirlpool. We shall doubtless receive the accurate account of the catastrophe in due time ; meanwhile, the recitals in the English newspapers being more or less confused, I thought an approximately accurate description of the scene of the disaster might be of some interest." Before the event, I wrote as follows in the Neiecastle WeeMij Chronicle : — " Captain Webb is more fitted than most men to battle with surging waves, more practised to maintain such actions as may give him the best chance of safety ; but if he escapes his escape must depend on a lucky chance causing his body — neces- sarily inert to all intents and purposes throughout the beginning of his course — to be carried towards the whirlpool on the least dangerous course, and to be brought under the surface only at intervals enabling him to breathe. No one who has seen the Lower Rapids, and studied the movements of the water there, can fail to recognise that Captain Webb's skill as a swimmer will avail him scarcely anything except at one critical part of his course, which he may perhaps never reach alive. He himself clearly recognises the risks he runs, though probably he has no clear idea of the conditions under which he will be exposed to them. Captain Webb's personal action in the experi- ment will be akin to the influence of a drop of water on the movements of a great roller in the Atlantic." The autopsy on Captain Webb's body showed that no bones were broken. There was no wound sufficient to cause death save one, three and a-half inches long in the cranium. This wound was made after death. ^STone of the symptoms of death by drowning were revealed, and it was concluded that death resulted from the shock from the force of the water in the Whirlpool Rapids coming in contact with the submerged body with such force as in.stantly to destroy the respiratory power, and, in fact, all vital action. The shock was of sufficient intensity to paralyse the nerve centres, partially dessicate the muscular tissues, and forestall death by drowning. Ox the Hamburg tramways a number of cars with flange- less wheels, much like omnibuses, and with turning gear, are working. To run on the lines, these cars are fitted with a shaft in front of the front wheels, this shaft carrying on a lever a disc wheel which the driver can lower into the tramrail groove as he requires, or raise it when it is neces- sary to get out of the way of obstructions. The arrange- ment works well, saves a lot of trouble, and the cars run easier than those with flanged wheels. Messrs. Lamplugh i Browx, the well-known saddlers of Birmingham, have recently brought out a new tricycle saddle, which will be preferred by a number of riders to any other saddle at present in the market. The leather is suspended from the opposite ends of the saddle, and sup- ported by a strong, flat, spiral spring, the tension of which can be altered to suit the rider's weight, while ventilation is provided far more efficiently than in any other saddle. The leather seat is slightly cushioned, so as to provide a soft surface to sit upon. At the back of the saddle there is a small upright nickelised support, and in place of the usual back-rest there is attached to this a solid cyclists' wallet, which answers the double purpose of forming a flexible back-rest for the rider and holding the tools, oil-can, or any other small necessaries required on a tour. The whole of the saddle is most ornamental in appearance, and is tastefully got up as well as excellently made. LAWS OF BRIGHTNESS. TIL By Richaed A. Proctor. ZOLLNER carefully observed the brightness of the superior planets in mean opposition. His results are as follows : — Prob. error per cent. San = 6,994,000,000 times Mars 5-8 Son = 5,472,000,000 times Jupiter 57 San = 130,980,000,000 times Saturn (without rings) 5-0 Sun = 8,486,000,000,000 times Uranus 6-0 Son = 79,620,000,000,000 times Neptune 5-5 It follows that, if the total brightness of Mars at mean opposition is set at 1,000, as in my former table, we have the following relative total brightness for the several planets as observed, and as calculated for the case of smooth spheres of equal reflective power : — observed Calculated Brightness. Brightness. JIars 1000 ... 1000 Jupiter 1278 ... 487 Saturn, without rings ..■ 534 ... 24'5 Uranus 0824 ... 0-30 Neptune 0088 ... 0058 Zollner deduces for the reflective powers of these planets' surfaces the values — Mars = 0-2072 Jupiter = 06238 Saturn = 04981 Uranus = 06400 Neptune = 0-4648. Zollner's observations of the moon at difierent phases between the two quarters and full have next to be con- sidered. It is obvious that as the diflferent parts of the moon's disc, when " full," do not shine with the brightness due to a smooth surface, we might expect to find her total brightness at any other phase differing markedly from the value estimated for the case of a smooth sphere. This Zollner found to be the case. The " full " moon is far brighter, by comparison with the gibbous moon (especially when little more than half full) than the relation illustrated in Fig. 10 would indicate. This relation is thus given by Lambert for the moon assumed to be a smooth sphere. Let V be the angular distance of the moon from the sun, then the moon's total brightness varies as sin. V — i- cos. V After carefully analysing the whole subject, discussing various hypotheses as to the moon's surface-contour, and " averaging " as only a German philosopher can do, Zollner treats the case finally, as though the moon were covered with hills ha^nng a slope of -52° (it is not easy to follow him on this point, for his formula does not corre- spond to the case of conical hills, or prism-shaped hills, or, in fact, hills of any shape with such a slope). But Zollner is led finally to substitute for Lambert's formula the following : — The moon's brightness, when she is separated by an angle v from the sun varies as sin. {v - 52^) - {v - 52°) cos. {v - .52°). This formula cannot, of course, be actually correct, since the expression vanishes when v = -52°, whereas we know that the moon's brightness is not zero when she is 52 from the sun. As an empirical formula for the moon's brightness when she is gibbous, however, it serves well, as will be seen by the foUo-ndng table (where the brightness of the full moon is taken as 100) : — Aug. 3, 1883.] KNOAVLEDGE ♦ 75 Calculated Brightness. Brightness. (' TT — V ZoUner's Zollncr. ^ Formula. Formula. 179 .... + 1 ... 99-98 .. ... 9S-U0 98-60 185 .... 5 .. 99-03 .. .... 92-79 87-20 172 ... 8 .. ... 99-06 .. .... 88-41 92-19 169 ... 11 ... 98-24 .... 84-04 88-76 193 .... .. -13 .. ... 97-57 . .... 81-21 82-60 ICl ... + 19 .. ... 94-93 .. .... 72-29 68-41 15G ... 24 ... 9213 . .... 0515 71-38 153 ... 27 .. ... 90-18 . .... 61-00 57-90 207 ... -27 ... 9018 . .... 60-93 63-47 152 ... + 28 .. ... 89-53 . .... 59-60 56-15 208 ... .. -28 .. ... 89-50 . .... 59-60 57-00 147 ... + 23 .. ... 85-82 . .... 52-90 48-60 219 ... .. -39 .. ... 80-87 . .... 45-00 41-70 140 ... + 40 ... 80-04 . .... 43-72 47-10 139 ... 41 .. .... 77-78 . .... 42-50 43-95 223 -42 .. ... 78-27 . .... 41-40 ..... 38-00 134 ... .. +46 .. ... 74-61 . .... 36-70 36-10 232 ... -52 .. .... 68-87 . .... 27-63 29-U 122 ... .. +58 .. ... 62-91 .... 24-30 27-10 242 ... .. -62 .. ... 58-89 . .... 20-60 20-40 249 ... .. -69 .. .... 51-82 . 15-20 14-60 It is remarkable that ZoUner's observations should agree so well -with calculations based on a formula -which is, on the face of it, erroneous.* ZoUner's -svork on the brightness of Mars when gibbous led to the strange result that the defalca- tion of the brightness of Mars when gibbous is greater than in the case of the moon. Instead of an inclina- tion of 52° for the Martian mountains, Zollner inferred an inclination of more than 75°. It must be admitted, I think, that this would be absurd, even though wo had reason to believe that the whole surface of ]\Iars is solid, which is certainly not the case. An equally complete, and much more natural explanation, is obtained, if we suppose the Martian air to be ordinarily somewhat cloud-laden, the clouds resembling in shape our own summer clouds, and lying far enough apart to show the Martian surface. This ex- planation is given and illustrated at p. 65 of m}' " Essays on Astronomy," where it is shown that as a consequence of the supposed state of things the edge of Mars's disc should appear brighter than the central part, which is actually the case. But I must here note that there is a mistake in what I there say, to the effect that ZoUner's observations would be equally well e.xplaine d by supposing that " when the sun is near the horizon of Mars, heavy mists hang in the air." The aspect of Mars when gibbous at once negatives this subsidiary explanation (as I ought to have noticed when I penned the above words, and as I should have noticed if I had followed my usual rule of reasoning out the matter * Thia table is taken from Klein's " Das Soiinonsystem." In the original paper by Zollner the logarithms of the quantities above tabulated are given, and Klein has been at great pains to substitute the natural numbers. But he fails to notice two mis- takes in the original tables, where, opposite 139° and 219°, Zollner sots as the logarithm of the brightness calculated by Lambert's method, 1-9985 and 1-9774 respectively, instead of 1-89S5 and 1-9079 respectively. Thus in Klein's table there is given opposite 219° the value 94-93, and opposite 139° the value 99-60 which ai-o obviously erroneous. Hero is another instance of the absolute neceiixitij of examinitiij everythiiuj resemhling a table which one may desire to make use of. No one would believe how readily mis- takes will escape the notice of oven the most careful tabulist. I am satisfied that the very care taken by Klein to make his table instructive caused him to overlook points aii'ecting its general accuracy. It w-ould be unfair not to point this out. There are tWQ ways in which tables may become erroneous : — Fii-st, when tables are simply pitchforked into a book by a compiler, one may be tolerably certain that they are erroneous; but secondly, when a careful worker like Klein really gives labour to a table, it will happen that while engrossed on such special work, he overlooks the nocuesity far general supervision. at the time of writing). For, near the terminator of gibbous Mars the light darkens perceptibly, precisely as it should do if my first explanation be correct (of which I now entertain no doubt) ; Vjut if morning and evening mists prevailed in Mars, the part near the terminator would be rather brighter than the part near the true limb. Com- paring this with my reasoning as to the first explanation, and noting how absolutely untenable is ZoUner's theory of sugar-loaf hills all over Mars, it appears to be as nearly demonstrated as the nature of things renders possible that the Martial clouds are for the most part cumulus clouds. (Tu he continued.) THE DISCOVERY OF THE CHIEF DIVISION m SATURN'S RING. MISLED by a categorical statement on page 217 of Breen's " Planetary Worlds," I last autumn wrote to Knowledge (Vol. II. p. 294) to inquire whether a letter written by Wallis to Huyghens, on the subject of the supposed duplicity of Saturn's Ring, was still e.^ctant, and, if so, where it was to be found. It was subsequently pointed out by Mr. Herbert Rix (p. 471) that it was not Wallis at all who wrote to invite the attention of Huyghens to what had been seen (or imagined) by William Ball, but the first President of the Royal Society, Sir Robert Moray. I am happy to learn, through Mr. C. Leeson Prince, F.R.A.S., that Moray's letter to Huyghens has been found in the library at Leyden by Dr. Bakhuyzen. The wording of this letter seems to me to be conclusive as to the idea which its writer entertained of the nature of the duplicity of Saturn's Ring, assuming it not to be a single appendage. " Quant au plus eloigne," says Moray, (" la planete Saturne) il y aurait plaisir a decouvrir que son corps tourna autour de son axe pendant que ses anses demeurent ferme, et si c'est un cercle comme vous avez prouve qu'il poitvra bien estre sans difficulte il ne pouvra avoir aucun mouvement autour du corps du planete si ce n'est qu'il garde tousiours une meme plaine. Mais il est temps que vous considerez avec grande attention la figure de ces anses a present pour ^•oir si vous n'y voyez rien qui vous fasse avouer que ce n'est pas un corps de figure circulaire qui embrasse la disque du planete, mais deux ; ce qu'il y aura quelque (word undecipherable) de croire :i ce qu'il me semble selon les observations qu'en ont fait le Dr. Ball et son frere tous deux de nostre societe, avec un fort bon telescope de 36 pieds." Hence it would seem that Moray was not quite convinced by Huyghens' reasoning that the ring of Saturn was a circle ; but rather imagined that each of the ans» was a separate curve, as shown in the strange draw- ing— or paper-cutting — by Ball, reproduced in Vol. I. of the "Philosophical Transactions" for 1665 and 1666, and engraved in facsimile on p. 307 of your second volume. At any rate, it is ob\-ious tliat neither Ball nor he had the most distant idea that Saturn was surroimded by two concen- tric rings. In the communication from which I have made the above extract. Dr. Bakhuyzen goes on to intimate that Joseph Campani may possibly have seen the outer and inner rings of Saturn, and even " traces of the inner dark ring," and he refers to a figure of the planet by Campani, in justification of this' surmise. Mr. Prince, however, has this engraving in one of the numerous early astronomical volumes in his library, and he informs me that no indica- tion whatever of a di\-ision in the ring exists in it. So far, then, I would venture to suggest, every attempt to deprive Oassini of the merit {quantum valeat) of having 76 ♦ KNO^AALEDGE ♦ [Aug. 3, 1883. been the first to see the chief division in the Saturnian Ring-system, has broken down xitterly. "William Noble. [I venture to add that in my opinion Captain Noble's conclusion is fully justified by the evidence. — R. P.] For a long time past actions have been pending between Mr. Bown, of ^5iolus ball-bearing fame, and various bicycle and tricycle makers. The action against Messrs. Humber, Marriott, i Cooper was concluded on Monday, the 19th inst., and resulted in a verdict for the defendants, Messrs. Humber ifc Co., with costs. The judge decided in their favour without calling on their counsel to speak. Evidence was produced that three machines had been made and sold with ball-bearings on them similar in construction to Bown's, before the date of Mr. Bown's patents. The decision in this case is likely to prove very important. Many makers will be able to turn out machines at a lower price when they are no longer compelled to pay a royalty on the ball- bearings. Size of Atoms. — Sir W. Thomson, in a discourse recently delivered before the Royal Institution, has pre- sented the various lines of reasoning which have enabled physicists to estimate the size of molecules. The result has been already made known, but is worth repeating. By four lines of argument it is shown that — with a very high degree of probability — in any ordinary liquid, transparent solid, or seemingly opaque solid, the average distance between the centres of contiguous molecules is less than the 1-5, 000, 000th of a centimetre, and greater than the 1-1, 000,000,000th of a centimetre. Expressed in relation to our more familiar measure the inch, this may, without science even, be represented by saying that the distance in question is less than the 1-2, 000,000th of an inch and greater than the l-t00,000,000th part of an inch. If a globe of water or glass, IG centimetres or 6 1-3 inches in diameter, were magnified to the size of the earth, each constituent molecule being magnified in the same propor- tion, then the magnified mass would be more coarse-grained than a heap of small shot, but probably less coarse-grained than a heap of 16 centimetre (or 6 1-3 inch) globes. Newspaper Science. — The following remarkable para- graph appeared in last week's Electrician: — The intelli- gence of the press on technical matters in this country is on a par with that of a liaby on soft soap. As soon as an exhibition opens the various papers commence to " report," but the peculiarity remains that the same errors run through scores of reports. One such error in matters electrical is now going the round of the press. We could, if we chose, point out the paper in which the error was made, but it would be impossible to point out the score or so of papers who have faithfully copied the error. Is the Leeds Forge Company's exhibit at the ]Metal Trades Exhibition lighted by a " storage," or by a primary battery ? The papers say it is from a storage battery, and is as suc- cessful as it is pleasing in eSect, and the result shows the progress made towards independent house lighting from storage batteries. We shall be glad to hear of the firm that claims this storage battery. The lighting may be successful, may be pleasing, may, indeed, be perfect, but whose is the storage battery 1 We are prepared to maintain, and we think we can prove, that not 5 per cent, of those who report exhibitions ever see the exhibits. [Our opinion of news- paper science is not high, but we feel convinced that the estimated percentage of dishonest reports is exaggerated.] GREATEST CONTENT AYITH PARCELS' POST. By Richard A. Proctor. THAT the new postal arrangements for parcels' delivery have given the greatest content to every British citizen is generally admitted. But I wish now to consider greatest content of another sort. The method of measur- ing parcels by the new delivery suggests a neat though simple little prolilem for the solution of which I propose to use the Diflerential Calculus, — to wit, what is the greatest content of a parcel which can be sent by post. It is well known of course that if a cylindrical solid has a given height and girth the content will be greatest if the solid is a right circular cylinder. This can easily be shown geometrically. What we have to determine then is this, — Given the sum of the height and girth of a right cylinder, what is its greatest content. Let h be the height, r the radius of the base, so that the given sum, the length of the measuring tape suggested in the postal directions = /( + 2!rr = Z say. Thus h — l-2Trr. Then Content of cylinder = 7rr-A = (?—2;rr) :rr-=7r (Zr-— 27rr'') Difierentiating this expression with respect to 0, and equating to zero, we get x(2W— 6;r/--) = 0 or /=3n-r wherefore I — 2Tr^7rr ; i.e., /t=i(2Tr) Thus the greatest content with parcels post, is given when the height of the cylindrical parcel is equal to half the girth. This makes the height of the cylinder, or what would usually be the length of our parcel, equal to 2 ft., for greatest content, and the girth equal 4 ft., making the radius of the base 2 ft. -. Putting -z = 22 7 this gives radius of the base 7/llths of a foot, the diameter 14 llths or loJy inches, and length 24 inches. If the parcel is to be a parallelopiped the shape which will give the greatest content may be thus determined : — Of course the section perpendicular to the length must be a square ; let the side of this square be a. Then the total length of the measuring tape being I, the length of the parcel is ! - ia ; and the content is ('~(l- 4a). a-l - 4a'. Difierentiating this expression with respect to a and equating to zero, we have — •2ki-Ua~ = 0 I, a = -I 6 Thus the girth = h, or 4 ft. a 3 The parcel therefore must be 2 ft. in length or height, and 1 ft. in breadth and thickness, or have a section 1 ft. square. The greatest solid content, then, by the new system is 2 cubic feet, for a flat-sided parcel. The actual maximum content is given in the case of the cylinder, the content of which is 1 7 < .-) 28 .-, a v x j. _x — x4x2= — = 2-^ cubic feet. 2 11 11 '' Takin'G the average amount of organic impurity con- tained in a given volume of the Kent Company's water during the nine years ending December, 1876, as unity, the proportional amount contained in an equal volume of water supplied by each of the metropolitan water companies and by the Tottenham Local Board of Health during May last was : — Kent, -9 ; Colne V^aUey, 1 -0 ; Tottenham, 2 ; Chelsea, 2-1 ; New River, 2-1 ; Grand .Junction, 2 '6 ; East London, 29; West Middlesex, 30; Southwark, 3-2; Lambeth, 3 0. 18&3.] ♦ KNOWLEDGE ♦ 11 THE FACE OF THE SKY. Feom Aobdst 3 TO August 17. By F.R.A.S. A PERIOD of seemingly renewed solar activity renders the study of the Sun's surface very interesting just now ; and no clear day should be allowed to pass without directing the telescope to his face. A representation of the night sky during the next fourteen days will be found in Map VIII. of " The Stars in their Seasons." Mercury sets after the Sun during the whole of August, and may possibly be caught with the naked eye over the W. by N. part of the horizon before 8 p.m. Venus is, for our present purpose, invisible. Mars rises before midnight half way between the N.E. and theN.E.-by-E. ; but he only looks like a bright red star. Jupiter will not come into view until later. Saturn, though, rises between 11 and 12 p.m. during the earlier part of our specified period, and between 10 and 11 p.m. during the latter part of it. His ring is now so open as to be discernible in a comparatively small telescope. Between the 9th and the 11th of August, and notably on the night of the 10th, the Earth passes through a stream of those curious meteorites which become visible to us on entering our atmosphere as "shooting stars." Their apparition on the 10th gained for them the appellation of St. Lawrence's tears. Tliey are now less poeti- cally, but more scientifically, known as the Perseids, from the fact of their paths all seeming to radiate from a point in the constel- lation Perseus, forming a triangle with n) and y in that con- stellation. As a rule, they leave more or less marked trains of light in their wake. The most remarkable thing in con- nection with this stream is, however, the fact that it travels in the orbit of a small comet (II.) discovered in 1862. Unfortu- nately, it will be moonlight during the earlier jiart of the night of the 10th, but not during the whole of it. One occnltation of a star by the Moon only will be observable during the fortnight covered by these notes. It will occur on the evening of August 15, when the 5^ mag. star p^ Sagittarii will disappear at the Moon's dark limb at 7h. 25m., at an angle of 49° from her vertex, reappear- ing at her bright limb, at a vertical angle of 297°, at 8h. 32m. p.m. The Moon's age at noon on August 3 is 04 days, and quite ob- viously, 14'4 days at the same hour on the 17th. She leaves Cancer about 4 o'clock this afternoon, and passes into Leo, where she remains until about 2 p.m. on the 4th, at which time she crosses into Sextans. She takes until noon on the 5th to travel through this, and then re-enters Leo, which she finally quits at 2 p.m. on the 6th for Virgo. It occupies her until noon on the 10th to tra- verse this great constellation, and at that time she passes over the boundary into Libra. There she remains until about 1 a.m. on the 12th, when she enters the northern part of Scorpio. It takes her about 13 hom-s to traverse this, and then at 2 p.m. on the 12th, we find her in the southern part of Ophiuchus. Across this she travels, and enters Sagittarius about 8 a.m. on the 14th. She does not reach the confines of Capricornus until 6 p.m. on the 16th, and at 10 o'clock the next morning moves into Aquarius. Wo there leave her. ^3araliov Column. [The following certainly seems worthy of a place in this column. — R.P.] A NEW THEORY OF COPERNICUS. To Mr. R. A Proctor Astronomer Sir. It appears you are estimated to be a star of the first magni- tude in astronomical circles, therefore I beg to introduce to you a few practical ]iroofs that the Copernican theory is the greatest, because the most popular delusion under the sun. being by trade a carpen- ter I know what a true triangle is. I have also had some experi- ence in leveling building by the horizon of the sea. which by a long straight ridge of a building may be seen to be iierfectly straight and level for at least 30 miles, tlierofore. Can you explain the mystery How it is possible if the earth were a globe 8,000 miles in diameter, for the visible liorizou to present an unmistakable straight and level lino for 30 or 40 miles, and at the same time bo sufficiently convex in 20 miles to hide from view the top masts of a ship some of which is no less than 140 ft high. ? Do the sea rise 140 ft in the centre of 20 miles. ? if (w How can 30 miles of sea be a straight lino. ? There is also a mystery respecting the supposition distance of the sun from the earth. Do the rays of the sun shine forth direct from the sun to the earth, if not. Can you explain what i)re- vonts their doing so. ? But. it the rays come direct, the visible oblique line of the sun's rays, tostifios that the now popular sup- position distance of the sun "from the eartli is more than 9 1.9i)6-000. miles distance from the truth, which is truly a distance of no mean importance, when we consider that on it is founded and being reared up the greatest antagonistic heresy to the source of Englands greatness that history has on record. An important question may truly be asked. Was Copernicus the Anti-Christ. ? 'The question is worthy of your careful consideration, and even refutation if its in your power to do so. the question may surprise you. and well it may. when yon consider the marvellous rapidity with which the supposition theory have spread itself over the face of the whole civilised world. It has come in the latter days, with haste, even as a cloud cover- ing the whole land with gross spiritual darkness. It has risen out of the sea pure and simple, it requires no mystifying of the text to prove its truth. It is in direct antagonism to the Spirit of the Bible from Genesis to Revelation. It have extended its influence over the whole civilised world». It have made rich many merchants of the earth. It have made war with the Saints and overcome them. Its advocates are constantly conjecturing something contrary to their predecessors, and publicly exposing their suppositions to be what they really were, hypothetical suppositions and nothing more. The foregoing characteristics are essentially the unmistakable prophetic characteristics of the Anti-Christ, and his numerous followers, they really agree in nothing except in trying to prove the Bible untrue, their suppositions is in reality aa unmixable as iron and clay. The theory presents mysteries greater than any other known invention under the Sun. Therefore. I am open to prove in any paper you may name, that the theory is a delusion from three seperate positions. First, from the Bible. Second, from the provable Level surface of the sea. and Third from the provable distance of the sun from the earth by Architectural measurements on the unerring triangulation principle, and I hereby challenge you or any other man to produce proofs (in the same paper) in favour of the theory First from the Bible. Second, from the convex surface of the sea. and then produce your proofs that, the Sun is 3 million or 95 million miles distant from the earth, which of the two distances you may imagine has the greatest number of substantial jjroofs. and in honour of Truth let the winner of the challenge be the one who has the greatest number of sub- stantial proofs in two out of the three suggested positions, an early answer will oblidge Yours Resptly. Wm. Hardy. St. Helens. Isle. of. Wight. [It will be shown next, I suppose, that in Knowledge with its far-wandering editor, sub-editor, and staff, its motto " Let Know- ledge grow from more to more," and its monthly increase, there is clear evidence of the approach of those latter days when, we are told, "men shall run to and fro and Knowledge shall be increased." — R. P.] " Let Knowledge grow from more to more." — Alfred Tennyson. Only a small proportion of Letters received can possibly he in- serted. Correspondents must not be offended, therefore, should their letters not appear. All Editorial communications should be addressed to the Editor of Knowledge ; all Business commrmications to the Publishers, at the Office, 74, Oreat Queen-street, W.C. If this is not attended to, DELAYS ARISE FOR WHICH THE EDITOR IS NOT RESI'ONSIBLE. All Remittances, Cheques, and Post Office Orders should be made payable to Messrs. Wyman & Sons. The Editor is not responsible for the opinions of correspondents. No com.munications are answered by post, even though stamped and directed envelope be enclosed. DRESS REFORM (CORRECTIONS). Sir, — May I ask you kindly to allow me to fill up two omissions in my article on " Dress Reform." The first occurs in the quota- tion itrom my lecture. Between " decked out in beatitiful colours," and " to which it has no claim," should be " which has given it a pretension to beauty." The second omission makes the continuation of my paper almost unintelligible, as the argument chiefly hinges on the words left out. The 5th requirement, as laid down in the circular of the Associa- tion is, " not departing too conspicuously from the ordinary dress 78 KNOWLEDGE ♦ [Aug. 3, 1883. of the time." The omission of the words "too conspicuously" completely alters the meaning of the sentence. E. M. Kxng. [We gladly give Mrs. King's letter insertion. The omission of the words was due to a printer's error. — K. P.] OLDEST HISTORICAL TREE. [891] — In answer to " Cosmopolitan," the Bodhi tree at Aiiarad- hapnree, Ceylon, is the oldest historical tree in the world — not the oldest tree. That at Buddh Gaya, near Gaya, from which it was taken, was destroyed, and two or tliree of its successors also de- stroyed. The iirst destruction took place under the orders of Asoka's Queen. The present tree is quite young. I send you here- with a printed account of my visit to it two years ago. K. S. Macdonald. LETTERS RECEIVED, AND SHORT ANSWERS. 51. DoiBLEDAY. Evil all the time, is there not ? — R. Thomsox. It would be difficult to say what the capsizing influence of the current would be on a ship launched as the Daphne was. — S. J. Potter. Foretelling destiny by aid of planets sheer nonsense now- a-days, but a not unreasonable notion in old times ; the most re- spectable of the old superstitions. — R. F. Keer. If I could define that word, I should know something indeed. "Can'st thou by searching," &c., they said in old times ; so must all say, throughout all time. — E. B. would be obliged if " Pedestrieune," through Know- ledge, would say where the pattern she speaks of, with instructions for making up, can be obtained. — Z. I should say, and so says the writer of the articles in question, a manifest swindle. You will find no chemist to make up the prescription sent you, so must send to advertiser, who charges an exorbitant sum, for a draught possibly worthless, but most probably exceedingly harmful. — W. Woods Smyth. Does Mr. Herbert Spencer's rule for moral action enjoin us to seek our own happiness supremely ? You astound me ! I thought there was precisely that principle of equi- libration in his system of ethics which there is in his system of philosophy generally. Really he seems to say so. But perhaps he does not know his own meaning. Let us wait to see what Mr. Foster makes of it. Only, frankly, if Mr. Foster shotild work out your result, or anything so remote from Mr. Spencer's own teaching, the editor wiU interfere in a very summary manner with his friend Mr. Poster's series of papers. This is not likely, though. — Tbos. Westlake. Out of your own mouth (or from your own pen) you shall be judged. " When wiU men see," you ask, that there are two revelations of God, one in his works, and the other in his Word ? We cannot perhaps always see at once how they harmonise. But we answer they do, and we shall by-and-by know how." Yet you are sorry that a series of articles should appear in these pages, the object of which is in the main, as I understand Mr. Foster's purpose, to show that practically the same moral laws result from natural processes affecting the condition and progress of God's work — man — which have been enunciated in those works which you regard as His word. Your contention is unreasonable. — E. C. H. I had the pleasure of conversing with several representative members of the Worthing audience, and think you are mistaken. Friends who were in the audience think so too. Though of course there were many there of the class you mention. — G. S. Question considered. — Leonard Brown. Shelley there obviously attacks the argument from design, but his sugges- tion of the line of reasoning followed later by Mr. Herbert Spencer (the real originator of the environment doctrine) is too vague to be regarded as an anticipation. — J. Russell, B.A. Question does not admit of a solution as stated. — Ixquiker. Two or three months ago the problem of 21 school-girls was solved in a systematic way ; easily extended to the case of 15. The problem is not in any case a simple one. — E. B.^rtox. Certainly hope to give a course of six evening lectures in Manchester before I leave Eng- land.— W. H. B. Ranixe(?). I believe the flat earth men have no knowledge of what has been done in the way of Antarctic ex- ploration.— C. Thosipsox. An instrument for assisting the hearing was invented by a Cliicagoan a few years ago ; it was a tautened surface of card or tin, japanned, and held by a handle with the middle of the outer edge between the teeth. As nearly as I can remember, it was about as large as a medium-sized fan. Possibly some reader may be able to give an account of it. — E. W. Tawom (?) . Thanks ; but the conjuring trick rather complex. — H. C. JoxEs. In that sense I am already a member of your " Society for correcting, detecting, and where necessary exposing slander." Much obliged for youi- very kind remarks about my South- ampton lectures, and your report of the kindly acceptance they met ivith from your friends. We lecturers are sup- posed to be so possessed with the sense of our constant rightness, and the eternal fitness of all we say and do, that we onght not to hear of any kindly things said of us, — whereas as a matter of fact we are a race of " nervous, shy, low-spoken men" like the Coxswain of the " Mantelpiece," and " not to be treated nn- benignly " as Tennyson puts it. — C. J. R. Richards. Those who often tell you that geology disproves evolution because in the lowest fossiliferous rocks animals of a higher organisation have been found than in the upper rocks, should often study a little geology. The statement is untrue in every sense except thus far that just as at the present time there co-exist higher and lower organisations, so has it been in past times ; and some of the organi- sations of an older epoch are necessarily higher than some of the organisations of a later one, even of the latest of all, the present. — A Student. Quite unable to answer such questions ; it would afford a bad precedent, and moreover lead to a great deal of annoy- ance.— Hugh Clements. " Great earth dominating planets." Great earth dominating fiddlesticks ! — J. W. C. " Say about one inch apart," — all right, I say that : but I do not say what the power of your telescope is. Seriously, one such question answered here would bring a hundred ; each of these many more, and Knowledge would be killed by kindness — its editor's. — H. T. Pekky. Thanks : but matter hardly important enough to be re-opened. — J. Greeves Fisbee. Yes : but your account of the puzzle does not tell us what would happen if some other number than " one " were thought of. — S. M. B. It should be tolerably obvious that Mr. Ledger and I both made the same blunder, speaking of the day as shortening instead of lengthening, though elsewhere we had each carefully shown that it is lengthening, and how, and why. ^^r iHatftcmatical Column* GEOMETRICAL PROBLEMS. By Rich.abd A. Proctok. PART X. Let us next try a problem which is the converse of Example 5. Ex. 13. — To determine the greatest of all the triangles which can be constructed upon a given base and with a given perimeter. Fig. 21. Let A B, Fig. 21, be the given base, C the sum of the remaining two sides. Now, with a knowledge of the property established in Ex. 5, it is of course very easy to see what is the solution of our problem. But we shall assume that the student is deahng with the problem in- dependently. With centre A and radius equal to C describe the arc D E F, and draw radii A D, A E, and A F. Then if from B we draw lines B G, B H, B K in such a way that B G is equal to G D, B H to H E, and B K to K F, it is obvious that each of the triangles AGB, AHB, AKB has the required perimeter. Now it is an obvious consideration that if B G is equal to G D the angle G B D is equal to the angle G D B (we here draw in B D) and, therefore, that in order to draw B G so as to be equal to G D, we have only to make the angle DBG equal to the angle G D B. So that having a construction for determining any number of triangles, it is pre- sumable that we shall find materials for determining the triangle of maximum area. But first let us see if anything is suggested by an examination of the figure. We see first that the triangle gradually increases as the angle at A increases. But there is clearly a limit to this increase. For it is obvious that we might have taken B as the centre of a circle with radius C, and thus have I shown that the triangle increases as the angle at B increases. We Aug. 3, 1883.] ♦ KNOWLEDGE ♦ 79 arc led, therefore, at once to the consideration that oui- triangle will have its greatest area when the angles at A and B are equal. To see whether this is the case, we construct a new figure (Fig. 22), in which we omit all unnecessary parts of the former figure, and draw A KF, so that when the triangle A K B is completed, the angle KAB shall be equal to the angle K B A. We then draw K L M parallel to A B, knowing that it is on the distance of this parallel from A B that the area of the triangle A K B depends. We take A E pretty near to A F (seeing that the triangle has obviously nearhj a maximum area when the angles at A and B are equal, so that any great departure from equality makes the triangle consider- ably smaller). Let AE intersect K L JI in L. Then, if we can show that B H, drawn as before, falls between B A and B L, our surmise will have been proved to be correct. Xow the angle U B E, by our construction, is equal to the angle H E B, therefore we must show that the angle L B E is less than the angle L E B, or L E less than L B (Enc. I., 19) ; therefore, adding A L, we have to show that A E (or C) is less than A L, LB together. This is the problem dealt with in Example 5, and thus the rest of the work corresponds with the work in that example. We find that A L and L B are together greater than A E, so that H does fall below L ; and the triangle A K B is greater than the triangle A H B. Our surmise is, therefore, shown to be correct, and the problem is solved. It will be noticed that a problem in maxima and minima loses a large part of its difficulty when, as is usually the case, we are merely asked to prove that such and such relations supply a maxi- mum or a minimum. In the case of Example 13, indeed, inspection supplied a tolerably obvious solution, but this seldom happens. Presented in the usual form, the above problem would run. Of all triangles on a given hase, and havi7ig a given perimeter, the isosceles triangle is the greatest. Thus given, the problem reduces immediately to the case of Example 5. Example 13 fitly introduces the following, which belongs to a class often found perplexing : — Example 14. — Of all triangles having a given perimeter, the equi- lateral triangle is the greatest. The difficulty in a problem of this sort resides in the fact that we have three elements to consider, all of which admit of being changed. In Example 13 we only had two sides to consider, and when a length had been selected for one, the other was determined at the same time. In Example 11 we have three sides, and must assign lengths to two before the final condition of the triangle is deter- mined. This would bo found to afford no assistance towards tho solution of the problem. The way to proceed is to assign a length to one side, pro%nsionally, and then to consider what relation must hold between tho two remaining sides, whose sum ia now assigned. Fig. 23. Fig. 24. in order that the triangle may be as largo as possible. This we have learned already from Example 13. Those two sides must be equal. Hence, whatever side we suppose assigned, the remaining two must bo equal, to make the area of the triangle a maximum. Therefore, obviously, the triangle must be equilateral. The proof of this would ran as follows : — Let ABC (Fig. 23) be the triangle having the greatest possible area with a given perimeter. Then ABC must be the greatest possible triangle on a given base B C and with the sum of the remaining sides equal to the sum of B A and AC. Hence B A is equal to A C. But also, A B C is the greatest triangle on the base AB with the given perimeter; hence, as before, AC is equal to B C. Therefore A B, B C, and C A are all equal. As another instance of the application of this important method, we give the following : — ■ Examplel5.—AB C (Ftj. 24) is an acute-angled triangle. It is required to determine the position of a point P within the triangle, such that the .s«ra of the distances PA,PB, PC, shall be a minimum.^ Assume P to be the required point. Then PA, P B, and P C together have a minimum value. Therefore, also, P A and P B have the least sum they can have so long as the length of P C remains unchanged : so that if we draw the arc D P E with radius C P and centre C, A P and P B are together less than the sum of any two lines which can be drawn from A and B to meet on the arc D P E. Hence (Example 11, Cor.), A P and P B are equally incUned to C P. Similarly AP and PC are equally inclined to B P. Hence the angles A P B, B P C, and C P A are all equal, and each, therefore, is one-third part of four right angles. ©m Cbtss Column. By Mephisto. SCORE OF THE NUREMBERG INTERNATIONAL TOURNA- MENT, ON SATURDAY THE 28th JULY, 1883. a o J. •c g w Names. K 1 1 s 1 0 5 1 0 s Si c i * 1 i "5 0 i 1 i 'o 9i Berger 0 1 i k 1 i i i J i i ,1 1 0 lOi Bier iO 0 — 0 0 1 * 0 0 1 0 1 ll i 0 Bird jl ^ 1 — 0 *■ 1 0 1 1 1 u 0 4 i u 10 Blackburne.i i 1 1 — 1 0 i 1 1 0 i (1 1 1 12i Fritz 0 i 0 i i 0 — 0 0 0 0 0 1 0 0 1 I 0 0 1 0 0 |0 0 i 0 0 0 1 bi Gunsberg ... 5 Hrnby 1 + i 0 0 i — 0 t * i u i * i 0 a 0 0 0 0 0 i 1 — 0 0 0 i 0 + ^ 0 0 b 0 0 0 * 0 0 0 — 0 1 0 0 0 i 0 i i 34 JL i 1 1 1 0 1 \ 1 * i k 1 i i 0 12 L. Paulsen . * i 1 0 i 1 k 0 — 0 0 \ 0 1 0 V W. Paulsen. 0 i- 0 0 0 0 \ * — 0 1 1 i i 0 tii Riemann ... i 1 0 0 1 k 1 1 — 1 i 0 i 4 10 Schallopp . . . 1 i 1 1 1 1 i 1 0 0 — 0 0 i 0 10 Schottliind'r i k 0 1 k 1 * 0 i 0 4 Jt -i 0 0 8* .1. Schwarz . 0 0 0 ^ 0 * \ * 1 ^ 1 1 *l- i 94 Weiss if 0 i 0 0 1 * A ^ 0 t i 0 ^ * — i Winawer ... I 1 1 1 0 0 1 t 1 1 i i 1 1 1 0_ — li As will bo seen from the score table published, this great tourna- ment is all but concluded, Winawer being at the head of the list, and Blackb\irne and Jlason following close behind. To speak of Winawer's play as being absolute best would be doing injustice to Blackburue, tliau whom none in this Tournament have played finer games — a fact acknowledged by all other competitors. Winawer, however, is fond of originality. He generally avoids the known openings by playing P to Q3. As second player he also deyelopes groat resources in difficulties. As a notable instance of this may bo cited Iiis game with Hrnby, one of the most complicated games iu the Tournament. At the adjournment the position stood very unfavourably for Winawer, in spite of his being a rook to the good, and it was the general impression that he would lose. Nevertheless, he scored a comparatively easy victory. Blackbuine, who defeated Winawer, has played several games in which, for powerless ]ilay in one given position, he has played in matchless style ; but he has erred in some instances in judgment of position, which cost him the first prize, notably in his game with Mason, when he repeatedly avoided the draw in a position slightly in his favour, and finally lost. This is a quality in play which re- flects credit upon him to the disadvantage of his score. The fact 80 ♦ KNOWI.EDGE ♦ [Aug. 3, 1883. of his having made several dran-s is owing to the strength of his competitors, his last draw being with Schottlander, a young player who combines rapidity and ingenuity of combination with con- siderable experience in tournament play. Mason has played carefully, the climax being reached on Satur- day, when W. Paulsen began ivith 1. P to QB3, to which Mason replied with 1. P to K3, to the general amusement of the lookers on. The game ended in a draw. Mason and most of the other players favoured the early advent of the QB in the close games on the Queen side. Bird has played some very fine games, notably one with Riemann, who has improved very much. Bird has, however, lost a game to Mason, in wliich he adopted his favourite defence to the close openings of P to KB4. In this game he had a superiority in the opening which, by careful play, ought to have enabled him to win the game. Gunsberg in the first week's play scored 5, defeating Winawer amongst others. He, however, strange to say, entirely broke down in the second week, neither winning nor drawing a game, nor even making any considerable show of resistance, but falling an easy ^•ictim to his antagonists. A notable example is his game with Berger, in which, after a well-conducted attack, he missed victory when within easy reach. The committee have been true to their promise, and rendered the stay of the players as pleasant as possible. Foremost amongst the entertainments prorided was a special grand theatrical per- formance, given in honour of the chess-masters, in which a game with Uving pieces was played instead of a ballet. Every plaj-er will certainly keep in pleasant recollection the third congress of the German Chess Association at Nuremberg. Nuremberg, July 30th. The Tournament was concluded to-day by Winawer taking first prize, having defeated Schwarz ; score 14. Blackbnrne, 13i, is second ; beat Gunsberg. Mason, 12, third. Berger, Hi, beat Schallopp, is fourth. Bardeleben, 11, fifth, beat Fritz. Bird, lOJ, and Riemann, lOJ, are sixth and seventh. Schallopp, 10, is eighth ; while Schwarz, 9i, takes ninth prize. GAME BETWEEN BIRD AND RIEMANN. PLAYED JULY 28th, 1883. White (Biraj. 1. P to KB4 -2. P to K3 3. Kt to KB3 4. B to KB5 5. P to B4 «. B takes P 7. Kt to B3 8. Castles 9. P to QKt3 10. B to Kt2 11. B to K2 Black (Eiemann). P to Q4 P to QB4 Kt to QB3 Q to Kt3 P takes P (a) P to K3 Kt to B3 P to QR3 Q to B2 P to QKt4 B to Kt2 White (Bird). Black lEiemann). 12. Q to K sq. R to Q sq 13. R to B sq. B to Q3 (b) 14. Q to Kt3 (c) RtoKKtsq(d) 15. Kt takes P P takes Kt 16. B takes Kt R to QR sq 17. QB tks QKtP K to B sq 18. B to K5 R takes P 19. R takes P (e) P to B3 20. B takes Kt P takes B (/) 21. P takes P B takes R 22. Kt to Q4 (oh) Resigns (g) NOTES. (a) This brings White's Bishop into good play; either P to QR3 or P to K3 was advisable. (6) Having regard to the dangerous position of the White QB bearing on the KKt file, B to K2 would have been safer. (c) A very good move, which prevents Black from Castling on account of Kt to K4. (d) This, of course, loses on the move, but Black hardly had a satisfactory reply, excepting, perhaps, B to K2, followed by H to Kt sq if Q takes P. (e) White plays in very fine style. Black cannot prevent the mpeiiding dissolution. (/) If B takes B, then Kt to Q4 wins. (g) A fine finish to this well-played game, if K to K2 then Q to Kto, mate. POSITIOX IN GAME BETWEEN BLACKBCSXE .\XD WI.V.4WER. Wl.NAWER. Black. The game proceeded with — B to Kt8 K to B3 B to Q6 P to Kt4 EP takes P en pas. K to Kt2 B to K7 P to B5 (ch.) P takes P P to Kt6 P to B5 Kt to Q5 ! K takes Kt ! P to Kt7 K to Qo Resigns If P to Kt8 (Queen), P to B6 (ch). K takes P (best), B to B5 (ch) and wins. Position in a game between Schottl.\xdee and Schallopp. Schallopp. Black. Schottl.\mjek. In this position White plaved- P to K6 R to B8 (ch) QtoQ2 Q to B2 (ch) Q toB2 P takes P KtoR3 R to KKt6 P to Kt3 Q takes P 1 to B7 (ch), mates in two moves. Contents of No. 91. How to Get Stri Fat . PAGB Bedacing The Birth and Growth of Myth. XII. Bv Edward Clodd 50 Spots on the Sun. By K. A. Proctor 61 Chemistry of the Cereals. II. By William Jago, F.C.S 53 The Great Pyramid 53 Principles of Dress Reform. By E. SI. King 54 The Moon in a Three-Inch Tele- scope [lUut.) ByF.R.A.S 56 FAGB Smi-Tiews of the Earth. {lUus.) Bt H. A. Proctor 57 Flight of a Missile 58 Editorial Gossip 59 Cholera (Preventive) 60 Correspondence : Geometrical and Real Perspective — Skyers — Dress Reform — Short Answers to Letters Received, ic 60 Oar Mathematical Column ; Geome- trical Problems 62 Our Chess Column 63 SPECIAL NOTICES. Part XSI. (July, 18S3), just ready, price lOd., post-free. Is. Id. Volume III., comprising the numbers published from January to June, 1883, just ready, price 7s. tid. The Title Page acd Index to Voltmie III. is now ready, ^rice 2d., post-free, 2^d. Binding Cases for A'olume III., price 2s. each. Includmg carriage per Parcels Post to any address in the United Kingdom, 2s. 3d. Subscribers* nombers bound (including Title, Index, and Case) for 3s. each. P. O. Orders and cheques should be made payable to the Publishers, Mbssbs. WvHiK & SoMS, London, at the High Holbom District Post-office. Agent for America — C. S. Carter, American Literary Boxeao, Tribtme Buildings, New York, to whom subscriptions can be forwarded. OFFICE : 74-76, GREAT QUEEN STREET, LONDON, W.C. Aug. 10, 1883.] KNOWLEDGE ♦ 81 AN ILLUSTRATED ^^-^ JC^ MAGAZINE OF SCIENCE^ 1^ RAINLrVyORDED -£XACTL|DES^RIB£D,, LONDON : FRIDAY, AUG. 10, 1883. Contents of No. 93. d Ischia. By E. A. Proctor The Birth and Growth of Myth. XIII. Bv Edward Clodd Pretty Proofs of the Earth 'a Eotun- dity. (/««».) By E A. Proctor The Moon in a Three-Inch Tele- Bcopo (/iiiis.) ByF.E.A.S Weather Forecaate, and How to Make Them, Bv John Brownintj The Fisheries Exhibition. IV. (Illus.) ByJohnErncst Ady ... PAGE The White Carna- tion. (/;/(M.) ByT. Kimber 89 A Steamer goes Safely Past Nia- gara AVhirlpool 90 Principles or Dress Eeform. By E. M. Kinf; 91 Chemistry of the Cereals, III. By William Jago, F.C.8 93 Editorial Gossip 94 Correspondence 94 Our Mathematical Colomn 95 Our Chess Column 96 VESUVIUS AND ISCHIA. By Richard A. Proctor. THE following pas.sages from an essay on Vesuvius, in my " Light Science for Leisure Hours," may prove of interest just now, when Vesuvius and Ischia have shown the close connection which exists between them. " In the volcanic region of which Ve.suvius or Somma is the principal vent, we have a remarkable instance of the deceptive nature of that state of rest into which some of the principal volcanoes frequently fall for many centuries together. For how many centuries before the Christian era Vesuvius had been at rest is not known ; but this is certain, that from the landing of the first Greek colony in Southern Italy, Vesuvius gave no signs of internal acti- vity. It was recognised by Strabo as a volcanic mountain, but Pliny did not include it in the list of active volcanoes. In those days, the mountain presented a very different appearance from that which it now exhibits. In place of the two peaks now seen, there was a single, somewhat flattish summit, on which a slight depression marked the place of an ancient crater. The fertile slopes of the moun- tain were covered with well-cultivated fields, and the thriving cities Herculaneum, Pompeii, and Stabire stood near the base of the sleeping mountain. So little did any thought of danger suggest itself in those times, that the hands of slaves, murderers, and pirates which flocked to the standards of Spartacus found a refuge, to the number of many thousands, within the very crater itself. " But though Vesuvius was at rest, the region of which Vesuvius is the main vent was far from being so. The island of Pithecusa (the modern Ischia) was .shaken by frequent and terrible convulsions. It is even related that Prochyta (the modern Procida) was rent from Pithecusa in the course of a tremendous upheaval, though Pliny derives the name of Prochyta (or " poured forth ") from the supposed fact of this island liaving been poured forth by an eruption from Ischia. Far more ])robably, Prochyta was formed independently by submarine eruptions, as the volcanic islands near Santorin have been produced in more recent times. "So fierce were the eruptions from Pithecusa, that several Greek colonies which attempted to settle on this island were compelled to leave it. About 380 years before the Christian era, colonists under King Hiero of Syracuse, who had built a fortress on Pithecusa, were driven away by an eruption. Nor were eruptions the sole cause of danger. Poisonous vapours, such as are emitted by volcanic craters after eruption, appear to have exhaled, at times, from extensive tracts on Pithecusa, and thus to have rendered the island uninhabitable. "Still nearer to Vesuvius lay the celebrated Lake Avemus. The name Avernus is said to be a corruption of the Greek word Aornos, signifying 'without birds,' the poisonous exhalations from the waters of the lake destroying all birds which attempted to fly over its surface. Doubt has been thrown on the destructive properties assigned by the ancients to the vapours ascending from Avemus. The lake is now a healthy and agreeable neighbourhood, fre- quented, says Humboldt, by many kinds of birds, which suffer no injury whatever even when they skim the very surface of the water. Yet there can be little doubt that Avernus hides the outlet of an extinct volcano ; and long after this volcano had become inactive, the lake which con- cealed its site ' may have deserved the appellation of " atri janua Ditis," emitting, perhaps, gases as destructive of animal life as those suffocating vapours given out by Lake Quilotoa, in Quito, in 1797, by which whole herd.5 of cattle were killed on its shores, or as those deleterious emanations which annihilated all the cattle in the island of Lancerote, one of the Canaries, in 1730.' "While Ischia was in full activity, not only was Vesuvius quiescent, but even Etna seemed to be gradually expiring, so that Seneca ranks this volcano among the number of nearly extinguished craters. At a later epoch, -liilian asserted that the mountain itself was sinking, so that sea- men lost sight of the summit at a less distance across the seas than of old. Yet within the last two hundred years there have been eruptions from Etna rivalling, if not sur- passing, in intensity the convulsions recorded by ancient historians. " I shall not here attempt to show that Vesuvius and Etna belong to the same volcanic system, though there is reason not only for supposing this to be the case, but for the belief that all the subterranean regions whose eflects have been shown from time to time over the district extending from the Canaries and Azores, across the whole of the Mediterranean, and into Syria itself, belong to but one great centre of internal action. But it is quite cer- tain that Ischia and Vesuvius are outlets from a single source. " While Vesuvius was dormant, resigning for awhile its pretensions to be the principal vent of the great Nea- politan volcanic system, Ischia, we have seen, was rent by frequent convulsions. But the time was approaching when Vesuvius was to resume its natural functions, and with all the more energy that they had been for awhile suspended. " In the year 63 (after Christ) there occurred a violent convulsion of the earth around Vesuvius, during which much injury was done to neighbouring cities, and many lives were lost. From this period shocks of earthquake were felt from time to time for sixteen years. These grew gradually more and more violent, until it began to be evident that the \olcanic fires w-ere about to return to their main vent. The obstruction which had so long impeded the exit of the confined matter was not, however, readily removed, and it was only in August of the year 79, after numerous and violent in- ternal tliroes, that the superincumbent mass was at lenctli hurled forth, Kocks and cinders, lava, sand, and scoria;, 82 ♦ KNOWLEDGE ♦ [Aug. 10, 1883.' were propelled from the crater, and spread many miles on every side of Vesuvius. " In this great eruption, Vesuvius poured forth lapilli, sand, cinders, and fragments of old lava, but no new lava flowed from the crater. Nor does it appear that any lava- stream was ejected during the six eruptions which took place during the following ten centuries. In the year 1036, for the first time, Vesuvius was observed to pour forth a stream of molten lava. Thirteen years later, another eruption took place ; then ninety years passed without disturbance, and after that a long pause of 168 years. During this interval, however, the volcanic system, of which Vesuvius is the main but not the only vent, had been disturbed twice. For it is related that in 1198 the Solfatara Lake crater was in eruption; and in 1302 Ischia, dormant for at least 1,100 years, showed signs of new activity. For more than a year earthquakes had convulsed this island from time to time, and at length the disturbed region was relieved by the outburst of a lava stream from a new vent on the south-east of Ischia. The lava stream flowed right down to the sea, a distance of two miles. For two months, this dreadful outburst con- tinued to rage ; many houses were destroyed ; and although the inhabitants of Ischia were not completely expelled, as happened of old with the Greek colonists, yet a partial emigration took place. "The next eruption of Vesuvius occurred in 1306 ; and then three centuries and a quarter passed during which only one eruption, and that an unimportant one (in 1500), took place. 'It was remarked,' says Sir Charles Lyell, ' that throughout this long interval of rest, Etna was in a state of unusual activity, so as to lend countenance to the idea that the great Sicilian volcano may sometimes serve as a channel of discharge to elastic fluids and lava that would otherwise rise to the vents in Campania.' " Nor was the abnormal activity of Etna the only sign that the quiescence of Vesuvius was not to be looked upon as any evidence of declining energy in the vol- canic system. In 1.538 a new mountain was suddenly thrown up in the Phlegr;L-an Fields — a district including within its bounds Pozzuoli, Lake Avernus, and the Solfatara. The new mountain was thrown up near the shores of the Bay of Baiaj. It is 140 feet above the level of the bay, and its base is about a mile and a half in cir- cumference. The depth of the crater is 421 feet, so that its bottom is only six yards above the level of the bay. The spot on which the mountain was thrown up was formei'ly occupied by the Lucrine Lake ; but the outburst filled up the greater part of the lake, leaving only a small and shallow pool. " The accounts which have reached us of the formation of this new mountain are not without interest. Falconi, who wrote in 1538, mentions that several earthquakes took place during the two years preceding the outburst, and above twenty shocks on the day and night before the eruption. ' The eruption began on September 29, 1538. It was on a Sunday, about one o'clock in the night, when flames of fire were seen between the hot-baths and Tripergola. In a short time the fire increased to such a degree that it burst open the earth in this place, and threw up a quantity of ashes and pumice-stones, mixed with water, which covei-ed the whole country. The next mornmg the poor inhabitants of Pozzuoli quitted their habitations in terror, covered with the muddy and black shower, which continued the whole day in that country — flying from death, but with death painted in their counte- nances. Some with their children in their arms, some with sacks full of their goods; others leading an ass, loaded with their frightened family, towards Naples. . . . The sea had retired on the side of Baiiv, abandoning a con- siderable tract ; and the shore appeared almost entirely dry, from the quantity of ashes and broken pumice-stones thrown up by the eruption.' " And now, for nearly a century, the whole district con- tinued in repose. Nearly five centuries had passed since there had been any violent eruption of Vesuvius itself; and the crater seemed gradually assuming the condition of an extinct volcano. The interior of the crater is described by Bracini, who visited Vesuvius shortly before the erup- tion of 1631, in terms that would have fairly represented its condition before the eruption of 79 : — 'The crater was five miles in circumference, and about a thousand paces deep ; its sides were covered with brushwood, and at the bottom there was a plain on which cattle grazed. In the woody parts, wild boars frequently harboured. In one part of the plain, covered with ashes, were three small pools, one tilled with hot and bitter water, another Salter than the sea, and a third hot, but tasteless.' But in December, 1631, the mountain blew away the covering of rock and cmders which supported these woods and pastures. Seven streams of lava poured from the crater, causing a fearful destruction of life and property. Kesina, built over the site of Herculaneum, was entirely consumed by a raging lava-stream. Heavy showers of rain, generated by the steam evolved during the eruption, caused in their turn an amount of destruction scarcely less important than that resulting from the lava-streams ; for, falling upon the cone and sweeping thence large masses of ashes and volcanic dust, these showers produced destructive streams of mud, consistent enough to merit the name of ' aqueous lava ' commonly assigned to it. " An interval of thirty-five years passed before the next eruption, but since 1666 there has been a continual series of eruptions, so that the mountain has scarcely ever been at rest for more than ten years together. Occasionally there have been two eruptions within a few months ; and it is well worthy of remark that during the three centuries which have elapsed since the formation of Monte Nuovo there has been no volcanic disturbance in any part of the Neapolitan volcanic district save in Vesuvius alone. Of old, as Brieslak well remarks, there had been irregular disturbances in some part of the Bay of Naples once in every two hundred years — the eruption of Solfatara in the twelfth century, that of Ischia in the fourteenth, and that of Monte Nuovo in the sixteenth ; but ' the eighteenth has formed an exception to the rule.' It seems clear that the constant series of eruptions from Vesuvius during the past two hundred years has sufficed to relieve the volcanic district of which Vesuvius is the principal vent." So I wrote a few years ago, but the great earthquake from Ischia shows that the old state of things has not so completely passed away as had been supposed. THE BIRTH AND GROWTH OF MYTH. By Edward Clodd. XIII. TRADITIONS of transformation of men into beasts are not confined to the Old World. In Dr. Rink's " Tales of the Eskimo" there are numerous stories both of men and women who have assumed animal form at will, as also inci- dental references to the belief in stories such as that telling how an Eskimo got inside a walrus skin, so that he might lead the life of that creature. And among the Red Races, that rough analogy which led to the animal being credited with life and consciousness akin to the human, .still expresses Aug. 10, 1883,]' » KNOV/LEDGE ♦ 83 itself in thought and act. If even now it is matter of popular belief in the wilds of Norway that Finns and Lapps, who from remote times have passed as skilful witches and wizards, can at pleasure assume the shape of bears, the common saying, according to Dr. Dasent, about an unusually daring and savage beast being, "that can be no Christian bear," we may not be surprised that lower races still ascribe power of inter- change to man and brute. The werewolf superstition is extant among the North- Western Indians, but free from those diabolical features which characterised it in medi.-eval times among ourselves. It takes its place in barbaric myth generally, and although it may have repellant or cruel elements, it was never blended with belief in the demoniacal. The Ahts say that men go into the mountains to seek their manitou (that is, the personal deity, generally the first animal seen by the native in the dream produced by his fasting on reaching manhood), and, mixing with wolves, are after a time changed into these creatures. Although the illustration bears more upon what has to be said concerning the barbaric belief in animal- ancestors, it has some reference to the matter in hand to cite the custom among the Tonkanays, a wild and unruly tribe in Texas, of celebrating their origin by a grand annual dance. One of them, naked as he was born, is burifed in the earth, then the others, clothed in wolf- skins, walk over him, sniif around him, howl in wolfish style, and then dig him up with their nails. The lead- ing wolf solemnly places a bow and arrow in his hands, and, to his inquiry as to what he must do for a living, advises him " to do as the wolves do — rob, kill, and rove from place to place, never cultivating the soil." Dr. Brinton, in quoting the above from Schoolcraft, refers to a similar custom among the ancient dwellers on Mount Soracte. As in past times among ourselves, so in times present among races such as the foregoing, their wizards and shamans are believed to have power to turn themselves as they choose into beasts, birds, or reptiles. By whatever name these professional impostors are known, whether as medicine-men, or, as in Cherokee, by the high-sounding title of " possessors of the divine fire," they have traded, and wherever credulity or darkest ignorance abide, still trade, on the fears and fancies of their fellows by disguising themselves in voice and gait and covering as the animal which they pretend to be. Among races believing in transformation such tricks have free course, and the more dexter'ous the sorcerer who could play bear's antics in a bear's skin proved himself in throwing olf the disguise and appearing suddenly as a man, the greater his success, and he more firmly grounded the belief. The whole subject, although presented here only in the barest outline, would not be fitly dismissed without some reference to the survival of the primitive belief in men- animals in the world-wide stories known as Beast-fables, in which animals act and talk like human beings. When to us all Nature was wonderland, and among our play- fellows were the four-footed, the birds, and the fishes ; when in fireside tale and rhyme they spoke our language and lived that free life which we then sliarcd and can never share again, the feeling of kinship to which the old faljlos gave expression may have checked many a wanton act, and, if we learned it not fully then, at least have taken the lesson to heart since. Never to blond our pleasure or our prido With sorrow of tho meanest thing that lives. And then those " Fables " of -.SEsop, even with tlie tedious drawback of the " moral," as powder beneath the jam, did they not lighten for us in school-days the dark passages through our Valpy (for the omniscient Dr. William Smith was not then the tyro's dread), and again give us com- munion with the fowl of the air and the beast of the field ? Now, our mature thought may interest itself in following the beast-myths to the source whence Babrius and Ph;edrus, knowing not its springhead and antiquity, drew their vivid presentments of the living world, and find in the storied East the wellspring that fed the ima- gination of youngsters thousands of years ago. With some authorities the Egyptians have the credit of first inventing the beast-fable, Vjut among them, as among every other advanced race, such stories are the remains of an earlier deposit ; relics of a primitive philosophy, in which wisdom, and skill, and cunning are no monopoly of man's. The fondness of the negro races, whose traditions are not limited to South and Central Africa, for such fables is well known, as witness the tales of which "Uncle Remus" is a type, and it is strikingly illustrated in the history of the Vai tribe, who having, partly through contact with whites, elaborated a system of writing, made the beast-fable their earliest essay in composition.* In former papers, the evidence in support of the common ancestry of the languages spoken by the leading peoples in Europe, and by such important historical races in Asia as the Hindu and the Persian, has been summarised. That evidence is likewise conclusive, not only as to the origin of the myths on which the great Indo-European epics are founded, but also as to the possession by the several clans of a common stock of folk-lore and folk-tale, in which, of course, the beast-fable is included, these being the relics Ln didactic or humorous guise of that serious philosophy concerning the life of man and beast amongst the barbaric ancestors of the Indo-Europeans, upon which stress enough has been laid. Even if the common origin could be disproved, the evidence would merely be shifted from local to general foundations, because the uniform attitude of mind before the same phenomena would be proven ; but the resemblances are too minute in detail to be explained by a theory of in- dependent creation of the tales where now we find them. The likenesses are many ; the unlikenesses are few, being the result of local colouring, historical fact blended with the fiction, popular belief, and superstition, all affected by the skill of the professional story-teller. As in the nu- merous variants of the familiar Cinderella, Beauty and the Beast, Punchkin, and the like, the same fairy prince or princess, the same wicked magician and clever, versatile Boots peep through, disclosing the near relationship of Hindu nursery tales to the folk-tales of Norway and the Highlands, of Iceland and Ceylon, of Persia and Serbia, of Russia and the lands washed by the Mediterranean. In the venerable collection of " Buddhist Birth Stories," now in course of translation by Dr. Rhys Davids,! and to which he has prefaced an interesting introduction on the source and migration of folk-tales, we are face to face with many a fable familiar to us in the " .Esop " of our school-days. There is the story of the Ass in the Lion's Skin, not in which, as ^ilsop has it, the beast dressed liimself, but which the hawker put on him to frighten the thieves who would steal his goods. Left one day to browse in a field whilst his master refreshed himself at an inn, some N\atchmen saw him, and, raising hue and cry, brought out the \illagers, armed with their rude implements. The ass, fearing death, * C£. Mahaffy'a " Prolegomena to Aijoient History,'" p. 392. t A'ol. I. Triibner & Co. See also, for some valuable illnstrations from early English and other sources, au article by Kev. Dr. Morris, in " Contomp. Kov.," May, 18S1. 84 ♦ KNOWLEDGE ♦ [Adg. 10, 1883. made a noise like an ass, and was killed. L^ng might he, adds the ancient moral, Clad in a lion's skin Have fed on the barley green ; But lie br.ayed 1 And that moment he came to ruin. The variants of this old fable are found in medic-eval, in French, German, Indian, and Turkish folk-lore, as are also those of the tortoise who lost his life through " much speaking." Desiring to emigrate, two ducks agreed to carry him, he seizing hold of a stick which they held between their beaks. As they passed over a village, the people shouted and jeered, whereupon the irate tortoise retorted, " What business is it of yours 1 " and, of course, thereby let go the stick and, falling down, split in two. Therefore Speak wise words not out of season ; You see how, by talking overmuch, The tortoise fell." In iEsop, the tortoise asks an eagle to teach him to fly ; in Chinese folk-lore he is carried by geese. .Jacob Grimm's researches concerning the famous media'val fable of " Reynard the Fox," revealed the ancient and scattered materials out of which that wonder- ful satire was woven, and there is no feature of the story which reappears more often in Eastern and Western folk- lore than that cunning of the animal which has been for the lampooner and the satirist the type of self-seeking monk say liis prayers, and flies off while the outwitted beast folds his hands and shuts his eyes. But I must forbear quoting further. Enough if it is made clearer to the reader that the Beast-fable is the lineal descendant of barbaric conceptions of a life shared in common by man and brute, and another link thus added to the lengthening chain of the continuity of human history. PRETTY PROOFS OF THE EARTH'S ROTUNDITY. CHIEFLY FOR THE SEASIDE. By Richard A. Proctor. (Continued from page 70.) IN my last I described the Bedford level experiment in which use was made of a telescope t at A, (Fig. 3 bis) and of a disc 6 at B three miles oS", to determine the deviation of the line of sight from t to c (another disc at C) six miles oH', from the disc b, — t, b, and c being all at exactly the same height above the water surface ABC. The result was, to show b several times its own diameter above c, a simple and decisive proof that the points t, b, c, were not in a straight line, — as of course they would have been if the water surface were plane and therefore ABC a straight line. Fig. 3, lis. and ecclesiastic. When Chanticleer proudly takes an airing witli his family, he meets master Reynard, who tells him he has become a "religious," and shows him his beads, and his missal, and his hair shirt, adding in a voice " that was childlike and bland," that he had vowed never to eat flesh. Then he went ofi" singing his Credo, and slunk behind a hawthorn. Chanticleer, thus thrown off his guard, continues his airing, and the astute hypocrite, dart- ing from his ambush, seizes the plump hen Coppel. So in Indian folk-tale, a wolf living near the Ganges is cut oS" from food by the surrounding water. He decides to keep holy day, and the god Sakka, knowing his lupine weak- ness, resolves to have some fun with him, and turns him- self into a wild goat. " Aha ! " says the wolf, " I'll keep the fast another day," and springing up he tried to seize the goat, who skipped about so that he couldn't be taken. So Lupus gives it up, and says as his solatium : " After all, I've not broken my vow." The Chinese have a story of a tiger who desired to eat a fox, but the latter claimed exemption as being superior to the other animals, adding that if the tiger doubted his word, he could easily judge for himself So the two set forth, and, of course, every animal fled at sight of the tiger, who, too stupid to see how lie had been gulled, conceived high respect for the fox, and spared his life. Sometimes the tables are turned. Chanticleer gets his head out of Reynard's mouth by making him answer the farmer, and in the valuable collection of Hottentot tales which the late Dr. Bleek, with some warrant, called " Reynard in South Africa," the cock makes the jackal To direct the telescope < to c it had to be slightly de- pressed, at least if c were brought exactly to the centre of the field of view. But it seems that although the telescope was apparently level — indeed one account says that it was carefully levelled — the distant disc c appeared to be in the centre of the Held, absolutely coincident with the intersec- tion of two cross-hairs marking the centre of the field. On the strength of this observation the loser claimed that the stakes should be handed to him. The claim was natural enough, and no doubt honestly made. Doubtless, also, the loser was convinced then and he may even be convinced still that wrong was done to him in the rejection of his claim. Be this as it may, it was probably unfortunate for him that he was thus led astray, as there is every reason to believe that his stake would have been returned to him by the winner but for the wild and angry ways into which this mistaken notion caused the loser to indulge. Now let us inquire where his mistake lay. We shall thus be led to a proof of the earth's rotundity which though not so simple and striking as the one described at page 69, is really as convincing. It can readily be tested at the seaside by any one of ingenious and handy turn. In the plan illustrated in Fig. 3, the disc b may be re- garded as part of the apparatus employed to measure the depression of c. Of course b is itself depressed below the true horizon plane through t, but c is depressed four times as much, and therefore seen below the disc b in the tele- scopic field. In the other test, the disc at b is not used to help the observer. Let us see what remains to show the earth's rotundity. Aug. 10, 1883.] ♦ KNOWLEDGE ♦ 85 Consider the geometry of the matter. It is simple enough : — Let A, B, C, lie, Fig. 5 represent the same points as the same letters in Fig. 3. Draw I h' c' square to < A producing B h and 0 c to meet I c' in U and c' respectively. Also join t h, and produce to meet C c in c". Then we know that the angle c tc' \s equal to the angle in the alter- nate segment of the large circle of which the is a part, The loser of the wager asserts that the signal c (not the central point c) was on the line h h\ though admitting that b was above c. Thus if the centre of c was on li h' the centre of h was above h It ; and if the centre of b was on h Id the centre of c was below /( h'. Either result would suffice to show that the explanation based on the straight- ness of the line t b c was certainly erroneous. Both b and c and therefore to twice the angle b tc on the arc b c (which is half of t b c). Hence, the lines B h', C c' being approxi- mately parallel, we see that hli =kb =6 ft. approximately ; cc"=c'z" ^j'k=V2ii. approximately; and (■ c' = 2c c" = 24 ft. approximately. Now when the telescope at t is truly levelled it is so directed that its optical axis is in the straight line t U c', — so that as the disc c lies in the direction t c, while b lies in the direction t h c", we ought if the centre of the field were exactly marked to see 6 below that centre by a certain small distance and c twice as far below that centre. Regarding these as small dots, we should see what is shown in Fig. 6 where a marks the intersection of the cross lines, b the centre of disc b, and c the centre of the remoter disc c. All this is nearly as obvious as what we found in the other test, only not quite so simple. If our telescope were perfectly levelled, the horizontal cross hair lih' absolutely central, b removed, and c were found to be exactly on li h', then — why then — Well, if the sky were to fall we should catch larks. The earth-tlatteners should hardly expect astronomers even then to admit that the earth is Hat, simply because there are a hundred other absolutely overwhelming proofs that the earth is a globe. It would be diliicult to explain such an anomaly as would thus be indicated. Either it would appear that the water surface ABC unlike the ocean surface, or any other liquid surface, was absolutely plane, perhaps through some abnormal local attractions — or else it would appear that some almormal refractive action of the atmosphere had raised c up to the true horizon of t. Not one jot would or could the faith of astronomers in the rotundity of the earth, proved a hundred ways, waver before such evidence. But, of course, no such I evidence has ever been obtained. were not on h h', as they must both have been had the straight line from t to c been in the real horizon. We know then already that either the observation on the strength of which c was supposed to be on h h' was but rough, or else the instrumental adjustments were imperfect, the telescope not truly levelled, or h K not truly across the centre of the field. But let us see how great the distance a c in Fig. 6 should have been, supposing the adjustments all perfect. Suppose the magnifying power of the telescope to have been 12, that being about the utmost magnifying power likely to be used in a levelling experiment of the kind — for long tele- scopes are never used with exact adjustments to bring the optical axis level. Then we have e (i (Fig. 5) = 24 feet But atmospheric refraction practically reduces cc' by about a fourth leaving 18 ft. only. Thus the angle cie' as observed with the naked eye {i.e., as distinguished from the geometrical angle ctd) is the angle subtended by 18 ft. at a distance of six miles or of eighteen times 1700 ft This is the angle sulitended by 1 ft at a distance of 1760 ft, or by 1 inch at a distance of 17 GO inches, or by the hundredth of an inch at a distance of nearly 1 S inches. As the telescopic magnifying power increases this angle twelve- fold, we have the angle actually observed with the telescope equal to that subtended by the hundredth of an inch at a distance of 1 i in. It is exactly one-tenth of the angle B O A in Fig. 7, and is fairly represented by the dark line B 0 pointed at end 0, Fig. 7. Is it likely that an unpractised observer (all the observers in the Bedford experiment were unpractised) would detect the depression of the distant signal c below h h' by this small angle — the signal not being a point but a disc — even if the cross hair h It had been precisely ad- justed to correspond with the real horizon ] But it is ex- ceedingly unlikely that /( It was properly adjusted. If not, and there are fi-w nicer adjustments in practical survey- ing, it is certain that none of the observers employed could have even detected, far less have corrected, the error. This particular test, then, under the conditions existing, was practically worthless, — the appearance of c below 6 was a hundred times better as a test, and indeed of itself proved (if the loser's statement about c being on the cross hairs can be trusted) that the levelling of the telescope and the adjustment of the horizontal cross hair were inexact 86 ♦ KNOWLEDGE ♦ [Aug. 10, lf<83. But there is a pretty way of testing the depression of the water horizon due to terrestrial rotundity, which requires no telescope, and only a little care in execution. Parallax used the method, in a purposely inexact way to show the earth to be flat. This method will be considered in our next. (To be continued.) THE MOON IN A THREE-INCH TELESCOPE. By a Fellow of the Royal Astroxomical Society. "XTTHEN the Moon is nine or ten days old, the Bay of * \ Rainbows (P in our map) presents a perfectly charming spectacle to the observer. This great, dark, semi- circular area appears absolutely level in the instrument we are using, but is surrounded by a mass of stupendous cliffs. It measures, from Cape La Place (134) to Cape Heraolides (135), nearly 135 miles. Heraclides rises some 4,000 feet above the level of the bay, but is as a mere hillock com- pared with some of the neighbouring highlands. As we travel in an easterly direction we arrive at Sharp (139), 15,000 feet in height, and some of the peaks in this chain probably attain an altitude approaching to 20,000 feet. Nearly due south of Cape La Place lie two little, but exceed- ingly deep craters — the Eastern one of which. Helicon, is marked 129 in the map. And now we arrive at a region covered with systems of light streaks, akin to those de- scribed on p. 56 as emanating from Tycho. Euler (125), a fine ring plain, 19 miles in diameter, \vith a central peak, is the centre of one of these systems of rays. Tobias Mayer (117), 22 miles across, is an interesting object under suitable illumination. Of all the formations, however, in this region of the Lunar surface, there is nothing to compare with that superb one, Copernicus (112), :^ Copernicus. Moon's Age, 10'27 days. our sketch of which above was taken with a power of 160, when the moon's age was 1027 days. This magnifi- cent ring-plain measures 5G miles across. There are, alto- gether, eight peaks rising from the interior — three bright ones, and four less so. With the instrument employed, however, and under the conditions of illumination then obtaining, two only of these were, as will be seen, visible at the epoch of our drawing. The terraced character of the wall is conspicuous enough, even in a 3-in. telescope, as is the disturbed and complicated character of the region imme- diately surrounding it. Two deep craters south of Copernicus, approximating in appearance to the figure 8, will at once strike the eye. So also will a conspicuous peak on the western wall, which is between 11,000 and 12,000 ft. high. The somewhat angular character of the contour of the wall is well seen from the shadows cast towards the east. Other features will strike the attentive observer. At full moon, Copernicus is seen to be the centre of a system of light streaks, uniting with similar ones from other formations, to which we shall hereafter refer. It is worthy of note that the streaks extending in a westerly direction from Copernicus are the most numerous ; though those which lie towards the north are individually more conspicuous. There is an enormous number of tiny craters between Copernicus and Eratosthenes (110) ; but even the largest of these require favourable illumination and conditions, to be seen in our instrument. Reinhold (114), 31 miles across, will repay scrutiny while the telescope is turned on this part of the moon's visible disc. Euclid (221), and Landsberg (222), furnish examples of craters surrounded by a kind of nimbus or light ring. This, as will be seen on examination, difl'erg in appearance from the streaks emanating from Tycho, CopCTnicus, Kepler, and Aris- tarchus. Kepler (144), by the way, may be here referred to as a crater, close upon 22 miles across, the centre of a great system of light streaks, uniting with those from Copernicus. Close to Euclid lie the Riphrean Mountains (220). Under oblique illumination they strongly suggest an exaggerated, or caricatured, bas-relief of a Uama or giraffe. One of the deepest craters in the Sea of Clouds is Bullialdus (213), to which a light sti'eak extends (as mentioned on page 56) from Tycho (180). This is 38^ miles across, with finely- terraced walls of considerable breadth, and a fine central mountain 3,000 feet high. The considerable crater or ring- plain, breaking into the southern wall, too, will at once strike the eye, while a very similar one (but detached from Bullialdus proper) will be noted to the south of this again. Campanus (226), a ring 30i miles across, in this neighbour- hood, is chiefly remarkable for the darkness of its interior. Hainzel (237) is a kind of pear-shaped ring-plain, 55 miles in its longest diameter, with high and precipitous walls rising some 11,600 ft. in places. The wall of Capuanus (238), too, will repay examination under suitable illumina- tion. Capuanus is one of the comparatively few craters that remain conspicuous and identifiable when the Moon is full. We are now in the neighbourhood of the Sea of Moisture (T in our map). The student may begin his ex- amination of this region with the large bay in this " sea," Hippalus (225). The chief interest, however, attaching to this locality resides in the wonderful system of " rills," or narrow and tortuous clefts, existing to the west of Hippalus. The majority of these require a large instrument for their detection, but one or two of them are within the reach of a three-inch telescope when the Moon is between nine and ten days old. The formation of ViteUo (229) .=eems to afford an illustration of the vulgar phrase, "a wheel within a wheel," inasmuch as the outer ring-plain encloses another one, from the interior of which rises a mountain, 1,600 ft. or 1,700ft. high. With the examination of Gassendi (232), on the northern boundary of the Sea of Moisture, we shall conclude another night's work. Our sketch of this fine and interesting formation was made with a power of 160, the moon being 11 -24 days old, and Gassendi very nearly on the terminator. The diameter of this great walled plain is fifty-five mUes. The height of its surrounding cliffs varies greatly ; in places they rise to an altitude of some 10,000 feet, while towards the south, as will be seen in the drawing we give, they diminish to a twentieth part of that height. It is worthy of remark that Madler asserts that the floor of Gassendi is in its northern part quite 2,000 feet above the level of the almost adjoining Sea of iloisture. It will be observed how the northern part of the wall has been destroyed by the s-ubse- Aug. 10, 1883.] ♦ KNOWLEDGE ♦ quent eruption in which the great spoon-shaped ring plain shown was formed. At the epoch of our sketch, the three central mountain masses, rising from the principal plain, were conspicuously shown. It will be seen that the western- most of these is the largest and highest, the tips of the Gassendi. Moon's age, 11'24 days. others only peeping, as it were, out of its shadow. This is a formation which may be advantageously studied con- tinuously during the eleventh and twelfth days of the moon's age, as it exhibits so many complicated features ; and it is most insti'uctive to the beginner to note how these come into view, and alter in aspect with advancing sun- light. Moreo\er, the student should observe it in different states of the moon's libration.* The changes produced in the aspect of formations in the neighbourhood of the moon's limb from this cause are most striking and remarkable. {To he continued.) WEATHER FORECASTS, AND HOW TO MAKE THEM. By John Browning, F.R.A.S. INTRODUCTION. NEARLY all the readers of Knowledge, I imagine, turn to the portion of their daily newspaper which contains the forecast of the weather issued by the Meteoro- logical Committee of the Board of Trade at 8.30 p.m. on the previous day, to see what weather is predicted. Very various are the opinions as to the accuracy of these predic- tions, some declaring them to be nearly always right, while others say they are nearly always wrong. INly own opinion, after noting them carefully for years, is, that where the weather is alike over large areas, the forecasts are in the main correct ; and when the weather is partial, observa- tions taken at a number of points in cither of the areas would show the forecast for that area to be fairly correct. But with partial weather, which we so often experience in England, many persons will find the pre- diction proves inaccurate. The only remedy for this is to forecast the weather for each district for ourselves. After the experience of several months, I am satisfied that this may be done with considerable accuracy. I was first induced to give my attention to this suliject from my desire to know when I might undertake long journeys on a tricy<'lo with a fair prospect of tine weather. But a very little consideration will show that the matter is one of * For ail explanation of lunar libration, see " Tlio Moon," by tlio editor ul' Knowledge (Longman & Co.), pp. 118, ct seq. national importance. There is enough good weather probably in the worst seasons to get in all standing crops safely if agriculturists only knew wlien to expect it and could take advantage of it. What is greatly required, is accurate predictions of the probability of rain. The weather forecasts of the Board of Trade are nearly always correct as regards the direction and force of the wind. Now to foretell rain it is well-known that the barometer is useful, but it should not be reKed on solely, as there are two instruments which give indications that are more serviceable ; these are the Rain-band Spectroscope and the Weather Compass. THE RAIN-BAND SPECTRO.SCOPE. To refer first to the rain-band spectroscope. For years it was known that there were many lines in the solar spectrum which could not be identified with the lines given by any of the metals. It was noticed that these lines were more numerous about sunrise and sunset. Jannssen, the French astronomer, showed that these lines were due to moisture — that is, the vapour of water being present in our atmosphere. The increase in their number and intensity about sunrise and sunset is due to the fact that the sun's rays at those times pass through a large amount of our atmosphere. The proof that Jannssen gave of the source of these lines, though exceedingly simple, was convincing. He placed a bright light of burning coal-gas, or oil, at one end of an iron tube thirty feet long, and a spectroscope at the other end. The spectrum of the bright ilame seen in this way was, of course, a continnous spectrum without any lines. Then he closed both ends of the tube with plates of glass, and filled the tube with transparent steam. The spectrum of the light seen through the steam contained a great number of tine lines which corresponded with those seen in the solar spectrum near sunset, and were most numerous near the red end of the spectrum. Professor Piazzi Smyth first observed that these lines were more numerous in the spectrum before a fall of rain, and proposed to use them for the purpose of predicting rain. But he used in his experiments a powerful and expensive instrument — diflicult to use and too expensive for general adoption. Mr. J. Rand-Capron has recently found that equally good results may be obtained by using a spec- troscope, which can be bought for as many shillings as the original instrument cost pounds. In his small pamphlet, " A Plea for the Rain-band," reprinted from the Meteorological Jfagazine, Mr. Rand- Capron has described his method of using the smaller instrument. The original papers, both of Professor Smyth and Mr. Rand-Capron, were, of course, addressed to the scientists. The editor of Knowi.ege having kindly asked me for some papers on this subject, I shall try my utmost to make my instructions for using the instrument as clear as possibla (To be continued.) TUB FISHERIES EXHIBITION. By John Ernest Ady. IN our last contribution we proposed to take a glance at the sponges which adorn some of the cases in the Exhibition, and to show how they came to occupy their present place in the system of zoology. At the outset we may state that their true systematic position has been only recently established, through technical methods of research 88 ♦ KNOV/LEDGE . [Aug. 10, 1883. into their minute structure and developmental history, ■without which their real nature could never have been determined. This, then, affords an explanation of how it was that the older naturalists looked upon them as plants, and subsequently regarded them as composite animals of a primitive type. The sponges are amongst the most useful and beautiful objects in the Exhibition. Their utility is obvious to everyone in the civilised world, and particularly to a large community of individuals who depend for their living entirely upon the sponge fisheries. ijij- Fig. S. — Commercial Sponge, showing outgoing cnrrents^of water. In modern times the chief sponge fisheries are'confined to the regions around the Bahamas and in the Mediterra- nean Sea, especially in the Grecian Archipelago, and the respective products of both localities are well represented in the foreign gallery of the Exhibition buildings which runs parallel with the aquarium. Fig 9 — Outer surfice of d fferei t k i Is f cj i <»(. (nat inl size). A, c„i, olcp^J Voi.oo^ , B, u^ucy^-u^.b ^^uu-c ; C, luhui,- sponge ; D, Bahamas sponge, partly in sections, showing projecting extremities and internal tubular character. Let us confine our attention at present to the external forms presented by these sponges, and revert in future communications to their anatomical characteristics and affinities. There are thousands of sponges which are of no com- itercial value, either from a strictly utilitarian or an aesthetic point of view. The useful sponges, known as the sponges of commerce, belong to one small group, the ySpongia, of which Fig. 8 is an example ; they are divided into two principal subdivisions : 1. The common sponges {Spo7i(jia officinalis) of large rounded or flat forms, soft tissue, convex beneath, and of coarse texture. 2. The fine sponges {Spoiiffia ttsilalissimuin) of concave or cup-like form and tine texture. Fig. 10.- -Siliceous skeleton of Tenus's flower-basket, Euplectella speciosa. It must be borne in mind that we are now speaking merely of the commercial article sponge, and not of the living animal of that name. The former is merely the skeleton of the latter, and consists, in the case of the sponges of commerce, entirely of a horny material called keralose, in the form of fine fibres matted together in such a way as to leave :.umerous large apertures and smaller pores throughout its substance. Fig. 9 shows these differences in texture of some of the principal sponges of commerce. As a rule, the sponges of the Mediterranean are liner than those of the West Indies ; they are, therefore, of higher value for domestic purposes. The usefulness of the sponge must also largely depend on the purity of the fiVires of its keratose skeleton and their elasticity, for upon these qualities do their absorbent powers depend. But some of the sponges of commerce live under such adverse circumstances, amidst debris of all kinds, that particles of grit, itc. , become inextricably woven into their Aug. 10, liti3.] KNOWLEDGE ♦ 89 skeletons. Such varieties are used in America for stuffing cushions, bedding, and other upholstery work. Yet other keratose sponges possess, in addition to their fibrous network, a number of siliceous spicules, which strengthen their skeletons, and also lie embedded in their fleshy substance {e.g. SpowjUIa, llalichoiidria) ; they are, therefore, of no special commercial value, although, as we shall show later on, they are of vast interest to the naturalist. When the siliceous spicules predominate, and, finally, when they entirely take the place of the keratose, the sponges are known as siliceous ; and amongst these are some of the most beautiful forms in nature. Fig. 10 is but a poor representation of the delicate beauty of one of these forms which occurs around the region of the Philip- pine Islands, and several specimens of which may be viewed in the Exhibition; more notably in Lady Brassey's .Sw;;,- heam collection, and in two beautiful groups encased in dome-shaped glasses at the end of the Natural History Galleries. We shall have occasion hereafter to give a brief description of the structure of these and other sponges. We are indebted for these figures to the kindness of Messrs. Griflith A- Farran, of St. Paul's Churchyard, from whose work, " The Commercial Products of the Sea," by P. L. Simmonds, they have been derived. T SEA ANEMONES AT THE FISHEKIES EXHIBITION. By Thomas Kimbee. II.— THE WHITE CARNATION. AcUnoldba iianiJius (Blainville). Actinia penta'petala {Verm). HIS is one of the largest of the British sea anemones. and also one of the handsomest. Large specimens- over a dozen of the purest white — may be seen in Ko. 10 livo princiiuil lubua siiliili tank, and still larger — -t or 5 inches across and 6 in height — in some of the other tanks ; while there are j-oung midgets not larger than a pea, with all intermediate sizes. Fig. 1. The disk, ttc. — In this species the piincipal lobes or petals vary in number from five to eight or nine, and each lobo is frequently subdivided and voluted, so that the entire disk, though truly circular in outline, will not expand into a plane surface. The tentacles are numerous in the adult near the mouth, and moderately long, but shorter near the margin ; and the edges of each lobe and its sub-divisions are fringed with fine short tentacles that defy numeration. When the disk is much convoluted, as is usual in large specimens, it assumes a semi-globose form, and has a feathery surface. Hence the expressive name plumosa, given to this anemone by several writers. The mouth has a thick lip, divided into lobes, and is generally rufous or orange, whatever the general colour of the animal may be. Fig. 2. — Column, edge of disk, kc. Fig. 2. The column, &c. — A full-grown specimen in fiower, as here shown, is a very beautiful object, and the greatest possible attraction to any aquarium. At the summit of the column is a thick, round rim, like a ring, and behind it the fosse. The base is always very much Itroader than the rest of the body. Tlie white variety, which Figs. 1 and 2 illustrate, is not at all uncommon, and to it is universally conceded supremacy in beauty. Gene- rally speaking, whatever the hue, it is uniform throughout in the same specimen. The commonest varieties are pro- bably buff and cream colour, and then pale red. Amber, dark brown, and olive are comparatively rare varieties. The brown and olive examples have whitish tentacles, marked with an opacjue bar. Several good examples of the olive dianthus with smoky-white disk, occur in the Exhibition. The Button. — This anemone is e.xceptionally flat when closed, and to-day (July 31), in Id tank, are good instances of the button form, both white and buff, and in difi'erent sizes. The outline of a large one is quite irregular, perhaps five inches across, thin as a card at the edges, and in the centre not more than the eighth of an incli in thickness. 90 ♦ KNOWLEDGE ♦ [Aug. 10, 1883. Small shrimps in the tank are constantly approaching the disk, a dianthus, and dart away several inches, as if stung, on touching the tentacles. The instantaneous movement has quite the appearance of being the result of an electric shock. Individuals of this species seem to vary in character. There appears to be a " quiet family," and a race much given to movement. Some of the more lively frequently change the contour of their figures, at one moment appear- ing tall and straight as a marble column, and the next constricted immediately below the margin (as if very fashionably laced), so that the fringed lobes droop over like a lily. This singular construction then gradually moves downwards, and, when half-way, gives the animal the form of an hour-glass. Gradually it descends almost to the base, but very soon moves up again, and the process is then reversed, until the lovely lily-like form is restored. This most interesting performance will sometimf s continue for an hour together, the animal never retaining its ordinary shape for a minute at a time. The same individual will at other times be perfectly quiet for an entire day, the only perceptible motion being in the ever-varying fringe of down-Uke tentacles which encircle the disk. Actinoloha. is the name given by Blainville, 1834, and followed by Gosse, 1860. It is, or should be, derived from uK-lv a ray, and Xopdc a lobe, and means an animal with lobed tentacles. The term diantlms is said to be thus named (c7o divine, ai Oor flower), from its extreme beauty. Miiller has named dianthus Actiniarmn 2>ulclier- rima, the most beautiful of all anemones, and so far as this verdict relates to European species, it is admitted to be just. Writers vie with each other in its praise. The whole creature, one aptly declares, is exquisitely lovely, and can be compared only to the most graceful flower formed of rich white or amber feathers. Besides its extreme beauty of outline, the contrast in colour between this lovely. creature and the medium in which it lives and moves is equally striking, and generally arrests the attention and elicits the admiration of the most careless observer. The next paper will give a further account of dianthus with respect to locomotion and reproduction, how to obtain specimens and keep them in health, with a description of the gorgeous examples obtained by the United States ex- ploring expedition. A STEAMER GOES SAFELY PAST NIAGARA WHIRLPOOL.* IN the year 1846, a small steamer was built in the eddy just above the railway Suspension Bridge to run up to the Falls. She was very appropriately named — The Maid of the Mist. Her engine was rather weak, but she safely accomplished the trip. As, however, she took passengers aboard only from the Canada side, she did little more than pay expenses. In 18.54 a larger, better boat, with a more powerful engine, the new Maid of the Mist was put on the route, and many thousands of per- sons made this most exciting and impressive tour under the Falls. The admiration which the visitor felt as he passed quietly along under the American Fall was changed into awe when he began to feel the mighty pulse of the great deep just below the tower ; then swung around into the white foam directly in front of the Horse-shoe and saw the sky of waters falling toward him. And he seemed to be lifted on wings as he sailed swiftly down on the * From " Niagara : Its History and Geology." By Geo. W. HoUey. flying stream through a baptism of spray. To many persons there was a fascination about it that induced them to make the trip every time they liad an oppor- tunity to do so. Owing to some change in her appoint- ments, which confined her to the Canadian shore for the reception of passengers, she became unprofitable. Her owner having decided to leave the place wished to sell her as she lay at her dock. This he could not do, but had an offer of something more than half of her cost, if he would deliver her at Niagara, opposite the Fort. This he decided to do, after consultation with Robinson, who had acted as her captain and pilot on her trips under the Falls. The boat required for her navigation an engineer, who also acted as a fireman, and a pilot. On her pleasure trips she had a clerk in addition to these. Mr. Robinson agreed to act as pilot for the fearful voyage, and the engineer, Mr. Jones, consented to go with him. A courageous machinist, Mr. Mclntyre, volunteered to share the risk with them. They put her in complete trim, removing from deck and hold all superfluous articles. Notice was given of the time for starting, and a large number of people assembled to see the fearful plunge, no one expecting to see either boat or crew again, after they should leave the dock. This dock, as has been before stat«d, was just above the railway Suspension Bridge,* at the place where she was built, and where she was laid up in the winter ; that, too, being the only place where she could lie without danger of being crushed by the ice. Twenty rods below this eddy the water plunges sharply down into the head of the crooked, tumultuous rapid which we have before noticed, as reaching from the bridge to the Whirlpool. At the Whirlpool the danger of being drawn under was most to be apprehended ; in the Rapids of being turned over or knocked to pieces. From the Whirlpool to Lewiston is one wild, turbulent rush and whirl of water without a square foot of smooth surface in the whole distance. About three o'clock in the afternoon of .lutie 1-5, 1861, the engineer took his place in the hold, and, knowing that their flitting would be short at the longest, and might be only the preface to a swift destruction, set his steam-valve at the proper gauge, and awaited — not without anxiety — the tinkling signal that should start them on their flying voyage. Mclntyre joined Robinson at the wheel on the upper-deck. Self-possessed, and with the calmness which results from undoubting courage and confidence, yet with the humility which recognises all possibilities, with down- cast eyes and firm hands, Robinson took his place at the wheel and pulled the starting-bell. With a shriek from her whistle and a white puff from her escape-pipe to take leave, as it were, of the multitude gathered on the shores and on the bridge, the boat ran up the eddy a short dis- tance, then swung around to the right, cleared the smooth water and shot like an arrow into the rapid under the bridge. She took the outside curve of the rapid, and when a third of the way down it a jet of water struck against her rudder, a column dashed up under her starboard side, heeled her over, carried away her smoke-stack, started her overhang on that side, threw Robinson flat on his back and thrust jSIcIntrye against her starboard wheel-house with such a force as to break it through. Every eye was fixed ; every tongue was silent, and every looker-on breathed freer as she emerged from the fearful baptism, shook her wounded sides, slid into the Whirlpool and for a moment rode again on an even keel. Robinson rose at once, seized the helm, set her to the right of the * See the map in om' last. "We hope to give next week a view of the Whirlpool Eapids, from a photograph in the Editor'a possession. Aug. 10, 1883.] • KNOWLEDGE ♦ 91 large pot in the pool, then turned her directly through the neck of it. Thence, after receiving another drenching from its combing waves, she dashed on withoiit further accident to the quiet bosom of the river below Lewiston. Thus was accomplished the most remarkable and perilous voyage ever made by men. To look at the boat and the navigation she was to undertake no one would have pre- dicted for it any other than a fatal termination. The boat was seventy-two feet long with seventeen feet breadth of beam and eight feet depth of hold, and carried an engine of an hundred horsepower. In conversation with Robinson after the voyage, he stated that the greater part of it was like what he had always imagined must be the swift sailing of a large bird in a downward liight ; that when the accident occurred the boat seemed to be struck from all directions at once ; that she trembled like a fiddle- string and felt as if she would crumble away and drop into atoms ; that both he and Mclntyre were holding to the wheel with all tlieir strength, but produced no more efl'ect than if they had been two flies ; that he had no fear of striking the rocks, for he knew that the strongest suction must be in the deepest channel, and that the boat must remain in that. Finding that Mclntyre was somewhat bewildered by excitement or by his fall as he rolled up by his side but did not rise, he quietly put his foot on his breast to keep him from rolling round the deck, and thus finished the voyage. The effect of this trip upon Robinson was decidedly marked. To it, as he lived but a few years afterward, his death was commonly attributed. But this was incorrect, since the disease which terminated his life was contracted at New Orleans at a later day. " He was," said Mrs. 1-lobinson to the writer, " twenty years older when he came home that day than when he went out." He sank into his chair like a person overcome with weariness. He decided to abandon the water, and advised his sons to venture no more about the Rapids. Both his manner and appearance were changed. Calm and deliberate before, he became thoughtful and serious afterward. He had been borne, as it were, in the arms of a power so mighty that its impress was stamped on his features and on his mind. Through a slightly opened door he had seen a vision which awed and sulidued him. He became reverent in a moment. He grew -^-enerable in an hour. ': ^Yet he had a strange, almost irrepressible desire to make this voyage immediately after the steamer was put on below the Falls. This wish was only increased when the first -Vaid of the Mist was superseded by the new and stauncher one. He insisted that it could be made with safety, and that it might be made a good pecuniary speculation. Ti[n total number of visitors to the Fisheries Exhibition reached 1,000,000 during the course of Tuesday, the last day of J uly, that is to say, within sixty-eight days of the opening on Whit Monday. This gives an average of about 11, 700 visitors per diem. The two largest days were Whit Monday and Tuesday, with 42,941 and 29,146 visitors respectively. For cementing rubber or gutta percha to metal Mr. Moritz Grossman, in his " Year Book " for 188.3, gives the following recipe : — Pulverised shellac, dissolved in ten times its weight of pure ammonia. In three .days the mixture will be of the required consistency. The ammonia penetrates the rubber, and enables the shellac to take a ♦inn hold, but as it all evaporates in time, the rubber is ininio\ably fastened to the metal, and neither gas nor water will remove it. PRINCIPLES OF DRESS REFORM. By E. M. King. IT is the theory of Herbert Spencer that imperfection in mankind is due to its being out of harmony with its surroundings. That " all evil results from the non- adaptation of constitution to conditions." That this non- adaptation is caused by having a faculty in excess or a faculty that is deficient. That finally, by the working of an unalterable law, " all excess and all deficiency must disappear, that is, that all unfitness must disappear ; that is, all imperfection must disappear." And, in this way, humanity must become completely adapted to its con- ditions, that is to say perfect.* There seems to me to be a flaw in this reasoning. There is a tacit assumption that " conditions " are perfect, and therefore that if character is adapted to conditions it must necessarily become perfect also. But the conditions which surround men may not l:>e perfect, they may tend to diminish a good faculty, and to increase a bad one, and this will not lead to perfection, but the reverse. Writers on social science whose works I have read do not seem to have recognised that mankind has two surroundings or conditions ; his natural surroundings and his social sur- roundings. The former, or laws of nature, are fixed and inexorable; the latter, or social laws, are not as " H. S." aflirmsjt " sure and inflexible," but fluctuating, and con- tinually made and unmade by society. I am not speaking here of mere social etiquette, but of all sociological laws. We are conscious, daily and hourly, of the powerful influence of our social surroundings; they even appear to shut us out from, or blind our eyes to, the more sure, but less apparent, laws of nature. Very often the two sets of laws are at variance, and thus it happens that an individual may be perfectly in harmony with his social surroundings or conditions, but out of harmony with his natural sur- roundings or conditions. Our social surroundings, for a time at least, shield us from some of the pains and penal- ties of disobeying — or being out of harmony with — the laws of nature. When this state of contradiction, or antagonism, is arrived at, the punishment appears to be, by slow degrees, distributed from the individual to the class, or race, or nation which disobeys. For instance, a man dealing dishonestly where there is a low standard of honesty in trade, suflers little from his social surroundings — he is in harmony with them, and they with him ; but instead of himself and his trade moving on to perfection by this adaptation of constitution to condi- tions, he is moving on to degradation of character and his trade sinking to decay and ruin. Again, a man who lives an impure life, in a society which allows laxity of morals as excusable in men, i.s in harmony with his social surround- ings, although he is at war with the laws of nature. His social surroundings are increasing his bad faculties and diminishing his good ones, and in the end that class, or race, or nation so degrading character to its social con- ditions, meets with its due reward. Before humanity reaches perfection it has a two-fold work before it, not only to adapt character, or constitution, to conditions, but so to modify, alter, and improve these latter, that they shall be favourable to the highest develop- ment of his faculties, whether intellectual, moral, or physical. Of necessity, then, the first step of every reformer must be to put himself out of harmony with his immediate or social surrounding or conditions. Socrates, Lloyd Garrison, and other such reformers, were all glorious men, who had ' Social Statics," chap. t Ibid., p. 55. 92 ♦ KNOWLEDGE ♦ [AcG. 10, 1883. a (good) " faculty in excess," which no laws, radical or social, could diminish. They voluntarily put themselves out of harmony with their surroundings, and had to endure the hate, abuse, ridicule, and misconstruction which their disobedience to the social laws of the time entailed upon them. The fashionably-dressed woman is completely in harmony with her surroundings. She feels this in herself by a delightful sense of self-complacency. Society pets her, and "pays attention" to her, for, on the whole, society likes fashionably-dressed women, however much fashion in the abstract may be abused. But the more the fashion- able woman is in harmony with her surroundings, and the more society is in harmony with her, so much the worse for society and for women. When people condemn fashion, they usually mean only the most glaring violations of good taste which they may happen to observe — especially if it is personally incon- venient to them — which fashion from time to time introduces. And this is generally only objected to on its first appearance, for the eye soon gets reconciled to it and ceases to object, and so the harmony between the fashionable woman and her social surroundings is soon re-established. While this even balance is kept up no reform can be expected to arise on either side. Something more is required than this occasional protest against, and avoidance of, the passing fashion-folly of the day. We must look a little deeper, and see what it is in ourselves and in our ordinary mode of dress which makes us liable to be caught by, and made victims of, the con- tagious disease of Fashion. It is this : that our ordinary mode of dress is not con- structed with any reference to the requirements of the body, nor to the beauty of its natural form. It has, there- fore, no firm and lasting basis in Reason. Nothing from which beauty can naturally grow as out of a stem — nothing upon which to base the eternal canons of loveliness — nothing, in short, which can permanently ensure us either fitness or beauty in our dress. Until, therefore, we lay the right foundation, any utility or beauty which those who pander to our morbid desire for change may oflfer us, will only come by chance or accident, and be swept away by the next turn of the tide. From my point of view, then, with regard to dress reform, the necessity, scope, and aim of which I have endeavoured logically to put before your readers, my fifth requirement — that we must not depart too conspicuously from the ordinary dress of the time — means that we must depart a little conspicuously. Bear in mind that for this, as for every other reform, two things are necessary — reform of the individual, and reform of the social medium in which the individual lives, and though the first process may be done in secret, every true-hearted and courageous reformer is bound to go on to the second, and is called upon to take a step which must, for the time, put him out of harmony with his surroundings. Dress appeals to the eye. It is through the eye that society has been educated in bad taste, and that our social surroundings tend to the increase of women's bad faculties and to the decrease of their good ones. AVe must there- fore begin this second process by an appeal to the eye, in however small a degree, so as gi-adually to modify, alter, and finally change the condition of our social environment, so that it may become favourable to the development of our best faculties, moral, intellectual, and physical. For this reason also (that dress appeals to the eye) I have struck here the keynote of beauty rather than of health, though on this latter head as much, or more, re- mains to be said which has not yet been said. Those who are alive to the necessity of reform must be content to remain in a state of change or transition until the twofold revolution in mind and act is completed. This is not the " morbid " desire for change, but the healthy desire for perfection. Those who desire progress in re- form must dread any bars placed across the road. Such a bar, I consider, the advice of " Pedestrienne " — that a garment must be of a certain shape and a certain definite width in inches. Any hard-and-fast line of this kind is a bar to progress. Such a one as this induces women to think that in making some little paltry advance they have done all that is needful, and that they may after that go comfortably to sleep for the next generation or two. No mental or moral faculty has been called into active exercise ; they have simply accepted a fashion which some individual or some society has succeeded in inducing them to wear, just as they would have received it from the shops or the fashion-books. I am so tired of hearing that women naturally shrink from making themselves " '""nspicuous." Everyone " natu- rally shrinks " from dom^ v. hat is disagreeable to them, because every one naturally shrinks from the pain of putting themselves out of harmony with their surroundings. But this is no reason why tbey should not do their duty, and dress reform is the imperative duty of every woman who can think, and who can raise a finger to act. But it is not the fact that women naturally shrink from making themselves conspicuous. The whole sex, both from natural and acquired propensities, loves to make itself conspicuous. In comparison with men, we may be called the personally-conspicuous sex. We ought, therefore, to be proud of being conspicuous in the cause of reason, as we have hitherto been in the cause of folly. But I would spare my sex as much as possible not because we naturally shrink from making ourselves con- spicuous, but because morbid self-consciousness and personal vanity have been so largely increased in us by our social environment that it gives us much greater pain than it does men to put ourselves out of harmony with it in a matter which touches so sharply on these tender points. As far as I am able, I strive to act upon the social medium, so that as little pain as possible may be felt in taking this first painful step. More especially I address myself to men, by arguments which they (some of them) can follow and appreciate. If they see flaws in my reasoning let them point them out. If they think them sound, let them help us. The Pilsen-Joel and General Electric Light Company (Limited), which possesses in the Pilsen lamp one of the best arc regulators yet invented, have presented a petition for winding-up. A Novel Literary Scheme. — In pursuance of a sug- gestion that the Parcels Post may be so utilised as to enable readers of current literature to see the magazines and reviews at a reduced cost, a central agency has been esta- blished for the promotion of this object. The scheme is, in brief, an adaptation of the principle of the circulating library, a selected parcel of periodical literature being passed on from one subscriber to another by mutual under- standing. The experiment may be regarded with interest from several points of view ; it is claimed that, if successful, it should rather increase than restrict the demand for cur- rent literature by placing it within the reach of a much larger class than hitherto. All particulars may be obtained of the Parcels Post Periodical Press Exchange, 160, Fleet- street, E.G. Aug. 10, 1883.] K^JOWLEDGE ♦ 93 CHEMISTRY OF THE CEREALS. By William J ago, F.C.S. No. III. IT has been the object of the former two papers to give some idea of the nature and properties of that interest- ing group of compounds, starch, cellulose, and dextrin. Viewing these bodies in their relation to plant-life, there is every reason to believe that starch is the first-formed of the three ; and that the plant, in the act of growing, draws on its store of starch for the production of cellulose, as that material is required for the building up of its structure. So far, the process is one of development : from one or- ganised substance, another, to be used for a more special purpose, is formed. Coming to the dextrin, we find evi- dence, not of life, but of death ; the starch-cells which, de- spite their minuteness, are so delicately fashioned, have lost all trace of structure, and are transformed into a perfectly homogeneous body. Notwithstanding this (as already known to the reader), the chemical composition is as yet unaltered, so far as the number of atoms composing the molecule is concerned. The starch undergoes yet another stage of degeneration within the grain, by which it is con- verted into sugar ; the gum and sugar of the cereals having thus a common origin, are classed together in the analyses given at the commencement of these papers. Starch, dextrin, and a number of other compounds are frequently termed " carbo-hydrates." This name is applied because they contain the element carbon combined with hydro- gen and oxygen in the proportions of those elements neces- sary to form water. Thus CsHioO., may be viewed as six atoms of carbon and five molecules of H.,0, although the actual groupings of the atoms within the molecule is undoubtedly more complicated than this idea represents. Reference has been made to this classification as carbo-hydrates, because we thus have a connecting link between the starch group and sugar, for this latter body is also a carbo-hydrate, having the formula CiiHjoOg. The number of carbon atoms is again the same ; but instead of five, there are here six molecules of H^O. Starch passing through the modifica- tions of soluble starch and dextrin is changed into sugar by a very simple chemical operation : — CeH, A + H,,0 = C„Hi,0,, To changes of this kind, which consist of the assimila- tion of the elements of water by a compound, the name " hydrolysis " has been applied. Starch and water if left to themselves do not readily combine to produce sugar, but their combination may be eflected by a number of bodies which do not necessarily themselves undergo change during the hydrolysis. Several of the dilute acids may bo used for this purpose ; the saliva also possesses the property in a remarkable degree. This latter fact admits of easy experimental proof in the following manner. Make a tolerably stiff solution of arrowroot or cornllour by boil- ing with water only ; let it cool, and when lukewarm, place a spoonful in the mouth, and mix it thoroughly with the saliva. Retain the mixture in the mouth, and very shortly the solution becomes thin and watery,and acquires a sweet taste; the starch has by that time become almost wholly converted into sugar. This change is also, under certain circum- stances, eflected by another group of bodies, and these are of special interest, because they are constituents of the grain itself. Sugar is so familiar to all, that it becomes scarcely necessary to mention that it is a soluble body, and that its great and leading character is its sweetness. Its further properties must bo dealt with somewhat later, and, as its production from starch is the foundation of some most important industries, we shall then describe these properties in detail. [The foot-note appended by the Editor to the last article of this series, giving a second version of the discovery of dextrin, afibrds a clue to one industry, at least, to which reference is here made.] All grains contain a certain small proportion of fat. This is not, however, a very important constituent. Chemical analysis shows the fats to be compounds con- sisting of carbon, hydrogen, and a small proportion of oxygen. We must in the next place turn our attention to re- maining group of constituents of the cereals. These will be found in the table of analyses, given at the head of the first paper, classed under the term "albuminoids." The percentage varies from 7 '2 in rice to IG'O in oats : wheat again occupies an intermediate position, with a percentage of 10'9. The albuminoids differ essentially in chemical composition from the bodies we have heretofore studied, in that they contain in addition to carbon, hydrogen, and oxygen, the elements, nitrogen and sulphur. On analysis they are found, on the average, to consist of carbon .5.3 '.3, hydrogen 7-1, nitrogen, 15-7, oxygen 22-1, and sulphur 1-8 per cent. From these proportions it is impossible to deduce a simple formula. The sulphur is only present in small quantity, but as in a molecule we must have at least one atom, we can get no formula simpler than that calculated by Lieberkuhn, which is written C7.,Hii.2Ni,0.j.,S. The albuminoids are so-called because, both in chemical composition and properties, they are strikingly like albu- men ; this latter substance is well known to everybody, occurring, as it does, in an almost pure form in white of egg. When wheat-flour is made into a paste, and then washed with a large quantity of water, a separation into three distinct substances occurs. As already described, starch is one of these substances, and renders the washing water milky in appearance ; gluten is another, and remains in the hand. It is a very sticky, elastic body, of a light-grey colour. On setting the washing water aside to rest, the starch falls to the bottom ; remaining in solution there is, however, a little dextrin and sugar, and also another highly important substance, viz., vegetable albumen. The gluten on the one hand, and the vegetable albumen on the other, are two of the most important of the group of albuminoids ; they represent respectively the soluble and the insoluble albuminoids ; this of itself is a most important subdivision of the group. The soluble albuminoids consist of two separate bodies — vegetable albumen, and legumin or vege- table casein. On l)oiling the solution, the albumen coagu- lates, and is deposited in white flakes ; the albumen thus obtained is to all intents and purposes identical with that of the white of egg and of blood. Another albuminoid of importance is found in the husk or bran of wheat. This body is soluble in water, and possesses in a remarkable degree the property of converting starch into sugar ; hence if an infusion of bran be added to starch solution, the latter speedily becomes thin and watery. As a result of this action, bread made of whole meal has always a specially sweet taste ; this is often so pronounced that the bread after very short use becomes distasteful to many. Corealiii shares with some of the other albuminoids tliis peculiar property. C.luten is quite insoluble in water, and has scarcely any taste ; when dry, it closely resembles glue in appearance ; in the grain, it exists in a pul\-erulent form, and acquires its toughness and elasticity on the addition of water. The toughn(>ss of gluten gives dough made from wheat-flour its peculiar elasticity, hence it becomes so deliciously light by 94 ♦ KNOWLEDGE ♦ [Aug. lu, loo3. the production from any cause of air bubbles -within its mass. Barley and other grains contain little or no gluten, and so do not yield the same highly elastic dough. Moist gluten puti'eties with great readiness ; in the manufacture of wheat-starch, the gluten is removed in this manner. Gluten is not a single compound, but may be separated into two bodies, known respectively as vegetable fibrin and glutLn. This brings us to the close of a very brief description of the principal constituents of the cereals. Our next paper must commence to deal with the chemistry of some of their uses. The production of bread will naturally occupy the first place in this series of studies. €iiitonaI (gossip. I HAVE been told, by one who ought to know, that the analysis of Sir W. Herschel's papers by Messrs. Holden and Hastings referred to in the Gossip at p. 59 is good and trustworthy work. I willingly notify this. It shows that the same man who writing anonymously has been dis- honest and untruthful is capable of better things when working in open daylight. The same correspondent who speaks with respect and something like gratitude (for reasons which I need not explain) of Holden's analysis of the elder Herschel's papers, appeals against my reference to a long-past offeoice against the unwritten laws of the literary commonwealth. It is unfortunately (for the offender, but fortunately for the world) a part of the punishment of offences against honesty that the recol- lection remains long after the mischief may have been repaired. I cannot but recollect, however, the terms in ■which this particular offence was spoken of (see the Enylish Mechanic, Vol. XX., p. .3-16) both in English and American papers, when as yet it was not known, and seemed likely to remain for ever unknown, who the offender might be. If there has been unfairness in this matter it has Ijeen in not directing against the offender, so soon as his identity was known, the condemnation which had been passed upon the anonymous writer, — even when it was supposed by many (naturally enough) that he was too far below contempt to be worth castigating. Is a singular way a singular misprint occurs in the paragraph on the size of atoms on p. 76, 1st col. In con- verting into ordinary measures the metric relations which Prof. Thomson rather affectedly (considering he was ad- dressing a popular audience) employed, I wrote that such and such numbers might vntliout serious error be repre- sented so and so. For the words italicised were sub- stituted, in a paragraph for the Xevxaslle Weekly Chronicle, without science even ! This was duly corrected in a proof received by me at Bournemouth, and the paragraph ap- peared correctly in the Newcastle paper. Unfortunately another proof was sent to me in town, and I cut out the paragraph from this uncorrected proof, forgetting that there was a serious error (without science even) in that "copy." *^* The Editor has been prevented by ill-health, the resxxlt of recent railway collision, from completing for this week an instalment of his article on Sun-Spots, or his Answers to Correspondents. The articles on the Earth's Rotundity were, fortunately, completed before the accident. The lectures announced for the next fortnight will not be given, but he hopes to be able to give those announced for Tunbridge Wells and Hawkhurst. " Let Knowledge grow from more to more." — Alfbed Tennyson. Only o small proportion of Letters received can possibly be in- serted. Correspondents must not be offended, therefore, should their letters not appear. All Kditorial communications should be addressed to the Editoe o» Knowxedge ; all Business cojmminications to the Publishers, at the Office, 74, Great Queen-street, W.C. If this is not attended to DELAYS AEISE FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should be made payable to Messes. Wtman & Sons. The Editor is not responsible for the opinions of correspondents. No COMUnNICATIONS ARE ANSWERED BY POST, EVEN THOUGH STAMPED AND DIRECTED ENVELOPE BE ENCLOSED. CHOLERA. [892] — As an old Indian who passed throngh two of the worst visitations known in the North-West during this centmy, I can fully endorse the recommendation of Mr. Herring. The prescrip- tion he gives, or others very similar, proved most beneficial on these occasions ; only they must be preceded by a pm-gative to remove the specific poison that is already at work in the system. For this purpose was most extensively and successfully employed a pill containing 5 grains calomel, I grain rhubarb, J grain opitun ; to be made up with oil of cloves or oil of cinnamon. This was con- sidered the dose for a woman or child, two being given to a man, and the pill should, if possible, be swallowed dry, mthout any liquid. When the vomiting was too severe to allow even this pill to be kept down, it was found beneficial to administer in small quantities (say a dessert-spoonful) carbonate of soda (10 grains), or powdered magnesia (15 grains), dissolved in half- pint of filtered water — which seldom faQed to allay both the vomiting and the distressing thirst. It may be added that the patient should be kept warm with flannel wrapped round the body, and in extreme cases hot water bottles or hoc bricks applied to the feet. J- W. B. ANOTHER LARGE SUN-SPOT. [893] — I hope you will not think I am troubling you too much about sun-spots in writing to say there is now another spot on the sun, so large as to be visible to the unaided eyes through smoked glass, I and several friends having seen it distinctly in that way on Saturday and yesterday (July 28 and 29). It is a spot that has been on the sun's disc more than a week, and is now getting near the western edge, bat I don't think it has been visible to the unaided eye before Saturday, as I looked for it several times before without success. I am much obUged to " F.R.A.S." for the information he gives in No. 91 of Knowledge (Letter 880, page 60) about the tremendous area of the disturbance comprised in the fine group of spots visible to the unaided eye at the beginning of last month. The information does interest me very much. There is considerable difference between that case and the present one, for in that case the one spot, as it appeared to the unaided eye, was really, as viewed in the telescope, composed of several distinct spots very close together, the penumbra of each being distinctly separated from the others, whereas in the present case it is one entire spot as regards the penumbra, the only division being in the actual umbra, which is cut up into several very irregular-shaped parts, and I believe it is the gradual opening out, within the last day or two, of two or three of these previously separate parts of the umbra, and their consequent meeting or joining together, which has caused the spot to become visible to the unaided eye. The observation of sun-spots is a subject in which I take yeiy great interest, and devote every opportunity I have to it, and it is in the hope that my communications are of some little interest to you and some at least of the readers of Knowledge that I venture to trouble you with them so often. Of course, if you regard them at all otherwise I hope you wiU not hesitate to intimate as much, as I have no desii-e to be an unwelcome trespasser on either your valuable time or space. Excelsior. Huddersfield, July 30, 1883. Aug. 10, 1883.] ♦ KNOWLEDGE ♦ 95 AMERICAN-ENGLISH. [894] — I take the liberty of sondiiif; you a few notes on the sub- ject of "British and American-English," suggested by your very interesting essay in " Leisure Readings," Vol. 1. P. 185 — Aberrjavenny. My family resided in this place for a great many years, and I never heard it spoken of under any other name than Aberga'ny until I went to school, where I had to use the former name to the exclusion of the latter. P. 195 — " Mad." In Devonshire, as in America, the word is used to express anger, crossness, ill-teniper. " Don't be so mad ! " " He is as mad as he can be." In both cases meaning cross, out of temper. I remember hearing that, when a child was born in a cer- tain family, the neighbours said, " Here is another mad G come," meaning that the child had possibly inherited the family temper, which was not very gentle. P. 195 — Ordinary. In Cambridgeshire and Suffolk I have often heard this word used to express inferiority, as in America. "An ordinary child" was "a plain child." P. 199 — Reckon. This word was formerly common in Sussex in the sense of "I believe," "I think," "It is probable, "He will go there to-morrow, I reckon." P. 202 — Sure. Formerly used in Sussex as it is now said to be used in America. I am an old woman, in my 80th year, and have outlived most of these expressions, but I believe that they are genuine English, although provincial. Maby P. Meekifield. ERRATUM. [895] — Your printer has made an omission in my description of the Magic Square in page 61 (888), which, in a manner, makes it unintelligible. It should run thus (fourth line from top of page) : — " By the angles from the corners or the middles to the centre, whether right, acute, or obtuse ; by the four corner, four middle and central cells; which will still hold good, &c." G. S. <^m iilattjematiral Column* GEOMETRICAL PROBLEMS. By Richard A. Peoctob. PART XI. IN Examples 12 and 13 we notice that, although the number of the triangles which can be constructed under the given condi- tions is infinite, yet all the triangles belong to a certain set, or family. In Ex. 12, the vertices of all the triangles on the base A B, lie on the circumference of the circle E F D. In Example 13 there is no ciu-ve along which the vertices are shown to lie ; but if the reader were carefully to construct a number of triangles according to the method described in that example, he would find that the vertices all lie upon a certain curve, which however is not a circle. These considerations introduce us to an important class of pro- blems, called problems on loci. If all points which satisfy certain relations can be shown to lie on a certain line (straight or curved), and if every point on this line satisfy the given relations, the Une is called the locus (or place) of Buch points. A few examples -will serve better than a formal statement to show (1), the nature of plane loci ; (2), the sort of problems founded on them ; and (3), the methods available for readily solving such pi-oblems. It must be premised that the complete solution of such problems requires that it should be shown that both the conditions stated in the above definition of a locus should bo fulfilled. Ex. 16. — The straight lines A B, A C (Fig. 25) intersect in A. From A equal parts A D and AE are cut off from AB, AC respec- tively. E D is bisected in F. Find the locus of all such points as F. Take A G equal to A H, A K equal to A L, and bisect G H in M, K L in N. Then it seems from the figure that the locus must be a straight line, whose direction is snch as will carry it through A. A moment's consideration shows that the locus — whatever it be — must pass up to A ; for if we conceive equal hnes, A 0, A P, very very small, the bisection of 0 P will be very very near to A. Again it will occur, from a consideration of the figure, that the locus is a straight line bisecting the angle A. Now, assuming for the moment that A F M N is such a line, we see that the triangles, A N L, AN K are equal in every respect (Euc. I., 4), and this leads us at once to the proof we require. For, because the base, K L, of the isosceles triangle A K L is bisected in N, therefore N lies on the bisector of the angle K A L. Similarly, every point obtained in accordance with the given conditions lies on the bisector of the angle K A L. It is clear, also, that every point in the bisector of the angle K A L fulfils the required conditions. For, let Q be such a point, and draw S Q R at right angles to A Q ; then the triangles A Q S and A Q R are equal in every respect. (Euc. I., 26.) Therefore, A S is equal to A R, and SQtoSR; that is, Q is a point fulfilling the required conditions. Fig. 26. Points in the production of Q A beyond A cannot be said to fulfil the requisite conditions, because nothing has been said of the pro- duction of B A and C A beyond A. Ex. 17. — Determine the locus of the vertices of all the triangles which stand v.-poii a given base, and have a given vertical angle. Let A B (Fig. 26) be the given base, C the given angle. Draw from A straight lines, A D, AE, AF, and from B draw B G, B H, B K, to make, with A D, A E, A F, respectively, the angles B G A, B H A , and B K A equal to the angle C* We see at once that G, H, and K do not lie in a straight line, so that we gather that the locus is circular, since loci of other figures are not dealt with in deductions from Euclid. Now we notice that wo might have drawn our lines from B instead of A, and that therefore the locus must have points, G', H', K', situated in the same manner with respect to B as G, H, and K with respect to A. It is already clear that a circle passing through, or near to A and B, contains all the vertices. Wo see also that the circle cannot but pass through A and B ; for if wo draw A L very very near to A B, then B L drawn so as to make the angle B L A equal to C, will clearly meet AL in a point very very near to B. We describe, then, a cii-cle through A and B, and also (of course the circle is dravni by hand through the points G, H, K, &c. At this point we cannot fail to be reminded of III., 21, which tells us that all the angles in the same segment of a circle are equal. We see, therefore, that our surmise is correct, and that the circular segment on A U, containing an angle equal to the angle C, is the locus we require. All the points on this segment fulfil the requii'od condition ; but points on the remaining segment, A M B, do not do so. If triangles are to be di-awn on one side only of A B, the segment. A K B, contains all the required points. For if any point, N, mthout the segment fulfil the given condition, join N A. and N B ; let N B cut the segment, A K B, in P, and join A P. Then the angle, A N B, is equal to C (hyp.), but the angle A P B is equal to C (Euc. III., 21). Therefore, the angle, AP B, is equal to the angle ANB, the greater (Euc. I., 16) to the less, which is absurd. In like manner no point within tho segment fulfils the required conditions. Therefore, the segment, A K B, is the required locus. * There is no problem in Euclid which shows us how to do this, but of course there is no difliculty in the matter. Among the sub- sidiary problems mentioned in tho first part, one should be given showing how to draw a straight line in the manner required. Here, however, we do not require tho problem at all ; since we are dealing with the practical construction of the figure — about which there is no difficulty — not with the mathematical treatment of tho problem. 96 ^ KNOWLEDGE ♦ [Aug. 10, 1883. (Bm Cf)f0s Column. By Mephisto. PROBLEM No. 90.— SECOND PRIZE THREE - MOVER IN THE PROBLEM TOURNAMENT OF THE GERMAN CHESS ASSOCIATION. By Herman Ascheboug, Cheistunli. ^ r^\-^®f '"^ "White. Wliite to play and mate in three moves. PROBLEM No. 91. By W. Teerill. Black. ■White. Wliite to play and mate in three moves, SOLUTIONS. Problem No. 8S, p. 32. 1. Kt to K5 K takes Kt, or 1. K to Kt4 2. Q to B sq K moves 2. Q to B sq. (ch) K takes P 3. Q mates accordingly. 3. Kt to B6 mate. Peize Peoblem No. S9, p. 64. 1. Q to R8. 1- R (R2) takes Q, or 1. R (Kt sq) takes Q 2. Kt to Q7 and mates accordingly 2. Kt takes KtP and mates ace. or 1. Q takes R 1. R (Kt sq) to Kt2 2. Q takes R (ch) Any move 2. Kt to Q7 R takes Kt (best) 3. Q to R sq mate. 3. Q to Ko mate. The other numerous variations of this beautiful problem are obvious. *** Correction in the game on p. SO — White's fourth move should be B to Kto. CoKRESPoxDEXTs Will kindly excuse omissions or delay in our answers on account of the late tournaments. We have made a terrestrial excursion in the Chess Domain ; but we will again revert to our former habit of giving Chess for its own sake, and disclose to our readers the beauties and intellectual charms of our noble game, free of earthly dust. As an exception to prove the rule of correctness, a mystifying error has occurred in our article on the tournament in our last number, p. 79, in the last paragraph. We meant to speak of Black- burne's " powerful " I^lay, which somehow got converted into " powerless." In the second tournament at Nuremberg, Herr S. Tarrasch, of Breslau, a young medical student, won the first prize. Messrs. Scheve, Lowentbal, and Neustadl tied for second, third, and fourth. Herr Rocamora, of Hamburg, won fifth, and Herr Bauer, sixth. ANSWERS TO CORRESPONDENTS. *«* Please address Chess Editor. W. — Yonr solution of End game very interesting, but you will, no doubt, have seen by the solution published on p. 48 that the main variation is untenable on account of, firstly, advancing the P to R7 ; secondly, playing R to QR8; and thirdly, first checking on KB8 before playing R to KKt8, which allows the K to escape by Kt2, R3, Kt3, &c. JoHX.— In Problem 88, if 1. Kt to K5, K takes Kt. 2. Q to K7 (ch), K to B4. 3. Q to K6, K to Kt4, and there is no mate. 2. (^ to B sq is correct ; solution otherwise correct. F. G. RiCHAEDSox. — See above reply. A. C. Geay. — We have had no special article on the subject, perhaps occasional references, such as in No. 73, p. 186; and No. 76, p. 228 ; or in No. 82, p. 313. T. C. — Solutions incorrect ; see p. 48. Amateue. — We are sorry, almost ashamed, to say there is no suitable book on the openings in print. If you cannot get Cook's or Gossipp's, take Staunton or Wormold. ^ Stettin. — For solution of this fine Ending see p. 48. CoREECT solutions received — Problems 86, 87, and 88 from Stettin. Problems 88 and 89 by W. Peoblems received with thanks from W. Terrill, E. W. Smith, J. C. S. Joseph Law. — Your diagnosis of the Prize Problem is not correct, as you may see by the solution published above. Fritz will there- fore honour himself by cheerfully keeping the prize. Contents of No. 92. PAGE A Naturaliat'3 Year. Wasps and Flowers. Bt Grant Allen 65 The Morality 'of Happiness : Con- duct and Duty. By Thos. Foster 66 The Chemisn-T of Cookery. XIT. By W. Matti'eu Wilhams 67 Pretty Proof of the Earth's Hotun- dity. (Illiia). By B. A. Proctor . 63 How to Get Strong 70 Pleasant Hours with the Microscope. (,111m.) By H. J. Slack 71 PAGI Niagara. (IHmi.) By E. A. Proctor. 72 Laws of Brightness.' VII 74 Discoyery of the Chief Diyision in Satnm''s King. By Capt. Noble ... 75 The Face of the Sky. By F.E.A.8. 77 Paradox Column : A New Theory of Copernicus 77 Correspondence 77 Our Mathematical Column : G-eome- tricai Problems. X 78 Our Chess Column 79 SPECIAL NOTICES. Part XXI. {July, 1893), just ready, price lOd., post-free, Is. Id. Volume III., comprising the numbers published from January to June, 1883, just ready, price 7s. dd. The Title Page and Index to Volume III. is now ready, price 2d., post-free, Sjd. Binding Cases for Volume III., price 28. each. Inciudjng carriage per Parcels Post to any address in the United Kingdom, 23. 3d. Subscribers' numbers bound (including Title, Indes, and Case) for 3s. each. P. O. Orders and cheques should be made payable to the Publishers, Messes. Wtmak & Sons, London, at the High Holbom District Post-office. Agent for America — C. 8. Carter, American Literary Bureau, Tribtme BuildingBf New York, to whom subscriptions can be forwarded. TERMS OF SUBSCRIFTION. The terms of Annual Sabscriptien to the weekly numbers of KironxBDoi are ao follows : — B. d. To any address in the United Kingdom 10 10 To the Comment, Australia, New Zealand, South Africa & Censda 13 0 To the United States of America $3.26. or 13 0 To the East Indies, China, &c. {vid Brindisi) 16 t All subscriptions are payable in adyance. OFFICE : 74-76, GREAT QUEEN STREET, LONDON, W.C. Aug. 17, 1833.] • KNOWLEDGE 97 MAGAZINE OF SCIENCE PLAINLY^tfORDED-EXACTLYDESCRIBED LONDON : FRIDAY, AUG. 17, 1883. Contents op No. 94. A Naturalist's Tear, AEaljbit's The Shoebill {///us^raifrf) 103 Skull. Bv Grant Allen 97 , The M orality of Happiness : Eto- The Chemis'trv of Cookery. XVI. lution of Conduct. By T. Foster 105 By W. .MauieuWiUiama 98 ! Laws of Briphtnesa. VIII. By How to Get Stronj; 99' R, A. Proctor IPR Pretty Proofs of theEarth's Eotun- The Death of Captain Webb Ins dity. (Illua). By R. A. Proctor 100 The Face of the Sky 109 The Amateur Electrician. Bat- : Correspondence 109 teries. Ill 102 I Our Mathematical Column : Geome- Plesssnt Hours with the Microscope. j trical Problems. XII Ill (lUui.) ByH. J. Slack 103 I Oor Chess Column 112 A NATURALIST'S YEAR. By Grant Allen. XIX.— A RABBIT'S SKULL. WALKING this sunny August morning on the breezy saddle "of the great chalk down, where the combes on either side are thickly overgrown with low scrub of stunted juniper l)ushes,at each step I take I see the twinkling white tails and tall ears of the pretty brown rabbits dis- appearing into their trusty liurrows hidden cosily beneatli the spreading bracken and the tangled gorse-runs. Poor timid wee things, how nervously they hurry and scurry away across the open patches, at the first sound of that dull thud which heralds to their watchful senses the approach of their heriditary foe, man, the possible hunter and probable gun-bearer ! It shames mo for my kind when 1 think that tliey took no heed at all of yonder philosophic old donkey, browzing quietly off the stemless thistles and dry carline on the windy hill-side, nor of the burly liell- wether himself who leads the flock of ruddled sheep in the deep hollow by the old yew-tree ; but the moment they heard the distant rustle of my foot-fall upon the dry stems of bramble and bracken, they lifted the danger- signal of their white tails forthwith to their young ones among the fresh furze-brake, and darted off to their holes in dismay, as from the dreaded pre- sence of a familiar enemy. It has come to this, tlien, that we men have waged needless war of exter- mination upon all these pretty wild creatures till they have learnt to condemn us all under a single cate- gory— omnes uno ordine Achivos — and to shrink in- stinctively even from those among us wlio would best appreciate their .sympathy and their confidence. It must e'en be so, though even now much may be done, with care and patience, in the way of establishing friendly personal relations with these, our timid fellow-denizens of the soil of Britain. I will sit quiet awhile on the edg(! of the disused chalkpit here till they have forgotten my sudden irruption, and liy-and-by I shall no doubt be rewarded by seeing them peep cautiously out from the mouths of their burrows, with eyes and ears alert for every symptom of danger, till at last they begin to disregard my presence, and gambol freely on the open greensward before the very facj of their once suspected but now unheeded visitor. See, here on the side of the pit is a dry, blanched skull, the sole remaining memento of some lost and nameless and forgotten bunny. Was he wounded by a casual gunshot, and left upon the ground undiscovered, I wonder ; or was he hawked at and devoured at leisure by some vigilant night-prowling owl ; or was he caught on the open, and miserably sucked to death by the sharp teeth of some cruel weasel 1 None of these, I can see at a glance ; it was Nature itself that failed my poor rabbit ; he died from sheer mal-adaptation to his own ingrained racial require- ments. Look closely at his lower jaw, and you will observe that the great gnawing teeth — the incisors from which the rodent group takes its scientific name — have grown out into an immense arch, until they have doubled in again upon them- selves, and at last caused the death of their unhappy owner by starvation. I have seen rabliits' teeth in this same condition before, and the reason for it is easy enough to understand. The big incisors of rodents have no roots, but spring from a permanent pulp, so that they continue growing uninterruptedly throughout the entire life of the animal. This arrangement has naturally been brought about by survival of the fittest, because the rodents have to pass their days in a perpetual round of gnawing, and they can't even be happy without something or other hard on which to exercise their teeth, as everybody has observed in the case of tame squirrels. But in order to prevent the teeth from getting entirely worn away by such continual use, it is necessary that they should keep on always grow- ing from below, to make up for the unceasing waste above. Now, in the dead rabbit before us, the two jaws were placed at a slightly irregular angle — too much underhung, as the dentists call it in the human species — and therefore the teeth did not meet, as they ought to do, and get worn ott' at the end by attrition against one another. The con- sequence has been that the incisors have bent round into a perfect semi-circle, and so killed the rabbit by preventing him from opening or shutting his jaws properly. Even in the normal state the teeth of hares and rabbits are very interesting from their evolutionary implications. This small group of rodents preserves for us, to some slight extent, an early intermediate stage between the original central mammalian stock and the thorough-going modern rodents. If you look at the skull of a squirrel or a mouse, or any other typical rodent, you will find that it has only two kinds of teeth, incisors and molars, without any canines ; and also that the incisors number two only in each jaw. This is clearly a great reduction of the primitive pattern, and it is accompanied by a great gap between the large specialised incisors and the far smaller but still somewhat peculiar molars. But if you examine the upper jaw of a hare or a rabbit, you will find that it contains, besides the big pair of working incisors, a small rudimentary pair, immediately behind them, and quite useless for any practical purpose. They are, in fact, a survival from the time when the ancestors of the rodents had at least four working incisors in each jaw ; and they mark out the hares and rabbits as being an earlier, more primitive branch of the rodent type than the two-incisored rodents, like the squirrels, rats, and beavers. I say at least four incisors, because we have good reason to suppose that there were once six ; indeed, the young hare has still six in the upper jaw at birth, Va't two of them fall out while he is still a mere baby. Thir> reappearance of ancestral peculiarities in very young animals is, we know, one of the greatest aids to the recon- struction of lost cr doubtful pedigrees. Fossil forms, again, often help us to piece out the scanty evidence thus afforded us by living species ; and one good bit of evidence in this direction is forthcoming evt u for 98 ♦ KNOWLEDGE ♦ [Aug. 17, 1883, the genealogy of so isolated and divergent a group as the rodents. South America is a iperfect mine of antiquated types, living or extinct ; its long separation from the rest of the world, before the restoration of communications viA the Isthmus of Panama, made it a Kort of rival to Australia and the Cape of Good Hope as an area for the preservation of early forms, superseded elsewhere by the higher moditi- cations which result from the fiercer competition and hardei- struggle for life in the great continents. In the pliocene deposits of La Plata, accordingly, there occur the bones of a singular early creature, a missing link in the ■way of a rodent, which helps to bridge over the gap to the main line of mammalian development. This most primitive known type of rodent (most primitive in organisation, I mean, for we have true squirrels and other perfect rodents much earlier in time) is known as Mesotlierium (or Intermediate Beast), and has four incisors in its lower jaw. The second pair are smaller than the first, and are placed behind them ; and in some other dental peculiarities this stranded type more nearly approaches the ordinary central form of mammals. In particular, the great incisors themselves are blunter and far less characteristically rodent-like than in all the existing species. Now, it is quite clear that the raison d'etre of the rodents as a group, the funda- mental diflerence upon which all their other class-diifer- ences depend, is the peculiar nature of their teeth ; so that in this isolated South American form we have, so to speak, a central mammalian type in the very act of grow- ing into a true rodent. In many ways Mesotherium recalls the hoofed animals, and especially thataberrant little Syrian creature, the so-called coney, the last survivor of an order now otherwise quite extinct. There are other points in which it resembles those other archaic South American mammals, the sloths and armadillos ; and altogether we may consider it as a late lingering form of a very primitive rodent type, preserved in the once insular Neotropical region long after all its kind had been lived down elsewhere by the more advanced and perfected true rodents. Thus, we may fairly conclude that the ancestors of squirrels and rabbits pro- bably started from a type hardly superior in organisation to the Australian marsupials, and linked on either hand to the hoofed animals and to the edentates ; that they gra- dually lost the two useless incisors in either jaw, except in the case of the hare and rabbit section, which still retains one pair in a rudimentary condition ; and that at the same time they gradually modified the remaining and functional pair in adaptation to their special habits, till at last they grew into the very long and efficient, sharp, cutting tools with whose appearance we are so familiar in the case of the rabbit, the mouse, and the squirrel. THE CHEMISTRY OF COOKERY. XV. By W. Mattieu Williams. A CORRESPONDENT of Manchester asks me which is the most nutritious, a slice of English beef in its own gravy, or the browned morsel as served in an Italian restaurant with the burnt sugar addition to the gravy '! This is a very fair question and not difficult to answer. If both are equally cooked, neither over-done nor under-done, they must contain weight for weight exactly the same con- stituents in equally digestible form, so far as chemical composition is concerned. Whether they will actually be digested with equal facility and assimilated with equal completeness depends upon something else not measurable by chemical analysis, viz., the relish with which they are respectively eaten. To some persons the undisguised fleshiness of the English slice, especially if underdone, is very repugnant. To these the corresponding morsel, cooked according to Francatelli rather than Mrs. Beeton, would be more nutritious. To the carnivorous John Bull, who regards such dishes as " nasty French messes," of question- able composition, the slice of unmistakable ox flesh, from a visible joint, would obtain all the advantages of apprecia- tive mastication and that sympathy between the brain and the stomach, which is so powerful, that when discordantly exerted may produce the ettects that are recorded in the case of the sporting traveller, who was invited by a Red Indian chief to a " dog-fight," and ate with relish the savoury dishes at what he supposed to be a preliminary banquet. Digestion was tranquilly and healthfully pro- ceeding, under the soothing influence of the calumet, when he asked the chief when the fight would commence. On being told that it was over, and that in the final ragout he had praised so highly the last puppy-dog possessed by the tribe had been cooked in his honour, the normal course of digestion of the honoured guest was completely reversed. Reverting to the fat used in frying, and the necessity of its purification, I may illustrate the principle on which it should be conducted by describing the method adopted in the refining of mineral oils, such as petroleum or the paraffin distillates of bituminous shales. These are dark, tarry liquids of treacle like consistency, with a strong and offensive odour. Nevertheless they are, at but little cost, converted into the " crystal oil " used for lamps, and that beautiful pearly substance, the solid, translucent paraffin now so largely used in the manufacture of candles. Besides these, we obtain from the same dirty source an intermediate substance, the well-known " Vaseline," now becoming the basis of most of the ointments of the pharma- copceia. This purification is effected by agitation with sul- phuric acid, which partly carbonises and partly combines with the impurities, and separates them in the form of a foul and acrid black mess, known technically as "acid tar." When I was engaged in the distillation of cannel and shale in Flintshire, this acid tar was a terrible bugbeai'. It found its way mysteriously into the Alyn river, and poisoned the trout ; but now, if I am correctly informed, the Scotch manufacturers have turned it to profitable account. Animal fat and vegetable oils are similarly purified. Very objectionable refuse fat of various kinds is thus made into tallow, or material for the soap-maker, and grease for lubricating machinery. Unsavoury stories have been told about the manufacture of butter from Thames mud or the nodules of fat that are gathered therefrom by the mad- larks, but they are all false. It may Vie possible to purify fatty matter from the foulest of admixtures, and do this so completely as to produce a soft, tasteless fat, i.e., a butter substitute, but such a curiosity would cost more than half- a-crown per pound, and therefore the market is safe, espe- cially as the degree of purification required for soap-making and machinerj' grease costs but little, and the demand for such fat is very great. These methods of purification are not available in the kitchen, as oil of vitriol is a vicious compound. During the siege of Paris some of the Academicians devoted them- selves very earnestly to the subject of the purification of fat in order to produce what they termed " siege butter " from the refuse of slaughter-houses, ic, and edible salad oils from crude colza oil, the rancid fish oils used by the leather-dresser, ic. Those who are specially interested in the subject may find some curious papers in the Comptes Aug. 17, 1»S3.] ♦ KNOWLEDGE ♦ 99 Rendus of that period. In Vol. 71, page 3G, M. Boillot describes his method of mixing kitchen-stuH' and other refuse fat with lime-water, agitating the mixture when heated, and then neutralising with an acid. The pro- duct thus obtained is described as admirably adapted for culinary operations, and the method is applicable to the purpose here under consideration. Further on in the same volume is a " Note on Suets and Alimentary Fats " by M. Dubrunfaut, who tells us that the most tainted of alimentary fats and rancid oils may be deprived of their bad odours by "appropriate frying." His method is to raise the temperature of the fat to 1 40" to 150° Centigrade (284° to 302° Fahr.) in a frying-pan ; then cautiously sprinkle upon it small quantities of water. The steam carries oft" the volatile fatty acids producing the rancidity in such as lish-oils, and also the neutral ofl'ensive fatty matters that are decomposed by the heat. In another paper by M. Fua this method is applied to the removal of cellular tissue of crude fats from slaughter-houses. It is really nothing more than the old farmhouse proceeding of " rendering " lard, by frying the membranous fat until the membranous matter is browned and aggregated into small nodules, which constitute the " scratchings " — a delicacy greatly relished by our British ploughboys at pig-kUling time, but rather too rich in pork fat to supply a suitable meal for people of sedentary vocations. The action of heat thus applied and long-contiiiued is similar to that of the strong sulphuric acid. The impuri- ties of the fat are organic matters more easily decomposible than the fat itself, or otherwise stated, they are dissociated into carbon and water at about 300° Fahr., which is a lower temperature than that required for the dissociation of the pure oil or fat (see No. 13 of this series, July Gth). By maiutaining this temperature, these compounds become first caramelised, then carbonised nearly to blackness, and all their powers of ofiensiveness vanish, as such ofteiice is due to slow decomposition of the original organic com- pounds, which now exist no longer, and the remaining caramel or carbon cinders being quite inofl'ensive or no further decomposible by atmospheric agency. In the more violent factory process of purification by sulphuric acid the similar action which occurs is due to the powerful aflinity of this acid for water ; this may be strik- ingly shown by adding to thick syrup or pounded sugar about its own bulk of oil of vitriol, when a marvellous com- motion occurs, and a magnified black cinder is produced by the separation of the water from the sugar. The following simple practical formula may be reduced from these data. When a considerable quantity of much- used frying fat is accumulated, heat it to about 300° F., as indicated by the crackling of water when sprinkled on it, or, better still, by a properly constructed kitchen thermo- meter* graduated to about 400° F. Then pour the melted fat on hot waici'. This must be done carefully, as a large quantity of fat at 400° poured upon a sma'l (juantity of boiling water will illustrate the fact that water when suddeidy heated is an explosive compound. Tlie quantity of water should exceed that of the fat, and the pouring be done gradually. Then agitate tin; fat and water together, and, if the operator is sufliciently skilful and intelligt^nt, the purification may be carried further by carcifully boiling the water under the fat, and allowing its steam to pass through ; but this is a little dangerous, on account of the possibility of what the practical chemist calls " bumping," or the sudden formation of a big bubble of steam that * I liavo a vaKi'O impression of having seen sucli iin instrument advertised, but cannot remember where, or by what maker. It may bo worth his wtiilo to benplit tlio readers of Kxowi.Ki>ciE, .and him- self, by re-advertising therein, with particulars of price, &c. would kick a good deal of the superabundant fat into the fire. Whether this supplementary boiling is carried out or not, the fat and the water should be lefc together to cool gradually, when a dark layer of carbonised impurities will be found resting on the surface of the water, and adhering to the bottom of the cake of fat. This may be peeled off and put into the waste grease-pot, to be further refined with the next operation. Ultimately the worst of it will sink to the bottom of the water. Then it is of no further value, and will be found to be a mere cinder. HOW TO GET STRONG. KEDUCING FAT. I HAVE received through the editor several letters re- lating to preparations — some patent medicines others ofl'ered in the form of prescriptions — for reducing fat with- out change of regimen or increase in the amount of exercise taken daily. Of all these preparations it is to be observed that they are advertised solely to make money. In every single case which has thus far been brought under my notice, the unfortunate heavy weight is invited to spend a large sum of money in the purchase of many bottles of some preparation in order that he may after many weeks find his weight notably reduced. Either the medicine is oflered without any account of its ingre- dients, or in reply to letters the advertiser gives a prescription such as no chemist would be likely to mix, and such as the advertiser asserts that few chemists can mix properly even if willing. In one case, the corpident are told in so many words that a number of bottles of the medicine are to be bought and consumed before any good efl'ects will begin to be recognised. In the other the advertiser seems to ort'er a prescription gratis ; but it comes really to the same thing ; he knows that the persons who answer his advertisement will apply to him for the medicine, and in the cases which have come under my notice he asks a monstrous price for a prepara- tion prolialjly qiiite worthless and possibly (when used as recommended in large quantities) most mischievous. As to the value of any medicine for reducing fat, it should be noticed that only a long course of experiments conducted on a great number of persons, and under very various condi- tions, could possibly prove that a preparation was a specific against obesity, — and certainly no such experiments have been made in the case of any of the advertised medicines. If there were any medicine by which fat could certainly be diminished in a few weeks or months, it is almost certain that the constitution would be injured far more seriously by the medicine than it had been by obesity ; and whereas undue fat can be removed by patient perseverance in health- giving regimen, the mischief done to the constitution by the long-continued use oi noblrums for reducing fat would pro- bably be permanent. Unquestionably it is most unwise for persons troubled with obesity to use any nostrum without medical advice ; and 1 believe no medical man would advise the use of any one of the advertised cures for obesity. 1 return to the \arious measures which a sensible person anxious to reduce fat without impaii-iug the general health may use with advantage. We come now to the measures by which tlie healthy action of the skin may be encouraged, and so fat reduced through increased perspiration. Exercise of course en- courages perspiration, but I am for the moment speaking 100 • KNOWLEDGE ♦ [Aug. 17, 18t3 not of exercise but of direct stimulation of the sudatory action. First, tlie question may be asked whether Turkish baths, \-apour Ijaths, hydropathic treatment, and so forth, tend to I'educe fat. We may take the Turkish bath as a typical process for directly reducing weight by increased perspiration. Many liave taken Turkish baths with the idea of diminishing their weight, and have been disappointed. I believe that those who most warmly advocate the use of the hot air liaths, including those who are commercially interested in establishments where these baths can be taken, claim no fat-reducing effect from them. It is cerfain, as T know from my own experience, tliat you may take a Turkish bath live or six times in a week, and for several weeks in succession, without appreciably affecting the weight. Two or three pounds may be lost in the hot rooms, but then two or three pounds will be added to the weight through increased drinking during the next few hours. Yet Turkish baths may be effectively used for the special purpose of reducing weight, if we remember that we are not to trust to the loss of weight by increased perspiration in the hot rooms, but to the improved condition of the skin. I have taken as many as twenty Turkish baths in a month without loss of weight, though" probably some forty pounds' weight may have been actually parted with in the hot rooms ; and I have lost as much as fifteen pounds of weight in ten days, indirectly through tlie action of five or six hot-air baths. This sounds paradoxical ; but it is strictly true. In one case, I had been ill, and I took so many Turkish baths, as an easy way of keeping the skin in a healthy state when I was unable to take much exercise. In the other case, I wanted to reduce weight, and I took much exercise, especially just after each hot-air bath. The same amount of exercise by which one would lose a pound's weight under average conditions will remove two or three pounds' weight after a Turkish bath. Thus hot-air baths used as subsidiary to active exercise, are effective fat reducers, — used as a substitute for active exercise they do not reduce fat at all. But the best method of at once improving the health and reducing the weight by increasing tlie action of the skin, is one which involves no expense and properly followed out supplies as much exercise, in itself, as one could get from a small gymnasium : — Every morning after washing and thoroughly drying the liead and neck, sponge with cold water (and a little soap, but not much if this is done every day) the arms shoulders chest and back, to the waist,— carefully rinsing. Then with a moderately-rough large towel, commence steady but brisk and energetic friction. Tirr. the right arm in drying and rubbing the left, then tire the left arm in doing the 'same by the right. Next tire both arms in drying and rublung tlie chest. Now fling the towel over the right shoulder, and holding it with the right hand in front(overarm)and with the left hand behind (underarm), draw it steadily backwards and forwards across the neck, right shoulder! and upper back, — till both arms are again tired. Do the like with the neck, left shoulder, and upper back, interchang- ing liands. Throw the towel over both shoulders, and alternately pull with right hand and left hand. Keeping the towel still behind, let it fall to a little aViove the waist, and repeat the steady alternate haul ins; with right and left hands and arms. You now want a little rest. Take it while you sponge with cold water and a little soap from the waist to the knees and carefully rinse. Tire both arms drying, rubbing, and polishing from waist to knees in front. Pass the towel behind the back as in the last movement of the former series, and haul awav alternately with right and left hand, till the back from waist to " small " is glowing and almost burning. Next, let the towel hang under the right thigh, and haul alternately upwards with right and left hands till the back of the right thigh, from seat to knee, is as nearly red hot as possible. Do the like with the left thigh. Again a rest is wanted. So take it while you sponge and rinse both legs from knee to foot. Then lastly, tire thoroughly both arms in drying, rubbing, and polishing both legs from knee to heels and toes. You can now dress at your leisure. There is no fear of taking cold, though you are likely to be rather slow at first, for the arms are or ought to be thoroughly tired out for awhile. In the evening, just before going to bed, it is a capital plan to repeat the rubbing, without the sponging ; or if you sponge at all it should be with warm water, drying before there is any time to feel cold ; for the body is not able to bear cold well at night. By a vigorous rubbing daily, in this way, and still better by two, the skin is kept not only clean, but as soft and free from rugosities as kid, its action is healthily stimu- lated, and the liver and kidneys are thus relieved from the overwork they have to accomplish when the sudatory glands are left clogged and hampered (as they are with many even of those who daily i-ponge and daintily dry the whole skin surface). We come lastly to those forms of exercise which tell most effectively in reducing fat. {To he continued.) PRETTY PROOFS OF THE EARTH'S ROTUNDITY. CHIEFLY FOR THE SEASIDE. By Richaed A. Proctor. (Continued from page 8G.) PAPiALLAX set a vertical mirror at a considerable height above the sea-level to face the sea horizon. Looking into this mirror you saw the sea liorizon behind your head in the glass, and apparently at exactly the level of the middle of the eye pupils. Now it is obvious that when you look at your own eyes in a glass, the line of sight from an eye to the corresponding imaged eye is at right angles to the reflecting surface, — and to the glass, if the glass is perfectly even in thickness. Therefore, said Parallax to the bystanders (it was on the Hoe at Plymouth, in 18G4, that / saw this mirror trick) the line from the eye to the imaged horizon, which you f:i;e at precisely the same level as your eye pupils, is perpendicular to the vertical mirror, or truly horizontal. Wherefore, my hearers, there is no depression of the sea horizon as astronomers tell us, and as their books show. (Here he had us, for too many of our books Jo show a monstrous depression such as has no existence in nature.) ]Many, who hieiv the earth to be a globe looked into Parallax's mirror and were perplexed. His reasoning was correct. If the sea horizon is really depressed below the real horizon, the sea horizon imaged in a vertical mirror ought to be below the imaged eye-pupils ; yet apparently it was not below. It looked as if there could be no depres- sion and that the earth's surface must be flat. But they knew right well (many of them were old sea-captains) that the earth's surface is not flat. To one or two, only one solution of the difliculty — to wit, punching Parallax's head — presented itself. Yet this would not have satisfied the company. Aug. 17, 1883.] ♦ KNOWLEDGE ♦ 101 It is easy, however, to see how the dilhculty arose, and to devise a way by which a vertical mirror may be made to prove instead of disproving the rotundity of the earth. Let us see what is the actual depression of the sea horizon, viewed from a goodly height, such as 200 feet. made uppermost either by changing the supports or by shifting the mirror in the pivot holes E and F. After setting the mirror exactly vertical, K uppermost, let the observer retire from it to such a distance — say two yards — that he can see with perfect distinctness not only Fig. 8. Let a (Fig. 8) be the place of the observer's eye, A a being 200 ft. ; A B the sea surface; a B the direction of the line of sight from a to the curved sea surface ; lib' h ver- tical at B, and a b the direction of the real horizon. Draw A b' parallel to a J to meet B i in U. Then obviously B6' = Aa = 6i' (since B 6 is appreciably parallel to A a. Therefore B i = 2 A a=400 ft. Hence the dip of the horizon, or the angle B a ^ is that subtended by 400 ft. at the distance n B or A m B (appreciably the same). Kow (Euclid, Bk. IIL) the square on a B is equal to the rectangle under A a and the earth's diameter. Hence with feet for our unit of length a B^ v/7920 x"l760 x 3 x 200 = 911:.')0ft. approximately ( = 17^ miles). Now 400 ft. at a distance of 914.50 ft. subtend the same angle as 1 ft. at a distance of about 228 ft., or about one-fourth of a degree. This is very different as anyone can see by looking at a circular protractor and noticing how small are the half degrees usually marked in, from the enormous depression usually indicated in pictures supposed to illustrate the globular shape of the earth. The real angular dip of the horizon is only three-fourths even of this, atmospheric refraction diminishing the true or geometrical dip by one-fourth. The real angle of dip is that subtended by 1 (foot or inch or tenth of an inch) at a distance of about 300 (feet or inches or tenths of an inch). In Parallax's experiment, supposing the eye one foot from the mirror or two feet virtually from the imaged eye, the imaged horizon (if the station were 200 feet above the iea level, would be tjo''^ ^^ ^ ^°o* o*" about 4-liun- Jredths of an inch above the imaged eye-level. This ■would not be discernible by ordinary eyesight, the line of the imaged sea horizon being intercepted by the imaged heid. But I shall now show how this difficulty can be renoved, and a pretty illustration of the earth's rotundity be ibtained by the mirror method. let A B 0 i) (Fig. 9) be a rectangular mirror, broad enoigh to include the imaged face (the breadth of which is alwtys exactly half the breadth of the real face), and to sho\i an inch or two clear on either side, as shown. Let a line I b be drawn with a line diamond exactly parallel to the sidesAB DC. I^ot the mirror be supported at E and F by rods I G, and F £1, which can be fixed into the ground pretty firmlj Let the observer so fix them into a turf sward some 200 feet (say) above the sea level, on a spot com- mandng a fine sea horizon, putting the face of the mirror seawaids. Suppose that at K there is a line thread K /.; bsarin; a blumb-bob P, by means of which the face of the nrirrormay be made perfectly vertical by suitably turning it on tie pivots E F. But as the glass of the uiin-or may no'} be of pcrfixtly equal thickness throughout, let the plunblne admit of being fastened at L, the side D C being the pupils of his eyes in the glass, but the diamond line. Let him bring the pupils of his eyes centrally on the line a b. He will then see that the water surface cd \b about a quarter of an inch below a b. On the other hand if by slightly lowering his head he brings the water surface to exact coincidence with the diamond line, he wiU see that the pupils of his eyes are about a quarter of an inch above /-^^ that line. Inverting the mirror and letting the plumb-line hang from L, he will get the same result precisely if the mirror is a good one, and very nearly the same result if the mirror is a bad one. By using a brightly polished plane of steel, which" need not be more than four or five inches square, a better result still will be obtained. But a polished plane of steel four or five inches long and only an inch broad or even less, may be very efiectively used without a plumb-line, as follows :- ^fe=s Fig. 10. Let A B 0 D (Fig. 10) be tlie polished steel plane, set on Se etlgo of a saucer E F, containing a little mercury (or ink). uppose the cup set on a little platform, admitting of ♦ KNOVS^LEDGE . [Aug. 17, 16 adjustment by a slow screw movement ; and having set A B across the cup, and levelled the cup's surface in direc- tion A B (nothing very exact is needed in this direction), slowly shift the surface in direction square to A B by means of the screw movement, until looking down the face A C its image on the mercury is reduced to a straight line. Then the face A B is perfectly vertical. Now, as before look into the steel mirror A C, bringing the centres of the pupils to the edge A B, as at a, b. The sea horizon will then be seen as at cd about a quarter of an inch below A B, if the eyes be about two yards from the mirror. For different heights, different depressions of the sea horizon will be noted in this experiment. For places near the sea level there is no observal)le displacement of e/ below a h ; for places much higher than the 200 ft. of our experiment the displacement is much greater. Let us see what is the law connecting h the height of the observer, with the angular depression c of the sea horizon. Call the radius of the earth r. The angle c is the angle ft a B of Fig. 8, or (appreciably it is the angle subtended by B b, or twice h, at a distance a B. Now (aB)- = 2rA (appreciabl^y) „ B6 ■2h /2A , ... , '^ 1 r /. c= -B= — A / , where a right angle = ;^= 1 -.5 Thus the angle of depression varies as the square root of observer's height. In the above, c is the geometrical depres- sion-angle. The apparent depression (which may, indeed, be called the real depression, since it is what is observed) that we are inquiring about is about three-fourths the geometrical depression. Let us inquire what height is required to give an observed depression of one degree, which would be very slight — far too slight to be noticed without the aid of Instruments. The above equation gives us, since c, the geometrical depression in this case, is four-thirds of a degree. O- V Qfl 5708 ■f- circ. measure of 1 de; unit of length. 39G0 1 taking a mile as our Now, circular measure of l° = -r^(l'.5708) = '01745 yo ' . 16 , 2 h •■• squaring, — {Ol'io)—^^^ say (roughly) 16 (-000.3045)=:^ or A= 3520 X -000.3055 = 1'0754 of a mile = 5678 feet One may say that by ascending to the height of a mile a depression of one degree (apparent) may be observed, if the sea horizon is visible. To attain a depression of two degrees a height of four-and-a-half miles must be attained. This angle would seem very small, scarcely to be recognised by the unaided eye, even if the sea horizon were visible. An ordinary landscape horizon would not seem lowered at all recognisably. Hence the singular optical illusion by which the region visible below a balloon at a great height seems shaped like a vast basin. (To he confitiued,) One Shulin-g each will be paid for copies of the Index to Volume 1. of Knowledge. — Apply or address The Publisher, 75, Great Qneen-street, London, W.C. THE AMATEUR ELECTRICIAN. BATTERIES.— III. YET one more " typical " cell before we enlarge on some of the many hybrid cells more or less useful to the amateur in his various experiments. The Leclanche cell, the form of battery upon which it is our present purpose to dwell, is one which is constantly increasing in its sphere of usefulness, and which will doubt- less long continue to hold its own against many of the so- called improvements which the recently increased demand for electrical sources have produced. "The cell consists of an outer vessel, generally (for convenience only) of glass ; inside this is a porous pot, which contains the negative element. The positive element is in the older patterns a circular rod of good but unamalgamated zinc, immersed in a saturated solution of sal ammoniac or ammonic chloride (NH^Cl or AmCl). The negative element consists of a rod, plate, or block of gas carbon, embedded in a mix- ture of the same material, crushed to about the size of peas, and similar-sized manganic peroxide or black oxide of manganese (MnOo). The last-mentioned is one of those substances so bewildering to the tyro, on account of the multiplicity of their names. The mixture, which should nearly fill the porous pot, should contain approximately equal quantities of its constituents and should be free from dust or very small pieces. A piece of paper, or some such substance is then fitted in the pot over the mixture, and pitch marine-glue, or other impervious material poured over it, so as to keep everything in its place, one or two holes, being, however, provided to facilitate the escape of polarising gases. It will be seen that no liquid is placed in the porous pot, the solution for which is provided by a portion of the sal ammoniac solution passing through the pores of the pot. As the function of the carbon rod is simply that of a conductor, it is apparent that its dimensions are immaterial, the chief feature in connection with it being the necessity for providing it with a cap and connections unassailable by ammonia fumes and solution. When the zinc and carbon connections are joined, chemical action commences, the zinc is dissolved, and converted into chloride of zinc (ZnCL) by combination with the chlorine of the sal ammoniac. The other portion (N Hj ammonium) of the sal ammoniac is further decom- posed into ammonia (N H,) and hydrogen. The hydrogen, which is in what is known as the nascent condition, attacks the manganic peroxide, reduces it to a lower oxide (sesqiL- oxide of manganese, Mn.,0..), and combining with tie released oxygen, forms water (OH.,). The series of «x- changes may be represented by equation thus : Zn-f 2NHjCl+2MnO,=ZnCl„-|-2NH3 + OH.,-f Mn/'s. Those of our readers who are versed in chenical notation will see that for every volumetric equivaleit of zinc dissolved, two equivalents of both the sal amnnniac and the manganic peroxide are decomposed ; the sohtion gradually losing its character and becoming instad a solution of chloride of zinc and ammonia, while thf man- ganic peroxide is gradually reduced to a brownish pwder and tends in time to make the mixture in the porois cell mudd}' and more or less impervious, preventing ali;e the advent of fresh solution and the exodus of unconbined hydrogen. It will be seen, on examination, that the Leclan;h6 cell differs very widely from either the Daniell or theBunsen cell. In the Daniell, it may be remembered, we lave tie hydrogen from the zinc division attacking suljhate of copper, forming sulphuric acid and copper, thf latter being deposited on the negative, or copper, plate, whi;his there- Aug. 17, 1PP3.] * KNOWLEDGE ♦ 103 fore kept constantly bright and of extreme purity. There being a reservoir of sulphate of copper, the Daniell cell remains constant for weeks. The Bunsen cell lasts Vjut a few hours, the liquid surrounding the carbon, or negative, plate, being rapidly weakened and the plate polarised. In this case, instead of the reduction of a metallic salt by the operation of nascent hydrogen, we get the reduction of a most powerful acid, accompanied by the evolution of highly- irritating fumes. In the Leclanche, the sulphate of copper peculiar to the Daniell, and the nitric acid of the Bunsen, are replaced by a dense black solid, viz., the manganic per- oxide. While, therefore, the Leclancho is, in the strict sense of the term, a single-fluid cell, there are, nevertheless, two compounds employed, one for the absorption of the zinc, the other for the absorption of the hydrogen. The continuous action of the cell is, in consequence of the com]iaratively weak affinity between the hydrogen and the manganic peroxide, of extremely short duration. It cannot be relied upon for more than a few minutes at a time, and is, therefore, useless where anything approaching the character of a permanent current is required. It, how- ever, soon recovers itself, or, in other words, becomes de- polarised. To make a Leclanche cell (which shall be able to ring a trembling alarm bell through such a length of wire as will reach from the basement to the top story of an ordinary house) the outer cell, which may be of any convenient material, should be of about one quart capacity. It is manifestly not essential that a square glass jar such as we are accustomed to see in the Leclanche cell should be adopted. The zinc may be a piece of half-inch rod — or, better still, a cylinder made from thin sheet zinc. An eighth of an inch would be more than ample thickness, and would help to give a current of increased duration, besides considerably reducing the resistance of the cell. As there is no acid in the cell, and as there is no chemical action going on when the cell is not giving a current, there is no necessity to amalgamate the zinc. The con- nection should be made by soldering a piece of copper wire or strap on to the zinc, and carefully covering the joint and the wire (except the remote end of it) with some pitchy substance to protect them against the ammoniacal vapoui's which are evolved as the solution gets saturated. Crushed carbon may be obtained at 2d. per lb., and man- ganic-peroxide at 3d. The carbon rod will cost a few pence, and will then require to be carefully capped. This is done by first dipping the heated top of the rod in melted paraffin wax, and, after allowing an inch or so of the rod to become saturated, melting on (with the aid of a mould) a lead cap. A brass binding-screw of a compact form should be so placed into the mould as to be fastened into the cap. The cap and exposed parts of the terminal then require to be painted with pitch. These rods, already capped, may, however, be purchased in some places for something less than a shilling. The crystallized sal am- moniac costs Od. per lb. Where the Leclanch6 is only required for a few minutes daily it will last for months without any further attention than the addition of a little water. The electro-motive force of the cell is 1'5 to I'G volts. The resistance varies, of course, with the size, but it is very low, the one above detailed being about 2 ohms. The peculiar traits of the Leclanche cell preclude its adoption for permanent current working, although modifi- cations of it, to Vie hereafter deserilied, are being used v(>ry extensively in the British telegraph service. its great forte is its ability to supply powerful intermittent currents at a comparatively insignificant cost. Of the little atten- tion it requires wu have already spoken. As we have now reached the length of our tether, we must defer a few more remarks on this highly interesting cell till another opportunity presents itself. PLEASANT HOURS WITH THE MICROSCOPE. By Henry .J. Slack, F.C.S., F.R.M.S. ONE great advantage of the microscope arises from the facility with which it can illustrate many of the most important principles of scientific investigation. Let us consider, for example, the hairs of plants. First comes the inquiry, What is a plant hair ? The popular answer might be, " Anything hair-like that grows from a plant ;" but this would not suffice, as many appendages of plants must be grouped with hairs, although thpy depart widely from the conception of a hair, founded upon the protective and decorative covering of the human head. Take up any hairy leaf or flower-petal, and with a sharp penknife cut some of the hairs off" just below their base. It is seen that this may be done by removing a piece of the epidermis, without penetrating into the leaf-substance. Go to a rose- tree, with stout, sharp thorns. Press one of these strongly on one side, and it will break off" without injuring the wood of the stem from which it is taken. Next pull a thorn off a small branch of quickset, and some of the wood comes with it. Here, then, is a distinction of im- portance. Hairs and rose-spines are structures growing out of the epidermis, and in any case all objects ranking as hairs spring " from the layer of cells which always remain outermost in roots, stems, and leaves, whether these out- growths occur as simple utricular (little liladder-like) pro- tuberances, rows of cells, plates of cells, or masses of tissue, or have the physiologiral character of woolly envelopes of the young leaves, rootrlike absorbing organs (mosses), glands, prickles, or spore capsules (ferns)." So says Sachs, in his "Text-Book of Botany." Amongst animals we have some similar variations from soft, thin hairs, to sheep wool, bristles of hogs, cats' whisker.s, por- cupines' quills, and rhinoceros' horns. The horn of the rhinoceros, says Owen, " consists of a uniform compact mass of epidermal fibres," that is hairs, and much the same may be said of rose-spines. The thorns of May-trees, &a, belong to the wood, somewhat as the horns of deer " consist wholly of bone " (Owen). There are two different scientific ways of studying the parts or organs of plants and animals — one, the morpho- logical, which investigates how they grow, and from what parent formation ; and the other, the physiological, which looks into the functions they perform, or the services they render. It is very often found that parts which are mor- phologically similar, have quite different uses. Thus, hairs of plants, which protect a young bud or leaf surface, are not like rose-spines, nor in their function the same. Plant hairs which are glandular, and secrete a particular fluid, are different in function from others which oppose a me- chanical obstacle to the entrance or exit of certain insects, and thus act as aids to the process of fertilisation. Similar iliu.strations of siuiilarity of origin and great difference of function abound in the animal world, and as a familiar example, we find the morphologist regarding the biting jaws of tlie spider as modified feelers (antenna^), and the nipping claws of scorpions as modified maxillary palpi. Plant hairs of all sorts recognised by the morphologist are technically called trichomes, which means hair-sort of things in origin and structure, whatever may be tlieir use or shape. The simplest hairs are unicellular ; other hairs 104 • KNOWLEDGE ♦ [Aug. 17, 1883. WbitG Alvssum hair, x 70. Drosera rotundifolia, 30. Deutzia scabra, x 70. Stinging-nettle hair, x 70. Heritiera minor, x 120. may have many cells at their base and cellular divisions in the upper part. Round the edge of a sweet-briar leaf are hhort, stumpy tubes ending in a pretty ruby-coloured gland. Rimilarhairs, but less brightly-coloured at their tip?, are abun- dant on the under surface of the leaf, and all are glandular, secreting the sweet scent. Extremely beautiful hairs of this type, but longer, decorate the stems of London pride. They form very striking objects when bril- liantly lit up and magnified about fifty times. The elegant pink heath (Erira titralix) is similarly orna- mented. Glandular hairs may absorb as well as secrete. The remarkable hairs of the Drosera and of other insectivorous plants are illustrations ; but the character of Drosera hairs entitles them to be called tentacles. They have a good deal of true leaf structure in them, and the glandular tips are composed of com- jilicated groups of cells. Botanists reckon them amongst the trichomes, but their whole structure shows how close they are to expansions of the leaf, and not, like the simplest hairs, mere outgrowths of epidermis. They are prey- capturing and digesting organs, much like the tentacles of anemones. The short hairs in the middle of the Drosera leaf can convey impressions to the marginal hairs, causing them to close and hold fast the prey which is attracted and caught in the secretion, which gives the popular and pretty name of Sun Dew to the plant. " If an insect adheres to only a few of the glands of the exterior tentacles, these soon become inflected, and carry their prey to the tentacles next succeeding them inwards ; these then bend inwards, and so onwards until the insect is ultimately carried by a curious sort of rolling movement to the centre of the leaf" (Darwin). Experimenting with other leaves, Darwin found the glan- dular hairs on those of two kinds of saxifrage, of a primula, and a pelargonium would rapidly al)sorb weak solutions of carbonate of ammonia and weak infusions of raw meat. The glands of an erica, a mirabilis, and a nico- tiana did not exhiliit such a nower. With reference to the above observations, Darwin remarked* : — " The glandular hairs of ordinary plants have generally been considered by physiologists to serve only as secreting organs ; but we now know that they have the power, at least in some cases, of absorbing both a solution and the vapour of ammonia. As rain-water contains a small percentage of ammonia, and the atmosphere a minute portion of the carbonate, their power can hardly fail to be beneficial, nor can the benefit be quite so insignificant as it might first be thought, for a moderately fine plant of Primula sinennsheess the astonish- ing number of about two millions and a-half of glandular hairs, all of which are able to absorb ammonia brought to them by the rain." The bails that form the pappus of thistles and allied plants are sometimes simple, and of others feathered, as in the Carline thistle. On the anther filament of spider- wort {Tradiscantia Virginica) the hairs are like chapleta of beads, and each bead shows the cell rotation of the sap, if put in a drop of water, covered, without squeezing, by thin glass, and magnified three or four hundred times. AH hairs of plants and trees are said to exhibit this sap movement at some period of their lives. A shrub, common in gardens, Deutzia Scabra, has an immense number of star-shaped hairs on its leaves, chiefly on the upper surface. These are thickened with an exquisite deposit of silex, and are fine objects under the polariscope and a magnification of from fifty to one hundred times. The rays of the larger Deutzia stars are usually four or five ; besides these there are multitudes of smaller star.-i with many more rays. Similar stellate hairs, but not so big, occur on the smaller-leaved Deutzia /jracilis. iSlany plants have multiple-rayed stars on their leaves. One of them, Ileritii'.ra minor, a tree found on the coasts of India and Africa, and cultivated in the West Indies, has * "Insectivorous Plants," pp. 354-5. Aug. 17, 1883. • KNOWLEDGE ♦ 105 the under-side of its leavers so white and shiny, as to be called the Looking-glass Tree. This appearance is caused by sun-rayed hairs, of which a sketch is given. Sketches are given of various hairs, with their names and magnification employed, drawn from the objects by Mrs. H. Slack. THE SHOEBILL. THE Shoebill (BaUenicejis re.v), a singular African bird, is a representative of the family Bal;enicipid;i'. It has a thick neck and large head, and a huge bill, which from its resemblance in size and shape to a shoe has gained for it the title of shoebill. _ Wood says : " The bill is enormously expanded at each side of the beak, the edges of the upp^r mandible overhang those of the lower, and its tip is furnislied with a large hook, which is well suited for tearing to pieces the sub- stances on which the bird feeds." It has very long legs and large feet whose long toes are provided with powerful nails, broad and long wings, and a short tuft of feathers at the back of the head. The general colour of the plumage is a beautiful ash- grey ; the edges of the large feathers are bordered with light grey. The eye is bright yellow, the bill horn colour, the foot black. Young birds are a rusty, brownish grey. The length of the male bird is a hundred and forty centimetres. The female is considerably smaller. These giant birds of the morass, according to the observations of Heuchlin and Schweinfurth, live by pairs or in scattered companies — as far as possible distant from all human settlements, in the huge, almost impenetrable morasses of the White Nile and some of its tributarie?, between the fifth and eighth degrees of north latitude. It has not been observed around the other waters of inner Africa. Usually this bird is seen standing fishing in the pools, in the midst of these swamps. It is very shy and cautious, and at the approach (if man it rises with a loud rustling noise, and flies low over the reeds, which soon hide it from sight. If it becomes frightened by the report of a gun, it rises high in the air, circles and hovers around for a long time, and will not return to the water as long as it suspects the presence of man. It is seldom seen on the banks of rivers. When walking it carries its body in a horizontal position, and rests its heavy head on its crop. When flying it draws in its neck. It makes a loud, rattling, cracking sound with its bill, which puts one in mind of the clatter of the storks. Its nourishment consists principally of fish, and it is often seen standing up to its breast in water, and thrusting its powerful bill suddenly under the water, in the same manner as herons do, in order to capture the fish. Petherick asserts that the Shoebill catches and eats water-snakes, and that it also feeds on the intestines of dead animals, the carcasses of which it easily rips open with the strong hook of its upper bill. Their breeding-time is in the rainy season, during the months of July and August, and the spot chosen for their nest is in the reeds immediately on the water's edge, or on some small, elevated, dry spot entirely surrounded by water. It builds from the dry stalks of the swamp, plants, sod, and mud, a very firm nest often a yard in height. Heuchlin says the eggs are comparatively small, about three inches long and two inches thick ; the shell is finely granulated. — From Brehin's "Animal Life." THE MORALITY OF HAPPINESS. By Thomas Foster. {Continued from page 67.) THE EVOLUTION OF CONDUCT. AS structures are evolved, so are the functions which structures subserve. And as the functions of the body are evolved so are tliose combinations of bodily actions evolved which we include under the general term conduct. We are considering the functions of the body when we are inquiring into such actions of the various structures internal and external as involve internal processes, simple or complex. But when we begin to consider combinations of actions externally manifested we are dealing with conduct, — except only in the case of such actions as are independent of control. But at the outset of the evolution of conduct even this distinction is scarcely to be recognised. Every external combination of actions is in the lower types of animal life a part of conduct, — at least of such conduct as is possible in the lowest orders of creatures. Evolution of conduct begins with the gradual development of purpose where 106 ♦ KNOWLEDGE ♦ [Aug. 17, 1883. at first actions were random and aimless. The Amoiha wanders from place to place, not by the action of limbs but by a process which may be called diffluence. In so doing it may come into the neighbourhood of objects fit to form its food ; these it enwraps, and absorbing what is digestible rejects the rest. Or its wanderings may lead it into the way of some creature by which it is itself absorbed and digested. There may be some higher law than chance guiding the movements of such creatures ; but so far as can be judged this is not the case. In other words there is but the suspicion of some- thing like conduct in the actions of the Amceba. Among other creatures belonging to the same kingdom, but higher in type, we find actions so much better adjusted, that though even yet we cannot recognise such evidence of purpose as enables us to describe their actions as conduct, we yet see in their adjustment to certain ends the develop- ment of something akin to conduct. The actions seem guided by what mimics purpose if it is not purpose itself. Now we note that with the improved adjustment of actions comes an increase in the average duration of life, or rather in the proportion of this average to the length of life possible among these several creatures. So when we pass to higher and higher orders of animals, we find in every case among the lower types irregular and seemingly purposeless actions, while among the higher we find actions better adjusted to the sur- roundings. And again we note that where the combination of actions, or what we may now call the conduct, is not adjusted to the environment, the creatures' chances of life are small, great numbers dying for each whose life approaches the average duration. An improved adjustment of conduct to environment increases the chances of sur- vival, many attaining and some passing the average of longevity in their particular type or order. Now structural development is guided by the fitness or unfitness of particular proportions in such and such struc- tures for the great life struggle in which all animal life is constantly engaged ; and functional development is guided by the corresponding fitness or unfitness of such and such functional activities. Just as certainly the development of conduct in all orders of living creatures is guided by the fitness or unfitness of such and such combinations of external actions for the constant life-contest. We might find illustrations of this in every kingdom, sub-kingdom, order, and type, of animal life. Let us, how- ever, content ourselves by noting it in man. In the lower races of man as at present existing, and in still greater degree among the lower races when the human race as a whole was lower, we see that the adjust- ments of external actions to obtain food, to provide shelter against animate and inanimate enemies, and otherwise to support or to defend life, are imperfect and irregular. The savage of the lowest type is constantly exposed to the risk of losing his life either through hunger or cold, or through storm, or from attacks against which he has not made ade- quate provision. He neither foresees nor remembers, and his conduct is correspondingly aimless and irregular. The least provident or rather the most improvident perish in greatest numbers. Hence there is an evolution of conduct from irregularity and aimlessness by slow degrees towards the regularity and adaptation of aims to ends, seen in advancing civilisation. The ill-adjusted conduct which diminishes the chances of life dies out in the struggle for life, to make way for the better-adjusted conduct by which the chances of life are increased. The process is as certain in its action as the process of structural evolution. In either process we see multitudinous individual excep- tions. Luck plays its part in individual cases ; but inexorable law claims its customary rule over averages. In the long run conduct best adapted and adjusted to environ- ment is developed at the expense of conduct less suitable to the surroundings. With man, as with all orders of animals, conduct which tends to incresise the duration of life prevails over conduct having an opposite tendency. Wherefore, remembering the ever-varying conditions under which life is passed, the evolution of conduct means not only the development of well-adjusted actions, but the elaboration of conduct to correspond with those diverse and multitudinous con- ditions. To these considerations we may add that the evolution of conduct not only tends necessarily to increased length of life (necessarily, because shortening of life means the diminution of such conduct as tends to shorten life), but it results in increased breadth of life, and (in the highest animal) in increased depth of life also. It is manifest that in the elaboration of activities by which length of life is increased, breadth of life is increased pari passu. For these activities may be said to constitute Vireadth of life. Passing over the numerous illustrations which might be drawn from the lower orders of animal life, we recognise in man a vast increase in the breadth of life as we pass from the limited orders of activity constituting the life of the savage to the multiplied and complex activities involved in civilised life. Increased depth of life we recognise only (but we recognise it clearly) in the most advanced races of that animal which not only thinks and reasons but reflects. We find then that the evolution of conduct is not only accompanied by increased fulness of life, but is to be estimated by such increase. We do not say that that con- duct is good in relation to the individual which increases and that conduct bad which diminishes the fulness of individual life in the individual. We assert, for the pre- sent, only what observation shows, — that conduct of the former kind is favoured (other things equal), and therefore developed, in the life struggle, while conduct of the latter sort tends to disappear as evolution proceeds. Thus far we have only considered conduct in relation to individual life. We have still to consider the evolution of conduct as related to the life of the species. (To be continued.) LAWS OF BRIGHTNESS. Tin. By Richard A. Proctor. I HAVE hitherto said nothing about the absorption of light, although it obviously affects the brightness of objects. The fact is that in considering the celestial objects we are more directly concerned with the absolute intrinsic lustre of their surfaces, whether that lustre be inherent or imparted. The absorption exercised by our own atmosphere of course afiects their apparent brightness; but as a rule we compare their lustre under similar circum- stances, selecting also those epochs when, owing to their considerable elevation, the absorptive effects of our atmo- sphere are as small as possible. And as respects absorptive efiects exerted by the atmospheres of the planets them- selves we need not specially concern ourselves, because it is, in point of fact, to a certain extent self-compensatory. If a planet possesses an atmosphere so rare and pure that nearly all the light falling upon it passes into and through it to the planet's surface, then, although a greater pro- portion of the received light is thus exposed to the Aug. 17, 18S3.] » KNOV\^LEDGE ♦ 107 absorptive action of the atmospheric medium, yet on the other hand the planet's surface is so much the more brightly illuminated, and the light so illuminating it passes so much the more readily on its return journey through the planet's atmosphere. On the other hand, if a planet's atmosphere is dense, although such an atmosphere much more completely absorbs the light which enters it, yet, on the other hand, it resists the entrance (so to speak) of a much greater proportion, and moreover it is itself illuminated by that which it absorbs. The compen- sation thus effected may not be, and probably is not coqi- plete ; but we are precluded (at least until we have much more exact information than has yet been obtained) from discussing satisfactorily the effects due to absorption by the planet's atmospheres. A similar remark applies to the difference between the absorptive effects of a planet's atmosphere near the centre and near the edge of the disc. At the centre more light passes through the atmosphere, and so the planet's surface is more brilliantly illuminated (apart from the consideration of the angle of incidence). At the edge the light has a longer course through the atmosphere, and is therefore much more freely absorbed, so that the planet's surface is much less fully illuminated than it would he if there were no atmosphere. Neverthe- less, there is no corresponding falling ofi' in the apparent brilliancy near the edge, for the atmosphere is itself illumi- nated. Whether this illumination will be greater or less than that which would result if there were no atmosphere, will depend on the nature, extent, and condition of the atmosphere. Passing from such considerations as these, which are of too difficult and complicated a nature to be here satisfac- torily discussed, let us consider how far our estimates of relative brightness are to be depended upon. It must be remembered that in all observations we have to deal with the experience of the senses, and that the senses are fallible. It is important that we should know to what extent the senses are fallible in this particular matter of the estimation of light. Unfortunately, we find the result of such an inquiry not altogether encouraging. There is, perhaps, no subject of research in which the senses are more apt to be deceived than they are in dealing with different degrees of lumi- nosity. For instance, I have often been asked if it is possible to believe that the faint light of " the old moon in the new moon's arms" is equal to that due to full moon- light ; still less, it is urged, can it bo equal to that due to full earthlight. Yet the darker part of the moon's disc at the time of new moon is illuminated by full, or nearly full, earthlight. Hence, some imagine that distance must reduce the apparent brilliancy of the light received from that portion of the moon. Of course I do not refer to this mistake for the sake of refuting it, but it affords an excel- lent illustration of the way in which the senses may be deceived. Let any person look at a distant hill bathed in full moonlight, note carefully its apparent brilliancy, and endeavour to retain the remembrance of it. Sixteen or seventeen days or so afterwards let him observe the young moon, and note tiie faint light of the part which is not in sunlight, and compare that light with till! light of the moon-illumined hill he had formerly observed. It will appear manifest, and so far as the sens(> of sight is concerned it is msuiifest, that the light of the hill is far the brighter. Nevertheless, nothing can be mor(i c(>rtain than that the light of the old moon is ten or twelve times as bright. The explanation is simple. When we are looking at ttie new moon, we see the light of the crescent which is illuminated by the fun, and the light of the rest of the disc whicli is illuminated by the earth. Sunlight exceeds full moonlight some 618,000 times, and it exceeds full earthlight some .50,000 times. It is clear that in the presence of a degree of brightness 50,000 times greater, the brightness of the earth-lit part of the moon must appear by contrast altogether insignificant. Then, again, we are apt to forget when we are looking at a moonlit landscape, that the brightness of the scene depends largely on the quantity of light, not on its in- trinsic brilliancy. Let a small round hole be pierced at the end of a blackened case ; let the observer be so covered that he can see only through that hole ; and let the hole be so placed as to correspond exactly in seeming magnitude with the full moon : then, if the observer look through that hole at a moonlit hill, he will at once see how utterly insignificant moonlight is by comparison with sunlight. And yet even then the comparison is made under circum- stances altogether favourable to the moonlight. For under the darkness in which the observer is enwrapped, the pupil of the eye dilates, and a much larger proportion of light is thus received than would be the case if no such change took place. But let the experiment be renewed at the time of new moon, and in such a way that only the light from the earth-illumined part of the disc is in the field of view ; then will the relative superiority of earthlight over moonlight be clearly recognised. T do not speak at random. I have tried these experi- ments. It would be easy to cite multitudes of similar instances. But let us pass from the consideration of eye-estimations of different degrees of light at different times, to consider how far the eye is competent to compare different degrees of lustre observable at the same time. It is very commonly stated, though not constantly, that the planet Jupiter shows brighter at the edge all around the disc, than in the middle. Certain observations of the satellites serve to show that the reverse is really the case. Noticing a passage in an excellent paper by Jlr. Browning on the planet Jupiter, in which the former view was stated, I expressed doubts on the point. " But," said Mr. Brown- ing, "I do not )epeat anything I have heard or read on this matter, I describe what I have seen." Knowing that to prove himself mistaken would be quite as pleasant to him as to prove himself in the right, I asked him to take an early opportunity of testing the matter by the use of a carefully-graduated darkening glass. He did so, and found that though .lupiter (when in opposition, — near quadrature there is a difference) look^- distinctly lirighter near the edge than in the middle, he in distinctly brighter in the middle than near the edge. The deception is due, no doubt, to the contrast between the edi^e and the dark sky. I have very little doubt that the apparent brightness of the moon's edge when she is full is to .win'' degree an effect of contrast ; though it remains recognisable when the test of the graduated glass is applied. And here another question suggests itself. What is the effect of either intensifying or reducing in the same degree all the lights of a surface variously illuminated ? Intensi- fying is not easy ; since there is absolutely no device by which any surface can be made to look brighter than it is* Nevertheless, as we sometimes see surfaces less bright than they really are, we may by removing the cause which had diminished the light intensify the apparent brightness. For instance, by travelling south, and getting to the summit of a high mountain, an Englishman can gain • I am referring to celestial objects cliiofly. We may, of coarse, illuminate a surface more or less brightly ; bnt extraneous lisht causes perplexity in nearly all experiments on the illumination of terrestrial surfaces. 108 o KNOWLEDGE ♦ [AcG. 17, 1883. views of the moon near the zenith considerably brighter than those he can obtain in his own country. However, the effects of darkening being more readily tested, I select them to consider here. When we use a very deep darkening glass in the study of the sun, for example, do we leave the relative degrees of brightness unchanged 1 We may or we may not. The matter is one for experimental research, and such research would be by no means easy. But one thing is certain. We reduce the lower lights in such cases to what appears to the sense of sight as absolute blackness — xero in our light scale — and we leave the brighter parts with a degree of light which is not zero, but a finite quantity. Now, since the smallest finite quantity exceeds zero in an infinite degree, we clearly have affected the apparent proportion between the brighter and darker parts of the sun in sucli sort that it no longer corresponds to the true proportion ; for assuredly the light of the brighter parts of the sun does not infinitely exceed that of the darker portions. Thus it is seen that in this instance, at least, we cannot safely assume that the relative brightness of surfaces variously illuminated, is left unchanged by a common darkening which theoretically should affect each in the same proportion. I think this will be enough to show how important it is in all questions relating to brightness to consider the pos- sible action of physiological causes. We ought to multiply our tests in order to evade deception, and not be too sure even then that we may not remain to some degree deceived by our senses. (To he continued.) THE DEATH OF CAPTAIN WEBB. THE Xew York Times gives some particulars of the find- ing of Captain Webb's body. A correspondent at Niagara Falls states that about ten o'clock on the morning of July L'S a stonemason named Turner was crossing the river in a small boat, about one and a half mile north or down stream from Lewistown, when he discovered the body floating face down, only a few rods out from the American shore, floating down with the current. He took it to Lewiston, where it was identified a few hours afterwards. The cloth was still around the loins, and the body appeared to have sufiered little from the rude force of the water. It was found a little less than four days after it entered the Whirlpool, which is a remarkable fact, as bodies passing into the dreadful vortex often remain there a whole week before being discharged into the Rapids below. A striking illus- tration of the shifting nature of the currents of the Nia- gara River above and at Lewiston has occurred contem- poraneously with the melancholy case of Captain Webb. On Monday, July 23, rather more than twenty-four hours before Captain Webb dived from McCloy's boat above the Suspension Bridge, a number of Indians clambered up the rough and precipitous bank on the American side to a point called the " Rocks " above Lewiston, and about mid- way between that place and the Suspension Bridge.* The river there is a narrow and foaming torrent, though less frightful than the Whirlpool Rapids. Yet it is in the few yards of swift, unbroken water next the shore at this point that the Indians have long been accustomed to bathe, and it is their favourite place for learning {sic) their boys to swim. Two of them, while bathing, ventured a little too far out, were caught by the roaring torrent, and hurried down the river like two corks. Their companions wit- * See Map of the Niagara Falls and Rapids, p. 72. nessed their fate, but were of course helpless to aid them. The bodies must have been detained by the deep-water eddies above Lewiston for five days. Within an hour of the time of the finding of Captain Webb's body the bodies of these two Indians were found at a spot only two miles from the place where they entered the water. On July 31, an inquest was held on the remains of Captain Webb. On the previous day Mrs. Webb, in company with her late husband's manager, Mr. Kyle, arrived at Niagara Falls from Boston. On viewing the Rapids, she said she be- lieved her husband could swim safely through them, and that he was killed by striking the rocks. Mrs. Webb and Kyle identified the body, and Dr. Palmer, of Lockport, who made the post-mortem examination, testified that he thought the reactionary force of the water had paralysed the nerve centres, and rendered breathing impossible. — The jury found a verdict that Captain Webb came to his death while attempting to swim the Whirlpool Rapids, but that they were unable to determine the immediate cause of death. The Glasgow Weekhj Mail says : — " It is imderstood that the Town Council have resolved to raise an action in the Court of Session to compel the North British Railway Company to remove the ruins and dtbris of the old Tay Bridge before proceeding with tho erection of the new one. The Council, in taking this step, are believed to be pro- ceeding upon the opinion of eminent Parliamentary and Scotch counsel as to their rights under the last Tay Bridge Act. The clause relating to the subject definitely states that the company are bound to remove the ruins and debris of the old 'Tay Bridge, and that the Town Council may force them by legal action to do this, but no time is stated within which the work shall be done." The soap-bubble colours upon glass are produced by a vapour, which is deposited on the hot glass before it goes into the annealing oven. According to the JjiiUetiii de la Socii'fe d' Encouragement the vapour comes from a mixture of protochloride of tin, carbonate of liaryta, and carbonate of strontia. It is said that the workmen of a Bohemian manufacturer, wishing to celebrate his arrival, kindled some Bengal lights in the annealing furnaces, and the pieces which were in the furnaces all became iridescent. The colours can be removed by hard rubbing. Messrs. Clcmandot and Fremy produced a pearly lustre, like that of shells, by means of different chemical agents, chlorhydric acid among others, under pressure of four, five, or six atmospheres. The Engineer notes that an important meeting of the directors of the principal steamship insurance companies in the North of England was held last week at Newcastle, to take into consideration the report of a subcommittee which was recently appointed to investigate sundry allegations of unfair dealing by some of the shipowners in that district. These gentlemen, it appears, have been in the habit of receiving large discounts off their repairing accounts with- out placing them to the credit of the insurance companies, who in this manner have, in the single case under con- sideration, been bled to the extent of several thousand pounds. It is stated that the shipowners offered a sum of no less than £10,000 to settle the matter. This, however, has not been accepted, and at the meeting it was unani- mously agreed that the steamers belonging to the firm in question should not be insured any longer in the various societies which were there represented. We understand that several other cases of a similar character are now under investigation, while strict inquiries are being made in certain quarters where dealings of the same kind are suspected. Auo. 17, 1883.] ♦ KNOWLEDGE ♦ 109 THE FACE OF THE SKY. Fkom August 17 to August 31. By F.R.A.S. THE recent exhibition of increased activity on the surface of the sun will, of course, prompt the student to keep a sedulous watch upon the solar disc for its consequent phenomena. Such a spectacle as that described by Mr. Slack (p. 70) will afford an ample reward for any amount of watching. The night sky will be found delineated on Map VIII. of " The Stars in their Seasons." Mercury is but indifferently placed for the observer, but may just possibly be caught on a very clear evening after sunset, close to the horizon and a little to th.e south of west. Venus remains, for our present purpose, invisible ; as do Uranus and Neptune. Mars rises before midnight, almost in the north-east. His telescopic diameter is too small to enable the observer to examine his surface. He still presents the appearance of a blazing red star, and is situated to the north-east of f Tauri (" The Stars in their Seasons," Map I.). Jupiter has not yet come into sight. Saturn rises, of course, sooner and sooner every night, appearing above the north- east by east point of the horizon about 10 p.m. at the end of August. Hence, by midnight, he will be some 18° high, and fairly well observable. He is moving slowly to the eastward in that void part of the sky north-east of * Geminoruni (ilap I.). The moon is 14'4 days old at noou to-day, and, quite obviously, 28'4 days old at the same hour on the 3lst. Hence, after about the 25th she will be but poorly placed for the observer during the working hours of the night. Two occultations of stars will occur during the fourteen days covered by these notes. The first will happen on the 21st, when the 4th magnitude star e Piscium will disappear at the moon's bright limb at 12 h. 20 m. p.m. at an angle from her vertex of 155°, and reappear from behind her dark lirub at 12 h. 42 m. p.m. at an angle of 197° from her vertex. The second occultation will be that of the 6th magnitude star B. A. C. 1206, which, on the night of the 24th, will disappear at the moon's bright limb at 10 h. 30 m. at an angle of 73° from her vertex ; re-appearing at her dark limb at a vertical angle of 235° at 11 h. 21 m. p.m. During the -whole of to-day and to-morrow, and, in fact, until 6 p.m. on Sunday, the 19th, the moon will be travelling through Aquarius, from which constellation, at the hour named, she will pass into Pisces. She will not quit Pisces until 9 p.m. on the 22nd, when she will travel into Aries. She will occupy until 1 p.m. on the 24th in crossing Aries, and will enter Taurus between 1 and 2 o'clock on the afternoon of the latter day. She continues in Taurus until 1 a.m. on the 27th, when she begins to cross the northern part of Orion. This occupies her until 2 p.m. on the same day. She then emerges in Gemini, and remains in that constellation until 7 a.m. on the 28th, at which hour she enters Cancer. It will be 11 o'clock at night on the 30th before she reaches Leo. There she continues until 10 p.m. on the 31st, when she descends into Sextans. We there leave her. In 1871 tlio total population of the seven Australasian colonies — which include the five Australian colonies, viz., Victoria, New South Wales, Queensland, South Australia, and West Australia, and the colonies of Tasmania and New Zealand — was only 1,978,7-tO. In 1881 the total population was 2,83.">,954, showing an increase in ten years of 8.^7,206, or an average of S^u per cent. Ten years ago the combined exports of the same colonics amounted to approximately .£07,000,000, and in 18S1 to £10."),000,000, showing an advance of more than 50 per cent. This is equal to about .£38 per head of population. The public revenue of the seven colonies during the year 1881 amounted to about £21,000,000, against .£18,000,000 in 1880, being an increase of £3,000,000. The colonies possess .''),426 miles of railway, 49,10.'') miles of telegraph, 78,000,000 sheep — the wool clip of wliich last year realised the sum of about £21,000,000— besides 8,091,910 cattle, and several millions of horses and pigs. During the year 18S1, 10,090 vessels, of an aggregate tonnage of 9,.">04,130, touched at the various ports of the colonies. The same colonies have 7,017,380 acres of land under profitable cultivation, and produce annually about 30,000,000 bushels of wheat, and 11,717,819 bushels of oats. Of these latter New Zealand alone produces 0,924,8-18 bushels. TO " Let Knowledge grow from more to more." — Alfred Tennyson. Only a small proportion of Letters received can possihly he in- serted. Correspondents must not he offended, therefore, should their letters not appear. All Editorial communications should he addressed to the Editoe of K.vowLEDGE ; all Business communications to the Publishers, at the Office, 74, Great Queen-street, W.C. If this is not attended to DELAT.S ARISE FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should he made payable to Messrs. Wyman & Sons. The Editor is not responsible for the opinions of correspondents. No COMMUNICATIONS ARE ANSWERED BY POST, EVEN THOUGH STAMPED AND DIRECTED ENVELOPE BE ENCLOSED. PRESCRIBING FOR CHOLERA. [896] — With reference to the letter appearing on page 60 of Knowledge, July 27, 1883, headed "Cholera" (preventive), I wish to make a few remarks. In the first place, the reverend gentleman should have defined cholera as he understands it and prescribes for it. Judging by the tenour of the letter, he draws no distinction between cholera and diarrhcea in its severer forms. Now, it is hardly necessary to say that a primary essential to correct and rational treatment is to understand what disease has to be dealt with. Again, filtration of water is not sufficient; it is necessary to boil it and preserve from absorbing impurities present in the atmo- sphere, whieh it will do readily on cooling. It cannot be too clearly understood that no prescription is indiscriminately applicable to several cases. In diarrhoea, pre-eminently, the treatment of a given case will depend upon its cause, and the sooner the doctor sees the case the better. It is folly to trifle away time that may be of vital importance. Why the crudely and imperfectly tran- scribed prescription should be called an " Indian remedy " I cannot imagine— nor can I imagine how an educated man can so lack in ordinary etiquette as to publish the result of other men's labours without attempting to acknowledge whence the information was derived. I take this opportunity to draw attention, through the columns of your journal, to the obvious irregularity of a clergyman taking upon himself to prescribe — unfortunately, of not infrequent occurrence. Surely a very recent example should prove a warning. A Reader. [We agree with " A Reader," that there is an objection to pub- lishing prescriptions in such organs as Knowledge, Health, &c., even though such prescriptions may have high medical authority in their favour. The prescriptions may be good bat their application may be bad. " Won't do so any more."- — R. P.] GIRTH AND THE PARCEL POST. [897] — It may be useful in view of the coming operations of the Parcel Post to inquire minutely into the restrictions which the authorities impose upon the size of the parcels that may be sent. These are — Maximum length, 3 ft. 6 in. ; maximum length and girth combined, 6 ft. The first presents no difficulty. A parcel has of necessity, like any other solid body, length, breadth, and thickness — i.e, it has three dimensions. The above restriction simply requires the greatest dimension to be less than 3 ft. 6 in. When we come to the second restriction we are met by the word "girth." Now girth is a good old Saxon word, and is connected with girdle. The scientific idea presented to the ordinary feminine mind is " how much round the waist ? " — unless, indeed, the answer come from a Girt(h)onite, and then something very precise may be expected. The word girth may bo parajihrased cii-cumference or perimeter. The old nmthcmatical term is periphery. Imagine a solid cylindrical pillar of circular section, such as may be seen in many churches and cathedrals. Suppose it were required to calculate the number of cubic feet in such a pillar the height of which was known. A string ]>asscd round wonld give the girth, say 10ft. Since the cir- cumference of a circle is three and one-seventh times its diameter, this would give the diameter about 3 ft. 2 in. Whence the area of no - KNOWLEDGE ♦ [Aug. 17, 1883. the cii'culai* sectiou aud cousequently the cubic contents of the pillai' conld be obtained. Now, imaj^ino the pillar to become very extensively dwarfed, so as to meet the requirements of the parcel post ; its length to be 3 ft. 6 in., and its girth consequently 2 ft. 6 in., so that the two are together 0 ft. Proceeding as before, we should get the diameter of the circular section very nearly 10 in. If, then, we conceive a cylindrical parcel about a yard in length, and each end about the size of a dinner-plate (10 in. in cUameter), this will represent the required limits. When the parcel is shaped like an ordinary box the girth becomes twice the breadth and thickness together; or, if the section be square, four times the edge of one end. The longest box, then, that can be sent is one 3 ft. 6 in. in length, and the edge of whose end is 7iin. If the box be of cubical shape the length of its edge must be one-fifth of 0 ft. ; or about 1 ft. 2 in. ; and this is the greatest-sized cubical box that can be sent. It may be shown by the differential calculus that the largest content to be got out of the box shape is when the dimensions are 2 ft., 1ft., 1 ft. or two cubes of 1ft. placed face to face. For the cylindi'ical shape this becomes length 2 ft. (as before), and girth 4 ft. giving a circular section of about 15 in. diameter. R. F. Davis, M.A., Cambridge, Queen's College ; Member of the London Mathematical Society. AUDITORY FANS. [808] — The fans, &c., spoken of in your answers to correspon- dents under C. Thompson, are sold with all particulars at a shop next door to St. Saviour's Deaf and Dumb Church, 419, Oxford- street. Xox. THE VORTEX-ATOM THEORY. [899] — The vortex-atom theorj', viewed from the physical side, is regarded by some as one of extreme simplicity. I must confess, however, that to me it appears to be far otherwise. In fact, I am unable to understand how the theory is to be reconciled with the first law of motion. According to that law no body possessing inertia can deviate from the straight line unless forced to do so. A planet will not move round the sun unless it be constantly acted upon by a force defiecting it from the straight path. A grindstone •will not rotate on its axis unless its particles are held together by a force preventing them from flying oft' in a tangent to the curve in which they are n:ioving. Centrifugal force must always be balanced by centripetal force. My diificulty is to understand what force counterbalances the centrifugal force of the rotating material of the vortex-atom. It has been said that the centrifugal ten- dency of the rotating material of the vortex-atom is con- trolled hy the exterior incompressible liquid. But it is also stated that this incompressible liquid offers no resistance whatever to the passage of the atom through it. In short, that in so far as the motion of the atom is concerned this liquid is a perfect void. Now, if this Kquid can offer no resistance to the passage of the atom as a whole, how then does it manage to offer such enormous resistance to the materials composing the atom so as to continually deflect them from the straight path and compel them to move in a curve ? The centrifugal force of these vortex-atoms must be enormous, for on it is assumed to depend the hardness or resistance of matter to pressure. Now the centripetal force which balances this centrifugal force must be equally enormous. Then if this perfect fluid outside the vortex-atom can exert this enormous force on the revolving material without being itself possessed of motion, then there does not seem to be any necessity for vortex-motion in order to produce resistance. It has further been advanced, by way of explanation, that this incompressible liquid surrounds the revolving liquid like a pipe, "and that if the liquid in this pipe were to fly out, a temporary void would be formed in it, which is impossible in a liquid that already occupies all space." The incompressibility of the surround- ing fluid sui-ely cannot be a reason why portions of the revolving material do not fiy out, for if incompressibility could prevent portions of the revolving atom from flying away, it would equally prevent the whole atom from doing so, but according to hypo- thesis this incompressible fluid offers no resistance to the motion of the atom. When the atom moves it is assumed that the fluid in front is dis]jlaced ; but then this simply makes room for an equal quantity behind, and thus no void is formed. The very same thing ought to take place, though only a portion of the atom were to fly off. The various portions of this revolving material are not supposed to be held together by any cohesive force like those of the grindstone. What then prevents the revolving material from being dissipated by the centrifugal force of rotation 'i* In short, how is the existence of the atom possible under the physical con- ditions assumed in the theory ? James Ceoll. LETTERS RECEIVED, AND SHORT ANSWERS. L. A. B. — The small magnets would very speedily have their polarities reversed by the more powerful fixed magnets, and resist- ance to rotation would ensue. Supposing, however, that the polarities were unaffected, the action would be in character with that which would result if a diamagnetic substance were substi- tuted for the small magnets — that is to say, resistance to motion would evidence itself. It will be seen that although repulsion would be exerted upon receding and approaching magnets equally, resistance to motion would be experienced owing to the "squeezing" effect exerted upon the magnets between the fixed poles — S. Qcint. If wo had a telescope of the power you mention, the movements of Jupiter's surface would un- doubtedly be magnified in the same enormous degree, and unless the effect of his rapid rotational motion were corrected there would be a rapid rush of the featm-es across the field of view, with the blurring you speak of ; but it would be the easiest thing in the world to correct this by the use of clockwork, keeping the telescope directed to a fixed point on any zone. In that case there would be no blurring at all. — E. A. Rowe. I am no arbiter of literary tastes. Nearly all the works you mention are popular. — F. Pitman. Have not seen the former work. A notice such as you send me would imply that I had and approved of it. — Geo. Joedak. What ivill you ask next? You want me now to explain why the moon is always full in the Arctic regions, why she never sets there, — and again you ask, "Can it be possible that there is a south pole as well as a north pole and the moon when crescented goes round the north centre and when at full she goes round a south centre ? " And yet again, when I say the moon is every month half the time north of the celestial equator and the other half south, you " suppose in that case," I "refer to the month of June especially and only in June." (Now, is June every month ?) Will you permit me to inform you, once for all, that the moon's behaviour in both the Arctic and Antarctic regions is precisely the same so far as her apparent form is concerned as it is anywhere else. When the moon is full here she is full wherever she can he seen, when gibbous gibbous, when crescent-shaped crescent-shaped. The moon is seen in the Ai'ctic regions (and here, be it noticed, I am speaking of places well within the Arctic circle, not upon or just within it, but say north of seventy-two or seventy-three degrees) during part of every month, the particular part of each lunar mouth in which she is best seen varying as the year goes round. In December she is full when highest above the celestial equator, and consequently she is then visible as a full moon all through the night. In high Arctic latitudes she is visible in December all through the night from a few days before full to a few days after full. In January the part of the lunar month when the moon is seen all night ranges over a week or so, in high latitudes, to about the time when she is full. In Febraary the week during the lunar month when the moon is visible all through the twenty-four hours ends a few days before the time of full moon. In March it ranges equally on either side of " half-moon before full." In April it cuds at about the time of half-moon before full ; and in May a few days earlier. In June there is no night, at least towards the end of the month; and at this time the moon is only risible above the horizon all through the tweuty-four hooi-s when near the sun or appearing as a fine crescent. She is invisible all through the twenty-four hours when nearly new in December near the time of midwinter ; for about a week, ending at time of new moon, in January ; a few days earlier in the lunar month in February ; for a week equally divided ou either side of half-moon after full in March ; for a week ending at about half-moon after full in April ; and a few days earlier in the lunar month, in May. The moon is invisible all through the twenty-four hours when nearly full near the time of Midsummer — in high Arctic latitudes — i.e., four or five degrees north of the Arctic circle. You should find no difficulty in extending these considerations to the remaining months. Again, for the Antarctic regions, you have only to write July, August, September, October, November, and December, resi)cctively, for December, January, February, March, April, and May, in the pre- ceding account, to have a correct description of the phenomena there. You are bound to tell me that some of your old captains deny all this, and say the moon is always full in the Arctic regions, never sets there, can be seen full in high arctic latitudes at midsummer, and so forth. But besides these old captains there have been, let me remind you, sundry old Arctic captains not altogether un- known to fame, such as Sir E. Parry, Sir Jas. Ross, McCIin- tock, and a few others, who have not — like yours — tried to recall, with obviously imperfect memories, what they Aug. 17. IX'^:?. * i^JNOWLEDGE 111 think they fancy they remember they saw, but have carefully noted all observed phenomena. It is hardly necessary to say that in all the multitudinous volumes of Arctic and Antarctic travels extautj nu such absurdities as your old sea captains have told you are mentioned ; but the moon, the guide of the sailor in remote seas, behaves witliin the Ai'ctic circles as she behaves elsewhere ; she is new, half full, gibbous, and full at the times given by the " Nautical Almanac" for the whole world ; and in fact if she has anything at all to say to your sea captains' stories, informs you simply that either they have blundered, or (which is far more iirobable) they have amused themselves by telling old "forecastle yarns" for your edification. — H. Askew. (1.) The geometrical problems willjjro- bably be published. They were submitted, almost in their present form to Messrs. Longmans, in 1868, who submitted them to Pro- fessor Goodeve and Mr. Cock, mathematical lecturers at King's College, who studied them so carefully as to find out that the problems might be more simply solved — as if it were the object of the papers to show how those particular problems might be most briefly solved. (2.) We have unfortunately no space for obituary notices in Knowledge, except in the case of a few very eminent men such as Darwin, J. W. Draper, H. Draper, &c., whose influence on the advance of scientific thought has been very marked. (3.) The Harton Coalmine experiments gave 6'565as the mean density of the earth. Mr. Sketchley probably means that this result raised the average of the best estimates to S'^iSO. — F. M. Di-plock. Pra}' excuse the misspelling of name ; *' I " was not responsible for the mistake, but the fault was as you say with " U " ; only U'say this and I say it with different significance. Thanks for kind inquiries as to effects of railway accident. Have felt the shaking a good deal ; but hope effects will shortly pass off. Though sitting with my back to the engine, only my knees show any marks ! both of them bruised by the counter shock, — in other words I " cushioned " off the seat behind me on to my knees on the seat in front of me, with enough force to mark them both and to bark one. Rather an unusual way of bruising the knees ! — G. S. See solution in our columns. — E. Const. May. Write down the first three odd inimbers in order, each repeated twice, — thus 113355, and divide the latter half of the number thus formed, 355, by the former half, 113. The result is the ratio of the circumference to the diameter of a circle, correct to the fiirst six decimal places : for the quotient is 3'1415y29, &c., which to the sixth decimal place would be written 3'141593 as would the true ratio, which is 3'141592G5, &c. — W. E. Drinkwater. The sun and moon both rule the tides, theii' respecting tide - raising influences being as the numbers two and five. When they combine their influence, the tidal wave bears to the lunar tidal wave about the ratio of seven to five ; while, when they oppose each others' influence, the tidal wave is less than the lunar tidal wave (i.e., the wave which there would be if the sun excited no effect) as three to five. Thus the solar influence produces no tidal wave separate from the lunar wave, but is, as it were, merged in the lunar influence. The tidal period follows the moon, but the variation of the tidal wave in height follows the sun. — T. M. Your theory is presented with assertion only. " The fact should be familiar to all," you say, and go on to give as a fact what is not only not familiar to all, but not a fact at all. As to alluvial and diluvial matter, astronomers find plenty of evidence of that in the moon ; but perhaps this, being a fact, is not familiar to you. — T. C. Fear many I'eaders would not see that you are jesting in finding " the number of the beast "in the name of the great and good man you mention — preposterous though the notion is. Some really do fancy they see the cloven hoof there, — not being quite able to see above his instep. — 11. F. Kekr. You are right in think- ing that I utterly decline to answer your question. I simply cannot tell you what 1 do not know myself. If Knowledge cannot be honestly sold unless the editor tells you what ho understands by what neither he nor any man who has ever lived can under.stand, then Knowledge must continue to be (in your opinion) sold dis- honestly.— J. C. S. That Daily Telegraph ai-ticle about the mid- night sun, earth's inclination, &c., belongs to a type which I had thought played out. It is nearly all nonsense, of course. If there were such a change as supposed, the present forms of vegetation in the temperate and Arctic regions would no longer be so well suited as they are at present. As for sudden change in earth's centre of gravity, tliat is nonsense, too. Adhemar's theory was wild enough in all conscience, without adding that absurdity. — W. Aston. I really do not know how you should set about to get a " cirtificate" to "an able " you to teach and pass pupils. — Geo. IIowakd. I'ardon me, though you may have taken in KiNowLEDGE from the first, you are not an original subscriber. A copy of the index was sent gratis to every subscriber. It most assuredly is not the proprietor's dutv to reprint tho index at heavy cost, because one or two failed to provide themselves with it when it was issued. I differ from you altogether as regards tho Whist Column. It has been discontinued dui-ing chess tourneys, but it will be resumed soon. Whist has as good a right to be described as a scientific game ai chess or draughts. Sm iJiattjematical Column, GEOMETEICAL PEOBLEMS. By Eichakd A. Proctor. PART XII. LET us next try the following problem : — Ex. 18. — Determine the locus of the middle points of all the chords of a circle which pass through a fixed point. The fixed point may be either within or without the circle. In nearly aU cases of this sort it is well to begin with a point within the circle, trusting to the result thus obtained to guide us in the case of a point without the circle. Let P (Fig. 27) be a point within the circle A B C D. We are to draw chords through P, and to bisect them. Draw, first, the diameter A P E C through P. Its bisection, E, is the centre of the circle. This is one point of the required locus. Draw next the chord B P D at right angles to A C. Then the point P is itself the bisection of D B (Euc. III., 3). Therefore P is a point on the required locus. Next draw a chord F P H of through P, and bisect in H. Then H, a point on the locus, is clearly not in the straight line joining P E, so that the locus is not a straight line. It is, therefore, probably a circle. Now we see at once that for every point we get above A C there must be a corresponding point below A C. We see, then, the pro- bability that the required locus is a circle of which P E is the diameter. But even if the student failed to see this at once, he would readily detect it when he had draivn several more chords through P (above and below P C), and bisected them. We de- scribe, therefore, a circle C H P, of which we assume P E to be the diameter, and we look for a proof that a chord drawn as F P H G would be bisected in H where it meets the circle thus drawn. It will clearly be well to join E H. When this is done, one of two well- known properties can hardly fail to occur to our mind. We might either remember that the angle in a semicircle being a right angle. Fig. 27. Fig. 28. E H will be at right angles to F G, if P H E really is a semicircle, or we might remember that the line from the centre of a circle to tlie bisection of any chord is at right angles to the cl'ord. so that the angle E H P is a right angle independently of aiv • ..nsideration of the assumed circle P H E. Of course, if we thous;iit of the first property we should be led immediately to the second, and vice versd. The two properties are, in fact, interdependent; and we see at once that their interdependence involves the solution of our problem. We now write out the solution in the following form : — Let A B C D be the given circle, P tho given point. First, let P lie within the circle. Draw any diord, F P H G, and bisect F G in H. Find E the centre of the circle A B C D, and join E II. Then E H is at right angles to F G (Euc. III., 3) ; therefore H is a point on the circle of which P E is a diameter. (Euc. III., 31). But F G is any chord through P. Therefore the bisections of all such chords lie on tho oii-cle E H P. Also it is clear that every point on this circle bisects some chord through P ; therefore, this circle is the locus required. Next, let P lie without the circle (Fig. 28). Then the proof is the same* up to the words, " therefore the bisections of all chords * It is important to notice that in such a case as tho above, by putting tho same letters at corresponding points in both jigures^ th& proof of one case may be made to apply to the other, either witliout change, or with such obvious changes as tho student can have no difficulty in making. 112 ♦ KNOWLEDGE ♦ [Aug. 17, 1883. tkrongh P lie on the circle E H P." Bnt it is clear that points on the arc L E II bisect chords through P ; and also that every point ■on this arc bisects some chord throngh P. A readiness in determining the loci corresponding to different con- ditions will often be found serviceable to the student engaged in solving problems of different classes. Suppose, for instance, that the following problem is set : — Ex. 19. — Let A, B, C (Fig. 29), he three given points, D a given straight line. It is refjuired lo find a point which shall be equidistant Jrom the points A and B, and at a distance from 0 equal to the line B. Fig. 29. In order that the distance of the point from C may be equal to the line D, it is clearly necessary that the point should lie some- where on the circumference of the circle described with centre C, and radius equal to D. Let G E P be this circle. Xext, we inquire whether there is any locus containing all points equidistant from A and B. We join A B and bisect in H, giving one point, H, clearly belonging to such a locus. Xert, either by applying tentative methods, as in the above instances, or by the consideration of a few obvious facts, we find that the indefinite" line, K H G E, drawn through H at right angles to A B, contains all points equidistant from A and B. The line K H G E does not necessarily intersect the circle F G E. If it intersects that circle in two points, G and E, it is clear that each of these points satisfies the required conditions. For C G is equal to D (const.), and G A is equal to G B (Euc. I., 4. See also Ex. 1.) Also, C E is equal to ■D and EAtoEB. IfKHGE touch the circle there is only one point satisfying the given conditions. And clearly, if K H G"E do not meet the circle, there is no point satisfying the given con- ditions. For if there were such a point, it would be at a distance D from C ; and, therefore, would lie on the circle F G E. Also it would be equidistant from the points A and B, and therefore would lie on K H E. In other words, the circle F G E a'ould have a point in common with the line K H G E, which we have supposed not to be the case. &ur €heS9 Column. By Mephisto. PROBLEM Xo. 92. By J. C. Black. GAME PLATED RECENTLY BETWEEN MEPHISTO AND ANOTHER STRONG PLATER (SCOTCH GAMBIT). White. Black. i WMte. Black. Mepbisto. Amateur. I Mephisto. Amateur. 1. PtoK4 P to K4 |lO. KttoK4 B to Kt3 (/) 2. KttoKB3 KttoQBS i 11. P to B4 Kt to Kto 3. P to Q4 P takes P ' 12. KttoB6(ch)(<7) P tks Kt (h) 4. Kt takes P Kt to B3 (a) 13. B tks P (ch) K takes B (t) 5. Kt takes Kt KtP takes Kt 14. Q to R5 (ch) K to Kt sq 6. B to Q3 (b) B to B4 (c) ] 15. Q to Kt4 (ch) K to R2 7. P to Ko Q to K2 ; 16. Q to E4 (ch) K to Kt sq 8. Castles Kt to Q4 i 17. P takes P Resigns (j) 9. Kt to Q2 (d) Castles (e) NOTES. (a) This defence was adopted by Zuckertort in his match against Blackburne. It leads to a difficult game for Black. (6) Steinitz is of opinion that the P should at once advance to K5. (c) P to Q4 ought to be played here ; it is the principal move in Black's defence, for if White plays P to Ko the Kt can conveniently retire to Q2. (d) Here P to QE3 first might have been preferable. (e) Castling is always dangerous when all the pieces are placed on the Q side, and especially when the adversary's B is posted on Q3. Black ought to have played Kt to Bo instead, which would have enabled him, if necessary, to play Kt to K3, but his position was a difficult one to handle. (/) If P to B4, then 11. P takes P en pas, Kt takes P. 12. B to Kto. (g) This combination forces the game. (h) Obviously Black could not reply with K to R sq., on account of 13. Q to R5, P to KE3. 14. QB takes P. (i) Here again Black has no resource but to accept his fate ; if K to R sq., then 14. B to B5 threatens mate by Q to E5, or, if K to Kt2, then Q to Kt4 (ch) brings about the same position. (j) There was no feasible way of preventing the threatened mate on Kt" ; an interesting variation arises from the following play: B takes P (ch). 18. K takes B best (R takes B would be bad' on account of Q to K8 (ch), and the R could not cover; Q takes B would be good, but it would render winning a little more difficult,) Q to B4 (ch). 19. K to Kt3, Q to Q3 (ch). 20. R to B4, Q to Q6 (ch). 21. K to B2, Q to R2, best. 22. Q to Kt3 (ch) and wins the Queen. Contents of Xo. 93. PAGE VesaviuB and Ischia. By E. A. Proctor SI The Birth and Growth of Jlyth. XIII. Bv Edward Clodd S! Pretty Proofs of the Earth's Eoti.n. ditf. (Illua.) By B, A. Proctor SI The Moon in a Three-Inch Tele- scope {Illus.) By F.H.A.S S6 Weather Forecasts, and How to Make Them. Bv John Browninj -,7 The Fisheries Exhibition. IT. [Illitt.) Bj John Ernest Ady ... b7 PAGE Sea Anemones : The White Carna- tion. (Illua.) BtT. Kimber 89 A Steamer goes Safely Past Nia- gara Whirlpool 90 Principles oi Dress Reform. By E.M. King 91 Chemistrr of the Cereals. III. By William Jago, F.C.S 93 Editorial Gossip 94 Corresponde: SPECIAL NOTICES. Part XXI. (July, 1833), just ready, price lOd., post-free, 1b. Id. Volume in., comprisiog the numbers published from January to June, 1883, just ready, price 7s. tid. The Title Page and Index to Volume III. is now ready, price 2d., post. free. 2\A, Binding Cases for Volume III., price 28. each. Including carriage per Parcels Post to any address in the United Kingdom, 23. 3d. Subscribers' numbers bound (including Title, Indei, and Case) for Ss. each. P. O. Orders and cheqaes should be made payable to the Publihera, Messrs, H ^MAif & Soirs, London, at the High Holbora District Poet-offc- Apent for America— C. 8. Carter, American Literary bu ew York, to whom subscriptiona can be forwarded. .l-rib ) fiuUdingB, White to play and mate in three moves. TEEMS OF SUBSCFJPriON. The terms of Annual Bub3cripti«n to the weekly oumberB of Ksowm foiiywB :— To any address in the United Kingdom T« the Continent, Australia, :Sew Zealand, South Africa & Canadb To the United States of America $3.26. or To the East Indies, China, &c. (c;ver ridden a tricycle. Let me say briefly, that large wheels are very weak as compared with small ones, unless they are made so stout as to be e.\cessively heavy, and that this extra weight greatly reduces the speed of the machine. The small wheels of tricycles are not greatly retarded by obstructions, because the rims of our wlieels have soft rubber tires, and most obstructions on the roads sink into these. Neither the machine nor the rider are lifted over them. Here is a proof; the Monarch is an excellent machine, probably the best niadi; for very rough roads, yet its driving-wheels are only 40 in. in diameter. If our roads were strewn with Kentish Hints or brickbats then large wheels might be necessary. Mr. Sliaw advocates, theoirtica/fi/, the building of " machines with driving-wheels of 56 in. or upwards in diameter, geared level or down to 50 in., for ordinary run- ning, with a second speed for hill-climbing, and a steer- ing-wheel not less than 24 in." Such a machine, to be fairly strong, would require to weigh from 1301b. to 1401b., if not more. Now I have found that, with a machine which has 50-inch wheels, weighing from SO lb. to 90 1b., I must gear down to 3G inches to travel easily, and my pace on a journey which takes several hours will be from live to six miles an liour. With a machine which has 38-inch wheels, weighing from 501b. to 55 lb., I can gear u]) to 46 inches, and travel for a greater number of hours at the rate of from seven to eight miles an hour. In other words, wheels 1 2 inches larger on a machine which weighs 30 lb. more reduces my pace by two miles an hour, and the distance 1 can travel by 25 miles in a day. For, on the heavy, large machines, from 30 to 40 miles in a day was a hard task for me, while on the small light machines I can travel without fatigue from 60 to 70. But look at the authorities I am supported by. Mr. Marriott, a partner in one of the first, if not the leading, firms of tricycle manufacturers, and our first long-distance rider, uses a machine with 42-inch wheels, geared to run as 56 inches. Mr. S. Salmon, the Secretary of the London Tricycle Club, whose experience in tricycles and tricycle riding on roads is certainly not less than that of any man in the kingdom, rides a machine which he has aptly named the " Shadow," with 40-inch driving wheels geared to 48 inches, which weighs only 40 lb. Mr. Grace, of Anerley, a most careful and thoughtful experimenter, who has several machines of various sizes, considers (I am quoting his own words) " 40 inches large enough for the wheels of any tricycle." Mr. Arthur Salmon, one of the finest riders in the London Club, who is 5 ft. 1 0 in. high, has for two years ridden a machine with 52 in. wheels, and which weighed 961b. This year he is riding a machine of the same pattern with 42 in. wheels which weighs 651b., and, after six months' experience, he informs me that nothing would induce him again to 'ride one of the larger and heavier machines. Three years ago it might have been said truly that I was urging the use of small wheels and light machines theoretically. I was perfectly aware of their disadvantages, and lielieved, as it is now seen correctly, that they might, in mathematical language, be neglected. But now that manufacturers, experimenters, and riders are agreed on adopting them, Mr. Shaw must give them something more than an array of figures — he must give them good reasons drawn from riding experience before he can expect them to go back to plans which he proposes as though they were new, but which they have already tried and found wrong. Certain results I have obtained lead me to doubt if I have yet reached the limit to which wheels may be reduced with advantage. I shall very shortly have made for mc a single tricycle, with 3G-in. wheels geared to 46, which will weigh about 45 lb., and a double tricycle with 36-in. wheels, which will not exceed in weight 100 lb., and, should these be slower tlian machines with larger wheels, I will acknowledge it. To conclude, I am charged with tempting makers to build machines so light that they will be unsafe. Here is my reply. At the commencement of this season, when Messrs. Ilumber \- Co. kindly undertook to build me my 3S-in. machine, wliich weighs about 51J lb., to my own specification, they stipulated that I should not ride the machine on macadamised roads. Since then they havG Hi ♦ KNOWLEDGE [Aug. 24, 1883. told me voluntarily that they are confident that the ma- thine would carry safely a rider encycling, two stone more than myself over any roads. In the last few weeks I have been trying four two- speed mahines, and very shortly will report ou tlieir performance. THE BIRTH AND GROWTH OF MYTH. By Edward Clodd. THE beast-fables cited in my last paper were drawn from widely-severed sources, as illustrative of ideas common to all barbarous races, concerning the community of life in man and brute. They are thus shown to embalm the relics of a serious philosophy, and the like is true of the great mass of folk- tales of wliich they are a branch. The connection of the two is, indeed, manifest in the group of which " Beauty and the Beast " is a well-known example, in which the husband or wife is of fair human form by night and a hideous monster by day, until freed from the sorcerer's enchantment. Such tales have not fallen in the East to the low level which they have reached here, because they yet accord in some degree with extant superstitions in India, whereas in Europe they find little or nothing to which they correspond. But, dismissing these, we will deal with a group of stories culled from various collections, the leading idea of which is the dwelling apart of the soul or heart, as the seat of life, from the body, in some secret place, as in an egg, or a necklace, or a flower ; the destruc- tion of the soul involving that of the body. In the Norse tale of " The giant who had no heart in his body," the monster turns six princes and their wives into stone, whereupon the seventh a^id only surviving son, Boots, sets out to avenge their fate. On his journey he saves the lives of a raven, a salmon, and a wolf, and the wolf, having eaten his horse, compensates Boots by carry- ing him to the giant's castle, where the lovely princess who is to be his bride is confined. She promises to find out where the giant keeps his heart, and by blandishments and divers arts known to the fair sex both before and since the time of Delilah, she worms out the secret. He tells her that "far, far, away in a lake lies an island; on that island stands a church ; in that church is a well ; in that well swims a duck ; in that duck is an egg ; and in that egg there lies my heart, you darling ! " Boots, taking fond farewell of the princess, rides on the wolf's back to the island. Then the raven he had befriended flies to the steeple and fetches the key of the church ; the salmon, in like return for kindness, brings liim the egg from the well where the duck had dropped it. Tben the wolf told him to squeeze the egg, and as soon as ever he did so, the giant screamed out. " Squeeze it again," said the wolf ; and when the prince did so, the giant screamed still more piteonsly, and begged and prayed so prettily to be spared, saying he would do all that the prince wished if he would only not squeeze his heart in two. " Tell him if ho will restore to life again your six brothers and their brides, you will spare his life," said the wolf. Yes, the giant was ready to do that, and he turned the sis brothers into kings' sons again, and their brides into Idngs' daughters. " Now squeeze the egg in two," said the wolf. With questionable morality, doing evil that good might come, Boots squeezed the egg to pieces, and the giant burst at once. Some interesting variants of this story are given by Mr. Ealston in his " Russian Folk-Tales," in which Koshchei is the counterpart of the giant, his death being brought about by the destruction of the object in which his soul is hidden. In one story he is killed by a blow on the fore- head inflicted by the mysterious egg — that last link in the magic chain by which his life is darkly bound. In another version the fatal blow is struck by a small stone found in the yolk of an egg, which is inside a duck, which is inside a hare, which is inside a stone, which is on an island. In another variant, Koshchei attempts to deceive his fair captive, pretending that his "death " resides in a besom, or in a fence, both of which she adorns with gold in token of her love. Then he confesses that his "death" really lies in an egg, inside a duck, inside a log which is floating on the sea. Prince Ivan gets hold of the egg, and shifts it from one hand to the other. Koshchei rushes wildly from side to side of the room. At last the prince breaks the egg, and Koshchei falls on the floor and dies. In Serbian folk-tale the strength of a baleful being who had stolen a princess lies in a bird which is inside the heart of a fox, and when the bird was taken out of the heart and set on fire, that moment the wife-stealer falls down dead, and the prince regains his bride. In Bohemian, Gaelic, Greek, Finnish, as also among the Hottentot and Samoyed folk-tales, the same incident occurs of an external soul, generally hidden in an egg, the breaking of which ends the life of giant or other monster. In the " Arabian Kights " the Jinni's soul is enclosed in the crop of a sparrow, and the sparrow is imprisoned in a small box, and this again in seven other boxes, which are put into seven chests, con- tained in a cofler of marble, which is sunk in the ocean that surrounds the world. Seyfel-Mulook raises the coffer by the aid of Suley man's seal-ring, and having extricated the sparrow, strangles it, whereupon the Jinni's body is converted into a heap of black ashes. The most venerable form in which we possess the myth of a man's soul outside his body comes to us from the valley of the Nile, but before narrating this we must seek in the " storied East " the close parallels to the folk-lore of the Western Aryans. As in the Rig- Veda we are in certain respects nearer to the older forms of the parent language of the Indo-European peoples, so in the folk-tales of Bengal and the Deccan we are nearer the earliest forms of the fireside stories of both east and west. In the story of " Punchkin " given in Miss Frere's " Old Deccan Days," a Rajah has seven daughters, and his wife dying when they were quite children, he marries the widow of his prime minister. Her cruelty to his children made them run off" to a jungle, where seven neighbouring princes, who were out hunting, found them, and each took one of them to wife. After a time they again went hunting, and did not come back. So when the son of the youngest princess, who had also been enchanted away, grew up, he set out in search of his mother and father and uncles, and at last discovered that the seven princes had been turned into stone by the magician Punchkin, who had shut up the princess in a tower because she would not marry him. Recognising her son, she plotted with him to feign agree- ment to marry Punchkin if he would tell her where the secret of his life was hidden. Overjoyed at her yielding to his wish, the magician told her that it was true that he was not as others. Far, far away, hundreds of thousands of miles from this, there lies a desolate country covered with thick jungle. In the midst of the jungle grows a circle of palm-trees, and in the centre of the circle stand six chattees full of water, piled one above another ; below the sixth chattee is a small cage which contains a little green parrot ; on the life of the parrot depends my life, and if the parrot is killed I must die." But, he added, this was not possible, because thousands of genii " surround the palm-trees, and kill all who approach the place." The princess told her son this, and he set forth on his journey. On the way he rescued some young eagles from Aug. 24, 1883.] ♦ KNOWLEDGE ♦ 115 a serpent, and the grateful birds carried him until they reached the jungle, where, the genii being overcome with sleep by the heat, the eaglets swooped down. "Down jumped the prince ; in an instant he had overthrown the chattees full of water and seized the parrot, which he rolled up in his cloak," then mounted again into the air and was carried back to Punchkin's palace. Punchkin was dis- mayed to see the parrot in the prince's hands, and asked him to name any price he willed for it, whereupon the prince demanded the restoration of his father and his uncles to life. This was done ; then he insisted on Punchkin doing the like to "all whom he had thus imprisoned," when, at the waving of the magician's wand, the whole garden became suddenly alive. " Give me my parrot ! " cried Punchkin. Then the boy took hold of the parrot, and tore off one of his wings ; and as he did so the magician's right arm fell off. He then pulled off the parrot's second wing, and Punchkin's left arm fell off'; then he pulled off the bird's legs, and down fell the magician's right leg and left leg. Nothing remained of him save the limbless body and the head ; but still he rolled his eyes, and cried, " Give me my parrot ! " " Take your parrot, then," cried the boy, and with that he wrung the bird's neck, and threw it at the magician, and as he did so, Punchkin's head twisted round, and, with a fearful groan, he died. Of course, all the rest " lived very happily ever afterwards," as they do in the plays and the novels. In the story of " Sodewa Bai," the Hindu Cinderella, the heroine's soul is contained in a string of golden beads. and in the Bengali tale, " Life's Secret," a Rajah's favourite wife gives birth miraculously to a boy, whose soul is bound up in a necklace in the stomach of a boal- fish. In both instances the jewels are stolen, and while they are worn by the thieves, prince and princess alike are lifeless, whilst with the recovery of the jewels, life returned to each. The family likeness of these Indian folk-tales to those given above is explicable on no theory of borrowing, and finds its sole and rational explanation in the possession of a common stock of folk-lore by the several ancestors of the Indo-European races. As Sir G. W. Cox remarks, " the substantial identity of stories told in Italy, Norway, and India can but prove that the treasure-house of mythology ■was more abundantly' filled before the dispersion of the Aryan tribes than we had taken it to be." 'The Egyptian taleof the "Two Brothers" is of great value on account of its high antiquity, and, moreover, specially interesting as recording an incident similar to that narrated in the life of Joseph. It is contained in the d'Orbiney papyrus preserved in the Bibliothequc Imperiale, the date being about the fourteenth or fifteenth century u c. There were two brothers, Anepou and Satou, joined as one in love and labour. One day Satou was sent to fetch seed-corn from Anepou's house, where he found his brother's wife adorning her hair. She urged him to stay with her, but he refused, promising, however, to keep her wickedness secret. When Anepou returned at even, she, being afraid, " made herself to seem as a women that had sull'ered violence," and told him exactly the reverse of what had happened. Anepou's wrath was kindled against Satou, and he went out to slay him ; bvit Satou called on Plira to save him, and the god placed a river between the brothers, so that when day dawned Anepou might hear the truth. At sunrise Satou tells his story, and, mutilating himself, he says that lie will leave Ancpovi and go to the valley of the cedar, in the cones of which he will deposit his heart, "so that if the tree be cut, his heart would fall to the earth, and he must die." Space forbids further outline of the venerable story, which finally ends with the reconciliation of the two brothers. For us the value of these folk -tales lies in the relics of barbaric notions concerning the nature of man and his re- lation to external things which they preserve. They have amused our youthhood : they may instruct our manhood. Not if we go to the solar mythologist for their interpreta- tion. We shall learn from Sir G. W. Cox that "the magician Punchkin and the heartless giant are only other forms of the Panis who steal bright treasures from the gleaming west," that " Balna herself is Helen shut up in Ilion . . . the eagles the bright clouds,"* and from Pro- fessor de Gubernatis that the duck is the dawn and the egg the sun. These venerable tales have a larger, richer meaning than tliis, expressive of the wonder deep-seated in the heart of man. Like the beautiful prisms of topaz and beryl re- vealed when a " drusy " cavity in granitic rock is broken open, they hold within them the crystallised thought of the past. The soul existing apart from the body, whether in bird or casket, and determining its fate, is the relic of barbaric belief in one or more entities in the body, yet not of it — a belief extant among tribes still uncivilised, and surviving in unsuspected forms among more advanced races. SEA ANEMONES AT THE FISHERIES EXHIBITION. By Thomas Kimber. III. (^Continued frovi page 90.) " Fnll many a flower is bom to blush unseen, And waste its fragrance on the desert air ; Full many a gem of purest ray serene The dark unfathomed caves of ocean bear." THE adult animal dwells in the deep sea beyond low- water mark, and in Torbay and ^Veymouth Bay is found in great abundance, at depths varying from three to thirty fathoms. The young, in large numbers, are met with between tide-marks in pools, or suspended from the roofs of rocky hollows, like white nipples, each with a dependent globule of water, resembling a dew-drop. These young dianthuses change their position spontaneously, and remove into deep water as they approach maturity. They are rarely ever met with between tide-marks exceeding, when in button form, an inch in diameter. In early youth the characteristic convolutions of the disk, with its feathery aspect, are not displayed ; and incautious observers are very liable to njistake a young dianthus for an anemone of another species. Both Dalyell and Gosse confess to this error of judgment. This species is gregarious ; the dredge and the trawl constantly bring up clustered groups, and sometimes the clusters are very numerous. A trawler (see Gosse, "Action," p. 21) brought into Torquay a board, two feet long and one foot broad, on which were crowded between four and five hundred specimens of A. dianthus. " What was curious was tliat all one side of the board were white, all on the other orange." The reproduction of this anemone by spontaneous divi- sion is very common. When ic chooses to change its posi- tion it does so by moving the base slowly — too slowly, " Mythology of the Aryan Nations," Vol. I., p. 140, ii. 116 ♦ KNOWLEDGE ♦ [Aug. 24, 1883. indeed, for the eye to appreciate its movement; yet if ita course be, as it usually is, from the bottom to the top of the glass frout of the tank, it will be marked out plainly by the track left behind. Minute fragments of the base are seen to adhere to the glass, which very soon contract into a rounded form, and begin to grow tentacles round a central mouth, and in time the minute creatures equal in size the elder original. This increase by separation of l)arts is analogous to the multiplication of plants by cuttings. In both cases the colour remains unchanged ; whereas, in the propagation of plants by seeds and of anemones by real germs, the colour of the new production is arbitrary and inconstant. Sometimes the irregular fragments, torn, as it were, from the base, in contracting make two circular forms united by a filament, and as the contraction continues, the uniting link becomes a tine thread, and finally breaks, when two individual anemones are formed. In this manner mon- strosities probably have their origin ; the conuectiog thread is not broken, and the two individuals grow up in contact, or united together, and an individual appears with one body and two disks. At the present moment, in tank No. 10, two very hand- some anemones, a white and a bufl" dianthus, are attached to the frout glass. They are nearly equal in siz", and correspond fairly well in dimensions to Figs. 1 and 2 in the preceding article (page 89), except that their bodies are much shorter than in Fig. 2, which is possibly in con- sequence of their position. A favourite practice with dianthus is to mount the side of the tank as high as the edge of the water, and to remain there protruding its column horizontally, and distending its frilled disk so that the air and water are equally and mutuallj' in contact with opposite parts of the base column and disk. No British anemone is more hardy, or more readily accommodates itself to confinement, than dianthus ; neither is it what is termed a coy or a shy creature. It freely expands and appears in flower during daylight. Still, it must be remembered that its natural habitat, and that of all the sea anemones, is in the " dark caves of ocean." Bearing this fact in mind, Mr. Gosse has very sagaciously Anemones are fed according to their appetite upon raw beef, mutton, fish, oyster, mussel, cockle, limpet, ic. A small fragment is held within reach of the feelers or placed upon the disk. All the varieties which feed freely soon degenerate in size and colour if they do not receive their supplies regularly. An American dianthus — and in accordance with the eternal fitness of things the biggest ever seen — is reported upon and figured in the great American work edited by J. W. Dana,* as follows : — Actinia Faumoieusis. From the coral reefs Paumotu Archipelago. Smooth exterior, G in. thick at middle, above very widely dilated (12 in.), tentacles numerous, covering the larger part of the disk, yellowish-white, tipped with lake, and marked with eight or nine transverse lines ; mouth but little prominent (•/. Drayton). This species was truly magnificent when seen in the water, the disk expanding at least a foot in diameter, densely covered with tentacles, the margin undulating so as to form numerous lobes, each of which had the appearance of being a separate actinia, the whole resem- bling a beautiful bouquet (J. P. Couthony). PRETTY PROOFS OF THE ROTUNDITY. EARTH'S CHIEFLY FOR THE SEASIDE. By Richard A. Proctor. (Co7itinued from page 102.) I HAVE received from a number of readers questions relating to the determination of the actual amount of depression of the earth's surface from a tangent line at any point at given distances from the point of contact. In particular some perplexity seems, strangely enough, to be occasioned by statements as to the distance at which light- houses of given heights have been seen from ships at sea. The actual depression of the earth's globular surface, below a true tangent, is almost exactly 8 inches at a mile's distance from the point of contact; four times this or 2 ft. 8 in. at two miles' distance ; nine times 8 in. or 6 feet pointed out the best way to make sure of seeing a tank of anemones under the most favourable possible circumstances, and at a time when all its occupants will be most likely to display the full beauty of their gorgeous bloom. His advice to the benevolent reader is that he should adopt Sir Garnet Wolseley's bean, siratagcme, so'success- fnlly executed at Tel-el-Kebir against the Egyptians ; which, of course, is to steal a night-march upon your enemy and catch them napping. His words are : — " Visit your tank with a candle an hour or two after nightfall." Some individuals of this species are voracious feeders ; they swallow and partially digest bits of raw mutton and fish once in two or three days, and grow wonderfully larger and handsomer after each meal. The portions of food eaten, so to speak, by anemones are retained for several hours — sometimes days — and then vomited along with true germs and egg-germs in many of the species. at three miles' distance ; and so on, — the depression in- creasing as the square of the distance. Thus if PABO (Fig. 11) is a part of the earth's surface, abc a tangent line at P, rtA, JB, cO vertical lines to the surface PABO ; then if Fa=ab=bc=l mile, Aa=8 in. ; B6 = 4Aa=2 ft. Sin.; Cc=9Aa=C}it. &o. But the optical horizon line, tangent at P, has a slightly curved course as Fb'c', owing to the refractive effects of the atmosphere. Though this curvature Aa, Bi, Cc are each reduced by about one-fifth so that Aa'=6|in.; B6'=4Aa'=2ft Ifin; Cc'=9Aa'=4 ft. 9|-in. j from the diflterentials of these equations, we get TT (x' — :evx''—y^') = yVx^ — y- or dividing by y' putting - = :, and reducing y TT^l. ■2t, -3 _ On a number of this batch leaving the bottom of the square, it is transferred to a corresponding square at the top, vertically above ; should it run out on the right side, it is transferred to the corresponding horizontal cell on the left hand side. The first of the second batch is placed two cells below the last term of the first batch, and the diagonal system continued. Should the first or any other of this batch fall without the square, it is brought in as before explained. The first term of the third batch is placed two cells below the last of the second, and so on. Thus the eightli square was formed. The other squares are arranged in accordance with it. The whole series, through 1, 2, 3 to 79, 80, 81, is divided into nine sets, 1, 2, 3, &c., 9; 10, 11, &c., 18 ; 19, 20, 4c., 27, &c. The first set is placed in the square corresponding with the cell in the small square represented by 1, i.e., middle of bottom row. The next set is put in the square corresponding with 2, i.e., the right upper comer, and so on. What Agrippa calls the seal or character of this square (dedicated to Saturn) is really the direc- tion in which theii' numbers are placed, as in figure. J. 0. M. CURIOUS STRUCTURE IN THE SQUIRREL. [904] — After removing the skin of a common squirrel, I was struck by observing two thin flaps of muscular tissue extending from the superior part of the fore-arms to the region of the floating ribs ; this flap formed part of the muscle of the back, and was open Contents ■■ 2-333 cubic feet. dy dy^l dX TT Putting for tt its value, and solving the equation (which has only one real root), we get ; = 5 = 1-9625 V also X + Try = Z Whence length of parcel = 2x = 2-307 feet. „ girth „ = 277y = 3-693 do. -. ^.r'- (a;--r'l'' j =: = 2i do. H. F. [H. F. also sends the correct solution of the problem dealt with at p. 76.— R. P.] LETTERS RECEIVED, A^"D SHORT ANSWERS. A. W. Should not care to-publish such wonders till I had seen them myself, and tested pretty closely. — Minnie. Saturn is in Taurus. — J. D. VdS. Fear I can only offer you the Paradox Column ; but I would point out, in a note, where your trisection of any angle by simple geometry was invalid, or for what reason it failed to solve the insoluble. — A. T. Fkasek. Prefer not to open a vexed and vexing question. — A Lady Mathematicun. " Mad Tom" was joking, of course. Non-Euclidean mathematics may be de- scribed as mathematics based on axioms inconsistent with our con- ceptions. A new arithmetic might equally well (as indeed Clifford, Helmholtz, and others suggested) be based on the axiom that 2 and 2 make three, which in some universe unknown to us, they may do. But we may wait before we give time to such new arithmetic or geometry until the unknown universe to which they belong begins to loom above oui- intellectual horizon. — G. G. Chisholm. Cannot say ; but have great difliculty in finding space for all which I should like to give in these columns. — ^W. H. B. Rannie. Quite impossible to bring out the Star Maps again in Knowledge — it would be unfaii' to a great number of our readers, who have already had these Star Maps. The great bulk of our first sub- scribers must (so far as can be judged) be with us still. — Jas. E. Rattle, M. Molynettx, D. E. H. R., Renfrew, Gr.4Vesenu Doctoe, and others. Think it best to insert no more prescriptions for Cholera patients. — Jas. .T. Hill. The problem is insoluble in that form, the velocity of a running stream depending on other matters than the fall. — Bank. The star atlas you mention must be imper- fect if it fails to show you to what part of the star sphere the earth's axis points, southwards. There is no conspicuous star there, but the place is in the constellation Octans, shown in the middle of the twelfth map of my School Atlas. Aug. 24, 1883.] ♦ KNOWLEDGE ♦ 127 #iir iftatftcmatical Column. GEOMETRICAL PROBLEMS. By Richakd A. Pkoctob. PART xra. LET us consider the method applied in our last. One condition shows us that the point we seek mtist lie on a certain curve ; another condition shows us that the point must lie on another curve. Therefore, the point we seek must lie at some intersection of the two curves. If there are more intersections than one, tlie problem has more solutions than one ; if there is but one intersection, there is but one solution ; if, lastly, the curves do not intersect, the problem is insoluble. Let UB take, as another instance, the following problem : — Ex. 20. — Let A B (Fig. 30) be a given straight line, C a giveyi angle, D a given point within the given circle EF G. It is required to determine a point at Schick A B shall subtend an angle equal to the angle C, and which (point) shall ie the bisection of a chord through D to the circle E F G. .30. In order that A B may subtend an angle equal to C at the required point, this point must lie, we find (as in Ex. 17), on the arc A E B, containing an angle equal to the Angle C. Again, in order that the required point may be the bisection of a chord thi'ougli D to the circle E F G, this point must lie, we find (as in Ex. 18), on the circle L K M, which has for diameter the line joining D with K the centre of the circle E F G. These two loci — viz., tlie arc A E B and the circle L M K, deter- mine by their intersection the points which satisfy the required con- ditions. There may be two points, as in the case illustrated by our figure ; or one point, if the circle L M K touch the arc A E B ; or the two loci may not intersect, in which case the problem does not admit of solution. Wo liave supposed that the point is required to lie above A B. If not, tlien an arc equal in all respects to A E B, but applied on the opposite side of A B, would include otlier points satisfying the first condition of our problem. It might happen that the circle L M K intersected the latter arc, instead of, or as well as, the arc A E B. Such point or points of intersection would also supply a solution of the problem. Fig. 31. Problems in maxima and minima also involve very frequently the discussion of loci. Suppose, for instance, that the following problem is given : — Ex. '21.— A, B, C, and D (Fig. 31) are four fixed points. It is required to determine a point equidistant from A and B, and such that the sum of its distances from C and D shall be a minimum. In this case we first find the locus of points equidistant from A and B. This, as in Ex. 18, is the line F G drawn at right angles to the line AB, through its bisection E, Fig. 31. We have, then, to find a point in F G such that the sum of its distances from C and D may be a minimum. We find (as in Ex. 11) that the point must be "so taken — as at H — that the lines from C and D to it shall make equal angles (C H F and D H G) with the line F G. To take another simple instance, suppose we had the following problem : — Ex. 22. — A triangle is constructed on a given base A B (Fig. 32), and with a vertical angle equal to the angle C, to determine its figure that its area may be a maximum. Here we first inquire what is the locus of the vertices of aU the triangles which can be constructed on the base A B with a vertical angle equal to the angle C. We find, as in Ex. 17, that the locus is the arc A D B, containing an angle equal to the angle C. After this we can find no difiiculty in determining the triangle of maximum area. The vertex must clearly lie at that point of the arc A D B which is farthest from A B ; and D, the bisection of the arc, is obviously the required vertex. The student will at once see this ; but perhaps he may find a little difficulty in proving it. We leave this part of the problem to him as an exercise, having already Fig. 32 Fig. 33. examined the treatment of problems of this class. We note, how- ever, that what he has to do is to show that a parallel to A B through D is fartlier from A B than the parallel through a vertex of any other triangle fulfilling the required conditions ; and this will be established if it be shown that the paraUel to A B through D is a tangent to the arc A D B. Sometimes a familiarity with the treatment of problems on loci, serves us in a somewhat more subtle manner, as in the following problem : — Ex. 23.— ^£ (Fig. 33) is a given finite straight line. It is required to show where a point must be taken in the given indefinite line DE, in order that the angle subtended by AB from the point may be a maximum. Suppose we take any point, D, at random, in D E, and draw the lines D A and D B. Then, in inquiring whether the angle A D B is a maximum or not, it would be an obvious consideration that the segment of a circle, A D E B, described on A B, contains all the points from which A B subtends an angle equal to the angle A D B. From the point E, therefore, A B subtends an angle, A E B, equal to the angle A D B ; and from any point, F, between D and E, it is clear that A B subtends an angle greater than A D B. For, producing A P to meet the arc A D B in G, and joining G B, we see that A F B is greater than A G B (Euc. I., 16), that is than A D B (Euc. III., 27). It is clear, therefore, tliat we cannot have a maximum so long as the arc described on A B, to pass through the particular point selected in D E, cuts D E in another point. Hence we ai-rive immediately at the solution of our problem— viz., that the required point, U, is so situated that the arc on AB through H touches the straight line D E. It is easy to draw a circle through two given points to touch a given straight line. But, strictly speaking, the solution of the above jiroblem is complete without the construction of the circle A HB, since wo have assigned a sufficient condition for the deter- mination of the required point in D E. The consideration of problems on loci leads ns to another class — or rather two classes of deductions — viz., those in which it is required to prove either that certain straight lines pass through one point, or that certain points (more than two) lie in a straight line. (To be continued.) 128 ♦ KNOWLEDGE ♦ [Aug. 24, 1883. ©ur Ctjcsfs Column. By Mephisto. PROBLEM No. 93. By Leonard P. Eees. Black. Whitb. White to play and mate in two moves. A FINE GAME PLAYED AT NURENBERG IN THE SECOND TOURNAMENT BY HERR TARASCH, THE FIRST PRIZE WINNER, IN THE FINAL HEAT OF THE WINNERS. ■White. HeiT Tarasch. 1. P to K4 2. P to Q4 3. QKt to B3 4. P takes P 5. Kt to B3 C. B to Q3 7. Castles 8. B to KKt5 9. P takes B 10. Q to Q2 (h) 11. Kt to K5 12. P to e;b4 13. B to R4 14. P to KR3 15. P to Kt4 FRENCH Black. Herr v. Scheye. P to K3 P to Q4 B to Kt5 (a) P takes P KKtto B3 Castles B to Kt5 B takes QKt QKt toQ2 P to B3 Q to B2 P to KR3 P to B4 (c) B to R 1. Pto B5 DEFENCE. ■WTiite. Black. Herr Tarasch. Herr v. Schere. 16. B to B5 B to Kt3 17. Btks QKt ((J)Kt takes B 18. Kt takes Kt Q takes Kt 19. P to B5 B to R2 20. P to B6 B to Kt3 (e) 21. R to B2 QR to K sq 22. QR to KB sq R to K.5 23. B to Kt3 (/) K to R2 24. P takes P K takes P 25. B to B4 K to R2 (g) 26. B takes P R to KKt sq 27. B to Kt5 Q to K3 28. B to B6 (h) R to KO 29. R to Kt2 (0 R takes P 30. R to B3 B to R3 White mates in fire. NOTES. (a) Not commendable. In most close games the B is necessary for the defence of the K side on K2 or Q3. (6) Showing good judgment. If Black now captures the Kt, White would get the open Kt file for his R, which in conjuuction with the two B's would soon become dangerous to Black. (c) Black has his B in a very uncomfortable position ; the more in the test does not help him in any way; his onlj' other alteruatire seems to be Kt takes Kt, which would turn out satisfactorily if BP retook, but White would obtain a superioritv as follows : — Kt takes Kt. 14. QP takes Kt, Kt to R2 (Kt to KS is bad, as after B takes Kt, and P takes B, the Black P on K5 would soon f,all). 15. P to B5 (threatening to win the B), P to B3. 16. P to KG, with a good position. (d) White is playing a spirited game. He prefers to continue a doubttid attack to winning a clear P by Kt takes B, and remaining with two B's against two Kt's. (e) P to Kt4 would be bad on account of 21. B takes P, P takes B. 22. Q takes P (ch), B to Kt3. 23. Q to R6. The likely- looking move of B to K5 would result in loss of time, as the B is required for the defence of the BP, i.e., B to Ko. 21. P takes P, K takes P. 22. R to B6, R to R sq. 23. QR to KB sq, QR to KB sq. 24. Q to B4, R to R2 (to avoid the threatened loss of the exchange bv R to Q6). 25. R to Q6, Q to K sq (as othenvise, B to K7). 26. B to B6 (ch), K to Kt sq. 27. R to Q8, Q to K3. 28. Q to Kt8, and wins. PuSITIOX AFTER WhITE's 20tH MOVE, P TO B6. Blacs. t i i i t 2 ■_ (/) To avoid any possible sacrifice of the R for the two P's and the B, and to make the B available for attack. (q) The P cannot be defended by R to KR sq, on account of B to K5 (ch). (h) With the object of playing Q to Kt5. (i) Very fine play indeed, which brings about a forced termina- tion of the game. White threatened to reach the R file fid B2, which Black could not prevent without loss. (j) The ending forms a termination quite worthy of the first prize winner, and is as follows : — 31. Q takes R (ch), K takes R. 32. R to R2 (ch), B to E4. 33. R takes B (ch), K to Kt3. 34. R to Kt5 (ch), K to R2. 35. R to R3, mate. SOLUTIONS. Problem No. 90, p. 96. K takes R R takes R K toK5 1. Kt to Kt' 2. Kt to Kt4 ! K to K4 Q, to R5 (ch) 3. Kt to BG, mate. Kt to B5, mate. Or, 2. R to K5 3. Q to B3, mate. Problem No. 91 we regret to say is incorrect. The author's idea being 1. Kt to B3, R to K4. 2. Q to B4 (ch), B takes Q. 3. Castles, mate. Bl.tck can, however, frustrate this artful design by playing 1. R to Q5. ANSWERS TO CORRESPONDENTS. •»* Please address Chess Editor, J. Berger Graz. — Games and problemsreceived ; our best thanks for same. Chess Editor, Times Democrat. — We have complied with your request, and hope to be favotired In return. Leonard P. Rees. — Accept otur best thanks for friendly expres- sions. Problem received with thanks. We hope you will have success in forming an association of the Surrey Chess Clubs. It seems strange that what is possible in Germany — a National Association — should not be attempted in England. 'The stirest road to that end is to form counties associations. You will no doubt have the support of all Surrey phayers. Joseph Farrar. — Solution of No. 92 correct. E. N. Parker. — Y'ou evidently did not read Note ( j) to the game p. 112. It contains the desired information. B. Hammond.— Problem 92. It K to K7, then P to B4. W. — Solutions correct. Very sorry you spent so much time over 91. Did vou guess the idea ? SPECIAL NOTICES. Part XSr. (July, 1883), just ready, price lOd., post-free, Is. Id. Volume III., comprising the numbers published from January to Ju just ready, price 7s. 6d. Contents of No. 94. PAGS A Naturalist's Year. A Rabbit's Skull. By Grant AUen 97 The Chemistry of Cookery. XVI. By W. JIattieu WiUiams 9S How to Get Strong 99 Pretty Proofs of the Earth's Rotun- dity, illlut). By R. A. Proctor 100 The Amateur Electrician. Bat- teries. Ill 102 Pleas ant Hours with the Microscope. illliui.) By H.J. Slack 103 PAOI The Shoebm (lUuitrated) 105 The M orality of Happiness : Eyo- lution of Conduct. By T. Foster 105 Laws of Bris-htness. VIII. By R. A. Proctor 106 The Death of Captain Webb 108 The Face of the Sky 109 Correspondence 109 Our Mathematical Column : Geome- trical Problems. XII Ill Oar Chess Coiomn 112 Aug. ;31, 1883.] • KNOWLEDGE ♦ 129 V AN IlLLLSTLRATED " MAGAZINE OF^IENC i PlainlyWorded -£xactlYDescribed LONDON: FRIDAY, AUG. 31, 1883. Contents PAGE A Naturalist's Tear. Wild Peas. By Grant Allen 129 Pleasant Hours with the Microscope. ByH. J. Slack 130 Tricycles in 1833 ; Small Wheels v. Large Wheels. By John Browning 131 The Amateur Electrician. (Illm.) 133 Laws of Brirhtness. IX. (Ilhu.) By E. A. Proctor 133 The Chemistry of Cookery. XVII. By W. Mattieu Wmiams 135 Evolution of Human Physiognomy. {lllus.) By E. D. Cope 138 OP No. 96. PAGB The Morality of Happiness : Evo- lution of Conduct. II. By Thos. Foster 133 Pretty Proofs of the Earth's Hotun- dity. {lUm). By R. A. Proctor 139 Punctuation and Printers. By Sir Edmund Beckett 140 The Face of the Sky 141 Correspondence : Luminous Riiig — Flight of a Vertical Missile, ic. 141 Our Mathematical Column 143 Our Whist Column 143 Our Chess Column 144 A NATURALIST'S YEAR. By Grant Allen. XX. — WILD PEAS. AMONG the hedgerows here, on the side of a deep Surrey lane, the lithe curling stems of the common English yellow pea clamber in their usual straggling fashion over the loose outlying sprays of bramble and haw- thorn bushes. Looking close into the hedge, you can see that they festoon themselves by means of their tight- twisted tendrils, which wind and insinuate their graceful coils round and round the successive supports by whose aid they struggle gradually upward towards the air and light. Strange as it sounds to say so, these thin spiral tendrils are in reality metamorphosed leaves, or perhaps one ought rather to put it, tlie abortive footstalks of un- developed leaflets. Pull off one of the whole leaves from the stem, and you will see it consists of a central midrib or common leaf-stalk, with two little arrow-headed stipules at its base, and one pair of very narrow leaflets half-way up ; but the end of the leaf-stalk bears no more leaflets, and in their place it ends in a branched tendril, which really represents the altered and modified remnant of the remaining blades. See here, by the side of the yellow peas I have picked for compari- son, two other leaves belonging to the same peaflower tribe; one is the pretty purple-tufted vetch {Viciti cracca), a common wayside plant over all Britain ; the other is the bright golden Hippocrepis, abundant in chalky pastures and on limestone banks in Southern England. You will observe that the tufted vetch has several pairs of leaflets to each leaf , arranged in couples on opposite sidcsof the common stalk, instead of one pair only, as in the yellow pea : but at the end, it terminates in a branched tendril of much the same character as that of its yellow ally ; while in the Hippocrepis each leaf-stalk, besides bearing some four or eight pairs of lateral leaflets, ends also in a single terminal leaflet, which occupies the place taken by the tendril both in the tufted vetch and in the yellow pea. These two cases help us to understand the line of development by which the leaflets at the end of the stalk in the most clamliering species of poailowers have been gradually meta- morphosed into twining tendrils. If wo take a rapid glance at the general type of foliage in the entire family, and at the special modifications which that type undergoes in adaptation to the varying environments of diverse divergent forms, we shall still better understand the nature and origin of these peculiar elongated leaf-organs. The original and central peaflower leaf, from which all the other leaves of the group are derived by suppression or alteration of particular features, consists of a long central leaf-stalk, terminating in a single leaflet, and with other similar leaflets arranged in pairs down the opposite sides. This form of leaf is very well seen in Hippocrepis ; and among other English plants of the family which e.xhibit it equally well, I may mention the pretty little bird's-foot {Ornithopus jjerjnuillus), the common lady's-fingers {An- thyllis vulneraria), and the beautiful pale pink sainfoin (Onobri/chis saliva), if not indigenous, at least now fully naturalised in the southern and eastern counties. That this long pinnate type of leaf is the original one we can gather both from the ease with which all the other forms can be derived from it, from their occasional relapse into it, and from the fact that it also appears in some of the simplest roses, of which the peaflowers are genetically a slightly specialised oflshoot. This central type of leaf occurs mainly in those peaiiowers which grow in open ground, where all the blade is freely e.xposed to air and sunlight. The easiest variation upon the central type is found in certain divergent peatlowers, like the clovers, which inter- mingle freely with the grasses in meadows, and have to compete with them for their fair share of space and sun- shine. In these cases the leaflets on the lower part of the leaf-stalk are never developed, because they could do no good to the plant ; they would be over-shadowed by the grasses and other tall weeds on every side of them. Hence they would naturally grow smaller and smaller by disuse with each generation ; while, at the same time, those plants which showed the greatest tendency to get rid of them, and to produce the three upper leaflets only (the terminal one, and a single pair below it), would be most highly favoured in the struggle for existence, because they wasted none of their material in places where it would be comparatively inefliective. So, in the long run, the clovers have come to possess the familiar trefoil type of leaf, consisting of three broad and expanded leaflets, all equally exposed to the sunshine at the top of their naked and elongated leaf-stalk. The common lotus shows us an intermediate stage between this type and the primitive pinnate form, for in that case there are five leaf- lets, three arranged in a trefoil at the end of the stalk, and two broad ones lower down, practically ururping the place and function of the original stipules. Other English pea- flowers of the trefoil group are lucerne, nonsuch, and the other Medicagos, besides the rarer Melilotus and Trigonella. Broom is a bushy example of the same sort ; but in it the two lateral leaflets are often wanting, and only the terminal one is developed. This last state, well adapted for shrubs and bushes, has become habitual in the English genistas, like petty whin ; but some exotic genistas, culti- vated in our conservatories, still retain the trefoil type of foliage. Furthest removed of all from the central type on this line of development is the common gorse, where the adult leaves are reduced to mere stiflP, simple prickles; but even in this instance we have some faint memorial left of the earlier habit ; for, as I have pointed out here already, the young seedling gorse plants have trefoil leaves, which only gradually merge as the shrub grows older, first into long, thin leafy, blades, and finally into sharp and rounded bristles. On the opposite line of development, towards tlie peas and vetches, we get this system of suppression among the leaflets exactly re\ersed. The climbing types get rid, not of the lowest, but of the terminal leaflets ; and for this very 13C ♦ KNOWLEDGE ♦ [Aug. 31, 1883. good reason, that they want to use the ends of their leaf- stalks as tendrils to fasten them firmly on their unwilling hosts. The vetches are not quite such highly-developed plants as the true peas, and they supply us accordingly with some very interesting gradations in this direction. There is one rather uncommon British form ( Vicia orobus), remarkable for its stem being more erect and its habit less climbiug than in other vetches ; and this form has a terminal leaflet to all the ujiper leaves, though in the lower ones the common leaf-stalk ends instead in a very rudimentary tendril, represented merely by a short point. In another slightly more advanced type (Vicia tetrasjyeriiia) there is always present a terminal tendril instead of the last leaflet ; and sometimes this tendril is branched, that is to say in other words, a pair of lateral leaflets have also been reduced to naked twining leaf-stalks. In our other vetches, the tendrils are almost always branched, and one very developed type (Vicia hithynica), confined in Britain to the West Country, has only one pair of leaflets left. Of course, as these two have to do all the work, they have grown comparatively large and long, while in the other vetches, where the leaflets are many, they are usually small and broad. The true peas, forming the genus Lathyrus, show us a still further progress in the same direction. We have one very rare British species (it occurs with us only in Perth- shire and Forfarshire, and is everywhere a dying mountain type) which resembles Vicia orubus in having a good many leaflets on each leaf, and in the occasional reappearance of the terminal leaflet in the upper foliage. But most of our peas have very few leaflets — indeed sometimes two pairs, and sometimes only one, all the rest being converted into tendrils to aid the climbing habit. At the same time the work of foliage is thrown a good deal on the stipules, which grow out accordingly into large, flat, leaf-like organs, far more conspicuous in the garden pea than the true leaflets, while the common leaf-stalk also shows a tendency to be winged or expanded at the side, which is very noticeable in the " everlasting pea " of our flower-beds and trellises. These two last tendencies find their final outcome in two English wild peas which have no real leaflets at all, having entirely substituted for them these auxiliary foliar organs. One is the so-called yellow vetohling (Lathyrus aphaca), a weed of cultivation which appears very occasionally in the cornfields of our southern counties ; it has the two stipules immensely enlarged into what looks like a pair of big opposite heart-shaped leaves, with only a slender branching tendril between them to represent the original leaf-stalk and leaflets. The other is the grass-pea (Lathi/rus nlssolla) a pretty, grass-like plant, with beautiful palered flowers ; it grows among tall grasses on the borders of fields, and has been compelled by its situation to imitate the shape of the surrounding blades, which it does by flattening out the common leaf-stalk into a long narrow ribbon, without stipules, leaflets, or even tendrils, save iia the form of a tine point. The everlasting pea, and some south European forms, give us a good idea of the stages bj' which this curious transformation has been efi'ected. The final result is that the grass-pea looks in foliage almost like a grass or sedge, and does not in any way recall its real ancestry from a highly compound pinnate leaf like that of sainfoin or Hippocrepis. *^* TuE jiicture of the Whirlpool Rapids promised for last number of Knowledge will appear next week. It presents the Rapias as shown in an instantaneous photo- graph, taken at a moment when the collision of the water particles, so graphically described by Professor Tyndall, had just taken place. PLEASANT HOURS WITH THE MICROSCOPE. By Henry J. Slack, F.C.S., F.R.M.S. AMONG the objects mentioned in the last paper as afford- ing beautiful specimens of plant- hairs strengthened by silex, was the cuticle of Dmlzia scahra leaves. It is not possible to make good preparations of this cuticle by mechanical means, but it is easily effected by chemical agency, and a similar plan is useful in a variety of other cases. A perfectly sound well-grown leaf of Dcutzia scahra should be cut into pieces about one-third of an inch square, and the thick mid-rib rejected. Pieces of this size will lie at the bottom of a large test-tube, six inches long and one inch wide. If the experimenter is not provided with any apparatus to hold such a tube, one can easily be made by sticking a piece of stout wire eight or nine inches long into a small square block of wood, and bending the top of the wire into a ring just wide enough to hold the tube by its projecting rim. The ring should be turned on one side, so as to keep the tube in a slanting position. This being arranged, pour some nitric acid into the test-tube, so as to cover the bits of leaf and occupy a space of about one inch in height. A spirit-lamp should be held under the tube, and the acid made quite hot. Small crystals of chlorate of potash should then be dropped in, one or two at a time. They excite a brisk efl'ervescence. If added too quickly, or the acid is heated too highly, the mixture swells up suddenly, and may even boil over. This must be avoided, as a violent treatment of the leaf tears the cuticle into minute fragments, and from these no fine slides can be prepared. If the frothing is too slow, a little more heat should be applied, and the dropping in of the chlorate of potash continued until nothing is seen but a collection of white films floating on a bright yellow fluid. The tube must now be allowed to cool, and then with a little dexterity all the yellow fluid can be poured off, and the films allowed to remain. They must be washed several times by filling the tube with plain clear water and pouring it oflT again. All these things must be done gently, so as not to tear the films. Those accustomed to chemical operations will not need more instruction, but for beginners further information is necessary. The process is one of oxidising, or burning away, all but the leaf cuticle. The oxygen is applied at the expense of the chlorate of potash and of the nitric acid, and as soon as the action goes on briskly, the latter gives forth orange fumes of nitric-oxide gas.* This is not only very unpleasant, but extremely unwholesome to breathe. A good mouthful of it, even when largely mixed with common air, is very suffbcatin" and highly injurious to the lungs. The fumes should be allowed to go up a chimney or out of window. The operator should notice which way the air-currents carry them, and keep, as sailors say, to the leeward. Beginners should make their first experiment on a smaller scale than has been mentioned. Nitric acid burns holes in clothes and stains the skin yellow. Having completed the process as described, the films may be kept in a small bottle, with a little water and a few drops of alcohol. To prepare a slide, take up a few films on a needle and drop them into a small shallow saucer of clear water ; or, if a very small quantity is on the needle, it may be placed on the centre of a glass slide in a water-drop. The first plan is the best, as most certain to remove any chlorate of potash that may not have * When nitric oxide meets common air, it instantly seizes its oiiTgcn and becomes the orange gas nitrous acid, which is readily absorbed by water and is highly corrosive. Aug. 31, 1883.] ♦ KNOWLEDGE • 181 been washed out in the former processes. If bhe films have lost all their air-bubbles they may not iloat, but stirring the water will make them do it, and a few small pieces can be fished out with a thin spoon or a knife-blade, and dropped on to a glass slide. They must then be spread out very carefully with fine needles stuck in wooden handles, or a tine sable pencil such as miniature painters use. The object is to get some films spread out quite flat. They will most likely be found folded up, or one over another. The least force tears them, but under a hand-magnifier or a dissecting microscope success is easily obtained. Having arranged a few films nicely in a water-drop, the slide should be allowed to dry slowly where no dust can get at it. When it is quite dry, put a drop of Canada balsam, thinned with benzine, on to a glass cover, and press it gently on to the films. The cover may be held with a spring clip, such as opticians sell for the pur- pose, and the balsam must be allowed to harden before the slide is fit for use. A hint may be given about the Canada balsam. It is much too thick for most purposes in the state in which it is usually sold. Pure benzine, or benzole, as it is also called, dissolves it readily, so much so that it is very useful in cleaning the superfluous balsam oft" slides. When used for thinning, it must be added cau- tiously, and the balsam bottle put in a warm place. When it is about as thick as golden syrup treacle — not quite thin enough for the films — further additions of benzine act rather suddenly, and the thinning may be carried too far. If so, the e.xtra supply can be evaporated ; but it is well to hit the right quantity. Amongst the objects which yield beautiful results with the acid and chlorate of potash treatment are the needle- shaped leaves of the pine-trees. Pinus Auntriiica, common in shrubberies, is a good one for the purpose. Quite clean leaves should be selected, of fresh growth. They should be cut into short lengths, so as not to require much acid to cover them, and treated exactly as the Deutzia leaves, but they want a little more cooking. When finished they are quite white, and in the state of hollow tubes, all their insides being eaten out. To prepare for the microscope, a piece of the tube must be slit opeft and flattened out on a slide with fine needles in a drop of water. If it curls up it must be flattened again and kept so by a covering-glass. When quite dry, mount in balsam, and view with a half- inch objective polarised light and a selenite film. A hand- magnifier is sufiicient to show that fir needles are orna- mented with rows of white glistening spots. In these the stomata of the plant are situated. Their action upon polarised light is very beautiful, and the changes obtainable by rotating tlie prisms very striking. Very elegant patterns that would be popular for ladies' dresses, window- curtains, itc, readily appear. So far as the writer knows, these pine needles have been generally neglected by microiicopists. TRICYCLES IN 1883. SMALL WHEELS v. LAKGE WHEELS. By John Browning, Chainnan of the London Tricycle Chtb. CONSIDERATIONS of space prevented me from ex- hausting this subject in my last article, though I had left several points of great importance untouched on. The weight of machines witli large wheels is nev(>r felt so injuriously as when pushing up hill. It has lieen roughly calculated that out of each ten miles of road in England one mile, at least, will be a hill too steep to be ridcal)le. Let any person take a ride of, say, even fifty miles in a day on a tricycle with small wheels, weighing 60 lb., over a moderately hilly road, and then repeat the ride over the same course on a machine with, say, 52-in. wheels, weighing 961b. to 98 lb., which is a common weight for such a machine. After pushing this machine up the hills, I will warrant he will have had enough of large wheels. Last year I rode a " Premier Sociable," with 48-in. wheels. As I wished to drive the machine throughout the day, if I pleased, without my wife once putting her feet on the pedals, I had it geared down to 36 in. The weight of this machine was 172 lb. My pace, when riding with my wife, was about four miles an hour, and our journeys averaged twenty miles a day. This year I have been riding an " ApoUo Sociable " I had specially made for me, with 44-inch wheels geared down to 36 inches, as in the former case, but the weight of this machine is only 1331b. Our pace on this is improved to five miles an hour, and we average about 30 miles a day with ease, and have ridden 7i miles within forty minutes, and 23 miles in four hours. These we did easily, though I pushed the machine vip more than three miles of bills alone. With the additional experience I have now gained I consider I should have done better by having the " Apollo " made with 36-inch wheels geared level I thoroughly disagree with all gearing-down. When a low gearing is required, let the wheels be made small instead, and the rider will have a lighter, stronger, and more compact machine. Weight is not everything, I admit ; but tricyclists must make it the first consideration. It is the principal cause of the exhaustion often complained of by riders. When I rode a single machine which weighed 109 lb., I could only ride fifteen miles without requiring a meal. Now I have a machine which weighs just over 50 lb., I commonly ride twenty-five miles between meals, and I have ridden twenty-nine miles without refreshment. Regarded as performances these examples are, of course, very poor, but being born almost without muscles, I am compelled to ride with my brains, and my illustrations are none the less useful on that account. Another point greatly in favour of small wheels is that they oft'er scarcely any resistance to wind compared to large wheels. I have frequently seen men almost pulled up by wind on machines with 50-in. wheels, while others, who were not stronger riders, were travelling without much difficulty on machines with 40-in. wheels. The truth is, that I have been advocating the use of small wheels for years with a definite object in view. I wished to see our machines combine the ease of the bicycle with the comfort and safety of a tricycle. To accomplish this, I saw that we must obtain a great reduc- tion in their weight. We cannot dispense with the weight of the third wheel and its friction on the road, but we need have no more. When I began my experiments, tricycles weighed about twice as much as bicycles. I soon found that the greater part of the weight was in the two driving - wheels. It was, therefore, absolutely necessary to reduce the size of these if we wished to make any considerable reduction in the weight of the machine. This can be done without any disadvantage of consequence, because the tricycle, unlike the bicycle, admits of being geared up so that the pedals need not make a greater number of revolutions with the smaller wheels. The driving-wheels must, of course, revolve oftcncr — let them do so ; with ball-bearings tlie small additional friction may be neglected. Some strong riders, I know, object to fast pedalling, Hnd prefer to work with greater pressure on their pedals. This 132 - KNOWLEDGE ♦ [Aug. 31, 1883. is no argument against small wheels ; on the contrary, I consider it is one of the strongest points in favour of them, that the rider may have them geared up to any degree that suits him, still keeping his machine as low in weight as possible. rj.5^aj' ^ '^, There have been complaints, I am aware, of machines with small wheels giving a painful amount of vibration ; but I have in every such case traced it to another source — namely, that with small wheels the makers have given very small tyres, in the endeavour to iiake the machine lighter with as little trouble to themselves as possible. Now, the smaller the wheels and the lighter the machine, the larger the tyres require to be to lessen the vibration, both to the machine and the rider. Small wheels must have tyres at least the same size as are usually put on large wheels, or they will be unfairly tested. Only one objection that I know of can be urged against small wheels. Some persons dislike their appearance. It is difficult to argue on matters of taste ; liut I think small wheels look best, because with large wheels the machine predominates over the rider, while with small wheels the man dominates the machine. THE AMATEUR ELECTRICIAN. BATTERIES.— IV. IT was observed in the preceding article that the Leclanche cell introduced a great peculiarity in the matter of the negative element and its surroundings. The utility of the Ijattery is so great that several modifications in its construction have been devised. One of them is the " Gravity " Leclanche. It is generally made in troughs of ten cells, each cell being separated from its neighbours by means of slate or other suitable material coated with marine glue.* Pig. 1 is an illustration of the battery. The zinc plate is of a peculiar shape (as shown in Fig. 2), and is supported by the strap resting on the slate partition. The carbon is in the form of a rectangular rod or block, which, passing through the hole in the zinc plate, dips into a quantity of broken carbon and manganic dioxide. Care * Marine glue is a substance insoluble in water and acids, but readily soluble in carbonic disulphide (CS.,). Originally it was composed of caoutchouc dissolved in naphtha and shellac, but the cost of the ingredients is too high for general purposes, and the material now known as marine glue is made from less costly con- stituents. It acquires a treacley subsistency on gently heating, and cools very rapidly. For such purposes as it is usually employed by amateurs it may be worked with little difBculty. It may bo heated in an old iron ladle over a gentle fire, and then poured out as required ; or small pieces of it may be laid on the substance to be coated, and an old file or other piece of iron, heated to a dull red, passed over it, but not allowed to touch it until the heat is consider- ably reduced. An even layer may be very easUy made in this way. Some complain that they cannot work the glue, but where this is the case it can only be through downright clumsiness. must be taken that the carbon black does not touch the zinc. A layer of sal-ammoniac is placed on the zinc plate, and water being added, it is gradually dissolved. A copper strap cast into the plate, and serves to connect it to the carbon in the next cell. The action is, naturally, the same as in the ordinary Leclanche, the advantage gained being a considerable re- duction in the resistance consequent on the omission of the porous earthenware pot. The resistance is 1 '.S Ohms, the E INI F being of course the same as in the ordinary form. Care should be taken not to disturb the battery, nor should it be forgotten that it is adWsable, if not absolutely neces- sary, to leave the lid of the trough (should it have one) slightly raised, to permit any free ammonia that may be given off to escape. As is the case with all batteries, cleanliness is essential. The salt (sal ammoniac) has a strong tendency to crystallise, but a damp cloth passed over the edges of the cells occasionally will suffice to prevent this. Another modification, having for its object the omission of the porous pot, but free from the difficulties attending the use of the gravity form, is that known as the " Agglomerate." This, too, has several varieties. It will be sufficient if we confine ourselves to two of them. In the first, the negative element consists of a plate or fiat block of carbon placed between two blocks of compressed manganic peroxide. India-rubber bands keep the three blocks in contact, the porous pot being thereby dispensed with. ^f Fig. 3. The form which has met with greater favour is, how- ever, of a somewhat different shape. Fig. 3 is a horizontal section of the negative element which consists of a ffuted block of carbon (c), having a circular rod of compressed manganic peroxide (B) in each of the six flutes. A piece of coarse canvas passed round and secured by a couple of elastic bands keeps the parts together. In the previously- described agglomerate cell the ordinary zinc rod is gene- rally used, but in this one zinc cylinders are used, the result being a very considerable reduction in resistance and greater constancy on circuits of high resistance. The resistance is but 0 1 of an Ohm, while as a demonstration of its greater constancy it may be mentioned that a battery of forty agglomerate cells has for a long time past been employed on one of the busiest London and Liverpool telegraph wires. It is also worthy of notice that no less than 2,000 of these cells are at present in use at the Aug. 31, 1883.] ♦ KNOWLEDGE ♦ 133 Central Telegraph Office in London. Were the resistance of the circuit low, polarization would speedily ensue. Nevertheless, the agglomerate cell is to be preferred to the ordinary Leclanchu, even for amateur purposes. The blocks are very durable, and after nearly two years' hard service show little or no signs of giving way. It is still an open question whether the agglomerate cells have any advantage over the parent form, other than is derived from the absence of the porous pot and the increased zinc surface. Consequently an excellent form is that known as the Grenet, in which the porous pot is replaced by a stitched canvas bag to hold the manganic peroxide and carbon. In this instance all the gain pertaining to the agglomerate is embraced. The Bennett cell is in principle somewhat akin to the Leclanche, but for general work is not to be compared with it. The positive element is a piece of zinc immersed in a solution of caustic soda, a compound which has the merit of being not only inexpensive but equally nasty. A porous cell containing the soda solution is stood in a tin, or rather tinned-iron, can, the space between the can and the porous pot being filled with iron turnings. The solution gradually penetrates the porous pot, and, damping the turnings, a circuit is formed and a current generated. This current is, however, very spasmodic, and even less constant than that from the Leclanche. It can, therefore, found no great claim on its efficiency, while on the other hand it enjoys the privilege pertaining to all batteries containing iron, of perfuming the air with sulphuretted hydrogen — an odour which, if it is like anything on this earth, resembles most strongly the delicious aroma of rotten eggs. When the cell was first introduced, accompanied as it was with loud and general acclamations, it was recom- mended as being extremely cheap in construction, the outtr or containing vessel being an old preserved meat-can. We noticed, however, that those sent out by the company which enjoyed the privilege of selling it, were contained in spe- cially made tins, having a closely-fitting cover, presumably to bottle up the scent. It is manifest from what we have said concerning the cell that it is impossible for us to re- commend its adoption for any purpose whatever. We shall next turn our attention to a large class of bat- teries, embraced under the generic appellation of " Bichro- mate," and amongst them we hope to see some of exceptional utility to the student. LAWS OF BRIGHTNESS. IX. By Richard A. Proctor. IT remains only that I should consider the effect of instrumental appliances for increasing the degree of light which we receive from objects. The telescope is an appliance of this sort ; in fact, we may regard as the main feature of the telescope its power as a light-gatherer. In whate\er proi^ortion the object- glass of a refractor, or the mirror of a rellcctor, exceeds in area the pupil of the eye, in the same proportion (neglecting loss of light by imperfect reflection, or through refraction) may the quantity of light received by the eye when the telescope is used exceed the quantity received from the same object when the eye is unaided. I say inai/ rather than does ; for matters may be so arranged that the full light-gathering power of the teUscope is not employed. Xow, it seems at first sight thut in consequciue of this relation the apparent briglitncss of an object observed with a large telescope must be enormously increased. And, as I mentioned in the first paper of this series, the idea seems monstrous to many that there cannot under any circum- stances be an increase of apparent brightness of an object, though there may be an enormous increase in the total quantity of light received from the object. " Do you mean to tell me," an esteemed friend of mine once remarked, "that the moon is no brighter with my 6i in. reflector than with the naked eye 1 It mngt be brighter. I can scarcely bear to look at the moon, it is so bright, when I use a low power and the moon is high up in a clear sky ; but I have never found any trouble in looking at the moon with the naked eye." Be it understood that there was no question as to the point under discussion. It was the intrinsic lustre of the moon's surface, not the total quantity of light received from her, that we were both considering. I pointed out, though I am bound to admit the argument was not found to be convincing, that there is the same intrinsic degree of pain when one tooth is pulled out as if a dozen were extracted at once, yet a man might easily bear one operation who would faint under the other.* But as a matter of fact the case of the telescope is exceedingly simple. Take, for convenience, the simplest form of the astronomical telescope, which gives the brightest images for a given magnifying power. Let 0 O' (Fig- H) be the object-glass, e v the eyeglass ; and let a pencU filling the whole object-glass converge to a focus at F, and after falling on the part mm' of the eye-glass emerge with parallel rays and fall on the pupil of the eye E. Its cross-section is either just equal in diameter to the pupil of the eye, or less, or greater. First suppose it equal. Then the total quantity of light received from the point of the image, exceeds the quantity which would fall on the pupil of the naked eye as (O O')- exceeds (w n'f. But the magnifying power of the telescope is represented by the ratio OF , • u • ii, ..00' , or, which IS the same ratio, — . F n n n' Therefore the apparent area of the object is increased in the ratio (O 0')- to (nn')- — the precise ratio in T which the total quantity of light received from the object is increased. This increase, then, is just competent to make the increased area as bright as the area seen by the unaided eye. But next suppose iiw' less than the diameter of the pupil, and call this diameter cl. Then, as the whole of the emergent pencil falls on the pupil, the increase of the total quantity of light is as O O'- to d'-, but the magnifying power of the telescope is, as before, ,, and the mag- '^ n n fication of areas is as O 0"- to (w n'f. Thus the magnifi- cation of areas is to the total increase of littht as (O o')- (o 0')- {niilf • dr- or as d- : (■« n')'. But d is greater than n n' ; hence the apparent area of * I suppose this to be the case, but do not speak from experience. I have heard, however, that even a man of the strangest frame would bo shaken if a dozen teetli were extracted in quick succes- sion : aud I presume tlio e-Ktraction of a dozen at the sume instant would be even more trying. By extraction, I mean fair dcliiicrato lugging out, such as the soul of the dentist loveth — not knocking out by a blow; thongh the knocking out of a dozen tep-h nt once can hardly be a pleasant experience. 134 ♦ KNO\A^LEDGE ♦ [Aug. 31, 1883. the object is increased in a greater proportion than the light. Therefore the apparent brightness of the object is diminished. Lastly, let us suppose n n' greater than d. Then the magnification of areas is, as before, represented by the ratio (OO'f (n n')' and the increase in the quantity of the light falling on the eye is as (0 0')" to d' ; but this quantity does not enter the pupil, because it comes out in a pencil of parallel rays having a cross-section of diameter n n', and the pupil has only a cross-section of diameter d ; the proportion ent(!ring the eye is tlius reduced in the proportion of the areas of these cross-sections, or as d- to {nnf. Hence the quantity of light actually received by the pupil is represented by the proportion (0 O'f d- ^^ (O O'f- d? {ii n)- [n n')'~ which is the proportion in which the apparent area of the object is increased. Hence the brightness remains un- changed, as in the first case. The only difference, in fact, between this case and the first is that the telescope is not in the last case pushed to the full power it will bear with- out a reduction in the apparent brightness of objects : in fact, only a portion of the object-glass is really used in bringing light to the eye from any point of the object. Light from each point of an oliject, in such a case as this, em- ploys (as it were) its own part (a circular part) of the object-glass.* Of course, the above reasoning does not apply in the case of a star, because a star is not apparently magnified by a telescope ; but on the contrary, owing to the operation of laws with which we are not at present concerned, the image is reduced. Thus, the brightness of a star is in- creased pretty nearly in proportion to the area of the object-glass or mirror. But even in the case of stars the law above considered has its analogue. Take an imaginarj' case, where (say) twenty stars form a cluster (each star being visible to the naked eye) and the telescope shows those twenty stars and no more ; then, the apparent brightness of the cluster, regarded as a whole, remains unaltered when the telescope is used ; for in precise proportion to the increase in the brightness of the individual stars is the increase in the apparent area of the cluster.! The application to the planets, moon, sun, kc, is obvious. It may be asked why night-glasses show objects which the unaided eye cannot see ; and again why, by the use of * The case corresponds to thut of an opera-glass (for it is easily seen that the reasoning would not be affected by substituting a Galilean for a simple astronomical telescope). Accordingly it will be found that in using an opera-glass we can hide or dim a' portion of the field of view by covering a part of the object-glass. But in the case of a telescope used (as the astronomical nearly always is) with its full power, covering a part of the object-glass dims the whole field equally. Dr. Huggins told me, six or seven years ago, of an old telescope he bought, in which the object-glass was four or five inches in diameter, and the focal length little more than a foot. The emergent pencil was an inch or so in diameter (with the power actually employed). As Dr. Huggins quaintly remarked, it was " a telescope for a horse, not for a man." t In passing, I may notice that the same law applies to the effects of distance. A cluster of stars, separately discernible, would remain just as bright regarded as a whole (thatis, not considering the total quantity of light received from it, but its brightness as related to its area), however far it might be removed, so long as the separate stars continued discernible. Nor would it grow any brighter, as a whole, however near it might approach to the observer. (It is assumed here for the moment, that there is no extinction of ] ight in the interstellar spaces.) single magnifying glasses we can read at dusk what would be undiscernible, or only discerned with difficulty, by the naked eye. The answer simply is that the quantity of light received from the object is increased. It is easy to test this. Let the observer look at the page of a book with a magnifying glass in the dusk of evening, and notice whether the part seen with the glass (and rendered legible by its means) seems a brighter circular spot on the darker ground of the rest of the page, or vice rers<1. If he is care- ful not to let the diffused light from the glass reach his eye, he will see at once that the legible part of the page looks darker than the part outside, which nevertheless is illegible. It is equally clear, but the point requires to be more carefully dwelt upon, that we cannot by increasing the size of telescopes increase the apparent brightness of such objects as nebula^, comets, the zodiacal light, kc. In the case of very large objects like the zodiacal light we cannot even increase the total quantity of light received by the eye. In the case of comets, nebulre, &c., we can do so; and so we can render objects of this sort discernible, or even conspicuous, which otherwise would remain unseen. But it is important to notice that we cannot increase their brightness. It is this which constitutes one of the great difficulties in applying the spectroscopic analysis of these objects ; for in such analysis it is often convenient to use a rather narrow slit, and therefore the spectroscopist cannot avail himself of the great quantity of light gathered up for him by his telescope. Some astronomers, therefore, in examining the nebulaj which give three or four bright- line spectra, use an open slit, or no slit at all, getting three or four images of the nebula, instead of three or four lines. In another kind of research — the study, namely, of those faint but widely extending nebulosities which Sir W. Herschel was the first to notice — a large telescope is of no great use. I am persuaded, indeed, that the naked eye can do more in work of this sort than is commonly supposed, care being taken to protect the eye from extraneous light, and also to conceal the lucid stars from view. Autumn Leaves. — Messrs. Sampson Low, Marston, k Co. are issuing for the autumn holidays a new edition of Mr. F. G. Heath's "Autumnal Leaves" — a work which the author claims to be the only one ever published in Europe or America giving actual facsimile representations in colour and venation of autumn-tinted foliage. A Cakbonaceous Meteorite. — An interesting meteorite which fell in the province of Entre-Rios, Argentine Re- public, has been examined by M. Daubrce. The meteorite recalls certain kinds of lignite and clay coals, such as the boghead coal. In the black paste of the meteorite are to be seen small angular grains of a bottle-green of a hyaline colour, others again are whitish. The whole appearance of the stone resembles some of our volcanic conglomerates. Brass-yellow grains like pyrrhotine are also visible, and reddish spots like the chloride of iron sometimes seen in meteorites. Chemical analysis shows that the meteorite contains iron, lime, and magnesia. The most important peculiarity of the meteorite is, however, that it contains carbon in an organic form. This is chiefly proved by the action of potash on it. In fact, Dr. Daubrce hopes yet to find a meteorite bearing organic remains. Other carbona- ceous meteorites have fallen in divers places, but none, so far as we are aware, have yielded traces of organic life. — Engineering. Aug. 31, 1883.] ♦ KNOWLEDGE • 135 THE CHEMISTRY OF COOKERY. XVII. By W. Mattieu Williams. PRYING IN OIL. EGARDING the fat used in frying as a mRclium for conveying heat, freedom from any special flavour of its own is a primary desideratum. Olive oil of the best quality is almost absolutely tasteless, and having as high a boiling point as animal fats it is the best of all frying media. In this country there is a prejudice against the use of such oil. I have noticed at some of those humble, but most useful establishments where poor people are supplied with penny or twopenny portions of good fish, better cooked than in the majority of "eligible villa residences" that in the front is an inscription ^-tating "only the best beef-dripping is used in this establishment." This means a repudiation of oil. Such oil as has been supplied for fish-frying may well be repudiated. On my first visit to Arctic Norway I arrived before the garnering and exportation of the spring cod harvest was completed. The packet stopped at a score or so of stations on the Lofodens and the mainland. Foggy weather was no impediment, as an experienced pilot free from catarrh could steer direct to the harbour by " following his nose." Huge cauldrons stood by the shore in whicli were stewing the last batches of the livers of cod fish caught a month before and exposed in the meantime to the continuous arctic sunshine. Their condition must be imagined, as I abstain from description of details. The business then proceeding was the extraction of the oil from these livers. It is, of course, " cod liver oil," but is known commercially as " fish oil," or " cod oil." That which is sold by our druggists as cod liver oil is described in Norway as " medicine oil," and though prepared from the same raw material, is extracted in a dili'erent manner. Only fresh livers are used for this, and the best quality, the " cold- drawn " oil, is obtained by pressing the livers without stewing. Those who are unfortunately familiar with this carefully prepared, highly refined, product, know that the fishy flavour clings to it so pertinaciously that all attempts to completely remove it without decom- posing the oil have failed. This being the case, it is easily understood that the fish oil stewed so crudely out of the putrid or semi-putrid livers must be nauseous indeed. I am told that it has nevertheless been used by some of the fish fryers, and I know that refuse " Gallipoli " (olive oil of the worst quality) is sold for this purpo.se. The oil obtained in the course of salting sardines, herrings, ifcc, has also been used. Such being the case, it is not surprising that the use of oil for frying should, like the oil itself, be in bad odour. I dwell upon this because we are probably on what, if a fine writer, I should call the "eve of a great revolution" in respect to fiying media. Two new materials, pure, tasteless, and so cheap as to be capable of pushing pig-fat (lard) out of the market, have recently been introduced. These are cotton-seed oil and poppy-seed oil. The first has been for some time in the market oU'ered for sale under various fictitious names, which I will not reveal, as I refuse to l)pcome a medium for the advertisementof anything — however good in itself — that is sold under false pretences. If the lamp of Knowledge, more fortunate than that of Diogenes, should light upon some honest men who will retail cottonseed oil as cotton- seed oil, 1 shall gladly (with the Editor's permission) do a little straightforward touting for them, as they will be public benefactors, greatly aiding the present movement for the extension of the use of fish food. As every bale of cotton yields half a ton of seed, and every ton of seed may be made to yield 28 lb. to 321b. of crude oil, the available quantity is very great. At present only a small quantity is made, the surplus seed being used as manure. Its fertilising value would not be diminished by removing the oil, which is only a hydro-carbon, i.e., material supplied by air and water. All the fertilising con- stituents of the seed are left behind in the oil-cake from which the oil has been pressed. Hitherto cotton-seed oil has fallen among thieves. It is used as an adulterant of olive oil ; sardines and pilchards are packed in it. The sardine trade has declined lately, some say from deficient supplies of the fi.sh. I suspect that there has been a decline in the demand due to the substi- tution of this oil for that of the olive. Many people who formerly enjoyed sardines no longer care for them, and they do not know "why. The substitution of cotton-seed oil ex- plains this in most cases. It is not rancid, has no decided flavour, but still is unpleasant when eaten raw, as with salads or sardines. It has a flat, cold character, and an aftertaste that is faintly suggestive of castor oil ; but faint as it is, it interferes with the demand for a purely luxurious article of food. This delicate defect is quite inappre- ciable in the results of its use as a frying medium. The very best lard or ordinary kitchen butter, eaten cold, has more ot . .ectionable flavour than refined cotton-seed oil. I have not tasted poppy-seed oil, but am told that it is similar to tliat from the cotton-seed. As regards the quantities available, some idea may be formed by pluck- ing a ripe head from a garden poppy and shaking out the little round seeds through the windows on the top. Those who have not tried this will be astonished at the numbers produced by each flower. As poppies are largely cultivated for the production of opium, and the yield of the drug itself by each plant is very small, the supplies of oil may be considerable ; 571, -542 cwt. of seeds were exported from India last year, of which 346,031 c«t. went to France. Palm oil, though at present practically unknown in the kitchen, may easily become an esteemed material for the frying kettle (I say "kettle," as the ordinary English fry- ing pan is only fit for the cooking of such things as barley bannocks, pancakes, fladbrod, or oatcakes). At present, the familiar uses of palm-oil in candle-making and for rail- way grease will cause my suggestion to shock the nerves of many delicate people, but these should remember that before palm-oil was imported at all, the material from which candles and soap were made, and by which cart-wheels and heavy machinery were greased, was tallow — i.e., the fat of mutton and beef. The reason why our grandmothers did not use candles when short of dripping or suet was that the mutton fat constituting the candle was impure, so are the yellow candles and yellow grease in the axle-boxes of the railway carriages. This vegetable fat is quite as inoffensive in it.self, quite as wholesome, and — sentimentally regarded — less objectionable, than the fat obtained from the carcase of a slaughtered animal. AVhen common-sense and true sentiment supplant mere unreasoning prejudice, vegetable oils and vegetable fats will largely supplant those of animal origin in every element of our dietary. Wo are but just beginning to understand them. Chevreul, who was the first to teach us the chemistry of fats, is still living, and we are only learning how to make butter (not " inferior Dorset," but " choice Normandy ") without the aid of dairy produce. There is, therefore, good reason for anticipating that the inexhaustible supplies of oil obtainable from the vegetable world — especially from tropical vegetation — will cr« long 136 ♦ KNO\VLEDGE ♦ [Aug. 31, 1883. be freely available for kitchen uses, and the now populai' product of the Chicago hog factories will be altogether banished therefrom, and used only for greasing cart-wheels and other machinery. As a practical conclusion of this part of my subject, T will quote from this month's number of Tlie Oil Trade Review the current wholesale prices of some of the oils possibly available for frying purposes. Olive oil, from £-13 to £90 per tun of 2.')2 gallons ; Cod oil £36 per tun ; Sardine or train (i.e. the oil that drains from pilchards, herrings, sardines, ic, when salted) £27. 10s. to £28 per tun. Cocoamit from £35 to £38 per ton of 20 cwt. (This in the case of oil is nearly the same as the measured tun.) Falm from £38 to £40. 10s. per ton ; Palm-iwt or copra, £31. 10s. per ton; Refined cotton seed, £30. 10s. to £31 per ton ; Lard, £.53 to £55 per ton. The above are tlie extreme ranges of each class. I have not copied the tech- nical names and prices of the intermediate varieties. One penny per lb. is = £9. Gs. 8d. per ton, or in round numbers, £1 'per ton may be reckoned as l-9th of a penny per lb. Thus the present price of best refined cotton-seed oil is 3J,d. per lb. ; of cocoanut oil, 3|d. ; palm-oil, from 3id. to i^d., while lard costs 6d. per lb. wholesale — usually 7d. I should add in reference to the seed-oils, that there is a possible oVijection to their use as frying media. Oils ex- tracted from seeds contain more or less of linoleine (so- named from its abundance in linseed oil), which, when exposed to the air, combines with oxygen, swells and dries. If the oil from cotton-seed or poppy-seed contains too much of this, it will thicken inconveniently when kept for a length of time exposed to the air. Palm-oil is practically free from it, but I am doubtful respecting palm-nut oil, as most of the nut-oils are "driers." EVOLUTION OF HUMAN PHYSIOGNOMY.* By E. D. Cope. THE ability to read character in the form of the human face and figure, is a gift possessed by comparatively few persons, although most people interpret, more or less correctly, the salient points of human expression. The transient appearances of the face reveal temporary phases of feeling which are common to all men ; but the constant qualities of the mind should be expressed, if at all, in the permanent forms of the executive instrument of the mind, the body. To detect the peculiarities of the mind by external marks, has been the aim of the ))liysiognomist of all times ; but it is only in the light of modern evolu- tionary science that much progress in this direction can be made. The mind, as a function of part of the body, partakes of its perfections and its defects, and exhibits parallel types of development. Every peculiarity of the body has probably some corresponding significance in the mind ; and the causes of the former, are the remoter causes of the latter. Hence, before a true physiognomy can be attempted, the origin of the features of the face and general form must be known. Not that a perfect physiog- nomy will ever be possible. A mental constitution so complex as that of man cannot be expected to exhibit more than its leading features in the body ; but these include, after all, most of what it is important for us to be able to read, from a practical point of view. * Abstract of a lecture delivered before the Franklin Institute of PLilidelphia, .Tan. 20, 1881, in exposition of principles laid down ill Tie Hy;otliess of Evolution, New Haven, IbTO, p. 31. The present essay will consider the probable origin of the structural points which constitute the permanent expres-, sion. These may be divided into three heads, viz. : (1) Those of the general form or figure ; (2) Those of the surface or integument of the body with its appendages ; and (3) Those of the forms of the head and face. The points to be considered under each of these heads are the following ; — /. — 7'Ae General Form. 1. The size of the head. 2. The squareness or slope of the shoulders. 3. The length of the arui.s. i. The constriction of the wai.st. 5. The width of the hips. 6 The length of the leg, principally of the thigh. 7. The sizes of the hands and feet, S. The relative sizes of the muscles. //. — The Surfaces. 9. The structure of the hair (whether curled or not). 10. The length and position of the hair. 11. The size and shape of the nails. 12. The smoothness of the skin. 13. The colour of the skin, hair, and irides. ///. — Tlie Head and Face. 14. The relative size of the cerebral to the facial regions, 1 5. The prominence of the forehead. te-*^ 1 6. The prominence of the superciliary (eyebrow) ridges.. 17. The prominence of the alveolar borders (jaws). 18. The prominence and width of the chin. 19. The relation of length to width of skull. 20. The prominence of the malar (cheek) bones. 21. The form of the nose. 22. The relative size of the orbits and eyes. 23. The size of the mouth and lips. Fig. 1, — Section of skull of adult orang-outang (bimia t^atyrus).. Pig. 2. — Section of skull of young orang, showing relatrirely shorter- jaws and more prominent cerebral region. The significance of these, as of the more important struc- tural characters of man and the lower animals, must be considered from two standpoints, the palicontological and the embrjologica'. Tl.e immediate pahcontological iMstory Aug. 31, 1883.] » KNOWLEDGE ♦ 137 of man is unknown, but may be easily inferred from the characteristics displayed by his nearest relatives of the order Quadrumana. If we compare these animals with man, we find the following general differences. The numbers correspond to those of the list above given. /. As to Ge7ieral Form. — (3) In the apes the arms are longer ; (8) the extensor muscles of the leg are smaller. //. As to Surfacf. — (9) The body is covered with hair which is not crisp or woolly ; (10) the hair of the head is short; (13) the colour of the skin, A'c, is dark. ///. As to Head and Face. — (14) The facial region of the skull is large as compared with the cerebral ; (1.5) the forehead is not prominent, and is generally retreating ; (IG) the superciliary ridges are more prominent ; (17) the edges of the jaws are more prominent; (1^) the chin is less prominent ; (20) the cheek bones are more promi- nent ; (21) the nose is without bridge, and with short and fiat cartilages ; (22) the orbits and eyes are smaller (except in Nyctipithecus) ; (24) the mouth is small and the lips are thin. It is evident that the possession of any one of the above characteristics by a man approximates him more to the monkeys, so far as it goes. He retains features which Fig. 3. — Portrait of a girl at five years of age. have been obliterated in other persons in tlie process of evolution. In considering the physiognomy of man from an embryo- logical standpoint, we must consider the peculiarities of the infant at birth. The nuniliers of the following list corre- spond with those already used. /. As to the General Form. — (1) The head of the infant is relatively much larger than in the adult ; (3) the arms are relatively longer ; (4) there is no waist ; (G) the leg, and especially the thigh, are much shorter. //. As to the Surfaces. — (10) The body is covered with line hair, and that of the head is short. ///. The Head and Face. — (14) The cerebral part of the skull greatly predominates over the facial ; (IG) the super- ciliary ridges are not developed ; (17) the alveolar borders are not prominent ; (20) the malar bones arc not promi- nent; (21) the nose is without bridge and the cartilages are flat and generally short; (22) the eyes are larger. It is evident that persons who present any of the cha- racters cited in the above list are more infantile or embryonic in those respects than are others ; and that those who lack them have kft them behind in reaching mat rity. We have now two sets of characters in which men may dilli.r from each other. In the one set the characters are those of monkeys, in the other [they are those'of infants. Let us see whether there be any identities in the two lists, i.e., whether there be any of the monkey-like characters which are also infantile. We find the following to be such : /. As to General Form. — (3) The arms are longer. //. Surface. — (10) The hair of the head is short, and the hair on the body is more di.stributed. ///. As to Head and Face. — (21) The nose is without bridge and the cartilages are short and fiat. Three characters only out of twenty-three. On the other hand, the following characters of monkey-like significance are the opposites of those included in the embryonic list : (14) The facial region of the skull is large as compared with the cerebral ; (15) the forehead is not prominent ; (IG) the Superciliary ridges are more prominent; (17) the edges of the jaws are more prominent. Four characters, all of the head and face. It is thus evident that in attaining maturity man resembles more and more the apes in some important parts of his facial expression. It must be noted here that the difference between the young and embryonic monkeys and the adults is quite the- Fig. 4. — Portrait of the same at seventeen years, showing the- elongation of the facial region, and less protuberance of the cerebral. same as those just mentioned as distinguishing the young from the adult of man (Figs. 1, 2). The change, however, in the case of the monkeys is greater than in the case of man. That is, in the monkeys the jaws and superciliary ridges become still more prominent than in man. As these characters result from a longer course of growth from the infant, it is evident that in these respects the apes are more fully developed than man. Man stops short in the development of the face, and is in so far more embryonic.*^ The prominent forehead and reduced jaws of man are cha- racters of " retardation." The characters of the prominent nose, with its elevated bridge, is a result of " acceleration," since it is a suporaddition to the qiiadrumanous type from both the standpoints both of paheontology and embry- ology.* Tlu^ devi'lopment of the bridge of the nose is no doubt directly connected with the development of the front of the cerebral part of the skull and ethnoid bone, which sooner or later carries the nasal bones with it. {To ho continued.) * This fact has been well stated by C. S. Minot in the 'Naturalist for 1S82, p. 511. * See Ciipe. The Ilvpcthcsis of Evolution, New Haven, 1870, p. 31. 138 * KNOWLEDGE ♦ [Aug. 31. 1883. THE MORALITY OF HAPPIXESS. By Thomas Foster. (Continued from page lOG.) THE EVOLUTION OF COXDUCT. Chapter II. IN considering the evolution of structures and functions we have not only to consider the influence of the struggle for individual existence, but also the effects of the contest in which each race as a whole is engaged, — and to •do this we have to consider, first, those circumstances which affect the propagation of the race, secondly the relation of the individuals of the race to their fellows, thirdly the rela- tions of the race as a whole to other races. Something akin to this must be done in considering the evolution of conduct. We have seen how modes of conduct which favour the continued existence of the individual are de- veloped at the expense of modes of conduct having an ■opposite tendency. These last die out, because the indi- viduals of the race who act in these ways die out. But it is obvious that conduct will be equally apt to die out which tends to prevent or limit the adequate renewal of the race from generation to generation. It is equally obvious that whatever conduct causes contests (whether for life or sul> sistence) within the race or species, tends to the elimination •of members of the race, and so diminishes the chances of the race in the struggle for existence with other races. Lastly the relations of a race to surrounding races are manifestly of importance in the evolution of conduct, seeing that conduct will equally tend to be diminished whether it is unfavourable to the existence of the race in which it is prevalent, or simply unfavourable to the separate •existence of an individual member of the race. Now with regard to conduct affecting the propagation of a race, we find that, like conduct affecting individual life, it has been developed from what can hardly be called conduct at all in the lowest grades of life to fully developed conduct, with elaborate adaptation of means to ends, in the highest. In the lowest forms of life, propagation pro- ceeds by mere di^nsion and subdivision, not depending so far as can be judged on any power of controlling the process, which such creatures may possess. In fact, the Protozoa multiply by dividing. We have to pass over many grades of life before we reach such imperfect care for propagation of the race as we find among those orders of fish in which the male keeps watch and ward over the eggs. Still higher must we pass before we find any trace of affec- tion for the young, and higher yet before we see care given to feed and protect and keep the young till they are able to provide for themselves. This brings us in fact very near to the human race, which, in its lowest races, is distinguished from other animals chiefly by the length of time during which it feeds, pro- tects, and trains its young. In the higher human races all these processes are conducted with greater care and elaboration ; more varied wants are considered and attended to, more elaborately varied means are used for the pur- pose. It is easily seen how such conduct by aiding the development of the race aids the development of the con- duct itself by which that result is favoured. Among those members of a race in whom the proper race-propagating conduct is not adequately shown, propagation proceeds less effectively, — which is the same as saying that, relatively, such conduct itself must be diminishing. This conclusion is not inconsistent, as at first sight it might appear, with the fact that mere numerical increase of propagation, though it means increase in quantity of life, is not always or even generally a proof of the growth of the race in what may be called race-vitality. Here as elsewhere adaptation of means to ends has to be considered, and that kind of conduct by which such adap- tation is secured has the best chances of development in the long run. Let us, for instance, take an illustration from civilised life : — An early marriage between two persons care- less alike of present duties and future difficulties, seems at fir>t to tend directly to the increase of carelessness and thoughtlessness ; for from such a union there will probably come into existence more than the average number of off- spring, repeating in greater or less degree the weak cha- racters of their parents : the totality of life characterised by undesirable qualities and conduct will thus be increased, and increased in a greater ratio than the totality of prudent, steady, and thoughtful life, by a well-considered union and well-judged conduct thereafter. Yet in the long run the result proves usually otherwise. (We consider only average results. ) The larger number of offspring of inferior quali- ties, receive less care and inferior training : so that for them there is greater probability either of early death or of defective adult life. The parents suffer also in the struggle thus brought on them, for which they are ill-fitted. A diminished amount of life is likely to result, and (taking the average of many cases) probably does result ; while certainly there is diminished life-quality. Hence results a correspondingly diminished amount and influence of the inferior kind of conduct shown by thoughtlessness or carelessness about life's duties. On the other hand, the well- judged and not too hasty union of two caretaking persons, though it maj- add a smaller number of individual lives to the life of the race, adds better and more enduring life, life more likely to maintain and sustain the qualities of the parents, giving therefore to these qualities in the race at once more stability and wider influence. In other words, the qualities best suited for the propagation of the race, and best suited for the race, will on the average be developed, while qualities having opposite tendencies will either be eliminated, or though they may remain will occupy a lower place and have diminished influence on the fortunes of the race — a circumstance tending of itself still further to their eventual elimination. {To he continued.) Pure nickel, after melting and casting, generally holds a greater or less quantity of oxygen in combination, and the metal is brittle. To hinder the injurious effects of the oxygen, it is necessary to incorporate in the melted nickel some substance which has a strong aflinity for oxygen, and also for the nickel itself. According to the " Comptes Rendus," M. .J. Gamier finds that phosphorus serves both of these purposes very satisfactorily, producing effects analogous to those of carbon in iron. If the phosphorus does not exceed three-tenths of one per cent., the nickel is soft and very malleable ; above this quantity the hardness increases at the expense of the malleability. Phosphorised nickel, when alloyed with copper, zinc, or iron, gives re- sults which are far superior to those that are obtained from the same nickel when not phosphorised. By means of the phosphorus Garnier has been able to alloy nickel and iron in all proportions, and always to obtain soft and malleable products. The contradictions of illustrious chemists are - thus explained, some saying that such alloys were brittle, others that they were malleable. The latter had alloyed the nickel to phosphorised iron. — Eiu/ineer. Aug. 31, 1883.] ♦ KNOWLEDGE • 139 PRETTY PEOOFS OF THE EARTH'S ROTUNDITY. CHIEFLY FOR THE SEASIDE. By Richard A. Proctor. {Continued from page 117.) BUT now, returninn; to the mirror proof of the earth's rotundity, porae readers of these paper.«, comparing together Fig. (as shown at p. 101) is l-228th part of a b. But ab in Fig. 13 represents 25 ft. Therefore B 6 represents 25 ft. -f- 228, or about 1 \ in. 140 ♦ KNOV^^LEDGE ♦ [Aug. 31, 1883. But it is clear that the triangles e « E' andya F' are also similarly proportioned to B « 6 of Fig. 8. For a e, like a b, is truly horizontal, and a E' like a B is directed to the sea-horizon. It matters not in what direction we look the mirror experiment of page 101, that, with a one-foot mirror and two yards distance would command an arc of less than five degrees of sea-horizon, and it would be pre- posterous to expect the slightest trace of curvature along such an arc. (To he continued.) seawards from a fixed point above the sea ; the sea-horizon has always from such a point the same depression. The only difference is that a e and a f are longer than a h, while e E' and J'Y are longer than h B in the same proportion. Whereas then B i is about 1 ^ in. in length, e E' and JY exceed Ig in. in the same degree that «« or a/ exceeds ah ; which is (appreciably) the same degree in which a E or a F exceeds a B, that is as the diagonal exceeds the side of a square (for a B and B E are equal and at right angles to each other). Thus since the diagonal of a square is about 1'414 when the side is 1, we have «E'=/F'= IJ in. X 1-4U and e E =./"F = 1^ in. (each being equal to B 6) ; .". E E' = F F' = \\ in. x 0-tl4 = -.5.5 in. approximately In reality, taking refraction into account the angles of depression are all reduced by about one-fifth, leaving E E' and F F' optically equal to only -W in., or ^ths of an inch. The actual curvature of E' B F' would be fairly shown if in such a diagram as Fig. 14, E B and B F were each 2-5 ft. long, E E', B H, and F F' each Jths of an inch long ; and if then the curve E B F were swept out in the narrow rectangle E F', whose length would he more O'ln thirteen hundred times its hreadth. So that even from so great a height as 2(. ft, a ridge roof so long as 50 ft., seen from a distance of 25 ft., com- manding therefore a range of a full right angle along the roof, and brought at the two extremities to exact apparent coincidence with the sea-horizon would be less than half an inch below the sea-horizon at its middle point, even if use were made of such a point as a (Fig. 13) to guide the eye. But all the observations ever made in this way, as by Parallax in 1864, by Mr. Hardy (see pase 77), and by a few perplexed students of this matter, have been made from lower levels than 200 ft , on ridges commanding a much smaller angle than a right angle, and without any such a point as a to guide the eye, though such a point is absolutely essential to exactness of observation. As for PUNCTUATIOX AND PRINTERS. I "WONDER what the Brighton Herald takes to be "the rights and privileges of the humble comma." Appa- rently the right of distraction ; for everything that unduly stops the continuity of thought in reading is distraction — parentheses, whether written so or not, unnecessary or too strong stops, all sorts of carts before horses, exceptions and conditions stated at the beginning instead of the end of a sentence, verbs before their nominative cases or after their accusatives, except for special reasons, anything that obliges you to wait till the end in order to realise what the sentence is about. These things, and not the mere length of sentences are the impediments to easy reading. I forget whether you noticed before the printers' passion for dUMing in a comma between every two adjectives not alread}' separated or joined by an and, without the least regard to its effect. For instance somebodv might write that I am a "good tall man," meaning only that I am above the average height : the average printer would forth- with exalt me into a "good, tall man"; and thereby would raise the indignation of every architect in England into a still hotter flame than it is in just now I see, at my having dared to rebuild part of a cathedral without paying them some £1,500 of black-mail for doing worse than nothing, or something like the Law Courts. But I want to go beyond commas, and to give even the Devil his due. Some men deliberately leave their punctua- tion to that inky Diabolus, and it is well for their readers and their own credit that they do. Within the last month or so I have had letters from two men of excellent educa- tion, lioth High Wranglers and men of science — one old and the other young — whose only stops were commas and dashes, dashed in pretty much ad libitum. Such writing would justify quite natural language from a printer's devil ; and if he is to be condemned himself for doing his best — and rather overdoing it — he may fairly call the world un- grateful. But, on the other hand, he must see in five minutes whether he is printing for a punctual punctuator like you or me, who, at any rate, mean to put in all our stops ; and when he sees that he ought to leave us alone to bear our own iniquities if we let our proofs go "un- peppered " more than he thinks right. We probably know better than he does. The fact is that any one who attempts either to punctuate or to write English entirely by rules is sure to disregard both sense and common sense sometimes. But one rule may be safely followed, viz., the advice of some judicious bishop to his clergy on the length of sermons, to " err on the side of leniency ;" and the other still older rule — Quid duhitas nefeceris, if you doubt about a comma leave it out. The Greeks were wiser than we are in not encumbering themselves with both colon and semicolon. Xobody can say with certainty i'lnot TrXiuv rjftiav -tiiroc, how much less a semicolon is than " the entire animal," from which it differs only by a tail. What is really wanted is a kind of minor comma, or both that and the ieniioolon reducing a little in power of obstruction. But that reform is as hopeless as an Easter by the sun instead of the (Act of Auo. 31, 1883.] KNOWLEDGE 141 Parliament) moon, though everybody would welcome it i£ it came somehow with no questions asked. If anybody doubts your opinion of Macaulay's style, which was always mine, let them try it by the test of reading it aloud, against Froude's, or Hume's old but matchless History, and they will soon find how tiresome it is. I have made his admirers give in by that test. Gibbons is sickening when you have learnt the trick of it, and its want of simplicity. I never saw Mr. Spencer's " Essay on Style " (is it a separate book ^i*). Some of his own is good enough ; but when he wants to be particularly precise and lucid he is often particularly the contrary, and his style, in my opinion, most abominable. Nevertheless, he may pi-each better than he practises, and inculcate better English than philosophy, in spite of Mr. T. Foster. Edm. Beckett. THE FACE OF THE SKY. Feom Aug. 31 to Sept. 14. By F.R.A.S. THE usual daily watch will be kept upon the sun for spots and facula). The aspect of the night sky is shown in Map IX. of *'The Stars in their Seasons." Mercury attains his greatest eastern elongation (26° 42') from the sun on the 11th, but sets too nearly with the sun now to be visible to the naked eye. Venus is ([uite invisible. Mars rises before 11 h. 30 m. p.m. now ; but, as wo said a fortnight ago, merely presents the appearance of a very largo red star in Gemini. Jupiter does not yet rise until after midnight. Saturn rises before 10 p.m. on the 1st of September, and soon after 9 o'clock by the 14th, so that he will be well above the horizon by midnight. He is situated between 3° and 4° north of Aldebaran, and just to the Bast of it. Uranus and Neptune are both invisible. The moon's age at noon on Aug. 31 is 28'4 days ; and at the same time to-morrow it will evidently be 29'4 days. Her age on Sept. 2, at noon, is 09 day, and quite obviously will be 12'9 days by the 14th. Two occultations of stars will take place on the night of the 14th — firstly of c' Capricorni, a 4i magnitude star, which will disappear at the moon's dark limb at 8 h. 44 m. at an angle of 171° trom her vertex, reappearing at her bright limb, at an angle of 208° from her vertex, at 9 h. 5m. p.m. At 8 h. 47 m. p.m. c- Capricorni, a star of the Gth magnitude, will disappear at the dark limb of the moon, at a vertical angle of 91°, to reappear at her bright limb, at 10 h. p.m. at an angle of 300° from her vertex. The moon, after travelling through a portion of Leo, descends into Sextans about 10 p.m. on Aug. 31, and (occupying about 9 hours in crossing the northern part of that constellation) re-enters Leo at between 7 and 8 p.m. on Sept. 1. It is between 9 and 10 o'clock on the night of Sept. 2 before she finally quits Leo and enters Virgo. It takes her until 9 a.m. on the 6tli to cross this constellation ; from which, at the hour named, she passes into Libra. Her passage through Libra occupies, as nearly as may be, 48 hours, and about 9 a.m. on the 8th she enters the northern part of Scorpio; over this she takes 12 hours to travel, and at 9 p.m. crosses into the southern part of Ophiuchus. Skirting, for a very short time, the extreme southern limit of Serpens, she travels into Sagittarius about 5 o'clock in the afternoon of the 10th. Sho does not leave this constellation for Cai)ricornus until 2 a.m. on the 13th. It takes her until between 5 and 6 p.m. (or some 15J hours) to go over the northern part of Capricornus, which she then quits for Aquarius. She is still crossing Aquarius on the 14th. It is stated that there are 3,985 paper-mills in the world, producing yearly 9.59,000 tons of paper made from all kinds of substances, including rags, straw, and alfa. About one-half the quantity is printed upon; and of those •170,000 tons, about 300,000 tons are used by newspapers. The various Governnumts consume in official business about 100,000 tons; schools, 90,000 tons; commerce, 1:^0,000 tons ; industry, 90,000 tons ; and private correspondence another 90,000 tons. The paper trade employs 19:^,000 hands, including women and children. • It is in the second volume of his collected easaya. — S. P. " Let Knowledge grow from more to more." — Alfeed Tennyson. Only a small proportion of Letters received can possihly he in- serted. Correspondents must not he offended, therefore, should their letters not appear. All Editorial communications should be addressed to the Editor op Knowledge; all Business communications to the Publishers, at the Office, 74, Great Queen-street, W.C. If this is not attended to DELAYS ARISE FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should ie made payable to Messrs. Wymak & Sons. The Editor is not responsible for the opinions of correspondents. No communications are answered by post, even though stamped and directed enwelope be enclosed. PHENOMENA OBSERVED IN RAILWAY TRAVELLING. [906] — Wheu travelling in a train and looking out of a window, the nearest objects appear to me, of course, to fly rapidly back- wards, and the more distant to go slower until those on the horizon seem to travel slowly in the same direction as the train. If I have been looking out of the window at the landscape for some time, and the train stops, the landscape appears to slowly unwind itself, as it were, the nearer objects moving slowly forwards, and the remoter just perceptibly backwards. I should like to know whether this is a common experience, or one peculiar to my own somewhat over-sensitive nerves. I should also like to know whether the phenomenon is analogous to that of complementary colours. I explain it to myself by supposing that while the train is in motion the nerves of the lower part of the retina are continually conveying impressions of forward motion (the nearer objects being, of course, reflected upon the lower part of the retina), and those of the upper part conveying impressions of backward motion. Then, when the nerves are no longer excited from the outside they rest themselves by complementary sensations, as in the case of comple- mentary colours. Hoping that I have not wasted your valuable time in describing what you are already familiar with, Leonard Browx. LUMINOUS RING. [907] — I enclose two photographic prints — one of my chemical laboratory, the other of my dining-room — both taken by gaslight. In each of these (and, of course, in the negatives) I observe a per- fectly well-defined circle of light surrounding the gas-flame. I showed the pictures to my friend Mr. Grcnsted, who gave what seems to me a very satisfactory explanation of the matter, and one, indeed, which is interesting as affording another instance of the analogy which exists between the human eye and the photographic camera. Chas. Harris. With regard to the above, I have for many years seen a prismati- cally-coloured similar ring, with the naked eye, when looking at a candle-flame against a background of shadow. I thought it to be either an emanation from the flame or caused by floating particles in the eye. The first hypothesis is disproved by the fact that one of the prints shows the ring overlapping the frame in which it is reflected. The constitution of a camera lens disproves the second. Is it a diffraction ring caused by reflections from the interior sur- faces of the lens ? Fred. F. Grensted. FLIGHT OF A VERTICAL MISSILE. [908] — Conservation of Angular Momnitum. By this principle practical engineers perform such operations as adjusting a balance- weight to the driving-wheel of a locomotive. Stated in this form it carries its own proof witli it, being simply another expression for the law that action and reaction are equal and opposite. Had the principle been generally known by this phrase, it would have guided your correspondent, Jlr. Bray, to a correct solution of the problem. The ball, instead of moving east with the velocity of a point on the earth'.s surface, moves east with a velocity inversely as its distance from the earth's centre. Measuring the arc so described at the mean height evidently doubles his former result. 142 . KNOWLEDGE [AcG. 31, 1883. The term " Kepler's second law " conveys no particular meaning —in fact, Clifford, in his " Dynamic," 187S, calls it Kepler's first law, and it is sometimes misunderstood to apply only to forces yaryin-j inversely as the square of the distance. "Angular momentum" seems a preferable term to " moment of momentum." " Conserva- tion of areas " is a very misleading designation. The ivriter suggests that in the same way as the term lialf the vis viva has been superseded by energij, so now might Kepler's second law be replaced >vith advantage by the expression Consena- timi of awjular jiiomentum. A. Babclat. WART-CHARMING (SO-CALLED). [909]. — I am both amazed and amused at the wonderful theories started upon the very simple subject of destroying warts. Will you allow me to give a simple explanation of a natural process, which has as little connection with the *' imagination " or the " influence of mind on body " as the moon has with green cheese ? Pasteur has killed small animals by inoculating them vrith the saliva of an ordinarj- living person. To this poisonous quality of the saliva (especially so in the mornings and evenings) most of the feats of so-called wart-charmiug may no doubt be traced. I myself had a wart on my left cheek for a very considerable time, caused, no doubt, by an unclean razor. I wetted the wart with my own saliva every morning and evening, and in about a fortnight the wart had entirely disappeared. It is evident thai; persons less fond of soap and water, or those with disordered stomachs, possessing, therefore, a more poisonous saliva, may effect quicker cures. I have always found it more reliable and satisfactory to seek for the natural cause of everything than to ascribe it to the super- natural and marvellous. Mephisto. [Our friend from warmer regions ought to know what is super- natural and what not ; but he appears not to do so. The influence of mind on body is among observed natural phenomena, and cases of so-called wart-charming are among the most interesting iUnstra- tions, but certainly not by any means the most surprising. The saliva is not used in one case out of twenty. — E. P.] SOME AMERICAN WARTS. [910] — When a boy in Concord, Massachusetts, only thirteen years ago, I had about a dozen warts on my hands. Another boy told me that Mr. C , the jeweller, could charm them away. I had two years before removed a lot of warts under direction of my mother by applying three times a day a saturated solution of sodic carbonate, and had much less faith in charms than in chemicals My playmate, however, maintained that his warts had been re- moved by the cliaraiing process, and so I went to the jeweller and asked the same favour. He rubbed his fingers over each one, and told me to put on them every day the juice of the milkweed (Asclepias cormiti). I did this as often as I thought of it, and the warts gradually became smaller, and after a few weeks I was sur- prised to notice that they were gone. The success did not convince me of the efficacy of charming, for "they say" in Massachusetts that milkweed juice will cure warts, and I have thought that the metals which the jeweller handled may have given some virtue to his touch. Feitz F. New York, Aurj. 7. GIXGER-BEER PLANT. [911]— The ginger-beer plant described by T. H. Perry (878) is probably an aggregation of one of the yeast-plants. The aeration of the water is no doabt effected by the vegetative process induced by the sugar. Snbstitute essence of lemon for the ginger, and you will have a " lemonade " plant. W. H. Shecbsole. IRON SHIPS AND FLOATING DOCKS. [912] — Will you kindly allow me to inquire through your columns whether the builders of iron sliips ever make allowance for the effects of wide differences of temperature in producing irregular expansion and contraction of the metal, and consequent cracks and fissures ? Fownessaysin his "Manual of Chemistry" that " the force exerted in the act of expansion (by heat) is very great. In laying down railways, building iroTi bridges, erecting long ranges of steam-pipes, and in executing all works of the kind in which metal is largely used, it is indispensable to make provision for these changes of dimensions." Yet I am told that this rule does not apply to iron ships, as in them the expansion or contraction is uniform. May I venttu'e to ask if the immersion in water has no neutralising effect, and whether also the building of iron ships has been tried to any extent in countries subject to great variations of temperature, such as Norway and Northern Russia ? To put the question as plainly as I can in my utter ignorance of the appropriate technical language, would a builder be willing to leave the shell of an iron ship the whole year through without any covering in such a country as those just named, and expect no harm to result from the vicissitudes of the weather, leaving out of view the liability to rust? I am induced thus to trouble you on account of a question which has lately arisen as to the immunity of iron floating docks from the risk of having their efficiency impaired by exposure to the wide variations of temperature that occur in certain climates. It has been stated positively by a presumed authority that " the expansion and contraction of the iron in a dock would have the same effect as in a ship," and yet it seems to me that the resemblance between the two structtires is not so exact as to make that proposition self- evident. Again, it has been publicly stated that " as the advanced science of the present day demands the use of iron and steel for the con- struction of ships, so it does for docks, and in the whole of Europe at the present time no engineer would think of using any other material in their construction." Is this true or is it not j" X + Y. HEIGHT OF ANCIENT EGYPTIANS. [913] — Being much interested in Egyptology in all its phases, I recently made a tour up the Nile, and having previously noted some statements respecting the sizes of certain mummies, when in Cairo I measured several, especially those of the recent great find in Thebes. I give my measurements below, and would be glad if it leads to an " official " publication, as it would settle a good many points in reference to this interesting and remarkable ancient race. Measitbemexts. King Unas VI. Dynasty 4ft. 9in. King Ea Skemen'XVII. Dynasty 5„ 8„ King Amenoph Ist XVIII. Dynasty 5,, 2„ King Amosis XVIII. Dynasty 5„ 0„ King Thothmes 2nd XVIII. Dynasty o„ 6„ King Sethi 1st XIX. Dynasty 5,, 2„ King Rameses 2nd XIX. Dynasty 5„ 1„ King Pinotem 1st XXI. Dynasty 5 ,, 0 „ Queen Nofritasi XVIII. Dynasty 5„ 4,, Queen Notimaut XIX. Dynasty 4„ 8„ Queen Makara XXI. Dynasty 4„ 6„ Baby of ditto 1 ., 0 „ Princess Trinkheb XXI. Dynasty 4„ 9„ High Priest Nebsemui XXI. Dynasty 5 „ 6 „ The coffin of Rameses measures only 6 ft. 3 in. over all, and the mummy does not reach to the wood (the thickness of which is 2 in.) by several inches. Wm. Oxley. SINGULAR XUMEEICAL PROPEETY. [914] — I send the following as curious example of figure-magic, with the hope that it may be of interest to readers of Knowledge :— If the number 142,857 be multiplied by 1, 2, 3, 4, 5, or 6, each result gives the same figures in the same order, only beginning at a different point. Thus : — 142,857x1 = 142,857 142,857x2 = 285,714 142,857x3 = 428,571 142,857x4 = 571,428 142,857 x5 = 714,2S5 142,857x6 = 857,142 If it be multiplied by 7, we get aU nines. Thus : — 142,857x7 = 999,999 If it be multiplied by 8, we get 1,142,856. Now add the first figure to the last, and we have the original number — 142,857. If it be multiplied by 9, we get 1,285,713, and then we find that the sum of the digits of the product is equal to the sum of the digits of the original number, each being 27. Moreover, the sum of the digits of each product is the same in every case but one, namely, when we multiply by 7. and then the sum of the digits is 54, or just double the sum of the digits in each of the other products. H. Askew. [The number 142,857 is 999,999-;- 7, and is also -what we get on dividing 1,000,000 by 7, less f. Now noting that 10, 20, 30, 40, 50, or 60, when divided by 7 leave remainders 3, 0, 2, 5, 1, and 4, &c., ail the digits less than 7, that 80 divided by 7 gives 11, with re- mainder 3, and that 90 divided by 7 gives 12 and remainder 6, we fiod all the above facts accounted for, seeing that the digits in dividing 1000000, 2000000, 3000000, &c., to 6U00O0O must recur in Aug. 31, 1883. • KNOWLEDGE ♦ 143 the same order, though beginning with a different digit of the set ; in the case of 8000000 and 9000000 we have 999,999 x 8 + If , and 999,999 X 9 + If .— R. P.] LETTERS RECEIVED, AND SHORT ANSWERS. W. Bavley. — Thanks for cuttings ; but of course the toads were never vomited. — J. Clayton. Handbook of stars out of print. — Jas. Paxman. Illness following i-ailway accident drove the matter from my thoughts. — J. Hakkison, sen. Slany thauks for the weather charts. — A Reader. You will have seen ere this that I quite agree with your objections to cholera-prescribing here, as in Bealth, and other such organs. — Ignoramus. Stephenson said to a perpetual motionist, " Carry yourself round the room by your own waist-band, and I will consider your plan." That is about what it comes- to. — W. W. W. Regret, but no space. — Ja.s. Lucking. Do not know where model of first pair of spectacles can be seen. Am also unable to say where a photograph of Adam and Eve is preserved. — A. H. Swinton. — Your determination of sun-spot maxima from years of great natural phenomena seems to me as funny as determining comets — otherwise unknown — from deaths of kings and rulers. Prove the connection between volcanoes and sun-spots and wo will see about it. — H. H. Thanks for kind wishes. — D. N. Certainly not new. A handred such relations could be written down in a few hours. — E. C. Castlebar. Earth's shape seems to trouble you. When and where have I said I admired the person you mention ? But reading the sickly works of the other writer would have had no influence one way or the other. — E. H. Stutter. Many thanks for your kind letter.— Senex. Not unusual. Showing want of symmetry, not that penumbra was not lower than photo- sphere.— H. W. Jones. No space or time for explanations of so much text-book matter. <^ur iHatDfinatiral Column, GEOMETRICAL PROBLEMS. By Richard A. Proctor. PART XIV. A READER of these mathematical notes sends for solution, by use only of EucUd's first three books, the following problem : — Prob. — A B C is a right-angled triangle. From any point D in the hypothenuse B C a straight line is drawn at right angles to B C, meeting C A at E and B A produced at F : show that the square in D E is equal to the difference of the rectangles B D, D C and A E, K C ; and that the square on D F is equal to the sum of the rectangles B D, D C omd A i\ P B. Wo notice at onco, that the rectangle A E, E C mentioned in first part of the problem is equal to the rectangle D E, E P, since the angles at D and A are right angles so that a circle will pass through tlio points C, D, A, P. Also wo notice at onco that the rectangle A P, P B mentioned in the second part of the problem is equal to the rectangle E F, FD, since a circle will pass through the points A, B, D, K. This leads us at once to think that wo may lind the solution of our problem, by using those theorems of the second book of Kuclid in which a squ£Lre on D E, a part of a line, is shown to bo the difference of two rectangles, and a square on D F, the whole of a divided line, is shown to be the sum of two rectangles. But in each case we must bring in the rectangle related to the line D E F which we have seen to be equal to a rectangle referred to in the puzzle. Thus, first, we ask how the rectangle D E, E F is related to the square on D E. We know that DE' = rect. DE . DP-rect. DE . EF. If then we can show that the rect. D E. D F is equal to the rect- angle CD, D B, what is required, so far as first part of our problem is concerned, is done. Now as we are dealing with the third book, this naturally leads to the idea that if a circle is carried around the points C B F, we may be able to show that F D which intersects C B in D, will when produced cut this circle in G, such that D G = DE. Foi v^e want to show that the rect. CD, DB = rect. D F, D E ; and we know that the rect. CD, D B = rect. F D, D G. But this leads us directly to the solution of this part of the problem. For if we suppose the circle through C, B, F, to cut F D produced in G, we have /;CGF=ZCBF in same segment = Z C E D (.since each is the complement of Z B C A) : hence the triangles C GD and O E D are equal in all respects, and D E = D G. The other part of the problem is found to depend on the same construction : for DF= = DF.EF + DF.DE = BF.AF -i- DF.DG = BF.AF-i-CD.DB We may put our solution into the following form : — Produce FD to G making D G = D E and join GC. Then since the angles at D are right angles ZCGD= i!;DEC = compt. ofZDCE= /CBA. Hence a circle will pass through the points C, 6, B, F ; also obviously a circle will pass through the points C, D, A, F ; and another circle through the points D, E, A, B. Hence rect. C D, D B = rect. G D, D F = rect. D F, D E rect. C E, E A = rect. E F, D E and rect. A P, F B = rect. D P, F E .-.rect. C D, D B -rect. C E, E A = re';t. D F, D E -rect. EF,D E = DE» and rect. CD,DB + rect. A F, F B = rect. D F, D E -h rect. DP, FE = DF' Q. E. D. r wins with the King, leads Ace, follows with the Four, leaving me with the thirteenth trump and the lead ; I play Ace of his suit, then the small one. Have I made the most of my hand ? Did I lose any- thing by taking his Queen with my King ? Are there any circum- stances under which 1 can lose by playing King on my partner's Queen, holding Ace, King, and one small one? Supposing my partner knows the conventionalities of modern Whist, I expect him to play from his long suit. No card in my hand or played by second player tells mo whether his lead is from weakness or strength; therefore I put on my King in order to get out of his way. If his lead is from two I assume ho lias not four trumps, and wishes to make a trump on that suit. If his lead is from Queen, Knave, and a small one, or Queen, Knave, and anything, I contend I lose nothing by playing my King. If he hold Queen and one other and I let it go, he plays the small one I put on my King. If I then play my Ace his discard is no use to him, or me eiilior, and instead of playing to win the game I am forced to feel my way to the end. He has exposed his hand to the entire party, and leaves me to get out of the mess the best way I can. If he holds a long suit, of which he leads the Queen, I contend that to play the small card would be wrong. The play succeeded. His suit proved to be a long one. Queen, Knave, ten, and others. He afterwards told me I knew nothing about the game, and ncv^r to do so again, although it " came off." " He had played Whist forty years." I being a young player, gave up the argument, believing I was right. He also advised me never to take my ]iartniu-'s trick ; but having brought off DeschapeUes' coup five times last winter, I voted my old friend a " duffer." Hoping I have not exhausted your patience, and that I may bo iufoiinod in your next, I am, dear Sir, yours, Ac. Mrrp. [If you had played your small card, the evil consequences which would "abnosl inevitablj- have followed would have emphatically justified the name you assume — without having made out any case for its use. Your partner only thinl;s he has played llViisf forty years. — Five of Clubs.] 144 ♦ KNOWLEDGE ♦ [Aug. 31, 1883. ©ur CI) ess Column. By Mephisto. PROBLEM No. 94. 3y E. N. Feankenstein. Black. Whitb. Wliite to play and self-mate in five moves. PROBLEM No. 95. By J. C. S. Black. m mm '^m. m m I w/^^mm"""'wm. White. White to play and mate in three moves. ENDING FROM ACTUAL PLAY. E. N. Fraxkexsteix. Black. '^"""'^'m" """ "' — '' White. De. P. Black to play and win in the least number of moves. SOLUTIONS. Problem No. 91, by W. Tebeill, p. 96. We are glad to say that this problem is quite correct as published, which may be seen on working out the solution. The position is as follows :— White— K on K sq., H QR sq., P QKt2, R KR3, P KB4, Kt Q5, Kt QR5, Q QB6, B K6. Black— B or KR sq., Q KB sq., R KR4, P Q5, B QKt6, K Q6, P K6. 1. Kt to B3 R to Q4 P takes Kt 2. Q to B4 (ch) B takes Q B takes B Q to Kt4 3. Castles mate. R to Q sq., mate. (if 2. K to B7, 3. Q to Kt2, mate. Problem No. 92, by J. C. S., p. 112. 1. B to B2 1. P to K6 2. R to B4 2. P takes B 3. P to K4, mate. ANSWERS TO CORRESPONDENTS- *«* Please address Chess Editor. W. — Castling is not prohibited in problems, although interdicted in some tournaments. CastHng being a legitimate move at Chess, we fail to comprehend why it should not be resorted to. Clearly, if there is no other way of effecting a mate than by Castling, it is evidently then the author's idea, as suggested by the non possibility of effecting a mate in any other way. We do not see any trickery about it. If a composer was to construct a problem which admitted of a mate being given by Castling as well as by another move, and in reply to the solution by Castling were to declare that move impossible on account of the K having previously moved, that would amount to deception, and would be inadmissable. In no other way can Castling possibly lead to a misunderstanding. However, as long as the majority of problemists are opposed to Castling, it ought not to be resorted to for that reason. W. Terrill.^ — Pray excuse our error ; we have been led into it by a correspondent. J. Bergee Gratz. — Letter and contents received with many thanks. Bereow. — If 1. P takes Kt, then 2. B takes B. See solution published above. C. Plaxck. — Problem received with thanks. WiLLLiM W. Thomsox.— If 1. B takes Q, P takes B. 2. Q to R sq. (ch) , the Kt can interpose on R4. See solution published above. R. B. Saegeaxt. — We shall make inquiries and inform yon accordingly. Peoblem No. 91 correctly solved by Schmucke, H. A. L. S., and John ; and Problem No. 93 by Stanley B. Baxter, M. T. Hooton, John Watson, John, Schmucke, Berrow, W. R. Edwards, and H. A. L. S. Contents op No. 95. PAGE Tricycles in 1883 : Small Wheels v. Large Wheels. ByJohnBrownijig 113 The Birth and Growth of Myth. XIT. By Edward Clodd 114 Sea Anemones. III. By Thomas Kimber 115 Pretty Proofs of the Earth's Eoton- dity. (Illitt.) By H. A. Proctor 116 How to Get Strong : Eeducing Fat. 117 The Comma. By K. A. Proctor ... 118 Chemistry of the Cereals. IV. By WilUam Jago, F.C.S 119 PACE Sun-Tiews of the Earth. (Illus.) By B. A. Proctor 121 The Moon in a Three-Inch Tele- scope [Itlut.) By F.E.A.S 122 The Fisheries Exhibition. T. (niu!.) By John Ernest Ady ... 123 CoBBBSPONT)ENCE : Light ftom Flowers — Wart - Charming — Magic Squares, &c 125 Otu- Mathematical Column : Geo- metrical Problems. XIII 127 Our Chess Column 128 SPECIAL NOTICES. Part XXII. (August, 1883), jnst ready, price Is., post-free, Is. 3d. Volume III., comprising the numbers published from January to June, 1883, now ready, price 7s. tid. The Title Page and Index to Voltmie III. ftlso ready, price 2d., post-free, 2^d. Binding Cases for Volume III., price 2s. each. Including carriage per Parcels Post to any address in the United Kingdom, 23. 3d. Subscribers' numbers bound (including'Xitle, Index, and Case) for Ss. each., 6d. extra for carriage for return journey per Parcels Post. P. u. urdera and cheques should be made payable to the PubUshers, Mbssbe. Wtmak & SoHB, London, at the High Holbom District Post-office. Agent for America — C. S. Carter, American Literary Bureau, Tribune Buildings, New York, to whom subscriptions can be forwarded. TERMS OF SUBSCBIPTION. 'Hie terms of Annnal Subscriptien to the weekly nnmbers of Kitowlidgi are a follows: — B. ' • To any address in the United Kingdom 10 lu T© the Continent, Australia, Xew Zealand, South Africa & Canada 13 0 To the United States of America $3.26. or 13 0 To the East Indies, China, &c. (rid Brindisi) 16 2 All eubscriptions are payable in advance. OFFICE : 74-76, GREAT QUEEN STREET, LONDON, W.C. Sept. le83.J KNOWLEDGE ♦ 145 PLAlNLY\yORD£D-£XACTLf DESCRIBED AN lULOSTRATED MAGAZINE OF S€IENCE LONDON : FRIDAY, SEPT. 7, 1883. Contents of No. 97. PAGE How to Get Strong : In Middle and Advanced Life 145 The Birth and Growth of Myth. XV. By Edward Clodd 146 Pretty Proofs of the Earth's Rotun. dity. (Illus.) By R. A. Proctor U7 The Fisheries Exhibition. VI. (Zitea.) By John Ernest Ady ... 149 Chemistry of the Cereals. V. By Williaii Jago, F.C.S 151 F»llv and Courage at Niagara 152 The'Whirlpool Rapids, Niagara ... 163 PiGB American Manners in Travelling By R. A. Proctor 154 The Coloured Curtain in the Eye By William AckroTd 155 The Harvest Moon." {Ilhia.) By R. A. Proctor 156 Obituary : Death of Professor Tobin 157 CoBBESPOXDENCB : Punctuation and Printers, &c 138 Matliematics 100 Our Chess Column 161 HOW TO GET STRONG. IN MIDDLE AND ADVANCED LIFE. IN the last few papers we have considered, with a purpose, how fat may most eflFectively and at the same time most advantageously be reduced. Our reason has been that several correspondents, not claiming to be entitled to become members of the Fat Men's Club, but still too fat for comfort, have asked whether there is any way in which they can participate without discomfort in exercises which they supposed meant only for those in good condition. It will be seen on a careful reading of our remarks upon their requirements that nearly every- thing recommended for them is good also for those who are not in the least troubled with obesity, nay even for those who are positively lean. Our suggestions for reducing weight are nearly all in reality suggestions for increasing flesh. A great deal of fat may inthe case of the corpulent be removed while little flesh is put on, and so the weight may be greatly reduced ; but it is almost impossible to follow any sound regimen for reducing fat without adding flesh. Indeed testing methods for reducing fat by merely weighing is not satisfactory. Taking two corpulent men of equal weight and equally fat, one shall by potions, unwholesome food, undue sweating (without exercise) and in kindred ways, take twenty flvc pounds ofl" his weight in a month ; while the other will in the same time by healthy exercise, cold bathing, and attention to the points touched on in preceding papers, lose no more perhaps than some five or six pounds ; yet the former shall feel weaker and more oppressed Iiy his weight than before, while the otlier will be altogether heartitir and more vigorous, lighter and more active, than he had been. In one case perhaps some twenty pounds of fat and some five pounds of flesh have been lost : in the other, some ten pounds of fat only may have been lost while five pounds or so of ilesh have been added. It is not diflicult to see which of the two has gained most by his fat-reducing cflbrts ; or rather one has gained all round, wliile the other though twenty or twenty- five pounds lighter is a much weaker man than before he lost the weight. When we consider the effect ef one and the other process on inferior organs such as the heart and lungs. itc, we see still more clearly the superiority of a system by which while fat is reduced flesh is increased. The fat man's heart for instance is not only overloaded with fat, but the heart-muscle is weaker than it should be : to reduce or even remove the fat by a process which at the same time weakens the muscle, is to do at least as much harm as good, — probably more. But a regimen which gradually removes the fat, while increasing not only the quantity but the quality of the muscle, is good all round. In the long run such regimen leads to the more complete and per- manent reduction of fat also. For the man who has simply wasted is not in a fit state to resist the return of fat which begins so soon as the wasting process has ceased. He is far more likely to be simply prostrate during the enemy's approach and unable to prevent it from re-occupying all the positions whence it had been expelled. On the other hand the wiser regimen gives vigour to circulation, respiration, and digestion, increases strength of will and purpose, and makes the attack on such undue deposits of fat as may remain not only eflective but pleasant work. And the good habits l>y which this result has been obtained are not likely afterwards to be dropped, — at least, to be dropped long enough to allow undue obesity to return. But other correspondents ask whether in middle and advanced life either the regimen or the special exercises which we recommend for the increase of strength or (where necessary) for the reduction of weight, can be pursued. We answer unhesitatingly that they can, due regard being had to such moderation as experience and common sense alike enjoin. As an introduction to the remarks we propose to make on this part of our subject, we quote a letter from a man who was eminent for literary ability and business capacity, who lived a full life as well as a long life, and who wrote what we are about to quote at the age of seventy-seven : — " I promised some time since," wrote the poet Bryant to a friend in 1871, " to give you some account of my habits of life, so far at least as regards diet, exercise, and occupations. I am not snre that it will be of any use to you, although the system which I have for many years observed seems to answer my purpose very well. I have reached a pretty advanced period of life without the usual infirmities of old age, and with my strength, activity, and bodily faculties generally in pretty good preservation. How far this may be the effect of my way of life, adopted long ago, and steadily adhered to, is perhaps uncertain. " I rise early ; at this time of the year about half-past five ; in summer, half an hour or even an hour earlier. Immediately, with very little encumbrance of clothing, I begin a series of exercises, for the most part designed to expand the chest, and at the same time call into action all the muscles and articulations of the body. These are performed with dumb-bells (the very lightest, covered with flannel), with a polo, a horizontal bur, and a light chair swung around my head. After a full hour, and sometimes more, passed in this manner, I bathe from head to foot. When at my place in the country I sometimes shorten my exercises in the chamber, and going out, occupy myself for half an hour or more in some work which requires brisk exercise. After my bath, if breakfast be not ready, I sit down to my studies till I am c.illed After breakfast I occapy myself for awhile with my studies, and then, when in town, I walk down to the office of the Evening Post, nearly three miles distant, and, after about three hours, retui-n, always walking, whatever be the weather or the state of the streets. In the country I am engaged in my literary tasks till a feeling of weariness drives me out into the open air, and I go npon my farm or into the garden and prune the fruit-trees, or perform some other work about them which they need, and then go back to my books. I do not often drive out, preferring to walk." Seven years later, soon after Bryant's death at the age of eighty-four years, Mr. William G. Boggs, who knew the poet intimately for many years, gave the follow- ing reminiscences to a representative of the Evening Post .— " During the forty years that I have known him Sir. Bryant has never been ill— never been confined to his bed, except on the 146 ^ KNOWLEDGE ♦ [Sept. 7, 1883. occasion of his last accident. Uis health has always been good. Mr. Bryant was a great walker. In earlier years he would think nothing of walking to I'atcrson Falls and back, with Alfred Pell and James Lawson, after office hours. He always walked from his home to his place of business, even in his eighty-fourth year. At first he wouldn't ride in the elevator. He would never wait for it, if it was not ready for the ascent immediately on his arrival in the building. Of gymnastic exercises he was very fond. Every morning, for half an hour, he would go through a series of evolutions on the backs of two chairs, placed side by side. He would hang on the door of his bedroom, pulling himself up and down an indefinite nnmber of times. He would skirmish around the apartment after all fashions, and once he told me even " under the table." Breakfast followed, then a walk down town ; and then he was in the best of spirits for the writing of his editorial article for that day He was a constant student. His daily leading editorial constituted, and was for many years, the Evening Post. Sometimes he would not get it written until one o'clock. ' Can't I have it earlier ? ' I asked him one day. ' Why not write it the evening before ? ' 'Ah,' he replied, 'If I should empty out the keg in that way, it would soon be exhausted.' He wanted his evenings for study. ' Well, then, can't you get doAvn earlier in the morning ? ' He said, ' Oh yes.' A few months afterwards he ex- claimed, with reference to the change : ' I like it.' I go through my gymnastics, walk all the way down, and when I get here I feel like work. I like it.' " Mr. Boggs also stated that Mr. Bryant's sight and hearing were scarcely impaired even up to his death. (To be cnntinvet.) THE BIRTH AND GROWTH OF MYTH. By Edward Clodd. XY. IN addition to the beliefs in the transformation of men into animals and in the transmigration of souls into the bodies of animals, we find among barbarous peoples a belief which is probably the parent of one and certainly nearly related to both, namely, in descent from the animal or plant, more often the former, whose name they bear. Its connection with transmigration is seen in the belief of the Moquis, an Indian tribe, that after death they live in the form of their totemic animal, those of the Deer family becoming deer, and so on through the several clans. The belief survives in its most primitive and vivid forms among two races, the aborigines of Australia and the North American Indians. The word " totemism,'' given to it both in its religious and social aspects, is derived from the Algonquin " dodaim " or " dodhaim," meaning " clan- mark." Among the Australians, the word " kobong," meaning " friend " or " protector," is the generic term for the animal or plant by which they are known. It is akin in significance to the Indian words " manitou," " oki," etc., comprehending " the manifestations of the unseen world, yet conveying no sense of personal unity," which are commonly translated by the misleading word "medicine;" hence, " medicine-men." The family name, or second name borne by all the tribes in lineal descent, and which corresponds to our surname, i.e., itiper noinen, or " over-name," is derived from names of beasts, birds, &c., around which traditions of their trans- formation into men linger. Sir Geo. Grey* says that there is a mysterious connection between a native and his kobong. It is his protecting angel, like the " daimon " of Socrates, like the "genius" of the early Italian. "If it is an animal, he will not kill one of the species to which it belongs, should he iind it asleep, and he always kills it re- luctantly and never without aitbrding it a chance of escape. The family belief is that some one individual of the species " Travels in N.W. and W. Australia," Vol. II., 229. is their dearest friend, to kill whom would be a great crime," as, in Hindu belief, when a Kajah was said to have entered at death into the body of a fish, a " close time " was at once decreed. Among the Indian tribes we find well-nigh the whole fauna represented, their totem being the Bear, Turtle, Deer, Hawk, Eagle, Pike, Buffalo, &c. Like the Australians, these tribes regarded themselves as being of the breed of their particular animal-totem, and avoided hunting, slaying and eating (of which more presently) the creature under whose form the ancestor was thought to be manifest. The Chippeways carried their respect even further. Deriving their origin from the dog, they at one time refrained from employing their supposed canine ancestors in dragging their sledges. The Bechuana and other people of South Africa will avoid eating their tribe- animal or wearing its skin. The same prohibitions are found among tribes in Northern Asia, and the Vogulitzi of Siberia, when they have killed a bear, address it formally, maintaining " that the blame is to be laid on the arrows and iron, which were made and forged by the Russians ! " Among the Delawares the Tortoise gens claimed supremacy over the others, because their ancestor, who had become a fabled monster in their mythology, bore their world on his back. The Californian Indians are in interesting agreement with Lord Monboddo when, in claiming descent from the prairie wolf, they account for the loss of their tails by the habit of sitting, which, in course of time, wore them down to the stump ! The Kickapoos say their ancestors had tails, and that when they lost them the " impudent fox sent every morning to ask how their tails were, and the bear shook his fat sides at the joke." The Patagonians are said to have a number of animal deities, creators of the several tribes, some being of the caste of the guanaco, others of the ostrich, &o. In short, the group of beliefs and practices found among races in the lower stages of culture point to a widespread common attitude towards the mystery of life around them. In speaking of totemism among the Red Races, Dr. Brinton thinks that the free use of animate symbols to express abstract ideas, which he finds so frequent, is the source of a confusion which has led to their claiming literal descent from wild beasts. But the barbaric mind bristles with contradictions and mutually destructive conceptions ; nothing is too wonderful, too bizarre for its acceptance, and the belief in actual animal descent is not the most remark- able or far-fetched among the articles of its creed. The subject of totemism is full of interest both on its religious and social side : — On its religious side it has given rise, or, if this be not conceded, impetus, to that worship of animals which assuredly had its source in the attribution of mysterious power through some spirit within them, making them deity incarnate. On its social side it has led to prohibitions which are inwoven among the customs and prejudices of civilised communities. But, before speaking of these prohibitions, the barbaric mode of reckoning descent should be noticed. The family name borne by any Australian tribe is per- petuated Viy the children, whether boys or girls, taking their mother's name. Precisely the same custom is found among the American Indians — the children of both sexes being of the mother's clan. Now, the family, as we define it, does not exist in savage communities, nor, as Mr. McLennan says in his very remarkable work on "Primitive Marriage," had " the earliest human groups any idea of kinship,. . . the phy.sical root of which could be discerned only through observation and reflection." Where the relations of the sexes were confused and promiscuous, the oldest system in which the idea of blood-ties was expressed Sept. 7, 1883.] KNOWLEDGE ♦ 147 was a system of kinship through the mother. The habits of the " much-married " primitive men made mistake about any one's mother less likely than mistake about his father ; and, if in civilised times it is, as the saying goes, a wise child that knows its own father, he was, in barbarous times, a wise father who knew his own child. Examples tracing the kinship through females, father and oflspring being never of the same clan, abound in both ancient and modern authorities, and perhaps the most amusing one that can be given is found in |Dr. Morgan's " Systems of Con- sanguinity." He says that the "natives of the province of Keang-se are celebrated among the natives of the other Chinese provinces for the mode, or form, used by them in address, namely, ' Laon peaon,' which, freely translated, means, ' Oh, you old fellow, brother mine by some of the ramifications of female relationship ! ' " The prohibitions arising out of totemism are two : 1. Against intermarriage between those of the same name or crest. 2. Against the eating of the totem by any member of the tribe called after it. I. Among both Australians and Indians a man is for- bidden to marry in his own clan, i.e., any woman of his own surname or Ijadge, no matter where she was born or however distantly related to him. Were this practice of " Exogamy," as marriage outside the tribe is called, limited to one or two places, it might be classed among exceptional local customs based on a tradi- tion, say, of some heated blood-feud between the tribes. But its prevalence among savage or semi-savage races all the world over points to reasons the nature of which is still a cniic to the anthropologists. The late Mr. McLennan, whose opinion on such a matter is entitled to the most weight, connects it with the custom of female infanticide, which, rendering women scarce, led at once to polyandry, or one female to several males, within the tribe, and to the capturing of women from other tribes. This last-named practice strengthens Mr. McLennan's theory. He cites numerous instances from past and present barbarous races, and traces its embodiment in formal code until we come to the mock relics of the custom in modern times — as, for example, that harmless " survival " in bride-lifting, that is, stealing, as in the word " cattle-lifting." Connected with this custom is the equally prevailing one which forbids intercourse between relations, as especially between a couple and their fathers and mothers-in-law, and which also forbids mentioning their names. (I have, by the way, heard more than one cynical son-in-law express regret that certain features of this custom had not survived among ourselves.) So far as the aversion which the savage has to telling his own name, or uttering that of any person (especially the dead), or_ thing feared by him is concerned, the reason is not far to seek. It lies in that confusion between names and things which marks all primitive think- ing. The savage, who shrinks from having his likeness taken in the fear that a part of himself is being carried away thereby, regards his name as something through which ho may Vie harmed. So he will use all sorts of roundabout phrases to avoid saying it, and even change it that he may elude his foes, and puzzle or cheat Death when he comes to look for him. But why a son-in-law should not see the face of his mother-in-law, for so it is among the Aranaks of South America, the Carilis and other tribes of more northern regions, the Fijians, Sunia- trans, Dayaks, the natives of Australia, the Zulus, in brief, along the range of the lower culture, is a question to which no satisfactory answer has been given, and to which referfMice is here made because of its connection with totemism. II. Tliat the aniui.al which is the totem of the tribe should not^be eaten,^even where men did not hesitate to eat their fellows, is a custom for which it is less hard to account. The division of flesh into two classes of for- bidden and permitted, of clean and unclean, with the resulting artificial liking or repulsion for food which custom arising out of that division has brought about, is pro- bably referable to old beliefs in the inherent sacredness of certain animals. The Indians of Charlotte Island never eat crows, because they believe in crow-ancestors, and they smear themselves with black paint in memory of that tra- dition ; the Dacotahs would neither kill nor eat their totems, and if necessity compels these and like barbarians to break the law, the meal is preceded by profuse apologies and religious ceremonies over the slain. The abstention of the Brahmins from meat, the pseudo-revealed injunction to the Hebrews against certain flesh-foods (that against pork has its origin, it has been suggested, in the tradition of descent from a boar) need no detailing here. But, as parallels, some restrictions amongst the ancient dwellers in these islands are of value. It was, according to Cajsar,* a crime to eat the domestic fowl, or goose, or hare, and to this day the last-named is an object of disgust in certain parts of Russia and Brittany. The oldest Welsh laws contain several allusions to the magical character of the hare, which was thought to change its sex every month or year, and to be the companion of the witches, who often assumed itsshajie.t The revulsion against horseflesh as fuod may have its origin in the sacredness of the white horses, which, as Tacitus remarks,! were kept by the Germans at the public cost in groves holy to the gods, whose secrets they knew, and whose decrees regarding mortals their neighings interpreted. That this animal was a clan-totem among our forefathers there can be no doubt, and the proofs are with us in the white horses carved in outline on the chalk hills of Berk- shire and the west, as in the names and crests of clan descendants. The survival of the totem in heraldry is worth more than a passing remark, and will have further reference in a succeeding chapter. PRETTY PROOFS OF THE EARTH'S ROTUNDITY. § CHIEFLY FOR THE SEASIDE. By Richard A. Proctor. {Continued from page 1-10.) NEARLY every one must have noticed that when you are in an inland road near the sea, at a consideralile height above the sea-level, you are apt when you get a sudden view of the sea-horizon to find it much higher than you had expected. This is particularly the case if there are steep side-tracks leading down towards the sea from the road you are following and if you have had reason to note the steepness and depth of these side-tracks as you adviince, without however seeing the sea itself for some time. Then when you come upon an opening leading to tlie sea, you look down for the sea-horizon and find that you must turn your eyes upwards to see it : not upwards in reality, nay * "Do Bell. Gall.," V., c. 12. t Elton's "Origins of English History," p. 297. t Gormania, IX., 10. § I beg to state that tliose are entirely mistaken who imagine that these papers are intended for the benelit or instruciion of the Hat earth paradoxers. They are meant entirely for those who know the earth to bo a globe, but (like myself) take interest in noting simple proofs of the fact. 148 • KNOWLEDGE ♦ [Sept. 7, 1883. in reality somewhat though not perceptibly downwards, but upwards from the direction in which you had first looked expecting to see the horizon. This is by many regarded rather as a difficulty than as a proof of the earth's rotundity. Yet no one can look at the sharply defined sea-horizon as seen from a considerable height, under favourable atmospheric conditions, without seeing at once that that sharpness of definition is inconsis- tent with flatness. When far beyond the sea-horizon land is in view, the contrast between the distinctness of the sea- horizon and the indistinct hazy look of the land lieyond affords another striking evidence of the rotundity of the sea-surface, for it shows that there is more haze between the eye and the land than there is between the eye and the part of the sea-surface where the sea-horizon line is formed. effective. I have never known any one who has over tried it under good observing conditions without finding that strong though his faith might already have been in the rotundity of the earth, it was much confirmed and strengthened by this particular observation. It makes the observer y>eZ as it were that the sea surface rises in a bold sweep between him and the more distant object seen in the same field of view. But this way of recognising the sea's rotundity may be improved upon. Let us suppose that our observer starts from A, to climb up the cliff (along the roadway will do very well) till, after passing the level a, he reaches the summit of the cliff at a'. When he is at A the line of sight to the sea-horizon meets the sea curve close by as at p and the clearness of the sea-line, supposing the observation made in good observing Thus if a (Fig. 1.5) be the place of an observer, A the sea-level beneath him, and aF b the line of sight touching the sea-horizon at P, and extending onwards to the cliffs at b, we are not merely convinced but feel instantly that P is much nearer than b, when we find that the sea-horizon at P is seen much more clearly than the clifl's at b. We know then that the surface must round itself above the straight line A B in order to have this relative nearness at P. r. But an even prettier proof of the rotundity of the water-surface may be obtained by using a powerful tele- scope at a station such as a, and directing it upon the horizon-line at P towards a ship as at s. It will be found that when the telescope is focussed so as to show the sea- horizon distinctly, the masts and sails of the ship s are seen indistinctly. Fig. 1 6 gives an idea of what is seen. To bring the ship sharply into view, the focussing rack- work must be used so as to carry in the eye-tube, as for a more distant object, and then presently the parts of the rigging in view are seen sharply defined as in Fig. 17, while the sea-horizon has become hazy and indistinct. Where a low magnifying power is employed on a large telescope, so that the focal range for different distances is relatively great,'this observation is singularly weather, is very striking, as is also the contrast between the sharp definition of the sea surface at ;; and the haziness of the cliff at b' if that is visible at all, as of a ship at s. If the telescope is used as in the experiment just described, at such a station as A, the amount of focussing required to correct from a clear sea-horizon into well defined ship rigging, or vice versd, is much greater than when the tele- scope is set higher above the sea-level. When the observer has reached a, the sea-horizon has retreated to P, and is less distinctly seen, though it is very marked against the distant clifi at b. But when, passing onwards to a', he brings the sea-horizon to B or even further from him, so that he sees to the very foot of the cliff, then the sea-horizon (on either side of the cliff Bb b' (which we suppose to be a cape projecting towards him) is no longer seen to be freer from the tflects of haze that the cliflf's face at b. If the observer has noted the sea-horizon from time to time during his ascent he will have seen (presuming the weather remains tolerably constant) that the sea-horizon gets lighter and lighter in tone as he passes higher and higher, showing that it passes farther and farther away and is thus more and more afiected by the presence of any haze that may be in the air Sept. 7, 1883.] KNOWLEDGE . 149 For even in the clearest weather there is always enough haze near the sea-level to affect the distinctness of the sea- horizon, when, owing to the observer's ascent, it is thrown twenty or thirty miles away. {To he continued.) THE FISHERIES EXHIBITION. By John Ernest Ady. LET us now look a little higher in the scale of sponge life. We find sponges which strongly resemble the simple Ascetta* already described ; they go a step further to form the family Leucmies, of which Lexicon (Fig. 13, d) is a type. The advance in structural complexity consists in this, — that the ectoderm or syncytium becomes greatly thickened, and, as a consequence, the simple pores which Pig. 13. — Diagrams to show the structure of Ascoxes and Lici:- CON'ES. A, Ascetta primordialis, one of the AscoNES. B, Portion of the body-wall of the same highly magnified to show e c, ectodermal syncytium with spicules ; e, flagellate cells of endoderm ; e', endo- dermal cells without flagella ; p, an inhalent pore. D, Leucon, to show greatly thickened syncytium with branched anastomosing canals, and ciliated chambers, c, One of the ciliated chambers of Leucon highly magnified ; e c, the syncytium ; e, endodermal cells of ciliated chamber. lead into the body cavity of Ascetta (which is typical of its family, the Asconea) are here converted into long tubes, which may branch, and unite at intervals. The endo- dermal ciliated cells, moreover, do not now form a con- tinuous layer lining the body cavity, but are parcelled out into groups which everywhere stud dilatations in the branching tubes. These dilatations are known as the ciliated chambers (Fig. 13, c; Fig. 14, c) or ciliated baskets of the sponge, and are the representatives of the once continuous endoderm. "•^^^ Fig. 14. — Hypothetical sriiinTi ol a >, s, superficial layer; s', deeper substance of sponge; .-, iiihalent apertures; c, exhalent aperture ; c, ciliated chambers. The arrows indicate the direction of the currents. (After Huxley.) • Ut supra, p. 124. In Spongilla fliiviatilis, the common fresh-water sponge, a growth something like that which has just been noted is developed as shown in Fig. 11, but with this difiference, that in place of the calcareous spicules of the Lev/ones there is a fibrous skeleton of keratose strengthened with spicules of silica, which are also scattered amongst the sponge-cells, or sarcoids, as the latter are sometimes called. In the curious Halisarca we have a sponge identically similar, but entirely devoid of a skeleton ; it has therefore been placed in a division by itself, the Mt/xosjionyici: In the sponges of commerce also (Spongict), the main difference lies in the nature of the skeleton, which is wholly fibrous and composed of keratose. The beautiful siliceous sponges, Euplectella and its allies, are likewise all resolvable into the type of structure which has now been explained. There is one peculiar process which we have before alluded to as an aberrant phase in the life-history of Spongilla to which we would now draw attention, as of importance to those who desire to follow its interesting details practically.* During the autumnal months several contiguous cells in the body of the sponge lose their ordi- nary appearances, and acquire bright granules, which finally obscure their other characteristics. The cells imme- diately surrounding the group so formed, unite to produce a kind of coat for them, and secrete in this a skeleton of keratose. Each central cell now develops a peculiar sili- ceous spicule, resembling two toothed-wheels united by an axle (Fig. 15). A small opening, or hilum, is left at one Fig. 15. — Spongilla fluiiatilis. — A, so-called "seed" or "gem- mule," external aspect showing hilum, h, and toothed tops of spicules or amphidiscs. B, diagrammatic section of gemmule, showing position of amphidiscs, a ; h, hilum. C, amphidisc seen in profile (after Nicholson). part of this amphidiscus ; its protoplasm dwindles away till nothing but the outer keratose coat and the peculiar spicules, arranged perpendicularly to the surface, as in Fig. 15, remains. This condition is arrived at in winter, and the bodies, now known as sponge seeds, remain thus during the cold months. On the advent of spring, however, the internal cells resume their activity, are extruded from the hilum, and settle down to develop into a young Spongilla. Lastly, there is a genus of sponges which bore into the shells of molluscs by means of curiously-shaped siliceous spicules, and live there parasitically ; these Clioiiida: have been found in some of the oldest geological formations, e.g., from the Silurian upwards. Their anatomy, and therefore their atiinities, has not yet been determined. We cannot here enter into the details of the arguments respecting the atiinities of the sponges. Suffice it to say, that the weighty evidence of the formation of a blastoderm, and its subsequent passages through the morula, gastrula, and other stages, is sufficient to place the group of sponges (Fori/'era) nearer the Culi'ittei-ala tlian the rroto^-ou. This will become apparent when we have defined what a cwlenterate animal is ; but, to avoid confusion, we must • Spnn[}ill(e may be obtained from Mr. G. H. King, 1G5, Great Portland-street, W. ; or from Sir. Thomas Bolton, of 57, Xewhall- strcet, Birminglmm, both of whom have shown specimens at their stands in the Exhibition. — J. E. A. 160 • KNOWLEDGE ♦ [Sept. 7, 1883. not anticipate matters here. We may merely remark that the presence of thread-cells detected Ijy Eimer* in certain sponges (Eenieridtr) helps largely to support these con- clusions. Before we leave the subject of the sponges let us look a little more in detail at one of the beautiful siliceous forms {Eitplectella), which finds so deservedly attractive a place in the Exhibition buildings. The first specimen of this sponge was brought to this country from the Philippines for the Zoological Society, and was carefully described -with figures by the distinguished Director of the British ^Museum in the "Transactions" of that Society. t Dr. Owen sup- posed that the upper broad end was buried in the sea bottom, and that the smaller extremity, with its tuft of fibres, was its upper free portion. It is now known that the reverse of this is actually the ease, and that the fibrous narrow extremity anchors the sponge to the sub- stratum. In Lady Brassey's case there are also a few examples of another beautiful sponge, commonly known as the glass-rope .sponge (Ili/alonema), and, strange to re- late, it also was long represented upside-down, with its glassy rope of siliceous fibres spreading out above, instead of serving to fix the sponge to the bed of the ocean. Both of these lovely organisms, Euplectella and Ilyalonema, belong to the same group of siliceous sponges, the Ilexac- tinellida; so called because their spicules are primarily six- rayed. Circumstances of great interest to naturalists may l)e observed in l>oth Euplectella and Hyalomma. In the former, it often happens that the body-cavity contains species of curious crustaceans, and it was thought that the poor little creatures were "the insects" which produced the exquisite .sponge. The presence of the crab within the body-cavity of the sponge, however, serves to illustrate a very peculiar and important occurrence in Nature, known as com- mensalism. The crab does not live at the expense of the sponge, and is not therefore a parasite ; it merely lives ivith the sponge at a place best adapted to the provision of its wants. It commenced its existence within the sponge as an egg or young animal taken into the body-cavity with other food ; instead of being digested, it survived, and grew there into an adult crab, living upon materials brought to it by the sponge ; it received all the necessary wants of life in a comparatively secure retreat, and trans- mitted the peculiarities, whereby it was enaViled to survive, to its offspring, fitting them to take up their abode within the same or some other Euplectella. Here we have an ex- cellent example of the survival of the fittest. Now, if we look at Hyalonema, we shall observe in most specimens that the glassy rope is covered over with a brown incrusta- tion. When perfectly fresh, this outer brown coating is resolvable into a number of closely adherent sea anemones of the genus Palythoa. To Palythoa the fabrication of the sponge was once attributed ; but careful researches into its structural i-elations has shown that Palythoa, like Euplec- tella's crab, is only a commensal. For many years Venus's flower-basket was considered to be a very rare organism, and found a place only in the cabinets of the wealthy ; specimens can now be procured at from four to ten shillings each. The demand for speci- mens made the fishermen of the Philippines very zealous about concealing their hunting-grounds, and Professor Owen, in descriliing the capture of the type specimen, J said that it was reported to have been obtained off the island of Bohol, at a depth of ten fathoms, and on a rocky bottom. All subseqiient experiences show that Euplectella lives only on a soft muddy bottom, at depths, according to Captain Chimmo, of from 120 to 140 fathoms.* In the voyage of the Challenger, numerous examples were procured off the island of Zebu, at from 95 to 100 fathoms, and only one solitary form [Euplectella suherea), with fragments of others, have been described liy the late Sir Wyville Thonisonf as coming from a depth of 1,090 fathoms in the Atlantic Ocean, ninety miles south-east of Cape St. Vincent. * " Nesseizellen und Saamen bei See-Schwammen," Arch, fiir Mik. Anat., Bd. viii., 1872. t Vol. iii. 18-11, p. 203. X " Transactions of the Liunaean Society, 1857." Vol. xsii. The American Granite Cutters' Journal says : — " From surveys and calculations made by Mr. J. A. Farrington, civil engineer, the famous Washington boulder, near Conway Corner, N. H., is found to measure 30 ft. in height, 46 ft. in length, 35 ft. in width, and to weigh 3,867 tons. This is the largest known isolated piece of granite in the world." The Washington correspondent of the Cleveland Leader writes : — " The Washington monument is the wonder of Washington, and its beauty the admiration of both Americans and foreigners. Already over 350 ft. high, it rises from the banks of the Potomac a great white marble shaft, piercing the clouds, and backed against the blue of the sky. It is already the grandest obelisk the world has ever seen, and in the a>ons of the future, should the nations of the day pass awaj', leaving no more records of their pro- gress than the mighty ones of the Egyptian past, it will surpass the Pyramids in the wonder of its construction. It is already higher than the Third Pyramid, and within 100 ft. of the size of the second. It is taller than St. Paul's Cathedral, and when finished it will be the highest struc- ture in the world." Sport and Science. — Medical science has for centuries experimented on live animals for the purpose of obtaining increased knowledge of the laws of health and disease in the human body. That often unnecessary researches of this kind have been prosecuted is probable enough ; and, unfortunately, it is but too certain that many who have, perhaps, begun such researches with no other wish but to extend knowledge, have grown not merely callous but cruel. In other words, it is certain that the practice of vivisection, which is a very old practice, has been subject to abuses. Yet the legislation by which medical researches conducted on the bodies of living animals have been re- stricted, has not altogether commended itself to the approval of men of science. In this country most of the restrictions were not required, and were little short of insults to the medical profession. Some of the restrictions also have proved mischievous in their operation. Be this as it may, it has been shown that the Legislature can deal with the wrongs of animals when only the researches of a learned profession are in question. It is otherwise when the sports by which our idlers amuse themselves are involved. The wretched sport of pigeon-shooting, as worthy of support as the street lout's practice of flinging stones at cats and dogs, receives protection from the House of Lords Temporal and Spiritual ; the latter indeed not positively voting in favour of the right of grown men to shoot at wretched half- winged pigeons, but by carefully abstaining from voting serving equally well the purpose of the wretched beings who find sport in pigeon-shooting, whether in the cruel work itself or in looking on at it. — Mr. R. A. Proctor in the Neivcastle Weekly Chronicle. * "Natural History of Euplectella axpergillum." By William Chimmo. (London. 1878.) f " Voyage of the Challenger, — The Atlantic," Vol. i., p. 133. Sept. 7, 1883.] ♦ KNOWLEDGE ♦ 151 CHEMISTRY OF THE CEREALS, By William Jago, F.C.S. No. v.— BREAD-MAKmG (Continued). IN our last paper an explanation was given of how by the action of fermentation the dough becomes charged with carbon dioxide gas. Let us be quite sure that this action is understood ; certain minute organisms possess the power, under proper conditions, of effecting the decomposi- tion of sugar into alcohol and carbon dioxide. When moist flour is exposed to air, seeds of the particular organism, which is a very low form of plant life, fall on the mass and fructify there. The flour is now changed into " leaven," and if a little be added to a further quantity of flour and water, the whole mass begins to ferment — that is to say, the growth of this plant proceedo through the whole, and sots up an active conversion of the sugar. From the earliest times this method of causing dough to " rise " has been in common use, a portion of the one parcel of dough being set aside as leaven for the next. The coarser varieties of bread, particularly the German black bread, are still made in this fashion. For the finer varieties of bread beer-yeast is now largely used. There are two forms of this substance known in England — V)rewers' yeast and "German" or "dry yeast." This latter is simply brewers' yeast from which most of the water has been squeezed out, leaving a slightly moist greyish mass. Dry yeast consists almost entirely of the cells of this particular alcohol-producing plant whose action we have been study- ing. It has the advantage over leaven of being more concentrated and of greater purity. In making bread with yeast, a small quantity of flour, yeast, and warm water are mixed together, and set aside in a warm place to undergo fermentation. This constitutes the " sponge " ; with yeast in a healthy condition the dough is seen to rise, and bubbles of carbon dioxide from time to time escape. The sponge is next mixed with the main quantity of flour and water, and the whole mass thoroughly kneaded with the hands, and sometimes with the feet. The dough is now allowed to remain for some hours, the fermentation going on all the time : it is next cut into loaves ; these go on fermenting until their size is nearly doubled ; they are then baked, and still further in- crease in volume through the expansion of the gases under the influence of heat. The heat of the oven rapidly arrests the fermentation by killing the yeast plant. On the continent the making of bread has attained greater perfection than in England ; Paris and Vienna are justly renowned for the excellence of the bread there made. Their method of proceeding differs considerably from that in use with us. A portion of tlie dough from one baking is reserved for the next, and after remaining for about ten hours, is mixed with an equal quantity of freshly-made dough ; this, after standing some hours, is again kneaded with a larger (juantity of fresh dough, and after another interval is mixed with more dough and also some beer yeast. About half of the fermented dough is made into loaves, which, after a time are baked. Tlit> remainder is mixed witli more fresh dough and yeast, allowed to ferment, again divided, the half being baked, and the rest mixed with more dough and yeast. This division and re-fermen- tation is altogether repeated some Ave or si.x times ; the bread last produced is of the finest and whitest quality. It will be seen that by the method of fermentation the carbon dioxide; is produced at the expense of the sugar, and indirectly of the starch of the grain ; the loss, however, ut a very small one, for 1 oz. of sugar yields when fer- mented about twelve pints, or 400 cubic inches of carbon dioxide. With good flour the operation of baking produces but little change in the composition of the interior of the loaf : the starch will be found to have undergone but little altera- tion, a small proportion will have been rendered soluble, but the greater number of granules have not even had their walls broken, being simply swollen by the absorption of water. As may be imagined, the quantity of this com- pound present in Ijread is considerable ; from the results of analyses of twenty-five diflerent loaves Dr. Odling arrived at a mean of 43-43 per cent, of water. But although the " crumb " of the loaf is but little changed, there is a decided alteration in the crust. In the first place, it has a much sweeter taste, and, secondly, by proper treatment, yields a sticky substance. These characters point re- spectively to the conversion of starch into sugar and dextrin. These bodies may be extracted from the crust by soaking it in hot water, and then gently evaporating the clear solution. Under the influence of the greater heat to which the exterior of the loaf is exposed, the starch has suffered decomposition. When bread is " burnt," the decomposition has gone a step or steps further; pro- vided the heat has not been too intense, the sugar is converted into "caramel." This is the material used so largely for browning gravies and other similar pur- poses. In composition caramel consists of a number of closely-allied substances produced by the evolution of water from the sugar in various proportions. As the intensity of the heat is increased, the sugar gets more and more changed, until at last only charcoal remains. It will be of interest here to mention the composition of a sample of good bread : After first removing as much of the water as possible, the following results were obtained: — sugar, 3 6; altered starch, 18 0; unaltered starch, 53 5; gluten, with a little starch, 20-7 per cent. Bread when new is very different to the same article when a few days old ; instead of being soft and spongy, a loaf will have become hard and almost brittle. The taste too will have altered, and that, with most peoples' palates, for the worse. The bread is usually supposed to have become dry ; and certainly the cracks which score a cut surface are suggestive of a loss of moisture. On weighing the bread it will be found, though, not to have lost much ; and what is far more striking, if the bread Ije re-baked, it again acquires the pleasant qualities of " new " bread. An experi- ment of re-baking stale bread showed it to have actually lost over 3 per cent, in the oven, so that, with less water, the bread had lost the peculiar dryness of taste. It is necessary, therefore, to go a step further in order to explain the change the bread has undergone in becoming stale : the water is still there, but instead of being in the free state, has gradually combined with certain of the com- pounds present, probably the starch. A gentle lieat again decomposes these compound.s, and the liberated water gives newness to the loaf. We have so far been supposing that the flour used in bread-making is perfectly sound and of the best quality. Failing these conditions, other chemical changes occur by wliicli the bread is more or less deteriorated. We have from time to time referred to the starch-converting power of the nitrogenous matters of grain ; the bran, owing to the presence of ccrealin, is particularly active in this re- spect. So, too, is gluten, after the flour has been ex- posed for some time to warmtli and moisture. The change of starch to sugar by these bodies is not well understood ; there, is, however, no reason to believe that it resembles fermentation by being the work of some livinf organism. There is some confusion on this point, 152 * knowledge; * [Sept. 7, 1883, because the older authorities class the -whole series of changes together under the name of fermentation. At the risk of tautology we -will again state that this term is now restricted to those changes produced by the presence of minute living organisms. Diflerent or- ganisms cause different kinds of fermentation — thus yeast produces alcohol, other organisms form acetic acid, lactic acid, ifcc. Xot only does the gluten of damp flour acquire the power of converting starch, but it also frequently un- dergoes the peculiar fermentation productive of lactic acid. (Lactic acid is present Ln sour milk.) On using such flour for bread-making, the gluten attacks the starch of warm dough and produces sugar in large quantities. The result is that the bread, instead of being white, porous, and pleasant -flavoured, is dark-coloured and sodden. The sugar and acid may be recognised by the objectionable sweetish-sour taste of the bread. Our next paper must deal with these morbid changes in bread, and methods of preventing them ; particular reference will be made to the use of alum for this purpose.]!^^^ k=T~^ FOLLY AND COURAGE AT NIAGAEA* THERE were daring men before Captain ^Yebb, and, of course, they have found their way to Kiagara. One jumped from the bridge, 192 feet, to the swirling current. For fifty feet he fell like a plummet. Then he turned over twice. At last he struck the water with an awful slap — what the boys call a "belly-whopper." After reading an account of a fatal accident, one of the numerous Mrs. Partingtcns asked if the man died. So I say plainly this man died, probably before he reached the water. And yet, perhaps, that idea, too, has gone to meet the exploded legend of William Tell. But such little accidents only stimulate the reckless. Another jumper soon appeared, as soon another swimmer may. He wore a harness over his thcukltrs. To it was attached a wire, running loosely over a cylinder on the bridge. That kept his feet straight towards Davy Jones' locker, and he survived the leap, to his considerable personal profit. From bridge to water he went in four seconds — the only time on record. Another foolhardy feat was performed by some of the reckless men who decorate almost inaccessible land- scapes with possibly truthful but most certainly inapropos putls of ague pills, liver-pads, and such. A log once lodged forty rods above Goat Island. For four years it lay there, seemingly as beyond human reach as the Korth Star. It touched the pride of certain sliameless and professional advertisers, who were famous for their vandalism, that such a chance should be wasted. 8o when the rapids were thinly frozen over they made their cautious way to the log, and soon there was a gorgeous sign fixed, twelve feet by four, a hideous eyesore, inescapable, on the very fore-front of one of the world's grandest spots, i e. : — Their deed almost met its deserts. They treated the log too roughly. A hole was made through the ice and the current soon did the rest. It was even betting that they would not get ashore. But they did. This was not a fatal accident. Of accidents some very strange ones are recorded. One lady stooped for a cup of water, lost her balance, and was * New York Times' Niagara Falls Letter. out of reach and over the falls almost before her amazed husband knew what had happened. Another lady stooped to pluck a flower on the brink of Table Rock. She was taken up dead from the rocks below. A rhyming irre- verent tourist on the same day recorded a bit of elegiac poetry that would have made him a man of mark in Phila- delphia. He simply wrote : — " At the early age of twenty-three Was pitched into e-ter-ni-ty." In 1875 an accident equally sad and foolish occurred. An engaged couple went behind the falls, into the Cave of the Winds, without a guide. The lady actually sought to bathe in a pool which even the guides never visited. Her lover lost his life Ln trying to save hers. Perhaps the most dramatic accident was the following : A playful young man caught up a charming child who was watching the tum- bling waves. " Kow, Lizzie, I am going to throw you into the water," he said, and swung her back and forth. She screamed, struggled, and slipped from his hands. He gazed after her, realised what he had done, and leaped. Rescue was hopeless. Perhaps he did not deserve death, and at least censure may die with him. Of escapes, tliere are one or two narrow almost beyond belief, and which involve stories of skill and bravery well worth telling. Not many years ago a painter was at work on Second Sister's Island, when he fell into the water. He was old and weak, and while his position was not very dangerous at first, he soon floated down and toward mid- stream, when, just as he seemed hovering on the brink, and exactly forty feet from it, if contemporary records are to be believed, he caught on a rock. How long would his muscles endure the strain 1 And who would rescue him^ and how ? The crowd was helpless until a guide appeared with a coil of rope. One end he left in trusty hands, and with the other he plunged into the boiling tide. When he reached the poor painter the old man still held in his hand the putty-knife with which he had been working. He shifted the knife to his pocket, tied the painter to the rope, and they reached the shore safely. In another case a boatman was crossing the river above the falls, when a fog suddenly came up. He lost his bearings and knew he was drifting to death. His cries alarmed the village, and bells were rung for him to row toward them. Then an oar broke. His only hope then lay in a paltry little anchor and a common rope, which was, moreover, much worn. He examined every foot, nay, every inch of it ; he tugged at the knots at each end. Time and space were precious, but he could not aflbrd to make a mistake. 'Then he threw it over. It bumped along the stones, and his heart beat each time it failed to catch a grip. At last it caught, and brought the boat up standing ^\hile the tense string throbbed like the bass gut of a harp. For the moment it held. How soon would it part? He shrank from feeling along the strands. He was more afraid not to lest he should read his fate in the twine tense and twanging under the current. Inch by inch his fingers travelled to his arm's length. So long as he held there he was safe. Time and time again through the long night he did this, but never, he said, without a heart like lead and hands quivering like a leaf. When morning dawned, as at last it did, he was easily saved. In another case the danger to life, tliough considerable, was not imminent. A tug was towing three scows, when one went adrift. With admirable promptness and address the captain of the tug cut loose the rest of his tow and steamed ahead of the drifting barge. There he held it by steam power, and when the others came along a line was passed, the throttle was Sept. 7, 1883.] KNOWLEDGE ir>3 THE WHUILPOOL RAPIDS, NIAGARA. (From nn Innlimttneom Phot'>graph.) thrown dead open, and it was sought to make way up stnaui. Hut tliey had drifted fairly within the grasp of the spirit of the waters, and for a time it seemed he would not let go his own. Finally a foot was gained, in a few minutes another, and then the tug of war was virtually over. An " escape " of another sort was that of a mur- derer. The Shcriir was behind him, the river in front, and only the wires of the old bridge at Lewiston to help him across. Hand over hand ho began the passage. His hands (luickly blistered, and then they bled. Again and again he rested his arms by hanging by his legs. At last he reached the opposite bank and lay panting fidl an hour before ho continued his flight The feat was certainly^a remarkable one for an amateur. 15i ♦ KNOWLEDGE ♦ [Sept. 7, 1883. AMERICAN MANNERS IN TRAVELLING. By RicHAHD A. Proctor. MR. PHIL ROBINSON'S diatribes, recently very widely circulated in English country newspapers, illustrate well the bias of patriotism. Consider the pleas- ing efleots produced by this " highest of civic virtues " as thus manifested. (Some will say I am not writing about science ; but in these days sociology has already begun to be a science, and it deserves to be regarded, and soon will be regarded, as among the most important of the sciences.) I do not know how long Mr. Robinson has been in America or how much he has travelled there ; but even if he has been no longer there than the twenty months which, in all, I have passed in America, I should say it was very unlikely that he had travelled more than I in that country, seeing that during nearly all those twenty months I have been busily travelling from place to place, and sometimes for weeks in succession have averaged ten or twelve hours' travel per day. Let me in passing also note that so much hard travelling does not tend to encourage fair judgment of manners, lems as the harvest moon, we consider the successive rising.^, southings, and settings of the moon we are dealing really with the lunar day. Lunar days vary, indeed it is their variation which has chielly to be con- sidered in discussing the harvest moon : but of mean lunar days, there are only about 2GA in a sidereal lunar month, and about 261 in a lunation. In fact in the lunar month the number of lunar days is one less than the number of solar days, the moon losing one diurnal circuit per lunation as compared with the sun. We are now in a position, knowing what are the moon's movements without reference to phase, to determine what they will l)e in any given month when her phase at the tinu! she is at any point of her own orbit, is known. (To he concluded in our next.) d^bituarp. DEATH OF PROFESSOR TOBIX. WE learn with sorrow of the death of Professor Thomas W. Tobin, at Louisville, Ky. He will be well remembered by- many in this countiy as a fellow-worker of Professor Pepper's at the Polytechnic ; but obtained a wider and more enduring reputa- tion in America as the inventor of the sine pendulum, and as a skilful exponent of scientific truths. He was bom in January, 1844, in London, so that he was not quite forty years old when he died, on Saturday, August 4th last. He went to America twelve years ago with Professor Pepper, and resolved to stay in that country when Professor Pepper, disheartened by failure, returned to England. The Legislature of Kentucky made an appropriation of SSdO for the construction of one of Tobin's sine pedulums, and Colonel Young was appointed as Commissioner to take charge of it when it was exhibited at Paris. The pendulum is now in the Agi-icultural and Mechanical College, Richmond, Ky. The Poly- technic Institution, Louisville, Ky., was founded chiefly through the exertions of Professor Tobin, Dr. Stuart Robinson, and Colonel Bennet H. Young. Professor Tobin was appointed scientific lecturer there, and held that position till the time of his death. Crowded audiences attested his skill in the art (more difficult than is generally thought) of so interpreting science as to interest the unscientific. Professor Tobin was a genial man, of companionable manners, wide-reading, and cultured tastes. He died of con- sumption, a disease to which his mother and all his brothers and sisters had already succumbed. A Cable for Cochin-China. — The recent operations of the French in Tonquin have directed public attention to that part of the globe ; but it is not generally known that the Eastern Extension Telegraph Company have for some time past made arrangements for laying a submarine cable between Tonquin and Cochin-China. It was intended to lay the cable from Saigon, where communication already e.xists, and Hai-Phong with a branch into Hanoi. Unfor- tunately, however, the French Chamber has rejected tie proposals of the English company in favour of a less ad- vantageous offer by M. Blanscube, deputy of Cochin-China. The Colonial Council of that possession have proposed to share the expense of constructing the new line, which there is every reason to believe will be made by French manufacturers and laid in French territory. — Engineerivij. A MEETING of the subscribers to the parliamentary fund of the Manchester Ship Canal was held on Tuesday week at Manchester. It was reported that the committee had received from subscribers £40,778, and that the ex- penditure amounted to -£47,510. The committee were of opinion that another application to Parliament would be successful. A motion was passed expressing regret at the action of the Committee of the House of Lords in stopping the Bill. The provisional committee was empowered to promote the Bill in the ensuing session of Parliament, in such manner as might be found expedient or desirable. It was stated that promises of .£5,000 had been received towards the cost of the second application to Parliament. Letters from Athens, says a contemporary, announce an interesting disco\ery, brought to light in the course of some excavations which are being carried out in the Island of Delos by the pupils of the French School at Athens. In the neighbourhood of the Theatre of Apollo, they came upon the remains of a private house, which apparently belonged to the Alexandrine epoch. A court surrounded by pillars and twelve chamliers lias been opened out The floor is composed of mosaic, which is a fine specimen, representing flowers, fishes, and other ornaments. In the middle of the court is a well, now quite choked up. The door of the house, and the line of roadway or street lead- ing to it, have also been discovered. The excavations will be continued, and it is hoped that a large portion of the old town will be brought to light. 168 KNOW^LEDGE [Sept. 7, 1883. " Let Knowledge grow from more to more." — Alfred Tennyson. Only a small proportion of Letters received can possilly be in- serted. Corresponde.its must not be offended, therefore, should their letters not appear. All Editorial comjnitnications should ie addressed to the Editor of Knowledge; all B-usiness communications to the Publishers, at the Office, 74, Great Queen-street, W.C. If this is not attended to delays arise for which the Editor is not responsible. All Remittances, Cheques, and Post Office Orders should be made payable to Messrs. Wvman & Sons. The Editor is not responsible for the opinions of correspondents. No communications are answered by post, eten though stamped and directed entelope be enclosed. [915] — With reference to the solution of the problem which appeared in your issue, No. 95, of the 24th inst., as to the height of Galley-Head Light, you have, it appears, assumed the distance to he twenty-one statute miles. I think it probable that Prof. Tyndall meant twenty-one nautical miles, which would, allowing for the mean refractive effect of the atmosphere, make the height of the light about 205 feet. The light is, as you say, known not to be as high as this, but most likely the data are not very correct. Hundredweight. [I cannot see why Prof. Tyndall should be assumed to have meant geographical miles. Most probably he really estimated the distance from the known height of the light. The fiat-earth men think any stick good enough to beat anyone with who talks of the sea's rotundity. — K. P.] PUNCTUATION AND PEINTERS. [916] — Sir Edmund Beckett's article on this subject is hardly likely to make converts either to his style or his mode of punctua- tion. Here is a phrase which I read several times before I could grasp either its sense or its grammar — " and when he sees that he ought to leave us alone to bear our own iniquities if we let our proofs go 'uupeppered' more than he thinks right." A comma after the word "that," which the jranctual punctuator neglects to supply, would have made his meaning clear. Now, as to style, what about the following sentence ? — " and thereby would raise the indignation of every architect in England into a still hotter flame than it is in just 7101V I see, at my having dared," &c. And again : — " If any- body doubts your opinion of Macaulay's style, which was always mine [not the style, surely ?], iet him try it by the test of reading it [reading what ? the opinion or the style ?] aloud, against Froude's," &c. Sir E. Beckett's letter confirms me in my opinion that one can punctuate another man's work better than one's own. F. R. [" F. R." should remember that Sir E. Beckett's communication came as a letter, not as an article, and that he had no opportunity to correct the proof. The contest showed the true meaning of the words "when he sees that" ; no one could suppose that that that (that that that that that " F. R." says refers to) was meant for a conjunction. I have noticed in Sir Edmund Beckett's style that it usually takes for granted a certain degree of attention on the reader's part to the subject-matter. Granted this, no one can ever mistake his meaning, — though one may readily show that, where what he has said and what he is saying is not attended to, a sentence here or there may admit of more than one interpretation. Perhaps it is not unfair to assume that a reader pays a little attention to what he is reading. So much attention as would prevent any one from misinterpreting Sir E. Beckett is not a distraction — like at- tention called away bv over-stopping, &o. — but tends the other way.— R. P.] SMALL WHEELS v. LARGE WHEELS. [917] — Mr. Browning's remarks advocating the use of small geared-up wheels for tricycles are sound, and will not be without their effect. But I have lately found out that (contrary to what he sup- poses) they -may also be used for bicycles, with the additional result of making them so safe that they would certainly be brought into successful competition with tricycles on the question of safety. I have recently invested^in a bicycle [with ," Sun and Planet " action — a small machine, geared up in the most ingenious way, which cannot add anything appreciable to the friction. (It was at the Stanley show, but little display was made of it.) Though simple, it defies explanation without a diagram, and should be seen in action to understand it ; but the chief point is that the very friction of the pedals on their axles is utilised to increase the speed, and has the effect of gcaring-up the wheel from 40 in. to 50 in. The pedals hang down so that a tall man can ride it. ' "=■ ■ Now, if a yet smaller wheel (say 36 in.) were used, the rider's feet could touch the ground when he stopp.ed, and it could be geared-up to 46 in. to 50 in. With such a bicycle there could be no real danger, the advantages of handiness, lightness, and speed would be retained, and no doubt many would ride who would not think of doing so now. S. J. REDUCING FAT. [918] — What is the use of yon devoting so much of your valuable space to the service of fat people. I am quite sure there are not tv'O " gross fat men " among your many thousands of readers. I can prove it, and that easily. Fat men are mostly stupid. Stupid men don't read Knowledge, therefore none of your sub- scribers are fat, and if you have no fat subscribers what is the use of your otherwise useful contributor wasting his energies in this hot weather by seeking to reduce adipose tissue that does not exist. He surely does not aim at reducing fatness in the abstract. I think it has been decided that it is impossible to imagine a fat man in the abstract, and I should like to know how you can administer a towelling to such an individual. But what has most annoyed me is your contributor's last article with its remarks on this said towelling. I am as thin as a rake, and for many years I have taken sponge and towel exercise such as he describes, in the belief that it tended to increase of flesh. Now, your contributor comes along and tells me in eft'ect that I have been rubbing it off. Must I, if I wish to accumulate flesh and make the acute angles of my anatomy more circular, to put it scientifically, leave off rubbing and scrubbing ? W. S. [The author of "How to Get Strong" was moved to write those particular papers by the appeal of several " heavy weights." He tells me (is it not impolite ?) that he had " Our Editor " also in his eye. But many of the rules for reducing fat are excellent also, he tells me, for adding flesh. Therefore your towelling is probably good for you as well as for us fat fellows. — R. P.] DIFFERENT DEGREES OF ILLUMINATION. [919] — Some remarks towards the close of the article on the " Laws of Brightness," in last week's issue of Knowledge, induce me to offer you an artist's experience and reflections upon the sub- ject. One of the undertakings I have ventured upon is that of substituting a science of art for the jargon which passes current. In the course of ray studies to this end, the fact that the colour and the chiaroscuro of a picture never have precisely the same values the artist intended, in any but the light in which the work was executed, set me thinking, and this was the form of my conclusion, that the ratios of the different reflecting powers nf objects vary under different degrees of illumination ; and the following was the mode in which I attempted to illustrate the change effected. Take any series of numbers, for instance, 2, 4, 8, IG, then, either the addition to, or the subtraction of the same number from each term of the series, yields two other series in which the ratios of the several terms to each other are entirly altered. W. Cave Thomas. COLOURS OF FLOWERS. [920] — Mr. Slack, in his " Pleasant Hours with the Microscope," has given us in Knowledge a short but interesting account of the hairs of plants ; how they perform the function of feeders or diges- tive organs by absorbing ammonia and carbon from the air. Plants also, I suppose, absorb silex and other primordial atoms from the soil. Can Knowledge, with the aid of botany, chemistry, and microscopy combined, assist us to understand how colour is formed in flmoers. Colouring matter from plants is a well-known province of chemistry, but how are the varied colours which delight the eye and decorate the garden given to flowers ? Is this capable of analysis or ratiocination ? Lucretius (Book ii.) thought all elementary atoms colourless ; Pliny (Book xxi.) that Nature, in sport, had bestowed the tints which man could not describe. Is this one of the mysteries wherein Nature laughs at the inquisitiveness of man ? — Your obedient, G. G. Hardingham. Sept. 7, 1883 » KNOWLEDGE ♦ 159 SUNSET ON THE MOON. [921] — Watching the moon to-night, I was trying to imagine what sort of event sunset would be if one could get over the little difficulty of reaching our satellite, and be independent of such slight details as respiration, extremes of heat and cold, &c. I was getting along splendidh- with the intensely black sky, the myriads of stars shining day and night, the enormous disc of the earth constantly in almost one direction, part of it bright with reflected sunlight, part just relieved from darkness by a faint reflection of moonshine, and the shading from light to dark by the refraction of our atmosphere. I supposed the sun's disc to have reached the horizon, and (roughly) in about an hour of terrestrial time his last fierce ray suddenly to fade, leaving not a suggestion of twilight to show he had been there. But here I was stopped. Would he disappear in this way ? Of course not. Every solar appendage that can be seen from the earth during a total eclipse would be always visible from the moon. Consequently, when the disc (such as we see it from the earth) had passed below the horizon, there would still remain a gorgeous sight for our adventurous traveller [please do not call him a lunatic]. Now, this is my point. Between the part of the moon which is in darkness and the part which is fully illuminated there must be a strip which is still receiving light from the parts of the sun that lie beyond the disc visible to us. Is it possible to separate and examine the light reflected to us by that strip of the moon's sm-face, and so to add to our knowledge of its source .' Probably the idea is already familiar to you, and its feasibility may have already been tested. Be this as it may, if I have furnished you with a text for some future article in Knowledge, I know I shall receive a hearty, though silent, vote of thanks from its readers. [I likewise bows. — B. P.] W. FIGURE-CONJURING. [922] — Referring to recent communications which have appeared in Knowledge, under the head of "Figure-Conjuring," I should now like to give an experiment, abridged from Professor Hoff- mann's book on " Modern Magic," which I think will give com- pleteness to the experiments above alluded to. The performer asks one of the company to take two dice and shake them secretly in his hands ; he must then turn them down on the table, shading them with his arm from all eyes but his own, and must then write down privately on a piece of paper, the numbers tm-ned up, placing the same apart from each other. The performer then tells him to multiply the left-hand number by 2, then add 5, then multiply by 5, and then add the right-hand figure. He then tells the performer the total thus obtained, and the per- former after mentally deducting 25 from the same, announces what two numbers were turned np by the dice. Tims, supposing one die showed 4 and the other 5, then the experiment would proceed thus : — X 2 8 + 5 Add right-hand fi'ntro Deduction mentally by performer 25 Leaving -1.5. the figures turned up. Now, if the figure-conjuror would show off this experiment in the first place, then follow it up by the one given by myself (858), and, in case of difficulty with some extra-sharp victim, cap the list by going through llio one given by Mr. Proctor on page 2G, I think he would then astonish his audience as much as if he had gone through a clever porfornuinco with the cups and balls. I cannot close this communication without thanking our indefatigable editor ior the article above rel'orred to; I consider it quite a valuable addition to the literature of the subject. To descend from the stars to the constructing of an article on Figure-Conjuring may appear to sonic persona a somewhat incongruous proceeding. I, however, am quite of a contrary opinion to this. To the truly great and fully-developed mind nothing is too great and nothing too small. The wonders revealed by the microscope are quite as astonishing and mysterious aa those revealed by the astronomer's tube. Ill truth, to (he scientific eye, "great" and "small" are synonymous. (;. M. GREATEST CONTENT OF A PARCEL WHICH CAN BE SENT BY POST. [923] — The problem on this subject, which you have solved on p. 76 by the Differential Calculus, can be solved without it, as follows : — First. — Suppose the parcel to be a parallelepiped. Since the sum of the length and girth is Oft., the sum of half the length, the breadth, and the thickness, or the three dimensions of half the parcel is 3 ft. It is plain that the bulk of half the parcel will be greatest when these dimensions are equal, each 1 ft. Therefore the content of the whole parcel is greatest when it is 2 by 1 by 1 = 2 ft. Second. — Suppose the parcel to be a cylinder. As the bulk of a cylinder has a constant ratio (that of 4 to tt) to the bulk of a parallelopiped of the same length and girth, the maximum cylindrical parcel must have the same length and girth as the maximum parallelopiped, that is, its length must be 2 ft., its girth 4 ft., its bulk ^ t. Algeenox Bray. [The problem was given as an illustration of the application of the differential calculus to simple questions. — B. P.] LETTERS RECEIVED, AND SHORT ANSWERS. Jas. M. Rodger. A "Bat upon a circle" may, for aught I know, be j'gth of the circle itself. I do not happen to know what a flat on a circle is. — Alg. Bray. Latest letter on flight of missile correct, but no space for so long an investigation. Thanks for other letters. — Thos. Saver. Will shortly put the list of Nos. in which articles on " How to Get Strong" have appeared at head of one of the forthcoming articles. — H.iKVEST Moox. There are " other causes than cold condensing moisture in the atmosphere to produce what is known to us as the harvest moon." — E. C. H. Thanks. Highest tide about three tides after full moon. — B. J. Jenki.ns. Thanks for correction. Reasoning in other letter scarcely convincing.— Jas. Cram. Squares causing so much anxiety that I shudder at the thought of magic cubes. — W. S. Why should that meteor not belong to our system ? Meteors often behave so. — Francis H. Have as yet had no opportunities to examine the system. — G. G. H. Fear no space for numismatics, though the subject is, no doubt, interesting. — A. M. Cobeold. The subject of spelling reform — and especially of ways in which practical attempts might be made to introduce it — is too wide for these columns. — H. H. Map of the Moon accompanied first of "F.R.A.S.'s" interesting papers. I have not vol. iii. by me for reference ; know the map is in that vol. — J. S. The angle cannot be trisected by simple geometry ; for the equations corresponding to the geometrical requirements is a cube. I am obliged to you for your kind expression of sympathy, though your " pleasure on hearing of my gradual recovery" might be misinterpreted.— W. Wilson. Ton are right in thinking that the Southern Cross affords a perfect proof of the earth's rotundity. Yet not quite as you present it ; for yon write as if the Southern Cross were a Polar constellation ; and you overlook the difference in rotation-time at which, in the opposite directions indicated by you, the Cross is visible. An earth-flatteuer of the foolish sort would find a ready answer to the argument derived from mere difference of direction in the journeys taken towards the icebai-rier. But you mistake in supposing the Pretty Proofs part of a discussion with the eai-th- flatteners. They are so few that such a discussion would be waste time. Proofs of the earth's rotundity ai-e interesting to those who know perfectly well that the earth is rotund. The existence of a Southern Celestial Pule round which as uniformly as round the Northern pole the stars revolve in parallel circles, is an absolute jiroof of the absurdity of the flat earth theory for all who have brains; but it is not sufficient for the flat earth men. — Q. Jordan. The Lunar Theory about which the Astronomical Society was talking is not what you mean by the Lunar Theory. The subject of the lunar acceleration is in no way connected with the elementary phenomena of the moon's movements. You are in deeper water than you think. 1 do not asso- ciate you with Hampden & Co. As to them 1 mention their ignorance and folly, only because of theirviolenco and rudeness.— A Would-be Observer. Cannot do that.— M. U. B. Knowing nothing can say no more. — F. LEriRiNGTON. Question outsideour scope. — Nigel Doble. Such a telescope would be almost worthless. — R. Jones. The answer relating to Text-book matter did not relate to the trisection of an angle. Cannot remember answering any question recently on this subject. Possibly some answer to another correspondent has misled you. 1 remember only that the question related to text- book matters, which would have occupied many pages of explanation 160 ♦ KNOAVLEDGE [Sept. 7, 1883. [Have just found your triscction question cmong unanswered and unopened correspondence. The trisection is perfectly sound, and if the secant could be drawn, by line and circle, to fulfil the conditions named, any angle could \ye trisected by line and circle. Unfortunately it cannot. — E. H. M. S. Would be glad to hear of a good book on the chemical constituents of garden vegetables. — LCTETIA Eediviva. An odd coincidence. But the history of the discovery of Uranus is well-known. Sir W. Herschel himself fully recorded it, and there is nothing in the slightest degree confirming Paris's statement. — E. S. Thanks; the idea is a good one. A series of pictures of the old constellation figures, with stars, names, and explanations of these, would probably interest many. Will try to arrange the matter. — A. Holdsworth. A telescope will not reveal the hull under those conditions. — IXFORMATlox. Pitman's I should say. Other questions belong to a kind we have been obliged to leave unanswered. — H. J. W. JIars has two satellites, both very small, — probably not more than fifteen miles in diameter. There is an essay on them in my " Poetry of Astronomy," entitled " Living in Dread and Terror," these being the Englished names of the two satellites of Mars (Demos and Phobos). — F. R. The "cold spells" are purposely omitted by smoothing off the temperature curves. — Ax Ixquiree. The institu- tion of Infant Baptism is a little outside our line. — T. H. K. The weight lifted is not great, — each raised Jess than 3 stone, each forefinger raised less than li stone. The inspiration, expiration, &c., only help I imagine by directing attention to the proper amount of lifting; so that all act together. But really lifting 40 lb. with the two forefingers is hardly a feat reciuiring special preparation or special explanation when accomplished. — E. T. L. Solution correct. MATHEMATICS. Peop. — AB, DC are equal chrtrds to the circle AB C T) , meeting inF; and tanr/ents FP, FQ are draicn, and FbOa through the centre 0. Shnxa that chords B D, A C iyitersect at P Q. It is clear from symmetry that G, their point of intersection, lies in « F ; and it will suffice to show that a perpendicular chord P G Q cuts the circle in the points P, Q, where tangents from F meet it. Join OB; then in the triangles 0 GB, D GF, angle OGB = opp. angle D GF ; and Z GO B (being angle at centre on B b) = angle at circumference at B C = angle B D F. Hence, the triangles are similar, and OG:GB::GD:GF .-.OG, GF = GB, GD = sq. on P G Wherefore, 0 P G is a right angle, and F P, F Q are tangents. Q.E.D. CoR. — Ij'F be n»v external point from which ta7igents FP, FQ are draxcn to a circle, and P Q cut F O at G, then straight lines F B, F D to the extremities of any chord B D G through G are equally inclined to F 0. ^ur Cbefis Column. By Mephisto PROBLEM No. 96. By J. Beeger Gr.\z. Black. Whttb. White to play and mate in three moves. FRENCH DEFENCE. Uerr Bodusilika. P toK3 P toQ4 KKt to B3 P takes P (a) B to K2 Castles QKt toQ2 K to K sq Kt to B sq (b) P to QKt3 B to Kt2 White. TI.MT lieivcr. 14. Q takes B 15. QR to Q sq IG. R to Q3 17. P to KR-t 18. P to Ro 19. P to RG 20. P to Kt4 21. P to Kt5 22. Kt takes B 23. Q to E4 24. E to Kt3 25. Q takes Kt Black. Herr Hoduschka. R to B sq P to B3 Kt to Kt3 Kt to K2 K to R sq (c) Kt to B4 Kt takes HP B takes P P to KB4 (d) K to Kt sq R to K2 P takes Q ' 26. KttksKP(ch)Resigns(e) White Herr Berger. 1. P to K4 2. P to y4 3. QKt to B3 4. B to Q3 5. Kt takes P G. KKt to B3 7. Castles 8. R to K sq 9. QB to KB4 10. B to K5 11. Q to K2 12. Kttks Kt (ch)B takes Kt 13. B to K4 QB takes B NOTES BY HERR BERGER. (a) P to B4 is the right move here. (6) If Kt to R4 tlien'foUows 10. B to K5 in reply. If then Black plays P to KB3, White could answer with KKt to Kt5 ! (c) This is a lost move, and strengthens White's attack. ((J) If Q takes Kt, White will either win a piece or the Q by R to Kt3. (e) After the exchange of pieces White will remain with a R ahead, i.e., K to B2. 27. Kt takes Q (ch), R takes Kt. 28. R to Kt7 (ch), K to B sq. 20. R takes R, K takes R. 30. B to B7 (ch), and wins. SOLUTION. Problem No. 93, by L. P. Rees, p. 128—1. Kt to B3, and mates accordingly. ANSWERS TO CORRESPONDENTS. *jf* Please address Chess Editor. Berrow.— If in Problem No. 90, 1. Kt to Kt7, P takes Kt, then 2. R takes P(ch), K to K3, 3. Kt to Q8 mate. H. Seward. — "There is no penalty if a player announces mate and fails to give it. Correct solutions received : — Problem 93, Hammond, John Wat- kins ; Problem No. 95, Clarence, M. T. Hooton, H. Seward, Berrow, L. F. Q., End-game, Clarence. Contents of No. 96. A Naturalist's Tear. Wild Peas. By Grant Allen 129 Pleasant Hours with the Microscope. By H.J. Slack 130 TricVcles in 1833 : Small Wheels u. Large Wheels. By John Browning 131 The Amateur Electrician. (/«u«.) 132 Laws of Brightness. IX. (Illus.) By R. A. Proctor 133 The Chemistry of Cookery. XVU. By W. Mattieu WiUiams 135 Evolution of Human Physiognomy. (IHiis.) By E. D. Cope 136 FAGl The Morality of Happiness : Evo- lutiou of Conduct. II. By Thos. Foster 138 Pretty Proofs of the Earth's Kotun- dity. (Illus). By R. A. Proctor 139 Punctuation and Printers. By Sir Edmund Beckett 140 The Face of the Sky Ill Correspondence : Luminous Ring — Flight of a Vertical Missile, &c. 141 Our Mathematical Column 143 Our Whist Column 143 Our Chess Column 144 SPECIAL NOTICES. Part XXII. (August, 1883), just ready, price Is., post-free, Is. 3d. Volume III., comprising the numbers published from January to June, 1883, now ready, price Ts. t>d. The Title Page and Indei to Volume III. also ready, price 2d., post-free, 2id. Binding Cases for Volume III., price 2s. each. Inciuttine carriage per Parcels Post to any address in the ITnited Kingdom, 23. 3d. Subscribers' numbers botmd (including Title, Index, and Case) for 3s. each., 6d. extra for carriage for return iourney per Parcels Post. P. 0. orders and cheques should be made payable to the Publishers, Messes, WrMAIt 4 SoKS, London, at the High Holbom District Post-office. Agent for America — C. S. Carter, American Literary Boreaa, Tribune Btiildings, New York, to whom subscriptions can be forwarded. TERMS OF SUBSCRIPTION. The terms of Annual Subscriptien to the weekly ntunbera of Knowledge are as follows :— s. d. To any address in the United Kingdom 10 10 Te the Continent, Australia, New Zealand, South Africa & Canada 13 0 To the United States of America $3.28. or 13 0 To the East Indies, China, ic. (lii Brindisi) 16 i All subscriptions are payable in sdyance. 0 FFICE : 74-76, GREAT QUEEN STREET, LONDON, W.C. Sept. U, 1883.] ♦ KNOWLEDGE ♦ 161 ^^' MAGAZINE OF^CIENCE PLAINLY"W0RDED-£XACTLYDESCR1BED LONDON: FRIDAY, SEPT. 14, 1883. Contents of No. 98. PAGB I PAGE A Naturalist's Year. The Bam Owl i Tricycles 169 Flies. By Grant Allen ISl W inds as Projectiles 170 Pleasant Hours with the Microscope. ' Dangers of Sea Bathing 171 {.Illut.) ByH. J. Slack 162 : Editorial Gossip 171 The Harrest Moon. (IUu».) By Face of the Sky 172 E. A. Proctor 164 Correspondence: The Bennett The Chemistry of Cookery. XVIII. , Battery — Small Wheels for By W. Mattieu WilLiams 165 Tricycles— A Curious Pheno- The Morality of Happiness. By menon— The Comma, ,ic 173 Thomas Foster 166 i Our Mathematical Column 175 Eyolution of Human Physiognomy. Our Whist Column 175 (lUua.) ByE. D. Cope 168 | Oar Chess Column 176 A NATURALIST'S YEAR. By Grant Allen. XXI.— THE BAEX OWL FLIE.S. AS the shades of evening begin to fall, the big barn owl, from the top of the old broken sham-castle on the hill-side, crawls out regularly every night from the over- sheltering ivy, and sets forth stealthily upon his predatory expedition in search of stray wandering rabbits, rats, and mice. A weird and uncanny thing he is to be sure, worthy to be held in superstitious awe as a bird of ill- omen ; and yet, I suppose, he merely flies by night from necessity, not from choice, because the creatures on which he has adapted himself to prey come out by night for their own feeding-time. Your common barn owl, in fact, is one of the remoter hangers on of civilisation, an outcast who follows close on the heel of the agricultural pioneer all the world over, till at last it has become almost impos- sible to say in what countries he is really indigenous, and in what he is merely a perfectly naturalised alien. The reason for this is simple and obvious enough. Wherever man sows and plants, the rat and the mouse, in one or other of their local forms, thrive and multiply most exceedingly. Kot only in houses, but even more in cornfields, barns, farmyards, and granaries, these unwelcome guesis of civilisation ilourish everywhere in the greatest abundance. Now, the barn owl was from the \"ery beginning, apparently, the member of his own race most peculiarly adapted to prey remorselessly upon these small and coni|)arative!y defenceless quadrupeds. So, as the mice, rats, and shrews increased in numbers with the increasing supply of food aftbrdcd them by the grain or the insects of cultivated fields, in like manner did the pre- daceous Ijarn owls increase side by side with them to prey upon them, as their natural food. All the owls, in common with other birds of prey, have a convenient habit of rejecting the bones of their victims from the stomach, un- digested, in little pellets, which saves their aliineutary canal a lot of useless labour ; and the examination of these pellets, in the case of our friend the barn owl, sufllciently dispels the wicked calumny of gamekeepers that he feeds mainly upon young birds, as the bones of which they are composed are almost entirely those of small mice, voles, shrews, and other petty rodents or insectivores. Though it is not quite formally correct to describe the owls, after the good old fashion, as the nocturnal birds of prey (for some of them hawk about in the broad daylight, while at least one of the falcon tribe, or so-called diurnals, has, j)er contra, acquired the habit of hunting bats by night), there can yet be no doubt that the owls as a group have really gained most of their distinguishing charac- teristics in adaptation to a night-flying existence. Their very shape and structure marks them out at once as widely different in liabit from the frank and bold birds of prey, like the eagles, hawks, and falcons, which mostly pursue their quarry in the open sky. Their oddly- shaped legs fit them for squatting in the peculiar, sleepy, owlish attitude ; their short necks and clumsy bodies are better fitted for prowling in the dusk after ground animals and game birds, than for pursuing swiftly-flying creatures like those which form the main food of the rapid hawks and falcons. But the big head, with its ruff- like disc, which is perhaps the most marked feature in our common English owl, bears still more distinct reference to the specially nocturnal habits of the entire race. Owls, apparently, are more highly developed hawks, specialised in many respects for night-flying liabits ; and therefore their sense-organs have had to undergo the usual modifi- cations in adaptation to their peculiar environment. As in most lemurs and other advanced nocturnal mammals, the eyes are very large and noticeable, and are surrounded by a sort of reflector of curiously-arranged concentric feathers. They are admirably adapted for vision in the dusk or with a minimum of light; but, at the same time, the peculiar organs in the retina which are supposed to be employed in the perception of colour are entirely absent. It is a noteworthy fact in this connection, that owls themselves seldom show any traces of colour in their own plumage, other thim various shades of black, white, grey, and brown. Their hues are generally protective, and enable them to pass mmoticed in the daytime upon the bark of trees. This is, indeed, what one might naturally expect, because Mr. Darwin has shown that ornamental colouration in birds is due almost entirely to the sexual selection of the most beautiful mates ; and a group like the owls, which are actually destitute of the nervous apparatus for per- ceiving red, blue, green, and yellow, cannot well show a marked preference for such gaudy hues in their own fellows. As a matter of fact, the few decorative ad- juncts to be found amongst them are entirely con- fined to pure white plumage, as in the snowy owl (a day-flyer), or to tufts and rings of feathers in the most conspicuous and visible positions, as in the long-eared owl of our own islands. In this respect, owls form a complete contrast to such brilliant fruit-eating groups as the parrots or the toucans ; yet it is interesting to observe that one very aberrant New Zealand parrot, wliich is also nocturnal in its habits, and closely resembles the owls in appearance, down even to the possession of the distinctive disc around the eyes, has toned down the prevailing green of its ancestral colouration into a very owl-like shade of dingy olive-brown, speckled with tawny yellow. This is one of the numerous cases which show us that similarity in mode of life will produce strong adaptive external resemblances between very diverse creatures originally descended from extremely unlike ancestral lines. Nocturnal animals require largely to supplement sight by hearing, a fact which is well illustrated in the enormous e.xternal etirs and peculiar apprndnges of many advanced forms of bats. In the owls, evidence of similar adaptation 162 ♦ KNOWLEDGE ♦ [Sept. U, 1SS3. is not ^vanting. The external ear-opening is extremely complicated, and its peculiarities are different in different genera of owls. One kind even has the ear-opening on the right side of a different shape from that on the left. Every- body who has ever watched our English barn owl closely, knows well that its sense of hearing is most keen and acute. It is, doubtless, this large development of the exterior sense-organs that makes the heads of most owls so dispro portionately big. There is one peculiarity of the whole owl group, however, which they share with a single other bird of prey- — the osprey — and which does not seem immediately connected in any way with their nocturnal habits, though it fits in admirably with their usual skulking mode of life, and that is, the power which they possess of reversing their outer toe, so as to turn it outwards or inwards at will. A peculiarity like this must probably descend to them from a common ancestor, who perhaps was not yet nocturnal in his mode of life. As a consequence, owls can sit with two toes on one side of the perch and two on the other, a thing impossible for hawks and eagles, whose toes are arranged to go three on one side and one on the other. Our own common barn, owl is a good representative of the usual habits prevalent among the race at large ; but, like most other successful groups, the owls have split up into a good many genera and species, several of which have diverged considerably in structure, and still more in habits, from the central type. While most of them hunt rats and mice, and such small deer, the great eagle-owl of Germany and Switzerland eats not only rabbits, hares, capercailzie, and pheasants, but even so large an animal as the fawn of the roebuck. Other owls, again, have taken to fishing, like their distant relative, the osprey ; and, like him, they have lost the feathers on the lower part of the leg, and acquired a series of small spikes on the sole of the toes, to aid them in holding their slippery prey. One of these is common in India, and three rarer kinds frequent the streams and inland lakes of Africa. A few owls have even reverted once more to the habit of hunting their food by day, like the snowy owl, which is perhaps the handsomest member of the entire race. Some of the tiny continental species have greatly degenerated in size, till they have grown no bigger than an ordinary robin. Such decrease of size, though it looks at first sight like a disadvantage, may really help a species in the struggle for existence by enabling it to procure smaller but more abundant food. The wee pigmy-owlet of the Mediter- iranean region could easily pick up a livelihood for himself in many districts where the great eagle-owl, adapted to broad, forest-clad plains, would starve hopelessly. Herbert Spexcer — "The work which Herbert Spencer has done in organizing the different departments of human knowledge, so as to present the widest generalizations of all the sciences in a new and wonderful light, as flowing out of still deeper and wider truths concerning the uni- verse as a whole ; the great number of profound generaliza- tions which he has established incidentally to the pursuit of this main object ; the endless rich and suggestive thoughts which he has thrown out in such profusion by the wayside along the course of this great philosophical enterprise, — all this work is so manifest that none can fail to recognise it. It is work of the calibre of th'at which Aristotle and Newton did, though, coming in this latter age, it as far surpasses their work in its vastness of per- formance as the railway surpasses the sedan-chair, or as the telegraph surpasses the carrier-pigeon." — Johx Fiske. PLEASANT HOURS WITH THE MICROSCOPE. By Hesky J. Slack, F.C.S., F.R.M.S. EVERYBODY knows that in the middle of an ordinary flower, say a geranium or a lily, there rises a column, usually slender, with a peculiar formation at the top. In the scarlet geranium this is five-fingered, in the lilies more knobby and with three divisions. The column is the style and the organ at the top the stigma. The two constitute the pistil. In a perfect flower the observer will notice a series of whorls, forming the calyx, the corolla, a group of filaments bearing anthers and surrounding the pistil, and, lastly, the pistil itself, more or less elongated, but in all cases rising from the simple of compound ovary. It is very interesting to notice the shape of these parts in various flowers. There is great variety in the anthers and in the stigmas, but the function of the former is always to pro- duce the pollen or male element, and the stigma is adapted to receive it, and cause it to convey some of its contents to the ovules in the ovary. Pollen is of various sizes and shapes — frequently round and frequently oval, or shuttle-shaped. In the melon it is round and spiked like a horse-chestnut, and provided with circular lids at certain spots. The passion - flower {P. ccervlea) has round pollen, covered with a network pattern, and provided with large lids. The musk plant, chicory, mallow, and many others exhibit interesting varieties of shape, and the " Micrographic Dictionary," pi. 32, gives a figure of the pollen of Basella alba like a square box, with the appearance of a roimd hole in the middle of each side. Many sorts of pollen look iinder the microscope as if they had holes in them, or slits, but these appearances probably in all cases arise from those parts being thinner or more transparent than the rest. When the pollen sprouts it is from these spots, and in those which have lids the out- growth forces them open. The stigma is provided with several means of holding the pollen conveyed to it. It is roughened with glandular papilla- in the scarlet geranium, and in many plants when it is ready for the pollen it pours out a glutinous secretion. It would lead us away from our present object to describe the various contrivances by which plants avoid self-ferti- lisation, and the different waj-s, by insect help and other- wise, through which they receive pollen from other indi- viduals. Let us suppose a pollen cell deposited upon a stigma. It finds itself stimulated to put forth a slender outgrowth, which has to work its way down the style and reach the ovule it is intended to fertilise. Some plants (gourds for example) enable this process to be traced, but only skilled observers and dissectors are likely to see much. Plants of the lily family offer the easiest means of seeing the growth of pollen tubes. A little pollen should be placed on a glass slide in a drop of the fluid secreted by the stigma, lightly covered with thin glass, and steadily watched. Lilium excelsum — the pretty, sweet-scented, buff lily — and Z. Auratum are recommended. The sketches given with this paper repre.^ent what occurred with the pollen of a very beautiful plant now frequently found in conservatories, and belonging to the Ginger family. It is called Iledychium Gardnerianum. A fine specimen in full flower is a splendid sight. The one in question exhibited a broad head of flowers nearly a foot high. Each corolla consists of six segments in two rows, the sixth being the biggest, with a notched lip. The arrangement of the anther and style is shown in Fig. D. The two lobes of the anther clasp the style and lower part of the stigma, which rises above them. The filament bearirs the anthrr i"; Sept. 14, 1883.] KNOWLEDGE • 163 grooved, and the style runs up it. When a corolla is fading, a gentle pull will draw out the style, and it is found to be very slender. The filaments are deep orange red, the petals bright pale yellow. This makes an elegant contrast, and the plant exhales a delicious scent of a honey- and-ginger character. To see it to perfection it should be placed in a sitting-room window, or cool corner of a con- servatory, as soon as any of the flowers begin to open. With such treatment it will display its beauty for several days, while in a hot place the corollas that first open fade before the others arc ready, and a shabby appearance is produced. A honey fluid drops freely from the stigmas, and is very viscid. Taking some of the pollen and putting it in this fluid slightly diluted with water, generally succeeded on a bright day in inducing some of the pollen cells to sprout. A.t first a little projection was found, as at B. This was quite clear and glassy. It gradually elongated into a tube, a clear space being always in advance, which showed the vital action to be in the tube walls. They were not puslied forward by the granular matter, but that waited for their growth, and then entered into the space provided for it. A represents one of the best developed tube.-? formed in the course of a few hours ; C, a group of pollen cells and tubes, one cell emitting a tube on opposite sides. Very often, instead of forming a regular-shaped tube, the pollen cell allowed the granular matter to escape in the forms shown by two cells, one on the right and the other on the left in the figure. That on the left was a mess from the beginning — that on the right began well and c^nded in a zigzag muddle. A represents the nearest approach to the right thing, but probably the tube is more slender when it grows out of the cell under natural conditions. Botanists distinguish the outer coating of the cell as cxtine, and the inner layer as intinc. The intine forms the tube, and the granular matter undergoes a development which fits it for the work of fertilisation. The time it takes for a pollen tube to develop varies with different plants. Ultimately it gets into an ovule through a small entrance (micropyle), and proceeds to its special work more quickly or slowly, according to the nature of the plant. Sachs observes : — " The time that intervenes between pollination and the entrance of the pollen tube into the micropyle depends not only on the length of the style, which is often very considerable (as in zea and crocus), but also on the specific characters of the plants. Thus, according to Hoffuieister, while the poUen tubes of crocus vernus only requires from twentj'-four to seventy -two hours to penetrate the style, which is from five to ten centimetres in length,* those of Arum maculatum take at least ti\^e days, although the distance they have to go over is scarcely more than 2 or 3 mm.f, and those of Orclndea: require ten days, or even several weeks or months, during which time the ovules first become developed in the ovary, or even are not formed till then." When the pollen tube has reached its destination, the development it induces may be quick, or, as is the case with many trees, may take weeks, or months. In the meadow saflVon (Colchicum antnmna/e) Hoflmeister finds the pollen tubes enter at the latest at the beginning of November, but it is not tUl the May fol- lowing that the formation of the embryo begins. The experimenter with pollen grains must not expect uniform success. Operating with those of the llcdychium several failures were encountered, and on a dull day with- out any instance of success. If the pollen cell shows no inclination to make the little bulge that is the commence- ment of a tube in an hour or so, it is well to begin again with a fresli lot. The pollen grains should not be too thickly crowded, and the viscid fluid only thinned just enough to flow freely amongst them. In some plants the fluid of the stigma may not require this, and it is as well to try it in the state in which it is exuded. * 10 centimJitres = 3'937 inches. + A nlillim^tl■e — 0 039 of an inch ; 2G are rather more than 1 in. 164 KNOWLEDGE [Sept. 14, 1883. THE HARVEST MOOX. By Richard A. Proctor. {Concluded from page 157.) OXOE ill each sidereal month the moon completes the circuit of her orlnt, sliown in its mean position in Fig. :.', the lunar day varying in length as the sidereal month proceeds as the solar day varies each year, only in greater degree because a lunar day is a larger proportion of a lunar sidereal month than a solar day is of a year. For, there are only ahout 20.', lunar days in a sidei-eal month, as compared with Si]~'\ solar days in a sidereal year. Suppose the moon at O on the half of the path M O m remotest from the eye outside the disc. Then at the end of a lunar day she is at ;(. Whereas then her path above the horizon would have been represented by E O E' had she remained at O on her path among the stars, her path above the horizon would now be represented by a n a', if she stayed for a lunar day at the point ii. Her point of rising will be at k, nearly enough for such an inquiry as the present, in which we may suppose EO E' her diurnal path in one day, and a n a! her diurnal path on the next day. >She rises then at the point k on the nearer half of the farther hemisphere were her setting point,* Thus suppose the circle a c a of Fig. 2 ( foreshortened there) opened out as in Fig. 3, the nearer half taking the position a da' while the farther half takes the position ad' a'. Then /(/ay represents the arc above the horizon, while /' n./' represents the arc below tht! horizon. The equal arcs df and (/'/■' indicate the amount Viy which the time of rising precedes and the time of setting follows the mid times between a' and a and between a and a'. This arc will be found, if the projection is carefully made according to the known position of the orbit 31 0 )n Fig. 2, and the moon's motion therein, to correspond to about half an hour's diurnal motion when M 0 m has its mean position as in Fig. 2, to about twenty minutes diurnal motion when the moon's orbit has its least inclination (m 0 m' Fig. 1, p. 156,) and to about forty minutes diurnal motion when the moon's orljit has its greatest inclination (M O M', Fig. 1). Thus the day after passing the point O of her orbit, the moon rises half an hour or so (on the average) earlier than she would if she remained all the time on the equator. In this last- named case of course she would rise day after day 50| minutes later, a mean lunar day being 1 mean solar day and .50 J. minutes. But when at this particular part of her path around the star sphere, she rises not .50^ minutes later on successive nights, but only about 20:'; minutes later the sphere S Z N Z', is carried to a her highest point above the horizon, and pas?es down to the western lioiizon at k again ; then bel iw the horizon to a' and so ba';k to k again, — though in reality by this time she has reached (in her path round the stellar heavens) the mark on 0 M next beyond ». Manifestly th^n the mion rises sooner an 1 sets later in traversing the dinrnal ptth a 0 fi' than in traversing the diurnal path EOE' The straight line A- c, is in reality the foreshortening of ' the arc by which the time of rising precedes what it would be if the middle point c (on the nearer hemi-phere) of her half circuit a c a' were her rising poin*^ : k c is also the foreshortening of the arc by which her time of setting follows what it would be if c on because her movement northwards from the equator makes her rise about 30 minutes earlier than she otherwise would.f * I take tliis opportunity to correct what I find to be a prevalent error, — the supposition that the sua is due east at six o'clock in the morning, and due east at sis o'clock in the evenin.sr, all the year round. A moment's study of Fig. 2 which gives the sun's path -U 0 m among the stars (as well as the moon's), shows tliat the points occupied by the sun at six morning and evening, which of course lie along the circle POP' (since thiscii-ole divides every transverse semicircle as a c a', M C m' into equal arcs) are to the north of east and west from the vernal equinox to the autumnal, and to the south, of east and west from the autumnal equinox to the vernal. t The sun when at the corresponding part of his orbit, namely at the vernal equinox, rises earlier by about 2} minutes on successive days and sets about 24 minutes later, so that the interval between succe.osive sunrises is less at this time than a mean solar day and at Sept. U, 1883 ] » KNOWLEDGE ♦ 165 This happens once in every sidereal lunar month, and may happen more than once in each ordinary lunar month, because the sidereal month is shorter than the lunation, and if the moon is at O very soon after the beginning of a lunation she will be again at O very soon after the end of the lunation, — or pass O twice in that lunar month. But it must happen once at least. We only notice the successive risings of the moon at nearly the same hour, however, when she is conspicuous, — that is, when she is full. We have to consider then at what part of the year she will be full when at O (on the farther hemisphere of Fig. 2), crossing the equator ascendingly, or from south to north. This is a simple matter to determine. As the moon is opposite the sun when full, it follows (since her path is, nearly enough for our present inquiry the same as the sun's), that if when full she is crossing the equator ascendingly from south to north, he must be near the opposite part of their common path, or crossing the equator descendtngly from north to south. This is where the sun is at the time of the autumnal equinox. Consequently that full moon which occurs nearest to the autumnal equinox, or say to September 23 or 2-1, is the full moon which of all the fuU moons in the year rises on successive nights most nearly at the same time. [I am quite aware of the inexactness of the wording in this sentence. The moon is only full at a certain moment. But I am speaking of phenomena as seen by harvestmen and field labourers, to whom the moon is full as long as her face looks round.] The full moon which thus rises nearly at the same time on successive nights is called the harvest moon, because her so rising is often convenient to harvest men. Often however, (oftener indeed than not to the harvest men at any given spot) the harvest moon occurs at such a time as not to be of any special use in the way indicated. For instance where I am writing (on September Gth) the harvest is already gathered, — the moon being not as yet half full. Harvest moon occurs on the IGth and will be of no special advantage in this locality. Last full moon, wliich was not harvest moon, was good enough in many places to serve all the purposes of a harvest moon. To correspond to lower latitudes than ours, the point S in Fig. 2 should be taken lower and the point N higher. For higher latitudes the point S should be higher and the point N lower. For the Arctic circle the point S should be at M' the point N at m'. The same reasoning applies, with a change of seasons by half a year, to the southern hemisphere. The same figure would serve in fact if S and N be interchanged. The harvest moon is manifestly as useful in the southern hemi- sphere as in the northern, and within similar limitations. All the lunar phenomena in the .southern hemisphere are precisely the same for e\ ery latitude as for the correspond- ing latitude in the northern hemisphere, — when we simply writ(! southern for northern, and speak of spring, summer, fall, and winter, instead of naming the months (which correspond to diil'erent seasons in the two hemispheres). In the German Empire, exclusive of Hungary, last year 139,-152 railroad servants were examined as to their capacity to distinguish colours. Of these, the liaUroad lid-i'lfe says, 998, or 0"72 per cent., were found to be colour blind. Of 11 .'ill-") I examined this year, only IG were wholly and 273 partly colour-blind — 0 28 per cent, of the whole number. its shortest, while the interval between successive sunsets is greater than a mean solar day, and at its longest. THE CHEMISTRY OF COOKERY. XVIII. Bv W. Mattieu Williams. I FIND that Sir Henry Thompson, in a lecture de- livered at the Fisheries Exhibition, and now reprinted, has invaded my subject, and has done this so well that I shall retaliate by annexing his suggestion, which is that fish should be roasted. He says that this mode of cooking fisli should be general, since it is applicable to all varieties. I fully agree with him, but go a little further in the same direction by including, not only roasting in a Dutch or American oven before the fire, but also in the side-ovens of kitcheners and in gas-ovens, which, when used as I have explained, are roasters, i.e., they cook by radiation, without any of the drying anticipated by Sir Henry. The practical housewife will probably say this is not new, seeing that people who know what is good have long been in the habit of enjoying mackerel and haddocks (especially Dublin Bay haddocks) stufied and baked, and cod's heads similarly treated. The Jews do something of the kind with halibut's head, which they prize as the greatest of all piscine delicacies. The John Dory is commonly stufi"ed and cooked in an oven by those who understand his merits. The excellence of Sir Henry Thompson's idea consists in its breadth as applicable to alljhh, on the basis of that fundamental principle of scientific cookery on which I have so continually and variously insisted, viz., the retention of the natural juices of the viands. He recommends the placing of the fish entire, if of moderate size, in a tin or plated copper dish adapted to the form and size of the fish, but a little deeper than its thick- ness, so as to retain all the juices, which by exposure to the heat will flow out ; the surface to be lightly spread with butter and a morsel or two added, and the dish placed before the fire in a Dutch or American oven, or the special apparatus made by Burton of Oxford street, which was exhibited at the lecture. To this I may add, that if a closed oven be used. Rum- ford's device of a false bottom, shown in Fig. 3, of Xo. 11 of this series, should be adopted, which may be easily done by simply standing the above-described fish dish, with any kind of support to raise it a little, in a larger tin tray or baking dish, containing some water. The evaporation of the water will prevent the drying up of the fish or of its natural gra\y ; and if the oven ventilation is treated with the contempt I have recommended, the fish, if thick, will be better cooked and more juicy than in an open-faced oven in front of the fire. This reminds me of a method of cooking fish which, in the course of my pedestrian travels in Italy, I have seen practised in the rudest of osterias, where my fellow guests were carbonari (charcoal burners) waggoners, road-makuig navvies, itc. Their staple " "ia^rro," or fast-day material, is split and dried cod-fish imported from Korway, which in appearance resembles the hides that are imported to the Bermondsey tanneries. A piece is hacked out from one of these, soaked for awhile in water, and carefully rolled in a piece of paper saturated with olive oil. A hole is then made in the white embers of the charcoal tire, the paper parcel of fish inserted and carefully buried in ashes of selected temperature. It comes out wonderfully well- cooked considering the nature of the raw material. Luxurious cookery en papiUote is conducted on the same principle and especially applied to red mullets, the paper being buttered and the sauce enveloped with the fish. In all these cases the retention of the natural juices is the primary object. 166 ♦ KNO\A/LEDGE • [Sept. 14, 1883. I should add that Sir Henry Thompson directs, as a matter of course, that the roasted fish should be served in the dish wherein it was cooked. He suggests that " portions of fish, such as fillets, may be treated as well as entire fish ; gar- nishes of all kinds, as shell-fish, &c., may be added, flavour- ing also with fine herbs and condiments according to taste." " Fillets of plaice or skate with a slice or two of bacon; the dish to be filled or garnished with some previously-boiled haricots," is wisely recommended as a savoury meal for a poor man, and one that is highly nutritious. A chemical analysis of sixpennyworth of such a combination would prove its nutritive value to be equal to fully eighteen- pennyworth of beefsteak. Some people may be inclined to smile at what I am about to say, viz , that such savoury dishes, serving to vary the monotony of the poor hard-working man's ordi- nary fare, aftbrd considerable moral, as well as physical, advantage. An instructive experience of my own will illustrate this. When wandering alone through Norway in 18.56 I lost the track in crossing the Kyolen fjeld, struggled on for twenty-three hours without food or rest, and arrived in sorry plight at Lorn, a very wild region. After a few hours' rest I pushed on to a still wilder region and still rougher quarters, and continued thus to the great Jostedal table-land, an unbroken glacier of -500 square miles ; then descended the .Jostedal itself to its opening on the Sogne fjord — five days of extreme hardship with no other food than flatbrod (very coarse oatcake), and bilberries gathered on the way, varied on one occasion with the luxury of two raw turnips. Then I reached a comparatively luxurious station (Rounei), where ham and eggs and claret were obtainable. The first glass of claret produced an effect that alarmed me — a craving for more and for stronger drink, that was almost irresistible. I finished a bottle of St. Julien, and nothing but a violent elibrt of will pre- vented me from then ordering brandy. I attribute this to the exhaustion consequent upon the excessive work and insuflicient unsavoury food of the pre- vious five days ; have made many subsequent observa- tions on the victims of alcohol, and have no doubt that overwork and scanty, tasteless food is tl;e primary source of the craving for strong drink that so largely prevails with such deplorable results among the class that is the most exposed to such privation. I do not say that this is the only source of such depraved appetite. It may also be engendered by the opposite extreme of excessive luxurious pandering to general sensuality. The practical inference suggested by this experience and these observations is, that speech-making, pledge-signing, and blue-ribbon missions can only effect temporary results unless supplemented by satisfying the natural appetite of hungry people by supplies of food that is not only nutri- tious, but savoury and varied. Such food need be no more expensive than that which is commonly eaten by the poorest of Englishmen, but it must be far better cooked. Comparing the domestic economy of the poorer classes of our countrymen with that of the corresponding classes in France and Italy (with both of which I am well ac- quainted), I find that the raw material of the dietary of the French and Italians is inferior to that of the English, but a far better result is obtained by better cookery. The Italian peasantry are better fed than the French. In the poor osterias above referred to, not only the Friday salt fish, but all the other viands were incomparably better cooked than in corresponding places in England, and the variety was greater than is common in many middle-class houses. The ordinarysupper of the " roughs " above-named was of three courses, first a " miiiestra," i.e., a soup of some kind, continually varied, or a savoury dish of mac- caroni ; then a ragout or savoury stew of vegetables and meat, followed Ijy an excellent salad ; the beverage a flask of thin but genuine wine. When I come to the subject of cheese, I will describe their mode of cooking and using it. My first walk through Italy extended from the Alps to Naples, and from Mei-sina to Syracuse. 1 thus spent nearly a year in Italy during a season of great abundance, and never saw a drunken Italian. A few years after this I walked through a part of Lombardy, and found the little osterias as bad as English beershops or low public- houses. It was a period of scarcity and trouble, " the three plagues," as they called them — the potato disease, the silkworm fungus, and the grape disease — had brought about general privation. There was no wine at all ; potato spirit and coarse beer had taken its place. ]\Iono- tonous " polenta," a sort of paste or porridge made from Indian corn meal, to which they give the contemptuous name of " miserabile," was then the general food, and much drunkenness was the natural consequence. THE MORALITY OF HAPPINESS. By Thomas Foster. {Continued from page 138). THE EVOLUTION OF CONDUCT. Chaptek III. BUT within a race and in the relations of the race to other races, there are causes which influence the evo- lution of conduct. Members of a race fight out the contest for existence not alone but more or less in the presence of their fellows and in the presence of members of other races. Each individual in providing for liis own wants or for his own defence aflects more or less others, either of his own race or of other races, in their efforts to defend or sustain their lives. Very often, as Mr. Herbert Spencer quaintly puts it, " a successful adjustment by one creature involves an unsuccessful adjustment made by ^another creature, either of the same kind or of a different kind." The lion and the lamb, for instance, already anticipate the millen- nium ; but the lion adjusts matters so much more success- fully than the lamb, as to take the outside place ; the lamb lies down with the lion, but — inside. Among all races, herbivorous as well as carnivorous, similar relations exist. The more vigorous get the better food, food which the weaker contend for in vain or have to resign, when obtained, to superior strength. Within one and the same race there is still the same law. The stronger monopolise, if they can, the feeding grounds of the race. The weaker, whether originally so, or become so through age or disease, succumb in greater numbers than the stronger in the struggle for existence. Only, while the death of those weak through age does not affect the evolution of the race, the greater mortality among those originally weaker than the rest modifies the race qualities. In these contests conduct plays an important part. Unnecessary contests involve unnecessary risks. That conduct must prevail best in the long run, and there- fore that conduct must eventually be evolved and developed, by which adjustments for the advantage of one creature do not needlessly interfere with adjustments for the advantage of other creatures. If we imagine a carnivorous animal carefully limiting his search for animal food to his requirements, not killing where there was no occasion, and keeping carefully all food he had once obtained, we see that his chances in the life struggle would Sept. U, 1883.J * KNOWLEDGE L67 be better than those of a carnivore of the same race who killed whenever he got the chance. It would be more the interest of other creatures (as for instance those who wanted the same sort of food) to eliminate the carnivore of the latter sort, than to remove the more prudent member of the race. In the long run this would tell even among the lower animals. But as we approach the relations of men to men and men to animals, we see more oljviously how conduct in which the interests or the wants of others are considered is safer in the long run, more conducive (in inindreds of ways more or less complex) to prolonged existence, than conduct in which those interests and wants are neglected. Hence there will be a tendency, acting slowly but surely, to the evolution of conduct of the former kind. More of those whose conduct is of that character, or approaches that character, will survive in each genera- tion, than of those whose conduct is of an opposite cha- racter. The difference may be slight, and therefoie the effect in a single generation, or even in several, may also be slight ; but in the long run the law must tell. Conduct of the sort least advantageous will tend to die out, because those showing it will have relatively inferior life chances. Mr. Spencer seems to me to leave his argument a little incomplete just here. For though he shows that conduct avoiding harm to others, in all races, must tend to make the totality of life larger, this in reality is insufficient. He is dealing with the evolution of conduct. Now, to take a concrete example, those of the hawk tribe who left little birds alone, except when they had no other way to keep themselves alive but by capturing and killing them, would help to increase the totality of life, by leaving more birds to propagate their kind than would l)e left if a more whole- sale slaughter were carried out. But this of itself would not tend to develop that moderation of hawk character which we have imagined. The creatures helped in the life struggle would not he the hawks (so far as this particular increase in the totality of life was concerned) but the small birds ; and the only kind of moderation or considerateness encouraged would be shown in a lessening of that extreme diffidence, that desire to withdraw themselves wholly from hawk society, which we recognise among small birds. But if it be shown that the more wildly rapacious hawks stand a greater chance of being destroyed than those of a more moderate character, then we see that such moderation and steadine.ss of character is likely to be developed and finally established as a characteristic of the more enduring races of hawks. And similarly in other such cases. It is, however, in the development of conduct in the higher races only, that this comparatively elaborate law of evolution is clearly recognised. Among savage races we still see apparent exceptions to the operation of the rule. Individuals and classes and races distinguished by ferocity and utter disregard of the " adjustments " of others, whetlicr of their own race or of different races, seem to thrive well enough, better even than the more moderate and considerate. Forces really are at work tending to eliminate the more violent and greedy ; but they are not obvious. As society advances, however, even this seeming success of the rapacious is found to diminish, though as yet there has been no race or society from which it has been actually eliminated. Conduct which is imperfect, conduct characterised by antagonisms between groups and antago- nisms between members of the same group, tends to be more and more reduced in amount, by the failure or by the elimination of those who exhibit such conduct. What is regarded as gallant daring in one generation is scorned as ferocity in a later one, resisted as rapacious wrong-doing yet later, and later still is eliminated cither by death or nearly as effectually (when indirect as well as direct conse- quences are considered) by imprisonment.* As violence dies out, and as war diminishes, — which usually is but violence manifested on a larger scale, — the kind of conduct towards which processes of evolution appear to tend, " that perfect adjustment of acts to ends in maintaining individual life and rearing new individuals, which is effected by each without hindering others from effecting like perfect adjustments," will be approached. How nearly it will ever be attained by any human race — Qnien sabe ? One further consideration, and we have done with the evolution of conduct, the right understanding of which is essential to the scientific study of conduct. The members of a society while attending to adjustments necessary for their wants or interests, may not merely leave others free to make their adjustments also, but may help them in so doing. It is very obvious that conduct thus directed must tend" to be developed. As IMr. Spencer says, such conduct facilitates the making of adjustments by each and so in- creases the totality of the adjustments made and serves to render the live of all more complete. But besides this (as he should also have shown, since it is an essential part of the evolution argument), it tends to its own increase : for, being essentially mutual, conduct of this kind is a favourable factor in the life struggle. We have next to consider what, seeing thus the laws according to which conduct is evolved, we are to regard as good conduct and bad conduct. (To be continued.) "The world embraces not only a Newton, but a Shake- speare— not only a Boyle, but a Raphael — not only a Kant, but a Beethoven — not only a Darwin, but a Carlyle. Not in each of these but in all, is human nature whole. They are not opposed, but reconcilable^not mutually exclusive, but supplementary." — John Tyndall. " When the Hebrew prophet declared that ' by him were laid the foundations of the deep,' but reminded us, ' Who by searching can find him out 1 ' he meant pretty much what Mr. Spencer means when he speaks of a power that is inscrutable in itself, yet is revealed from moment to moment in every throb of the mighty rhythmic life of the universe." — John Fiske. " Joyfully accepting modern science, and loyally follow- ing it without the slightest hesitation, there remains ever recognised still a higher ilight, a higher fact, the eternal soul of man, (of all else, too,) the spiritual, the religious, which is to be the greatest office of scientism, in my opinion, and of future poetry also, to free from fables, crudities and superstitions, and launch forth in renewed faith and scope a liundred-fold. ... To me the crown of savantism is to be, that it surely opens the way for a more splendid theology and for ampler and diviner songs." Walt Whitman. The Tricycle.— The article on " High Wheels v. Low Wheels" referred to by Mr. John Browning in this week's Knowledge appeared in No. 8, Vol. II., of G. L. Hillier's Journal. * JIany overlook the bearing of imprisonment on the evolution of conduct,— its influence (when long terms are considered) in diminishing the numerical increase of particular types of character and therefoi-o in diminishing the quantity of particular forms of conduct. 168 KNOWLEDGE ♦ [Sept. 14, 1883. EVOLUTION OF HUMAN PHYSIOGNOMY. By E. D. Cope. {Continued from parje 137.) IF we now examine the leading characters of the pliy- siognomy of three of the principal human sub-species, the Negro, the Mongolian, and the Indo-European, we can readily observe that it is in the two hrst-named that there is a predominance of the quadrumanous features which are retarded in man ; and that the embryonic characters which predominate are those in which man is accelerated. In race description the prominence of the edges of the jaws is called prognathism (forward jaws), and its absence or- thognathism (straight jaws). The signilicance of the two lower race characters as compared with those of the Indo- European, is as follows : — Xegro. — Hair crisp (a special character), short (quadru- manous acceleration); prognathous (quadrum. accel. ); nose flat, without bridge (quadrum. retard.)*; malar bones pro- minent (quadrum. accel.) ; beard short (quadrum. retard.) ; arms longer (quadrum. accel.) ; extensor muscles of legs small (quadrum. retard.). i^ Fig. 5. — Profile of a Luchatze negro woiiian, showing deficient bridge of nose and chin, and elongate facial region and progna- thism. Jloni/olian. — Hair straight, long (accel. ); jaws progna- thous (([uadrum. accel.) ; nose flat or prominent with or ■without bridge ; malar bones prominent (quadrum accel ) ; beard none (embryonic) ; arms shorter (retard.) ; e.xtensor muscles of leg smaller (quad, retard.). Indo-European. — Hair long (accel.) ; jaws orthogna- thous (embryonic retard.) ; nose (generally) prominent ■with bridge (accel.); malar bones reduced (retard.) ; beard long (accel.); arms shorter (retard.); extensor muscles of the leg large (accel.). The Indo-European race is then the highest by virtue of the accelleration of urowth in the development of the muscles by which the body is maintained in the erect position (extensors of the leg), and in those important ele- ments of beauty, a well-developed nose and beard. It is also superior in those points in which it is more embryonic than the other races, viz., the want of prominence of the jaws and cheek-bones, since these are associated with a greater prominence of the cerebral part of the skull, * In the Bochiman^:, the flat na=al bones are codssified with the adjacent elements, as in the apes (Thulie). increased size of cerebral hemispheres, and greater intel- lectual power. A comparison between the two sexes of the Indo-Euro- peans expresses their physical and mental relations in a definite way. I select the sexes of the most civilised races, since it is in these, according to Broca and Topinard, that the sex characters are most pronounced. They may be con- trasted as follows. The numbers are those of the list on page 136 already used. I first consider those which are used in the tables of embryonic, quadrumanous, and race characters : — iI.\LE. Female. /. The General Form. 2. .Shoulders square. Shoulders sloped. 4. Waist less constricted. Waist, more constricted. 5. Hips narrower. Hips wider. *t. Legs longer. Legs shorter. S. Muscles larger. lluscles smaller. II. The Integuments, etc. 10. More hair on body, that of Less hair on body, that of head head shorter; beard. longer; no beard. 12. Skin rougher (generally). Skin smoother. III. The Head and Fate. 10. Superciliary ridges more Superciliary ridges low. prominent. Eyes often larger. 22. Eves often smaller. Fig. 6. — Face of another negro, showing flat nose, less progi a* thism and larger cerebral region. From Serpa Pinto. The characters in which the male is most like the infant are two, viz , the narrow hips and short hair. Those in which the female is most embryonic are five, viz., the shorter legs, smaller muscles, absence of beard, low super- ciliary ridges, and frequently larger eyes. To these may be added two others not mentioned in the above lists ; these are (l)the high-pitched voice, which never falls an octave as does that of the male ; and (2) the structure of the generative organs, which in all mammalia more nearly resemble the embryo and the lower vertebrata in the female than in the male. Nevertheless, as Bischoft' has pointed out, one of the most important distinctions between man and the apes is to be found in the external reproductive organs of the female. From the preceding rapid sketch the reader will be able to explain the meaning of most of the peculiarities of face and form which we meet with. Many persons possess at least one quadrumanous or embryonic character. The strongly convex upper lip frequently seen among the lower classes of the Irish is a modified quadrumanous character. Many people, especially those of the Sclavic races, have more or less embryonic noses. A retreating chin is a Sept. IJ, 1^83. • KNOWLEDGE ♦ 169 marked monkey character. Shortness of stature is mostly due to shortness of the femur, or thigh ; the inequalties of people sitting are much less than those of people standing. A short femur is embryonic ; so is a very large head. The faces of some people are always partially emVjryonic, in having a short face and light lower jaw. Such faces are still more emVjryonic when the forehead and eyes are pro- tuberant. Retardation of this kind is frequently seen in of the monkeys. The gluteus muscles developed in the lower races as well as in the higher, distinguish them well from the monkeys with their flat posterior outline. Fig. 7. — Ksequibo Indian women, showinj^ tlio following pecu- liarities : deficient bridge of nose, prognathism, no waist, and (the right-hand figure) deficiency of stature through short femur. From photographs by Endlich. children, and less frequently in women. The length of the arms would appear to have grown less in comparatively recent times. Thus the humerus in most of the Greek statues, including the Apollo Belvidere, is longer than those of modern Europeans, according to a writer in the "Bulletin de la Socictc d'Anthropologie," of Paris, and rc- resembles more nearly that of the modern Nubians than any other people. This is a quadrunianous condition. The miserably developed calves of many of the savages of Australia, Africa, and America, are well known. The fine swelling gastrocnemius and soleus muscles characterise the highest races, and are most remote from the slender shanks : Fig. 8. — Portrait of Satanta, a late chief of the Kiowas (from the Red Eiver of Texas), from a photograph. The predominance of the facial region, and especially of the malar bones, and the absence of beard, ai'e noteworthy. Some of these features have a purely physical signid- cance, but the majority of them are, as already remarked, intimately connected with the development of the mind, either as a cause or as a necessary coincidence. TRICYCLES. THE article in Knowledge (No. 96) from the able pen of Mr. Browning prompts me, a rider of some fifteen years' experience of both bicycle and tricycle, to address you a few remarks upon the same subject, as I fear that Mr. Browning's deductions have led him to enounce theories concerning tricycles which, if acted upon by the novice, will assuredly cause him to become disgusted with his first eftbrts. Small wheels are a great mistake from every point of view, and it is far easier to propel a machine with 50-inch wheels geared down to, say, i'2, than it would be to drive a machine of even less weight with 36-inch wheels. It is absurd to talk of anyone being content with a speed of four or rive miles an hour, as such a pace can only lead to the rider becoming disgusted with the affair altogether. It is as easy to ride a machine with large wheels at tlie rate of seven or eight miles an hour as it would be to ride one with 36-inch wheels at the rate of four miles an hour ; nay, easier. A man perched upon a machine with such small wheels looks as if riding a child's go-cart, and is hailed with deri- sion by the drivers of carts, who are much more likely to give way to a machine that they can see is a vehicle than 170 * KNOWLEDGE . [Sept. 14, 1883. to take any note of a thing that creeps along at the rate of four miles an hour and has toy wheels. To a rider of even average strength there are very few hOls that need be walked, and those only the very steep ones, and it is a mistake to inculcate the impression that one mile in ten has to be walked. I have a great regard for Mr. Browning, but feel compelled to endeavour to set aside such fallacies as this, as I think they must serve as a deterrent to would-be cyclists. The fact that Mr. Broioning Jinds tltis to he the ease is in itself enoi'gh to condemn the ti/pe of machine he advocates, as it is certainly not my experience, nor is it the ex- perience of anyone I know, neither will it be the experi- ence of anyone who possesses even an ordinary amount of strength. I know an aged clergyman, very nervous and very feeble. When he first commenced to ride, he, of course, found it rather trying to ride the steepish hills in the north of London, but now he goes on his way, and very seldom walks up any but the very steepest of hills. Anyone who wishes to begin to ride a tricycle will inevitably ere long strive to improve his pace, no matter how meek his preliminary aspirations may be ; Vjut if he starts with a very small wheel he will never be able to improve his speed, but will be a perpetual snail along the road until he goes to the further expense of a new machine. If, on the other hand, he at the outset goes in for a machine that will travel fast at pleasui-e, he can ride it as fast as he pleases or as slow as he pleases. It follows as a mere matter of course that a machine that can he driven at a very high rate of speed must from that very fact he an easy running machine, as otherwise it could not be driven at a fast speed. Therefore, this is the machine to select, and while going slowly the utmost ease of propulsion is existent ; and it is, at the same time, always possible to improve the speed as experience is gained. To recapitulate, a fast machine imi&t ipso facto be an easy machiue to propel. I fully endorse Mr. Browning's view as to lightness, as I have always urged this as a sine qua non — i.e., for a not too heavy rider, and I myself ride an Imperial Club which weighs under 60 lb., and yet it has -50 in. wheels. This machine is geared up to a 60 in., and still I ride all the hills I come to, seldom or ever dismounting ; and I have several times ridden nearly, and even over, 100 miles a day. This machine is as easy to drive and as fast as a bicycle, and I can always hold my own on the road with anything, and yet when simply riding slowly I can move along with the slightest possible exertion. Nothing wearies so much as rapid pedalling, and nothing looks so ungraceful ; and it is obvious that with small wheels the pedalling must be very rapid indeed to get any pace at all. With my machine, however, my feet pass very slowly round and round, and still the gearing up (which, of course, consists in having the lower chain wheel larger than the top one ; so that the wheels go round faster than the feet and the pedals) always keeps up a fair pace, and this is attained without fast pedalling. The machine that I am sure will give the best result will be one weighing little, and that has wheels no less than 48 in. in diameter, and if this be fitted with the recently- perfected " speed-gear," either a fast speed or a low speed can be used for the level or for mounting hills, as the case may be. I fear that I have already trespassed too far upon your space, but there are several other points which might have been dilated upon for the advantage of your readers, many of whom are absolutely certain to " go in " for tricycles when they realise how extremely useful they may be made for exploring the country and for means of exercise. Sigma. WIXDS AS PROJECTILES. MJ. C. HOUZEAU, referring to observations on • the formation of clouds made b\- jM!M. Lancaster and Tempel, and by Mr. R. T. Armstrong, communicates to Ciel et Terre an article on " The Nature of Wind." He remarks that although wind is air in movement, the move- ment cannot be likened to that of a liquid sheet of vast extent, nor to that of a vein of liquid, nor to that of the sea- waves. If the air flow were in vast continuous sheets, its pressure would only vary slightly and gradually over the area it acted upon. It would not exhibit abrupt changes and intermittences. The aspect of a field of wheat on which the wind blows suffices to show that the air neither moves as a sheet nor as a vein. In squalls there is often complete repose between the blasts. On Nov. 11, 1878, M. Houzeau witnessed a remarkable instance of this about 200 kilometres south of the Lizard. The pufTs were of extreme violence, w-hile in the intervals the air scarcely moved. These intermittences, although reminding him of waves bursting on a shore, could not be considered like them. Between two succeed- ing sea-waves there is no water ; the hollow is filled with air ; if it were occupied with the former fluid the inter- mittence would give place to continuous action. Cut between the wind blasts there is air, which is not carried on with them. M. Houzeau does not deny that there is often a general movement of translation of air, as a proper motion, or as the result of blasts dragging it with them ; but the phenomenon appears to him to consist of the move- ments of detached masses, which, to give precision to the idea, he compares with projectiles traversing the general mass of the atmosphere. The limited area to which storm- action is often confined, bending some trees violently and not aflecting their neighbours, shows that these aerial projectiles have little breadth. Another fact, he con- siders, points to the same conclusion, for, if when the wind is strong, its pressure per square metre is observed on anemometers of dilTerent sizes, the larger ones show the highest proportional results. The greater the surface, the greater the chance of its receiving the shock of the projectiles. If there were no divisions in the air-streams, the pressure per square metre would be independent of the dimensions of the anemometer plates. The friction of air is so slight that there is nothing astonishing in the feeble entraining power of the pro- jectiles. What is less easy to conceive is the nature of the force which impresses upon sharply-defined portions of air the furious velocities which sometimes animate them. But before attacking this question Mr. Houzeau advises study- ing what may be called the texture of the air in tempests, and to ascertain the number, dimensions, and relative spacing of these projectiles which traverse the atmosphere as a kind of mitraille. If, as M. Houzeau states, it is a general fact in storms that large anemometers show a much greater average pres- sure than small ones, it is evident that calculations founded upon the velocities of the cups usually employed give no indication of the resisting power required to prevent a recurrence of such incidents as the Tay Bridge disaster. But M. Houzeau should indicate the experiments upon which he bases this statement, as exactly the opposite is affirmed by other persons. Sept. 14, 1883.] ♦ KNOWLEDGE ♦ 171 DAN GEES OF SEA-BATHING. WE have recently had evidence of the three chief dangers of sea-bathing. First it was a case akin to the fatal bath of Alexander the Great, where death was caused by suddenly plunging the body, when hot and tired, into very cold water. Then came a case in which cramp afl'ecting all the lower part of the body caused death. Lastly, at Eastbourne, on Sunday, August 26, a young man was drowned through bathing too soon after a full meal. It is singular how people underestimate the nature of the trial to which they expose their bodies in sea-bathing. The trial is indeed one which can be borne safely by any one in average health, under reasonable con- ditions. But even for the healthy it involves a shock, the reaction from which is what does good, not the shock itself, which so far as it goes tends to lower the vital energies. But to plunge into cold water when the vital energies are already below par, or under conditions which are likely to overtax the force of reaction is dangerous in the extreme. Another dangerous practice is that of staying in the water too long. To sea-bathing for the health Hesiod's old saying may be applied. Half is better than the whole, when the whole means the full time which the bather can stay in the water without suflering. If a man can bear twenty minutes in the water he will do well to take but ten ; if he can bear ten, to take but five. When he stays in the water for the shorter period he comes forth braced lip and invigorated ; when he keeps in as long as he can bear the cold he comes out at last tired and wearied, feels depressed and languid for hours or perhaps for the rest of the day, and probably sutlers from headache or other evidence that the ner\ous energies have been overtaxed. — Neivcdstle Chronicle. ©ijitorial (goeieiip. It is hard when some quality — mental, moral, or phy- sical— on the strength of which any one has come before the public — is specially criticised as the one quality in which such person is deficient. For instance, let us sup- pose that when Disraeli told his constituents that " he 'stood' on his head" some one had rudely remarked that that was his weakest place : this would have been as hard as it would have been untrue. So, if I were told in connection with my teachings in astronomy, that astronomy is just the subject in which I am most ignorant, I suppose I should not be greatly pleased : even if I were modest enough to admit the soft impeachment, I should Ije pained at the thouglit that my special ignorance on that subject had remained so long unknown to me. It occurs to me to note, l)y tlie way, that only a day or two since I came across a passage in the Ollaim Free Press from which I learnrd that ]Mr. Wiggins, the predictor of the famous storm which was to have destroyed every ship at sea last March, but somehow failed to do so, had pointed out so far back as 1S7G my ignorance of astronomy. I had lectured at St. John's, N.B., — I remember well that mild Christmas time (where I had expected intense cold, but walked from my lecture, in evening dress, with over- coat over my arm); and I remember too my kindly greeting there. I had said in the course of my lecture that the moon has very littk; if any atmosphere. But next day (wlien ] was half way towards New York) Sir. Wiggins obser\ ed that as the moon reflects sunlight she must have an atmosphere of considerable density, and also showed how ignorant I must be not to know that So he found out that when I slightly criticised his storm-prediction, casually referring to knavery or folly in explanation thereof — I had been lying in wait six or seven years to attack him. "All this time," he says "the Professor has lain in his lair"! &c. It will be seen that I know or ought to know how painful must be a charge of shortcoming in some quality where one had imagined oneself rather excep- tionally well off. I can sympathise therefore with Mr. Oscar Wilde when a play of his is condemned for vulgarity and coarseness by the Americans whom he sought to soften and harmonise. And now more distressing news still comes from across the Atlantic. A person went over there not on the strength of head or understanding (other than legs and feet) but trusting to beauty of limb and charm of manner; and here is the Courier Journal, of Louis\-ille, Ky., rejoicing that those hideous limbs and monstrous hands and feet are gone from out the land. But the Kentuckian — who usually sits on five chairs at once, so long is he of limb, and so expansive in manner — is unusually critical about feminine hands and feet. The ladies of Kentucky are singularly favoured by nature in that respect, insomuch that though the feet (for in- stance) of an average St. Louis lady would not be thought large in England it is a standing joke in Louisville, Ky. that St. Louis shoes sent to the Centennial Exhibition, were by a natural mistake placed in the canoe department. Still the Kentuckian paper has not been over-polite to our English visitor, who rather "stood" on her feet. Mr. Rojieike, whose " Artistic and Literary Corre- spondence " I am willing enough to advertise gratis, seems determined to show me that I ought to recognise the value of his agency for distributing press notices to those men- tioned in them. I was hard-hearted enough to say that these were things to be avoided rather than sought. He suggested in reply that though I might receive numbers of ordinary notices from publishers, I might not see those which attacked me, and he implied that these ■were more ninnerous by far than I probalily imagined. Xow my own idea has been, and is, that that ancient institution {vide Job passim) the "d — d — (/e(fr good-natured friend," had long since anticipated Mr. Romeike's agency, and that I need not fear lest anything unpleasant about myself should fail to reach me. But Mr. Romeike thinks dif- ferently ; so, though I had expressed no burning desire to see such notices, he has sent me all he has come across, — to wit, within the last six months two out of seven (all the seven having reached me earlier through the D. G. X.). The last he sends me is ratlier pleasant than otherwise, only Mr. Romeike carefully underlines (courteous gentle- man that he is) the parts which he thinks likely to hurt. Here is the passage, as it appears in Life, except only that those words wliich the gentlemanly !Mr. Romeike under- lines for my benefit appear here in italics : — " A paper on ' Poker Principles and Chance Laws,' by Sir. R. A. Proctor, whose right to discuss this topic, otherwise indis- putable, would be fortilied, in case it needed fortification, by his famous victory over 'Boss.' Vnhappilij Mr. Proctor's numerous iiccomplishments do not incUtde an accurate knozvledi/e of Ms native tongue. In this article, for instance, he talks of ' the verhiage of Poker' and of 'astrological ierbik magnitude, will disappear at the bright limb of the moon, at an angle of 30" from her vertex, to reappear at her dark limb at a vertical angle of 243^ at 1 h. 19 m. the next morning. The moon occupies all to-day and a great deal of to-morrow in traversing Aquarius, passing into Pisces about 5 a.m. on Sunday, the 16th. It is 4 a.m. on the 19th before she has performed her path across this great constellation and entered Aries. She travels across Aries until 7 p.m. on the 20th, when she passes into the confines of Taurus, her passage across which takes until 6 a.m. on the 23rd. At this hour she enters the northern boundary of Orion, which she occupies twelve hours in crossing, emerging into Gemini about 6 p.m. At noon on the 25th she enters Cancer, which she quits for Leo between 5 and 6 o'clock in the morning on the 27th. At midnight on that day she descends into Sextans. We there leave her. Sept. U, 1883.] ♦ KNOWLEDGE ♦ 173 " Let Knowledge grow from more to more." — Alfeed Tennyson. Only a small proportion of Letters received can possibly he in- serted. Corresponde:its must not be offended, therefore, should their letters not appear. All Editorial comm^mications should be addressed to the Editor of Knowledge; all Business communications to the Poblishers, at the Office, 74, Great Queen-street, W.O. If this is not attended to DELAYS arise for WHICH THE EDITOR IS NOT KESPONSIBLF. All Remittances, Cheques, and Post Office Orders should be made payable to Messrs. Wymak & Sons. The Editor is not responsible for the opinions of correspondents. No communications are answered by post, EVEN though stamped and directed envelope be enclosed. THE BENNETT BATTERY. [924] — My attention has been calleil to a paragraph in your issue of Sept. 1st, which contains several grave misstatements in connection with the voltaic battery which bears my name. You are, of course, at liberty to publish the results of honest experi- ments made with the battery, and to remark thereon in an impartial spirit, but you are not entitled to publish distinct untruths, with tlie apparent object of injuring it in public estimation. Your contributor states that the battery gives forth an odour of rotten eggs to such an extent as to contaminate the air, and attributes the smell to sulphuretted hydrogen (!) As a matter of fact, the battery is quite odourless, and cannot, under any circumstances, emit sulphuretted hj-drogen, for the very sufficient reason that there is no sulphur in any form in the cell. Your contributor .states that the cell is of no use whatever to anybody. Perhaps you are unaware of the fact that it is in exten- sive use in Scotland and elsewhere for several purposes, and is giving better results than the Leclancbe. An exhaustive comparative trial has licen in progress, on a jn-actical scale, since March last, by independent persons in Glasgow, with the result, so far, altogether in favoiu' of my battery as compared with the Leclancbe. These results, in a tabulated form, are to be pub- lished on the completion of the experiment, which has been prolonged owing to the durability of the battery. The bias of your contributor is evident from the fact that he makes an equally untrue statement regarding the Leclancbe battery. He states that, even with hard work, the agglomerate blocks last two years. All practical men know this to be false. With such work as they get in the Glasgow Central Telephone Exchange, agglomerate blocks last from three to four months, and then require complete renewal. Sept. 5, 1883. A. B. Bennett. [J[y remarks on the Bennett cell were based on experiments made upon it some months since. The odour of SII.. was unmis- takable, and I attributed it to the presence of impurities. The cell did not show such good results as were obtainable from the six-rod agglomerate Leclancbe, and I could not, thorofore, recom- mend amateurs to adopt the cell. Practical men would judge for themselves. May be the invention of Mr. Bennett has been lately improved. If so, I shall be glad to hear from him, and he will find that no journal is more ready to bestow praise where it is deserved than Knowledge. Anent the durability of the agglo- merate, all practical telegraph men praise it highly for what it has done and is still doing. I could have shown Jlr. Bennett a number of blocks which had been working hard, night and day, for upwards of eighteen months. The resistance of a telephone line is very low in comparison with the average telegra])h line, and that may help to account for the bad result Mr. Heiuictt has obtained. Or it may be that he has had a largo number of short circuits drawing upon one battery at a time. — W. Slinod.] SMALL WHEELS FOR TRICYCLES. [925] — I am obliged for the reminder of your rorrespondent "J. S." that the "Sun and Planet" is a small-wheeled bicycle gearcd-up. I have seen the machine, though I have never cidden it as I have the "Facile." If the merits of the machine are great, it is a pity it is not more advertised, as, being a rotary machine, some would prefer it to any machine with a lever action. As "J. S." suggests, there may be a great future for small geared-up safety bicycles. Will " J. S." oblige me by stating the true weight, of his own knowledge, of his machine ? I am glad that so thoughtful a rider agrees with my conclusions as to the desirability of reducing the size of the wheels of tricycles. Since my papers on this subject have appeared in Knowledge, I have received assurances from the following well-known riders that they agree with my conclusions : — Messrs. Marriott, Nixon, Letch- ford, S. Salmon, A. Salmon, and Howard, and also Messrs. Grace and Bennett. It must be recollected that all these riders have tried first large wheels and then small, and have proved small to be the best. John BROWNnNG. A CURIOUS PHENOMENON. [926] — Can any of my brother readers of Knowledge offer a feasible explanation of a very remarkable phenomenon which I witnessed at lOh. 35m. p.m. on Tuesday, August 28 ? I was just coming out of my observatory when, on the E.N.E. point of the horizon beneath the Pleiades, I saw a bright light. My first thought was that the moon was rising, but an instant's reflection sufficed to remind me that she would not be up for the next two hours. As I watched the light becoming brighter and brighter, I saw that it threw a kind of radial illumination upward, the effect of which I have tried to reprodncc in the accompanying rough little sketch. As will be seen, a few distant cumulo-stratus clouds, close to the horizon, crossed it. For a moment I imagined that I was viewing the apparition of a new and most glorious comet ; but, as I watched, the "tail" disappeared, and what would represent the nucleus flashed up brilliantly. Then I made up my mind that some distant house, barn, or ■ haystack was on fire, and returned to the observatory for a 3 inch telescope, which I keep for looking over the landscape. Before I had time, however, to enter the door, every vestige of illumination disappeared as suddenly as it had come into view, and after waiting in vain for some time, I left the observatory and came into the house. I have diligently inquired if there was a fire anywhere in this part of Sussex on the night of which I am speaking, but there was none. Were the Crystal Palace concealed by the high ridge from behind which this strange apparition arose, the con- cluding burst of a grand pyrotechnic display might reproduce what I witnessed ; but merely its a matter of topography the Crystal Palace is not on Ashdown Forest, nor on Crowborough Common (which lies beyond it in an E.N.E. direction from here) either. Nor, oddly enough,"does any house, or even any agricultural buildings, lie upon the line drawn from my observatory through the point at which this light arose, as any one may see from the Ordnance Map, whereon, of course, Forest Lodge is marked. I m.ay add that the latitude of the observatorv is 51° 0' 56' N., and its longitude 17-8" E. of Greenwich. ' William Noble. STORMY PETREL. [027]— On going into the yard at the back of 13, Guildford-strcet, Birmingham, about 7.30 a.m. on Sept. 4, I saw a strange bird lying with wings extended, quite dead, but warm. It had evidently dropped from exhaustion. On examination it tamed out to be the stormv petrel (Procellaria pelatjica). I attribute it to the very heavv" srales that have occurred lately. You may insert tliis if you think it will be of interest to any of your readers of Knowledge. E. W. BURFORD. 174 ♦ KNOV\^LiiDGE ♦ [Sept. 14, 1883. THE COMMA. [928] — I send you an exam]ile of a printer's comma whicli maj- interest you : Matthew sxvii. 23, " Why, what evil hath he done?" The original reads, ri yap kokcii' itroit)(!tv. The printer's comma makes a double question and causes the " why " to refer to " Let him be crucified." It is so read by ninety-nine out of a hundred. I trouble you with this, because I believe it is not generally known, and it appears interest insr to me. A. H. Tate White. A RABBIT'S SKULL. [929] — I see you have an article in Knowledge of Aug. 17, on " A Babbit's Skull." I may here mention that m}- father has in lus possession a skull very similar to that spoken of, but still more interesting, as in this case the top rifjJit incisor, which is quite three inches in length, has grown right up through the roof of the mouth on the left side, and passing down once more, ends just where it began. The one in the lower jaw is an inch and a half long, and has grown out almost straight from the mouth. There appear to be two incisors in the top jaw, but only one in the lower, and, although it was impossible for the front teeth to close, yet the rabbit seemed in perfect health, and was in good condition when shot. Leila C. LIGHT FROM FLOWERS. [930] — The following extracts from a book entitled " Lessons in Physical Science " (Simpkin, Marshall, & Co., 1872) may meet the wishes of j-our correspondent (882) on the above subject. They may be found in the chapter commencing at page 151 : — • " The spark elicited by stroking the back of a cat, or by the action of an electrical machine, does not differ in its nature from the lightning which flashes from the storm-cloud, nor from the brilliant and variegated auroras which stream through the upper regions of the atmosphere in Polar latitudes, and which, to some extent, compensate, in those dismal abodes of winter, the long absence of the solar beams. To the same source — electricity — we probaby owe the light which, at certain seasons, and at certain times of the day, issues from a number of yellow or orange-coloured flowers, such as the marigold, the sunflower, and the orange-lily. The daughter of Linnaeus, the great naturalist, is said to have first observed these sparks and flashes playing about garden flowers during the summer twilight of 1762, but similar phenomena have been witnessed by several naturalists. Plashes, more or less brilliant, have been seen to dart in rapid succession from the same flower. At other times the tiny flame-jets have followed one another at intervals of several minutes. . . . Sir H. Marsh gives an account of a female about whose head strange luminous appear- ances were observed. Shortly before her death several attendants saw a pale bluish light, like that of the moon, proceed from her head ; and Professor Donovan witnessed, in the case of a man in the later stages of consumption, mysterious lights, once in the form of a luminous fog, resembling the aurora borealis, and twice in the form of scintillations like the sparkling phosphorescence exhibited by sea infusoria." A similar instance is given in " Notes and Queries " of Aug. 25, page 15S, nnder the heading of " The Nimbus." G. M. GINGER-BEER PLANT. [931] — In reply to Mr. F. H. Perry's query, the following infor- mation from my own observation may prove useful. The fimgus he mentions is precisely similar to yeast in its action on a solution of sugar and water. 'The process of making " ginger-beer" may be carried on very well without the " ginger," but if the sweet solution is left too long it becomes vinegar. Mr. Perry has, I think, been slightly misinformed concerning the nature of the so-called " ginger-beer plant." It can only live and propagate in a saccharine fluid. F. W. Halfpexxy. COFFEE. [932] — Would yon be kind enough to ask Mr. M. Williams to give a receipt for mixing or flavouring coffee with burnt sugar, as lately described by him in his papers on " Scientific Cookery" in KXOWI-EDGE ? The papers are very interesting, and having long wished to get a hint as to obtaining coffee at home as we get it at Gatti's restau- rant, I felt disappointed that the paper in question did not give a fuller account of it, viz., of quantities and proportions required of each for mixing. If Mr. Williams would oblige with these par- ticulars, no doubt they would be very acceptable to many other readers of Knowledge. " W. G. Mortimer. OPTICAL PHENOMENON. [933] — The following account of a phenomenon which came under the notice of a friend and myself the other day on one of the Cumberland mountains, may be of interest to the readers of Know- ledge, as it is, I believe, of rather rare occtu-rence. The mountain in question was Great Gable, one of the highest in the Lake district. We ascended it on Aug. 23 last, being on the summit between 6 and 7 p.m. The day had been very hot and fine, and the light evening clouds were floating on the tops and sides of Great Gable and the surrotmding heights. One of these clouds was just passing oil wlien we suddenly saw our shadows (or reflections) on the receding mist, with a double rainbow round both. They gave us the impression of being perhaps 100 to 200 yards away, and 10 or 15 feet in height. The rainbow was of small radius and very bright. This appearance lasted about two minutes, as far as I can judge, coming on for a short time a minute or two afterwards. The clouds were moving in a direction from the sun, and we were, of course, in a line with the sun and our spectres. The outline of the figures was very sharp and distinct, and answered to our move- ments. G. G. LETTERS RECEIVED AND SHORT ANSWERS. Mr. H. Phillips. — The paragraph was taken from a highly- respected contemporary. The fact of the praise bestowed on the lamp being inserted demonstrates the absence of an inimical spirit. In fact, you can rest assured that the reverse is actually the case. We insert a correction. — C . T. Parsons. You do not mention yotir telescope's size : a good deal depends on that. — D. E. Samuel. There are many ways of showing, or seeming to show, by algebra, that 1=2. They mostly depend on the property that once nothing is equal to twice nothing. 'Thus, let a = b ; then «- = !)•, and a-— b- = 0 = a — f). Dividing by a — i we have a-»-b = l. NowpHta = b = l. Then our result is that 2 = 1 : which is absm-d. Hence something in our process must be absurd. The place is soon found. We had a- — h-=a—l; that is, (a + h) (a — li) = l (a — b). When a = b, a—b = 0; so that this equation means that 2 x 0=1 x 0, which is true enough. But dividing each side by 0 and making 2 = 1, is mani- festly an absurd process, leading to an absurd restdt. One might as well proceed thus : — A million times nothing equals twenty times nothing ; therefore a million is equal to twenty. — T. J. Beardwell. Have you not made a slight mistake in your first problem ? If the death rate is 21 per 1,000, and the births 25-0645 per 1,000, the increase per cent, is •40645, not 2-50645 as you make it. Getting the population to double in 28 years would be a rather serious matter. Tour formula is approximately true. — Thos. H. D. Evening time. The moon map referred to illustrated the first of F.R.A.S.'s papers on the Moon, in the beginning of Yol. 3. Have not the volume by me to refer to. — L. C. C. I could not let the author of articles " How to Get Strong " give advice under the circumstances. The case is one for most careful medical advice. — R. Donald. (1) Such lightning indicates usually the progress of a distant thunderstorm. Not seen in day because daylight hides it. (2) Minnows grow but (3) not into trout. — Ch.as. Wood. Perhaps some correspondent knows of a " black sympathetic ink, to act as the green one produced by dilute muriate of cobalt, — viz. to be invisible when applied on paper and by heat to be produced, and as it cools to vanish again." — H. T. B. See fortnightly " Face of Sky " in our columns. — D. King. Railway accident put my work back so that the subject has not been resumed, but it will be next week. — Seveual Correspondents point out that the quotation at the head of the last instalment of Mr. Kimber's accoimt of anemones is incorrect. The alteration of the order of the lines was probably intentional ; as suiting the application of the lines best ; " fragrance " for " sweetness," is a frequent mistake. The lines escaped my atten- tion.— J. F. Rounthwaite. I should certainly much like to visit Manitoba, when I return to America (18S4, not 1885, I think) ; and you may be assm-ed it would add greatly to my pleasure to meet an old Lady Somerset captain. — W. W. T. A good lunar chart (Mr. Webb's) appears in '• Webb's Celestial Objects for Common Tele- scopes" and in my book on the Moon. — Uncertain. So am I. At least about the use of tlie words Natural and Snpernattiral. But 1 am certain you ought not to swear when you hear them. To answer your questions wo ought to know much more than we do, or than we are ever likelv to do. The Pilsen Joel axd General Electric Light Com- pany (Limited). — A petition presented last month for winding up this Company -ivas dismissed -with costs. The petition was erroneously said to be presented by the Com- pany, -who, however, opposed it, and, as we see above, suc- cessfullv. Sept. 14, 1883.] • KNOWLEDGE ♦ 175 ^ur iHatftematical Column* EASY LESSONS IN GEOMETKICAL PROBLEMS. By Richard A. Proctok. {Continued from page 127.) SUCH problems as I mentioned in my last, usually belong to a more advanced stage of study than that for which these simple papers are intended. They also often require the u.se of the Si-xth Book. It will suffice here to consider a few of the simplest cases. Suppose we have such a problem as this given : — Fig. 34. The sides of the trianrjle ABC (Fig. 34) are hisected in the points a, b, c, and the three straight Ihies ak, b 1, and cm are draion at right angles fo B C, A C, and A B respectively, shoiv that these three straigh t lines, a k, b 1, and c m, pass through a point. Here the student might at once refer to the Fourth Book, and find a proof in the cu'cumstance that a k and b I have there been shown to meet at the centre of the circle through the points A, B, C. So also by the same book do the liues a 1; and c m meet at the centre of the circle through tlie points A, B, C. Now there is but one circle passing through these points ; for if there were two, two circles would intersect in three points, which is impossible. Hence a k, b I, and c m pass through the same point. But although this proof is sound enough, it is not independent, as a proof of this sort should be. Yet an actual and sufficient ])roof will run closely, as might be expected, in the lines followed in Book IV. It is hardly necessary to say that the proof must be indirect. We can show, as in Book IV., that if ak and b I meet in 0, the lines OA, OB, and OC are all equal. Then since AO = OB, a line from O perpendicular to A B roiist bisect A B, in other words, must pass through c, and coincide with c m. Hence if wo wished to put the proof in Euclidean form, wc might begin by saying, — If possible let cm not pass through the point O in which a k and bl intersect, but have some other position as cmo. Then after proving that A 0 = O B, we could show that 0 c is at right angles to A B. But c iH 0 is at riglit angles to A B, wherefore from the same point c, there can be drawn two straight lines, at right angles to A B and on the same side of it, — which is impossible, since all right angles are ecjual. Therefore the line through c at right angles to A B cannot lie otherwise than through 0. In a similar way we can deal with the problem — Ifilie three angles of the triangle ABC {Fig. 35), be bisected by the' Hues A a, H >'. m,,! C •• these straight lines will all pass through one point. But now suppose we have this problem, — From the angles A, B, and C, of the triangle, ABC, Fig 36, lines are drawn at right angles fo B C, C A, amd AB respectively. These three straight lines shall all pass through one point. / / V \ l/^-""^ Fig. 36. Here again the indirect method must be employed. We may draw A a, B b, at right angles to B C, C A respectively, and inter- secting in O ; then if we can prove that C 0 (produced if necessary) is at right angles to A B, what is required is done. We have in this case the angles at b and a right angles ; and it is nearly always well to try in such cases whether any good comes from noting that the angle in a semicircle is a right angle. This at once shows that a circle on O C as diameter \n& pass through bo; as will also a circle on A B as diameter. Suppose these circles drawn ; or if any difiiculty arises from the effort to conceive them as drawn, draw them in, as in the figure. Also it will obviously be convenient to draw in the lines ab,b c, ca. We have now to show that C 0 c is at right angles to A B. If this be so, the angles c C A and c A C together make np a right angle, or are complementary to each other. Of these the angle c AC is a known angle; so that if we look for an angle known to be complementary to c A C, we may be able to prove that so also is c C A. Now the angle A B b is complementary to c A C by the construction. Can we show that ZABb= ZcCA? We must try our circles. We see that ZABb=ZboA on the same segment A b ; and we see that Z b a A or b a O = Z b C 0 on the same segment b 0. This clearly serves our purpose. For we have ZbC0= ZboO= ZbBA = compt. of CAB wherefore angle C c A is a right angle. {To be continued.) i&uv asaftist Column* By " Five op Clubs." WHIST QUESTIONS. Returning Partner's Suit. — " It hath been given out," " usually return your partner's lead, unless you have a good suit of your own." "what am I to understand by a "good suit" to return? Suits that are considered good to load from a hand next to the dealer are not always good suits to commence with, after having won your partner's trick. Can suits be called good that require more than two leads coming from a tlurd hand to establish ? MUKF. [Cavendish says, retm-n only if you have a " very goi>d suit." For my own part, I attach so much importance to kuow-ing early where my partner's strength lies, that I should say to him, Show your own suit if it is anything above medium strength, besides of course being long. — FrvE ok CtUBS. Long Weak Suits. — Is there any use trying to establish a suit of Five, headed by a Ten, with three or four small trumps in the same hand? The greater number of gentlemen I have had for partners during the ])ast twelve months have always led from their long suit, and wluit is most extraordinary, none of them have played the game less than " forty years." Muff. [Tlierc can be no doubt they are right in so leading. The object 176 ♦ KNOWLEDGE ♦ [Sept. 14, 1883. is not so much to establish the long suit, as to play a safe defensive ffame. Any other lead would be unsafe. — Five of Clubs.] Signalling for Trumps. — (In reply to "Muff"), this is playinp; an unnecessarily hic^h card, — as a seven first round, five second round. *#* Most of the back numbers of Knowledge in which Whist principles were explained can be obtained by applying to the Office in Great Queen-street. ©ur Cftrss Column. By Mephisto. POSITIOX IN A GAME BETWEEN STEINITZ AND AN AMATEUB. It was Black to move, and the game ended in the following pretty manner : — Kt takes P B takes Q Kt takes Q Kt to K7 (ch) K to R sq. RP takes Kt QR takes B B takes Kt B takes B R takes P (ch) K takes R R to R sq. mate. PROBLEM No. 97. By C. Planck. Black. m ^ Whitb. White to play and mate in two moves. PROBLEM No. 98. By J. C. S. Black. I A 'w^A y'''^'^'' "WM 'm„„, 'S-i^'^ ^^ ^^fe '^*^' ' 'Q^*' White. White to play and mate in three moves. SOLUTIONS. Problem No. 91, by E. 1. Kt to Q.-) (ch) R takes R 2. Q, to Kt8 (ch) Kt to K3 3. B to R2 (ch) R takes B N. Franke\.stein, p. 144. 4. Q to Kt2 (ch) R takes Q 5. Kt to B4(ch) Kt tks Kt (ch) Mate. No. 95, BY J. 1. R to K8 Q takes R 2. Kt to BO (cli) K to B5 3. Q takes P (ch) mate. C. S., p. 114. Q to K7 (ch) R takes Q (ch) K to B4 Q to B8 (ch) mate. Ending, p. 114. 1. Q to K8 (ch) 2. K to R2 B takes P (best) 3. R takes B R takes RP (ch) 4. K or P takes R Q mates aecordinglj-. ANSWERS TO CORRESPONDENTS. *»* Please address Chess Editor. Stettin. — Solutions correct ; in the ending, 2. B takes P is the correct move. Walter Waring. — Problem received with thanks. W.— If R to Q4, there is no dual. Solutions of 93, 94, 95, 96, and End Game correct. G. W.— Solutions of 93, 94, and 95 correct. In the Ending you will see that 2. B takes P is more forcible. R. Sargeant. — The Endeavour, Vassal-road, Brixton ; or the Surrey Chess Association, Hon. Sec, L. P. Rees, Annandale, Anerley. Correct Solutions Received. — Problem No. 95, Ipswich. Problem No. 96, Stanley B. Baxter, Clarence, H. A. D., Berrow, H. A. L. S., Purssell's, Cornhill. Contents of No. 97. PASS How to Get Strong : In Middle and Advanced Life lio The Birth and Growth of Myth. XV. By Edward Clodd 146 Pretty Proofs of the Earth's Kotnn- dity. (Ilhia.) Bv E. A. Proctor 117 The Fisheries Eihibition. TI. (/;;«».) By John Ernest Ady ... 149 Chemistry of the Cereals. V. By William Jago, F.C.S 1.t1 Folly and Courage at Niagara 152 TheWhirlpool Kapids, Niagara ... 153 The Colo By Wi The Har Procto uary : Death d Curtain in the Eye 1 Ackroyd 1 Moon. (Illu$.) By 15D Professor Tohin 157 CoERBspoNDENCE : Ftmctuation and Printers, &c 158 Mathematics IttO Our Chess Coin 161 TERMS OF SUBSCRIPTION. The terms of Annual Subscription to the weekly nomberB of Knowledge are as follows:— 8. d. To any address in the United Kingdom 10 10 To the Continent, Australia, New Zealand, Bonth Africa & Canada 13 0 To the rnited States of America J3.26. or 13 0 To the East Indies, China, ic. (ltd Brindisi) 16 2 All subscriptions are payable in advance. OFFICE : 74-76, GREAT QUEEN STREET, LONDON, W.C. Sept. 21, 1883.] ♦ KNOV/LEDGE ♦ 177 J^ MAGAZINE orSGIENCE ^ fe PLAmUfWORDED -£XACTi:( DESCRIBED^ LONDON: FRIDAY, SEPT. 21, 1883. Contents of No. 99. FAGB Oar Boya at School. By E. A. Proctor 177 The Sun in a Three-Inch Telescope. (//(«».) ByF.E.A.S 177 The Fiaheriea EihibitioQ. (Illm.) By John Ernest Ady 179 Tricycles in 1883 : Small v. Large Wheels. By John Browning 181 The Birth arid Growth of Myth. (/««».) By Edward Clodd I>i2 Sun Views of Great Britain and the Earth. (llUs.) By E. A. Proctor 18i PAOB Notes on Punctuation. By E. A. Proctor 188 Sea-Anemones. IV. The Daisy. (Illiui.) By Thomas Kimber 187 Jack Ketch. By E. A. Proctor 188 Eclitorial Gossip 189 Eeviews ; Our American Cousins ... 190 COERBSPONDKNCE : Visual Pheno- menon — Colours of Flowers — Wart Charming — Deaf Cats — Letters Eeceiyed 130 Our Chess Column 190 OUR BOYS AT SCHOOL. By Richard A. Proctor. OUR youngsters are returning to their schools, where they are to be taught, besides those subjects which appear in school prospectuses, etc., many things which are not so generally mentioned. A lad may be under an Arnold or a Temple, and learn either directly or indirectly from the example and precept of his masters, to be manly and honest, generous, truthful, and brave. If his own nature unfortunately does not predispose him to good, he yet finds himself surrounded by an atmosphere of honesty and gene- rosity, and breathing it is purified and strengthened. But all our boys are not so fortunate. They may be under head-masters who are weak or worse, who let the masters with whom the boys come more into contact be cruel and vindictive, mean, unfair, and false. Men speak of schools often as if their boys were not likely to be injured in character by weak or bad masters. A generous manly boy may escape the evil influences, direct and indirect, which .such masters (whether headmasters or not) necessarily exert. But he has to breathe an uncon- genial atmosphere. For, where masters are dishonest, a dishonest tone soon begins to prevail among the boys. Honesty is at a discount in such places ; dishonesty pays : it is not in human nature, at least in boys' nature that among boys so placed the prevalent tone should not ere long become dishonest. Fathers should talk to their boys over such matters, not to listen to mere faultfinding, but to find in converse with them what sort of tone prevails among their fellows. Of course with many boys such a course fails. But an honest manly boy, who regards Jiis father as a friend not as " the governor," will very soon show, more clearly than he himself perhaps imagines, the nature of his school sur- roundings. One docs not find that a boy worth anything objects to strict if honest discipline. 1 know that my own boys talk with enthusiasm of the strictest of the schools at which they have lieen placed. Go on to talk with them of their school life there, and you presently find that the manly toiu! of the masters was reflected among the boys. Lying and nuibbling, cruelty and treachery took no root in a soil so unsuited to them. A boy that can talk of even punishment as "fair," and of his schoolmates- as "good fellows," gives the highest possible praise to the masters of his school, and specially to the headmaster from whom as a rule the rest take their tone. If you send a boy who has been in such a school to one where vindictive ill-tempered and dishonest masters are allowed their own way, where boys are taught by example to give way to their passions, to be treacherous, cruel, and mean, you will very soon learn from him (if you are sensible enough to take interest in his talk of school life) the disgust with which he notes the difference. It is singular, too, how along with falsehood and meanness, im- purity and profanity prevail where the tone among the masters is mean or false, where the better sort are outnum- bered by the worse and too weak to make a manlier tone prevail. Boys who have been at such a school as I have described above, speak with as much contempt of swearing and foul language, as of sneaking or lying : but all these faults flourish as in a kindred soil, where masters are vin- dictive and dishonest. This too may sometimes be seen even at schools where e.denmUi/ a specially religious tone prevails. Unfortunately the masters in our schools are not tested or examined at all as to their fitness for the most important part of their work. We know that masters set to teach mathematics, classics, modern languages, and so forth, have a certain degree of familiarity with these subjects ; for they have passed certain examinations in them. But we have no means of knowing beforehand that a master who may have chief or sole charge of our boys at school has learned to control his temper as well as to construe Greek and Iiatin, to teach honesty by his example as eftectively as he may be able to deal with mathematical examples on the blackboard, and to be fair and just as well as to be a ready speaker in French and German. School- boys are often full of tricks, but chiefly when their masters set them the example. Parents should if possible learn what is the tone among the boys at a school before they send their boys there. Though there can be no public examinations to test this, inquiry among the boys will often disclose a good deal. But if previous inquiry has not been possible, friendly talk with sons about their school life will soon show any one who understands boys' ways the real position of afl'airs. If there are many " mean fellows " among the boys, fellows who let others be punished for their offences, who cringe when they are not bullying and bully when they are not cringing, be sure there is something wrong among the masters. Such evidence is far better than actual complaints of unfairness on the masters' part, — for boys, like men, may complain without cause. But among a given number of boys there will always be a large proportion whose characters take their tone from the masters' : they will be among the good fellows if the masters help them that way ; but they will sink into the ranks of the bad fellows, (sneaks, bullies, and cowards) if the masters are of that kind. THE SUN IN A THREE-INCH TELESCOPE. By A Fellow of the Royal Astronomical Society. SO far our observations have been all made by night : it now only remains to show what may be done with a three-inch telescope while the sun is above the horizon. Naturally the ruler of our planetary system, our great centre of light and heat, the Sun himself, is the first object 178 KNOWLEDGE ♦ [Sept. 21, 1883. which -will invite our attention, and to which our instru- ment will be directed. Let us see what we may expect to view upon his surface. But here, at the outset, a caution is necessary. On no account whatever must the observer attempt to look at the sun under the same instrumental conditions as he has been viewing the stars. To try to do so without either the interposition of a dark-coloured eye- glass, or the employment of a device to be immediately explained, is almost certain to involve permanent blind- ness altogether. Sir William Herschel lost an eye in such an attempt ; an attempt against which we earnestly warn the student. As a matter of practice, however, opticians send out each astronomical or Iluyghenian eye-piece with a dark-glass cap, which must be screwed on whenever the sun is to be looked at directly through the telescope. Should the purchaser of an instrument have his choice of colour in these eye-caps we would recommend very dark green or blue, or else what is known as " London smoke," as the most agreeable tints for use. Red glasses are less liable to crack with the sun's heat, but they are by no means so pleasant to look through. Whatever colour, however, the observer selects, let him take care that it is dark enough ; and as dark glasses are, as we have hinted, liable to crack with the sun's heat, means must be taken to diminish that heat as much as possible. This will involve, though, one of two things, either the cutting down of the aperture of the instrument to two inches, or even less, if the observation is likely to be a protracted one ; or the turning away the object-glass from the sun at short intervals, should the whole of the object-glass be employed, to give the eye-piece time to cool. There is a device which, should the possessor of a telescope choose to go to the cost of it, enables the sun to be viewed for an almost indefinite period with the whole aperture. In con.sists simply of a perfectly plane plate of glass placed at an angle of 45° with the axis of the telescope, so as to reflect the image formed by the objective in a direction square to the optical axis. The outside of this plate is ground, so as to destroy any secondary reflection ; and, pretty obviously, a very large proportion indeed both of the sun's light and heat, passes through it. The ordinary Huyghenian eye-piece (which may now be covered with a lighter eye-shade) is still employed. Or, finally, we may view the sun without looking through our telescope at all ; and, for getting a general idea of solar detail, the method we are about to describe is perhaps the best of all. Moreover, it enables half-a-dozen people to view the solar disc at once, if necessary. In this way of using the telescope we convert it into a kind of solar microscope or magic- lantern, and throw the sun's image on to a sheet of very tine, clean, hot-pressed cardboard, which we shift to and from the eye-piece, and move the focussing tube until a sharp and distinct image of the sun is obtained. It will be necessary to have a large sheet of pasteboard covered with black paper, through a hole in the middle of which tlie eye-piece comes, in order to shield the card on which the image is projected from direct sunlight. The same end would be more perfectly attained by passing the olject-end of the telescope through an aperture in the shutter of a completely darkened room ; but this is rather too elaborate an arrangement for the ordi- nary observer. Where only one person wishes to see the sun at a time the receiving disc may be fastened at the bottom of a pasteboard cone fitting over the eye-end of the telescope, and with an aperture cut in the side to look through. An arrangement of this sort is illustrated on p. 136 of the " Lessons in Rudimentary Astronomy," by the Editor of Kn'owledge, published by Cassell i Co. (Limited). Whichever of these ways we select to view the sun in, we shall be struck by three or four salient features of his surface. The first thing we shall note is that the limb or edge of the sun is perceptibly darker than the middle of his disc, which gradually shades ofl as we approach his circular outline. The eflect of rotundity which this gives to his image is very striking. A little consideration will show that this must be the eflect of an atmosphere surrounding what is technically called the photosphere, or light^radiating surface of the sun. The next thing that will arrest our attention- — perhaps just now the first — wil] be the dark spots which diversify the sun's face. Fi-. 1.— Spot on Snn, Sept. 12, 1883, 11.23 a.m. The above figure may serve as an illustration of an individual single spot, and was drawn with a power of SO, on Wednesday, September V2, at ll.L'-") a.m. It will be seen to consist of two well-distinguished parts, a dark interior one, known technically as the Umbra (three of these umbrie at least will be observed to be included in the penumbra in the sketch above), surrounded by a lighter fringing which is called the Penumbra. By the use of a peculiarly constructed eye-piece, and a telescope of con- siderable aperture, the late Mr. Dawes discovered black spots within all large umbrre, and even some small ones. If the observer knows exactly what to look for he may sometimes pick these up even with a 3-inch telescope. It will, however, be necessary to cover the diaphragm in the eye-piece with a circular disc of glazed visiting card (with the glazed side towards the field-glass) centrally perforated with a minute hole made with a fine red-hot needle. The telescope is moved until the spot occupies this exceedingly circumscribed field ; and thus cut ofl' from the suiTounding glare, the nucleus may often be detected. We have so far spoken as though spots were isolated, liut they perhaps most frequently appear in groups, involving the most enormous areas on the sun's surface, of the disturbances of which they are the outward and visible sign. Our next figure represents a group of spots visible on the sun at 9..50 a.m. on June "Oth of the present year, and was drawn, like every other figure illustrating this series of Fig. 2. — Group of Spots, Jane 30, 9.50 a.m. (visible to the naked eye). papers, at the telescope. As a reflecting eye-piece was used in this particular case, though, everything is turned right for left in the engraving. It will be noted how the curves of the penumbrw connected the umbra?. Micro- metrical measurement made immediately after our sketch Sept. 21, 1S83/1 » KNO\A/LEDGE ♦ 179 gave the superficial area of the left-hand group as 702,940,200 square miles, and that of the right-hand one 1,074,370,000 square miles, or, in all, 1,837,310,200 square miles of the sun's surface, as involved in this stupendous disturbance alone ! It could be seen with the naked eye when defended by a darkened or smoked glass. There were other spots on the sun's disc at the time. Careful study of the spots under the most favourable definitions will reveal certain striking features. The umbrw, under ordinary circumstances, seem to be black ; but the student who has the opportunity of watching a partial solar eclipse, or a transit of Mercury, will at once be struck with the extreme blackness of the moon's limb or of the planet, as contrasted with the (now, by contrast) brown hue of the spots. A distinctly brown, and even orange tinge may often be seen in the images of spots projected on to a sheet of cardboard, in the manner described above. Attentive study of the penumbra will reveal a kind of fimbriated or fringed appearance in it ; and it will be further noticed to be darkest at its outer edge, and seem- ingly to get lighter as it approaches the umbra. Returning now to the limb, or edi;e of the sun, which, as we have pre- viously said, will be perceived to be notably darker than the centre of his disc, we shall find the shading diversified by curious and often rather complicated streaks of light. These are called " facula;," and are most numerous and con- spicuous about spots which are close to the limb, or where such spots are aliout to break out. We have sometimes traced facuhe for some considerable distance on to the brighter part of the sun's disc ; but, as a rule, they are only seen near the limb. The sketch which follows represents a group of faculfe which was visible on the morning of Aug. 25, at 9 h. 40 min. : — ■ Fig-. 3.— Facul;i^ on Sun's limb, Aug. 25, 1883, 9.40 a.m. It was drawn on the paper on to which the image of the sun was projected, in the manner previously described. The fourth piece of solar detail of which we need here speak is tlie mottling or graining of liis surface. This is best caught by shifting the telescope a little, so as to make the sun's imago move about in the field. If this be done, the eye will soon receive the impression of a roughness or grain upon the sun's face, akin to that of a piece of magni- fied loaf-sugar. In large instruments this is seen under the best definition to consist of markings which have, not unaptly, been compared to rice grains, but its resolution into these appearances is whoUy beyond our instrumental power. Such are the leading features observable on the surface of the sun with the means at our disposal. Mutatis mu- tandis, we may say, as we did concerning the moon, that we are not writing a heliogi-aphical treatise ; and hence, for their interpretation, must refer the reader to " The Sun," by the Editor of this Journal, or to the volume of the " International Scientific Series," bearing the same title, by Professor Young. We have simply essayed — not, we trust, wholly without success — to indicate what may be seen upon the sun in a three-inch telescope. By the aid of Browning's star spectroscope, with a very narrow slit, the spectra of prominences (those huge uprushes of hydrogen gas known as the " red flames " which are seen during a total solar eclipse) may often be detected on the sun's limb, even in a telescope of the size of that whose use is pre- supposed ; but the mention of the fact must sufiice here. THE FISHERIES EXHIBITIOX. By John Ernest Ady. AMONGST the numerous exhibits which bear upon our subject, there are perhaps few which call for more attention than those concerned with the supply of water for domestic use. On the left-hand side of the passage leading to the aquarium gallery, a remarkable filter is being exhibited by Mr. P. A. Maignen, called the " Filtre Eapide." For sim- plicity in design and efficient working qualities, this filter deserves some notice in these columns, especially as a short description may bring a very useful article within easy reach of many of our readers. In Fig. 16, two sectional diagrams are given of this apparatus. The explanation under the figures will suffice to convey an idea of their structure, which shows that the filter itself consists of movable pieces, which can thus be thoroughly cleansed and replaced with very little trouble, and at a merely nominal expense ; the cleansing process, moreover, need not be repeated oftener than once during the course of about three months. '^rr^'z -::3 Fig. 10. — Shxriox.iL Views OF MAUNtx^ ■■ I'li.ritE Kapide." — A, reservoir for the filtered water ; B, the filter ease, which is re- movable ; D, conical sac of asbestos cloth tied over the filtering frame, which consists of a funnel-shape jierforated piece with outlet, W, and aSrating pipe, C. On the outside of the asbestos cloth a charge of powdered " carbo-calcis " is deposited, by being mixed with tlio first water run into the filter. This forms a layer on the clotli through wliich all subsequent water must pass and be purified. E, scrroii for protecting the filtering medium. The figure to the right-hand side is a different form of the same apparatus. In the majority of filters now used, two types of con- struction have invariably been followed, both of which are 180 ♦ KNOWLEDGE ♦ [Sept. 21, 1883. more or less open to very serious objections, either on account of their mechanical details, or because they fail after a time to " fulfil their f mictions " adequately. In the tirst form of filter just alluded to, the working portion is securely cemented down, and when it requires to be cleansed, an amount of delay and expense is occasioned which is often very disheartening to the unfortunate possessor. The second variety consists either of a solid mass of porous carbon, or other material filled in to produce a dense aggre- gate through which the water is made to pass. It is obvious that, in these arrangements, there is a tendency for the filters to become " foul " through the accumulation of noxious materials within their porous recesses, which then necessitates a laborious cleansing process. It is a prevalent notion amongst those who have not paid any attention to the subject, that drinking water harbours countless strange organisms which pass collectively under the name of " animalcule'," very likely for the same reason why Rotifers, Diatoms, and Desmids were classed together with the Injusoria by the earlier microscopists. Doubtless this popular belief had its origin in such pictures as Fig. 17, taken from Dr. Hassall's valuable little work on " Food and its Adulterations," as well as from indis- criminate displays of a drop of stagnant water under the microscope at Sunday-school soiries, or other delightful heterogeneous gatherings. But, when it is known that these monstrous-looking creatures can be captured from drinking water only after diligent search and Ijy straining oceans of the water, and that only in very ill-conditioned water do they congregate in numbers, much of the ardour and wonderment of the inquiring novice is dispelled, and he feels that he is disappointed because he does not actually swallow a few millions of them with every tumbler-full of water. Fig. 17. — A, animal and vegetable productions contained in the water of the Thames taken at Richmond. B, organic matter, living and dead, especially the Thames Paramceciv.m and husk of wheat (from Hassall). Nevertheless, it is a patent fact that these minute forms of life do live and thrive in drinking-water, a fact attested to by Fig. 18, which is also taken from Dr. Hassall's book.* Some of these little creatures are harmless ; indeed, they are even useful, in endowing the water with a certain palatable freshness through the gases which they eliminate ; but others — and alas ! by far the larger propor- tion— are highly deleterious. Take, for example, the Paratiuecia in Figs. 17 and 18 ; they are the invariable concomitants of decaying vegetable matter, and are often accompanied by minuter forms, whose very names, Bac- terium, Bacillus, kc, have recently been associated with the most virulent maladies which " flesh is heir to." Most of them have already been described in these pages by Mr. Slack ; we therefore refer the reader to his ^excellent articles.t * We are indebted to Mr. Maignen for the use of these figures, t r^ supra June 1st, June 20th, and July 13th, 1883. Fig. 17 shows, that beside living creatures, water is apt to contain foreign particles of dead matter in various stages of decay, such as the husks and straws of wheat, &c., and inorganic particles — e.g., sand, itc. Whilst mostly harmless in themselves, they aflbrd food and shelter to the more un- welcome living things. At all events, everybody will admit that, taking all these circumstances into considera- tion, it is desirable to free the water from them by some means, and then to try to render that water palatable. Both of these ends are met by Maignen's filter, which purifies, and at the same time aerates, the water. Although we have seen the exhibitor quaft' from a glass of purified Fig. 18. — A, Watee t.^ken from Cistern, a, blood-red Annelids; h, Brachionus polyacanthus ; c, Euplotes charo7i ; d, Paramoicia ; e, Amphileptus ; f, Actinophrys Sol ; g, Actinophrys viridis ; h, Pedia- strum Boryanum; i, Closterimn Lunula; k, Scenedesmus quadri- canda ; I, Scenedesmus aciitus ; ■m, Scenedesmus ohtusus ; n, Cyclo- tella operculata ; o, Nitzchia Sigma ; j). Sy7iedra minutissima ; r, Melosira varians ; s. Threads of slender fungus ; t, Minute star- shaped bodies ; r, Organic and earthy matter. Mag., a 12 ; ft 100, the rest 200 diameters. B, Watek taken fro.m Service Pipe. e, Paramcecia (2 species) ; b, Vorticella convallaria ; c, Coleps hirtus ; d, Pandorina Moruvi ; e, Scenedesvius quadricanda ; f, Naricula Amphishcena ; g, Navicula sphxErophora ; h, Asterionella formosa ; i, Fragilaria Capuoina ; i'. Brown active sporules ; I, Stationary green sporules ; m, Threads of slender fungus ; n, Organic and earthy matter; o, Anguillula fluvialis. sewage which had simply passed through the patent inven- tion, yet we are inclined to advise a previous boiling of the water, to ensure the death of such things as Bacteria. The aerating tube, C, Fig. 16, may also be loosely plugged with cotton wool, so that stray germs can be intercepted, and if a cork be fitted into the aperture so prevent aeration, the filtered water we have found to be admirably adapted to the wants of a naturalist's laboratory, where distilled water is not always necessary. The next series of exhibits which demands our attention is that comprised under the head Ccelenterata, with its two principal classes, the I/ydrozoa and the Actinozoa. A C ct'Jenti'rate animal consists essentially of a sac-like body, the walls of which are primarily composed of two layers, an outer, ectoderm, and an inner, endoderm. There is gene- rally a radial arrangement of parts, observable chiefly in the tentacles with which nearly all of them are provided ; and, although they do not possess any marked ner\'Ous system, they are characterised by the presence of " thread cells," or peculiar urticating organs, used as weapons of oflence and defence. It will be seen from this definition that they approach very nearly to some of the sponges, and their reproductive processes, both by gemmation and division, as well as in the simpler forms of sexual genera- tion, link the two groups together still more closely. At Stand 75G, a series of microscopes, under the care of Mr. Bolton, of Birmingham, are invariably supplied with living forms of one of the simplest, and certainly most beautiful, of the ILjdrozoa — viz., Hydra viridis, or the fresh-water polype. The little Hydra consists of a simple cylindrical green sac-like body, closed at one end, which serves to attach it at the will of the creature to some Sept. 21, 1883.] KNOWLEDGE ♦ 181 foreign olyect. The other end contains a central ajierture, or mouth, which leads into the simple sac-like body cavity ; around tlie mouth a circlet of tentacles, or arm-like hollow slender process, are spread out. Careful examination with a high power of the microscope shows that the wall of the body cavity and of the tentacles, which are co;cal prolonga- tions of that cavity, are composed of two layers of cells, constituting an ectoderm and an endoderm ; and that between these there is the early indication of a third layer, or mesoderm, which arises from the basal extremities of the ectodermal cells. This layer is called, after its discoverer, Kleinenberg's neuro-mti.scular layer, because it is supposed that it represents a nascent form of muscular and nervous system combined. Many very complicated forms of Ihjdrozoa, which include the peculiar plant-like sea-firs (^Sertularida), and their strange independent reproductive members, termed medu- soids, or jelly-fishes, may be seen in bottles of spirit at the extreme corner of the East Quadrant. These specimens are each worthy of a careful description, so exquisitely have they been prepared. We may state here, without fear of any contradiction, that each specimen in the collec- tion from the Zoological Station of Naples is a masterpiece of museum mounting, and we would therefore draw the special attention of students to this section of the Exhibition. In spite of the extreme variety of form exhibited by the Ilydrozoa, the primitive sac-like nature of the organism, consisting of two layers, is never wholly disgnised, and this fact, which was first generalised by Huxley,* has led that eminent observer to make the following statement : — " Thus there is a very real and gennino analogy between the adult hydrozobn and the embryoni'i vertebrate animal ; but I need hardly say it by no means justiiies the assumption that the Hydrozoa are in any sense arrested developments ' of higher organisms. All that can justly be affirmed is, that the hydrozoon travels for a certain distance along the same great liighway of development as the higher anima), before it turns off to follow the road which leads to its special destiuation."t TRICYCLES IN 1883. SMALL WHEELS v. LARGE WHEELS. By John Browning, Chairman of the London Tricycle Chih. " C1IGMA" has completely missed my point. He has kj evidently written under the supposition that I am advocating theoretically the construction of tricycles with small wheels, whereas I am showing that three or four years ago I was advocating their use theoretically, while now the most advanced and skilful manufacturers are making them, and the fastest and best riders are adopting them, and having proved my case experi- mentally, I have only written with the intention of hastening the inevitable revolution; but I am obliged to my friend " Sigma " for giving me the opportunity of making my views clearer on this subject. He has totally misund(;rstood me, and others may have done the same. He has also completely misrepresented what I have said, though this, I feel sure, he has done un- wittingly. I find " Sigma " accusing mo of recommending tricycles which will travel at four or five miles an hour, and, by implication, calling me absurd for doing so. My reply is simply that I have not done so. * Proc. Linn. Soc, 1849. t " Monograph of the Oceanic Hydrozoa." Eay Society's Pub- lications. 1859. I find myself accused also of theorising. I have nowhere referred to theories in my articles, but only given facts, and conclusions which must follow from them. Next I am told that it is easier to ride a machine with large wheels at seven or eight miles an hour than a machine with 36-inch wheels at the rate of four miles an hour. I reply that " Sigma " has not tried the ex- periment or he would not say so. / have, and knov} it is not. " Sigma " supposes that I recommend small wheels because they are easy, though slow. I do so because, as I state, they are easy 'nid fast. The person who begins with one of the small-wheeled machines could, as he wished for more speed, have his machine geared up even to 65 inches if he pleased, at a trifling expense. This would avoid all the rapid pedalling " Sigma " declaims against. " Sigma " says the machine he rides has .50-inch wheels, is geared up to 60 inches, and yet weighs only 60 lbs. I reply that if it had wheels 40 inches diameter they might be geared up to 60 inches, and the weight of the machine might be reduced to about 40 lbs., and yet be equally strong and it would be faster. " Sigma " is an exceptionally strong rider and I am a weak one, but Mr. Nixon, who is a more powerful rider even than himself, will tell him that I gave him the slip in Croydon, not long since, and that he had to ride for half an hour, at the rate of certainly more than ten miles an hour before he could catch me. Mr. Nixon had 50in. wheels, and I had 38-in. geared to 48-in. Had I been riding a machine like his own, Mr. Nixon would have had no trouble in catching me in five minutes. No one knows better than " Sigma " how much I have the interests of tricyclists at heart. Surely he may trust me on a mechanical matter not to mislead them. The fact that the Coventry " Eotary," one of the fastest machines, has two 20-in. wheels on one side is a sufKcient proof, if any were required, that small wheels will not prevent a machine from travelling quickly. Early this year, I had the pleasure of acting as judge in the 100 miles road ride of the London Tricycle Club. " Sigma " will not be likely to forget this, as, with a disabled hand and foot and a broken machine, the result of an accident only two days before, he won the 100 miles time medal in an exceptionally plucky manner. The first thirty-six miles of road — from Boston to Peter- borough— was so rough that it broke the front wheels of several machines. Rough roads are supposed to be un- rideable by small wheels, yet Mr. Arthur Salmon was amongst the first two or three men in, thoiiyh he wasridiTig a machine with i'2-in. w'heeh. A few weeks ago, Mr. A. Salmon and myself rode 65 miles in a day together. Mr. Salmon rode his 42-inch, geared up, I believe, to 58, I rode my 38-in., geared to 48 in., wo stopped about three hours for rest and refreshment, and I was home before eight o'clock in good daylight. I leave " Sigma " to imagine whether our pace was anything like four or five miles an hour. Not a single remark was made about the smallness of our machines by drivers or others, nor has there been either before or since, and I am sure our Editor will agree tliat some D.G.N.F. would, if we looked awkward on them, be sure to tell us so. The L.T.C. is strong in chaff as well as riding. Mr. Salmon is 5 ft. 10 in. at least, and finds 42-in. wheels large enough for him. In proportion to this, as I am only 5 ft. 4 in., a machine 182 * KNOVV^LEDGE * [Sei'T. 21, 1883. ■with 36 in., •which I shall have geared up to 50 in., should be large enough for me, and I shall ride nothing larger than this after this season. If my friendly antagonist, instead of trying to prove I am wrong — on paper (a hopeless task, though he is so able a writer that he is sure to make out an apparently good case), will use the influence he has to get the manufacturers to make him an Imperial Club, with 40-inch wheels geared to GO inches to weigh under 45 lb. or 40 lb., if possible, and will try the machine, I am certain he will go no further with his arguments against small wheels. In the .50 miles Road Ride, which took place last Saturday, ]\Ir. Marriott for the first time used a tricycle which had wheels only 40 inches in diameter. These were geared up to •'iG inches, that is, ran as if they were wheels 56 inches in diameter. The machine weighed only a trifle over 46 lb. Mr. Marriott covered the distance in less time than it has been done on any jrrevious occasion, though the road was hilly and muddy, and the wind very strong ayaiiist him on returning. In this ride !Mr. Marriott really covered 54 miles in 4 hours 7 minutes, and was unavoidably detained ten minutes, so that the 54 miles were actually ridden in 3 hours 57 minutes on these small wheels. The future of the tricycle now lies with small-wheel machines. Unfortunately, this is a matter easily mis- understood by those who have not practically experimented on the subject. Herbert Spencer begins a wonderful series of delusive illustrations thus : — " It stands to reason that salmon will be cheaper in Aberdeen than in London " — which is the reverse of the fact. Similarly, I would say : — It stands to reason that a large-wheeled tricycle will pass over an obstacle easier than a small one. To make this proposition true, it is necessary to add — other things being equal. But other things are not equal in our case, as by using small wheels we get a much smaller and lighter machine, and one that wDl pass more easily over obstructions than a hea%-ier machine on larger wheels. " Sigma " altogether ignores the support my views have received from the following authorities : — Mr. Marriott, one of the first manufacturers and the finest rider of the day, whose letter I have forwarded to the Editor. Messrs. Nixon and A. Salmon, the two best riders of the London Tricycle Club, and Mr. Percy Letchfour, one of the fastest riders of the Finchley Tricycle Club, all racing men. Also Messrs. Salmon, Howard, and Grace. If, instead of instancing an aged clergyman, with but slender experience, he can quote the names of some well- known riders, who, having tried the new small-wheeled machines, have gone back to large wheels, then he will have gone some way towards proving that I may be wrong. On one point I can excuse " Sigma " for misunderstand- ing me ; that is, where I intimated that I pretty well agreed with the rough estimate that about one mile in each ten of road will be found unrideable. I did not wish to occupy space by explaining that, by unrideable I did not mean that they cannot actually be ridden, but that it does not pay to ride them. A hill which is just rideable will require the expenditure of more than four times the power to ride it than it will to walk it. Why do engineers make tunnels for locomotives to run as nearly on a level as possible 1 Simply because it is a great disadvantage to have to mount steep inclines on wheels. THE BIRTH AND GROWTH OF MYTH. By Edwaud Clodd. XVI. As we have seen, the totem is the clan-name indicating descent from a common ancestor. It is also the clan- symbol, badge, or crest. Where the tribes among whom it is found are still in the picture-writing stage, i.e., when the idea is expressed by a portrait of the thing itself instead of by some sound-sign — a stage in writing corresponding to the primitive stage in language, when words were imitative — there we find the rude hieroglyphic of the totem a means of intercourse between difl'erent tribes, as well as with whites. A striking example of this is given in the sketch (Fig. 1), which is a copy of a petition sent by some Western Indian tribes to the United States Congress for the right to fish in certain small lakes near Lake Superior. The bird represents the leading clan, the crane ; then follow three martens, as totems of three tribes ; then the bear, the man-fish, and the ca(>fish, also totems. From the eye and heart of each of the animals runs a line con- necting them with tlie eye and heart of the crane, to show that they are all of one mind, and the eye of the crane has also a line connecting it with the lakes on which the tribes have their eyes, and another line running towards Congress. In the barbaric custom of painting or carving the totem on oars, on the bows and sides of canoes, on weapons, on pillars in the front of houses, and on the houses themselves ; in tattooing it on various parts of the body (in the latter case, in some instances, together with pictures of exploits; so that the man carries on his person an illustrated history of his own life) we have the remote and forgotten origin of heraldic emblems. The symbols of civilised nations, as, e.g., the Im- perial eagle, which so many states of ancient and modem renown have chosen ; the crests of families of rank, with their fabulous monsters, as the cherub, the Greek gryi^s, surviving in the griffin, the dragon, the unicorn, which, born of rude fancy or terrified imagination, are now carved on the entrance-gates to the houses of the great ; the armorial bearings on carriages ; the crest engraven on ring or embossed on writing-paper, these are the lineal de- scendants of the totem ; and the Indians, who could see no difterence between their system of manitous and those of the white people, with their spread-eagle or their lion-ram- pant, made a shrewd guess that would not occur to many a parvenu applying at the Heralds' College for a crest. The continuity is traceable in the custom of the Mexicans and other civilised nations of painting the totemic animals on their banners, flags, crests, and other insignia ; and it would seem that we have in the totem the key to the mystery of those huge animal-shaped mounds which abound on the North American continent. The arlntrary selection in the " ages of chivalry " of such arms as pleased the knightly fancy, or ministered to its pride, or, as was often the case, resembled the name in sound, togetlier with the ignorance then and till recently existing as to the origin of crests, and also the discredit into which a seemingly meaningless vanity had fallen, have made it diflioult to trace the survival of the totem in the crests even of that numerous company of the Upper Ten who claim descent from warriors who came over with the Conqueror. But there is no doubt that an inquiry con- ducted on the lines suggested above, and not led into by- paths by false analogies, would yield matter of interest and value. It would add to the e%'idence of that common semi- civilised stage out of which we have risen. Such names as the Horsings, the Wylfings, the Derings, the Ravens, the Sept. 21, 1883.] ♦ KNOWLEDGE ♦ 183 Griffins, may hold within themselves traces of the totem name of the horse, wolf, deer, raven, and that " animal fantasticall," the griffin. In Scotland we find the clan Chattan, or the wild cat; in Ireland "the men of Osory were called by a name signifying the wild red deer." On the otlier hand such names may have been given merely as nicknames (i.e., ekename or the added name, from eke, " also," or " to augment "), suggested by the physical or mental likeness to the thing after which they are called. But it is time to turn to the religious significance of the totem, as shown among races worsliipping the animal which is their supposed ancestor. At first glance this seems strong argument in support of Mr. Herbert Spencer's theory that all forms of religion (and all myth) have their origin in ancestor worship. The mysterious power of stimulation, of excitation to frenzy, or of healing and soothing, or of poisoning, which certain plants possess, has been attributed to indwelling spirits, which, as Mr. Spencer contends, are regarded as human and ancestral. Very many illustrations of this occur, as, e.ff., the worship of the Soma plant, and its promotion as a deity among the Aryans ; the use of tobacco in religious ceremonies among the tribes of both Americas ; whilst now and again we find plants as totems. The Pueblos have a tribe called the tobacco-plant, and also one called the red grass. One of the Peruvian Incas was called after the native name of the tobacco-plant ; and among the Ojib- ways the bufl'alo grass was carried as a charm, and its god said to cause madness. Its manlike character is seen in the accompanying picture (Fig. 2.) The worship of animals is on the like theory explained as due to the giving of a nick-name of some beast or bird to a remote ancestor, the belief arising in course of time that such animal was the actual progenitor, hence its worship. We call a man a bear, a pig, or a vampire, in syml)olic phrase, and the figure of speech remains a figin-e of speech with us. But the savage loses the metaphor and it crystallises into hard matter-of-fact. So the tr.aditions have grown, and Black Eagle, Strong BulFalo, ]5ig Owl, Tortoise, ic, take the shape of the actual forefathers cf the tribe having their name and crest. According to the same theory, the adoration of sun, moon, and mountains, kc, is due to a like source. Some famous chief was called the Sun ; the metaphor was forgotten ; the personal and con- crete, as the more easily apprehended, remained ; hence, worship of the powers of nature " is a form of ancestor- worship, which has lost in a still greater degree the character of the original.'* The objection raised in former papers of this series to the extreme applicaion of the solar theory applies, so it seems to me, with equal force to Mr. Spencer's limitation of the origin of myth and religion to one source. Having cleared Scylla, we must not dash against Charybdis. Religion has its origin neither in fear of ghosts, as Mr. Spencer's theory assumes nor in a perception of the Infinite inherent in man, as Professor Max Muller holds. Rather does it lie in man's " Principles of Sociology," p. 413. 184 ♦ KNOWLEDGE . [Sept. 21, 1883. sense of vague wonder in the presence of powers whose force he cannot measure, and his expressions towards wliich are manifold. There is underlying unity, but there are, to quote St. Paul, " diversities of operation." There is just that surface unlikeness which one might e.xpect from the dill'erent physical conditions and their resulting variety of subtle influences surrounding various races ; influences shaping for them their gods, their upper and nether worlds ; inlluences of climate and soil which made the hell of vol- canic countries an abyss of sulphurous, stifling smoke and everlasting fire, and the hell of cold climates a place of deathly frost ; which gave to the giant-gods of northern zones their rugged awfulness, and to the goddesses of the sunny south their soft and stately grace. The theory of ancestor-worship as the basis of every form of religion does not allow sufiicient play for tlie vagaries in which the same thing will be dressed by the barbaric fear and fancy, nor for the imagination as a creative force in the primitive mind even at that lowest at which we know it. And, of course, beyond that lowest lies a lower never to be fathomed. We are apt to talk of primitive man as if liis representatives were with us in the black fellows who are at the bottom of the scale, forgetting that during unnumbered ages he was a brute in everything but the capacity by which at last the ape and tiger were subdued within him. Of the beginnings of his thought we can know nothing, but the fantastic forms in which it is first manifest compel us to regard him as a being whose feelings were uncurbed by reason. That ancestor-worship is one mode among others of man's attitude towards the awe-begetting, mystery- inspiring universe, none can deny. That his earliest temples, as defined sacred spots, were tombs ; that he prayed to his dead dear ones, or his dead feared ones, as the case might be, is admitted. From its strong personal character, ancestor-worship was, without doubt, one of the earliest expressions of man's attitude before the world which his fancy filled with spirits. It flourishes among barbarous races to-day ; it was the prominent feature of the old Aryan religion ; it has entered into Christian practice in the worship of saints, and perhaps the only feature of religion which the modern Frenchman has retained is the culte des morts. That it was a part of the belief of the Emperor Napoleon III. the following extract from his will shows : — " We must rememlier that those we love look down upon us from heaven and protect us. It is the soul of my great Uncle which has always guided and supported me. 'Thus will it be with my son also if he proves worthy of his name." But the worship of ancestors is not primal. The re- marks in my former paper on the late recognition of kin- ship by savages, among whom some rude form of religion existed, tell against it as the earliest mode of worship. ^Moreover, nature is bigger than man, and this he was not slow to feel. Even if it be conceded that sun-myth and sun-worship once arose through the nick-naming of an ancestor as the Sun, we must take into account the force of that imagination which enabled the unconsciou.q myth- maker, or creed-maker, to credit the moving orVis of heaven with personal life and will. The faculty which could do that might well express itself in awe-struck forms without intruding the ancestral ghost Further, the records of the classic religions, themselves preserving many traces of a primitive nature-worship, point to an adoration of the greatness and bounty, as well as to a sense of the malefi- cent and fateftd, in earth and heaven wliich seem prior to the more concrete worship of forefathers and chieftains. If for the worship of these last we substitute a general worship of spirits, there seems little left on which to differ. As aid to the explanation of the belief in animal ancestors and their suljsequent deification and worship, as of the lion, the bull, the serpent, &c., we have always present in the barbaric mind the tendency to credit living things, and indeed lifeless, but moving ones, with a passion, a will, and a power to help or harm immeasurably greater than man's. This is part and parcel of that belief in spirits everywhere, which is the key to savage philosophy, and the growth of which is fostered by such secondary causes as the worship of ancestors. SUX-YIEWS OF GREAT BRITAIN. THE .-ispect of Great Britain, France, Denmaik, &c., as supposed to be seen from tlie Eun at noon (Greenwich time), at this season of the year is shown in Fig. 2, Pig. 1 showing the aspect those regions had at noon in midsummer, an 1 Fig. 3 showing the- aspect they will have at noon in midwinter. Fig. 3. At noon, Midwinter (Greenwich time). Sept. 21, 1883.1 ♦ KNOV\ALEDGE ♦ 185 OnK JfoXTH AFTER SlMMER SOLSTICE. OnE JfoXTII BEFORE AUTIMNU, EfJIINOX. At THE AVTUMXAL E^O -."OX. SUiS VIEWS UF THE EARTH; OE, "THE SEASONS ILLUSTRATED." By Richard A, Proctor. I GIVE tliia week the Sun Views for tlic moiitli, sliowin;^ tlio aspect of tlie ei rth as suppiseil to be seen from tlie sun at six in tlio morniup, noon, six in the evening, aiul niitlnif^ht, Groenwiuh solar time., nt tl.e antmiinal oquiuo.'C. For comparison, the Sun Views for July and August are repeated. 186 * KNOV/LEDGE ♦ [Sept. 21, 1883. NOTES OX PUNCTUATION. By Richard A. Proctor. THE Brighton Herald contends zealously for the rights of the humble comma, though now somewhat changing the figure by speaking of the comma as a humble but willing soldier, always ready to do its duty. The Herald is with us so far as the appearance of the comma before " who " or " which," when not wanted there, is concerned. A recent e.xample has illustrated the mischievous effect of such excess of zeal on the part of the humble but willing soldier. Writing of " the Brighton Liberals who met yesterday, ic," the Hi'mld found a Conservative con- temporary had altered the meaning of the words by pressing a humble soldier in before the " who." But the Herald maintains its position about the use of the comma on either side of " therefore," in such a sentence as, " He called for help ; and therefore I struck him," which the Herald writer would punctuate, " He called for help ; and, therefore, I struck him." He reasons thus : — Onr position, and we think it a strong one, is that the "there- fore" is a parenthetical introduction, quite independent of the " and," which, indeed, it in no way qualifies. The " and " is the conjunction," the "therefore" an explanatory aUasion, not to the " and" but to the sentence preceding it. Mr Proctor thinks that if the "and" were omitted, no one would think of addins: a comma after " therefore." Possibly not, though even that is an open issue ; but we must point out that the omission of the " and " implies a re-construction of the sentence, and, therefore, that what would hold good in one case need not necessarily be held to be bad because it does not hold good in the other. The same remark will apply to Mr Proctor's other illustrations. After reading the article very carefully, we cannot adopt Mr Proctor's contention that " and, therefore," is " simply monstrous," and we are afraid that we shall persist in the " absurdity which no good writer ever allows to remain, if he can possibly help it." How many well-intentioned gentlemen who imagine tliemselves to be " good writers " will this sentence shock ! [I am doubtful whether " this sentence " means the quoted sentence of mine or the whole sentence : if the former I can only say that I had no wish to shock "well- intentioned gentlemen who imagine themselves good writers."] Now though the question thus raised is not a very important one it illustrates well the general principles in- volved in punctuation. Here is a writer who, after careful study of the matter, arrives at the conclusion that certain commas are necessary or at least desirable soldiers in a simple sentence, while here (at his desk perusing these words) is another who considers them simply monstrous, or at least described them so when he supposed that no practised writer would stand up for them, after a little consideration of what appeared to him their inherent absurdity. Of course the word " monstrous" is withdrawn now, out of courtesy. But my objections remain. Suppose for a moment that we regard the word " there- fore " as a parenthetical introduction, would that justify its enclosure between commas ? Not at all ; for " commas" are entirely different from parentheses in their meaning and effect. The best proof of this is that there may be three or five commas in a correctly punctuated sentence, whereas parentheses always come in pairs. Thus consider the sentence "He insulted me; and, therefore, I struck him, but not violently." Here there are three commas, the two first put in according to the HerakTs plan and the compositor's constant rule, the third manifestly necessary. Where now is the parenthetical introduction % Is it the word " therefore," or is it the statement " I struck him " ? If commas and parentheses were interchangeable it might as well be one as the other ; in other words, the sentence, judged by the Herald's way of treating commas, bears more meanings than one. But again, (wliich compositors nearly always change into But, again,) suppose we write " and (therefore)," or " and, therefore," agreeing to regard the commas as paren- theses, what liave we done by thus carefully nursing our parenthetical introduction? Have we helpid the .sense'! Have we made it clearer than it was before; that the word " therefore " relates to the preceding sentence. On the contrary, so far as we have done anything besides cum- bering the sentence, we have made it appear that the word " therefore " relates specially to the " and " ; for a paren- thetical introduction is always referred to what imme- diately precedes, or belongs specially to the place where it is brought in. (In this indeed consists the whole art of using parentheses properly). Apart from the logical pressure thus brought to bear on the unfortunate little " and," consider the pressure which falls on it from the mere effect of pausing before and after the word " there- fore." Read aloud successively, — He called for help ; and therefore I went to him, He called for help ; and, therefore, I went to him, making in each case a proper pause for each stop, and the absurdity of the commas attending on therefore becomes at once apparent. Try these sentences again, — He insulted me ; and therefore I went away, He insulted me ; and, therefore, I went away, He insulted me ; and therefore (not wishing to make a scene) I went away. He insulted me ; and, therefore, (not mshing to make a scene) I went away. The last two show the proper use of parentheses. In the former (of these) commas might have been used in accord- ance with the custom which allows them sometimes to replace parentheses ; but parentheses are better, since they interrupt the sense less. Some who object to parentheses altogether, would prefer He insulted me ; and therefore I went away : for I did not wish to make a scene. But there can be no doubt that the use of parentheses in such cases as these diminishes what may be called the mental friction in reading. In connection with the parenthetical value of the comma, examine the first sentence in the passage quoted above from the Brighton Herald. It is a curiosity in its way. The fact is, however, that apart from all questions of logic, punctuation, and so forth, the spirit of our language, I may say the spirit of language, rejects altogether the idea that such words as so, yet, tlius, hence, therefore, again, however, indeed, and the like, are to be regarded as paren- thetical introductions. They may be described as ad- verbial conjunctions, with no more right, usually, to be defended on either side by the humble comma, than and, hut, and other conjunctions possess. Sometimes commas are wanted, however. The Brighton Herald cannot see why in the sentence " In quite a number of cases however the commas are better omitted " I leave " however " alone, while in the sentence, " Here, however, these is room for the practice " I put a comma on each side of the word. I had good reasons. In the first sentence the commas could be omitted ; and whenever they can be they should be : nothing is more suggestive of inexperience in writing than failing to throw overboard every comma which can be spared. In the other case, putting in the commas threw the emphasis on " here," which was what I wanted. There is a very just objection to the unnecessary or too frequent use of parentheses, but the feeling against them Sept. 21, 1883.1 ♦ KNOWLEDGE - 187 is with many a mere prejudice. The proper rules for paren- theses and the use of the dash, are, Use them when by so doing you diminish distraction, Avoid them when their use increases distraction. (I speak of diminishing and increasing distraction ; for there is always some distractive effect in written matter.) I use parentheses freely, and some imagine that this results from over-quick writing, matters being thrown in between parentheses as a sentence runs on, which, had I written more slowly, would have come into a separate sentence. This is not the case. On the contrary, I am often at the pains to put within ]iarentheses afterwards, matter which I had originally put by itself, judging (wrongly sometimes, mayhap, but still always after reflection) that the attention of the reader would be less distracted if a part of my reasoning came in as a passing thought, than if it were formulated separately after the break of a full stop. The passage Vietween paren- theses in the last sentence is a case in point : 1 wanted to show that I did not claim to lie always right in opinions formed about parenthetical passages; but I did not deem it well to make such a remark separately after my sentence was finished, so I threw it in where it was wanted and where it would receive as much attention as it needed and no more. With regard to colons and semicolons, I must say I differ from Sir Edmund Beckett. If there are any two "points" about whose use I never feel any doubt, the colon and the semicolon are the two. Apart from the work of the point-pepperer, who may have marred my intentions, I may confidently say that in all I have written since I first penned a line for publication — now just twenty years since — there is not a single colon which I would willingly see changed into a semicolon, or vice rersd. My own particular rule on that head is simply that a colon only should be used to separate complete sentences, which would be separated by a full stop were it not that you wish to indicate some con- nection between them, — as for instance that they both relate to the same subject, that subject not being the subject of the paragraph itself in which the colon-divided double sentence appears. (See the last sentence in the preceding paragraph, and also the last sentence in the next. ) The writer in the Brighton Herald objects to my theory that we should be economical of the comma ; for he says it is wanted in long sentences though it may be spared in shorter ones. He has not quite apprehended my argument. It is precisely because the comma is so useful in long and involved sentences that we should economise it. In a short sentence we can throw in commas without fear of anything but distraction to the reader : in long sentences if we use the comma before it is wanted we are left without resource, save the too cumbrous semicolon, when the time of real ne(!d arrives. I may in conclusion mention what T think some of my readers may be interested to learn. Twenty years ago, as I have said, I began to write. I was moved by a strong desire to give a clear and popular explanation of Doppler's Theory of the Colours of Double Stars, liy which I had been much interested. I found myself so hard to satisfy, so far as forms of e.xpression were concerned, that to write an article! of nine pages I took about two nionths, writing sometimes only three or four lines a day. The article appeared in the C'ornliiU Jfnffazine for December, 18G;). Later (in 18C4) when I was writing my book on Saturn, I still had so much difficulty in writing to my own satisfac- tion, that I would retain in my mind the reasoning of a whole chapter rather than begin the work of conuuitttng it to paper. I remember that when some delay occurred about the printing of the long and difficult cliapter on "The Great Inequality," I imagined the printers must have lost the MS., and I wrote to tell them that I could replace the chapter, if they told me of the loss in time, knowing the whole of it by heart, — so laboured had been its produc- tion. It may be noticed by those who possess the fir.st edition that there is but one passage, from beginning to end of the book, where any attempt is made at poetical description. That is in the concluding paragraph of Chapter III. ; and though my mind was overflowing with thoughts of the beauties of the ringed planet, my pen refused to transcribe more than six lines. I went to school as a writer under a severe taskmaster — myself. SEA ANEMONES AT THE FISHERIES EXHIBITIOX. By Thomas Kimbee. IV.— THE DAISY. Actinia hellis (Ellis and Solander.) Actinia pedunculata (Pennant.) ACTINIA BELLIS in contour is very much like a daisy, but bears no resemblance to one in colouring. This anemone is highly valued by collectors, partly for its own sake and also because it is not easily obtained in good con- dition, on account of its habit of ensconcing itself in crevices and holes. When, therefore, the difficulty of capture has been overcome and a perfect specimen is secured, it is very much esteemed. In addition to which, when once settled in a tank or vase Daisy is almost in- variably in full bloom, it is also very hardy and easily kept in health. Fig 1. The liloom or Flower. — The general surface of the disc is a horizontal plane, though in some instances it is slightly concave. The ordinary appearance of this anemone is fairly described as that of a saucer set upon a slender pedestal. The edge of the calyx is usually circular but sometimes it is frilled like a half-opened flower, and then has the appearance of Iwing lobed. The tentacles, arranged in about six rows, are inclined towards the centre or nearly erect in the inner row, and are much longer tlian those in the other rows. The total number of them in the six rows is estimated at about TjOO, arranged as follows, beginning with the innermost, 12-|- 12-f 2^^1-1- IS-|-9G-fJ88 = 4S0.^ Thegonidal radii are frequently strongly marked, and in fine specimens this marking is extended Ijy two tentacles, one on the side opposite to the other, which are larger by one third than any of the others, and not mottled like them, but of uni- form colour, either cream-white or ochre. In some in- 188 ♦ KNOWLKDGE ♦ [8£FT. 21, 1883. dividuals there is only a sinj;le radius and one tentacle of this character, and in others there is no trace of either. The lips are rather thin and minutely furrowed. There are two principal varieties of bellis, distinguished by the colour of its disk — one a dark chocolate brown, closely and evenly striped with bright scarlet, radiating from the centre to the edge. The lip in this variety is tinged with violet, and the tentacles are of a rich brown colour, relieved with blue-grey and opaque white The other variety is of a tamer brown, in several shades, relieved with grey and opaque white, and occasionally enlivened with light blue tints. There is a good coloured representation of this variety — disk, column, and button — in Gosse's " Ilambles on the Devonshire Coast," p. 28, pi. 1. Fig. 2. The calyx, d;c. — The calyx and the upper half of the pedunculus — i.e., the stem — are studded with the whitish protuberances called warts, which are suckers. To these ordinarily, when the animal is first captured, sand- grains and fragments of shells are attached, and ettectually conceal the parts so covered. When unobscured, the calyx is found to be grey, inclining to blue, which is toned down along the stem to whitish lirown, and not mifrequently to a beautiful pink. The foot is invariably expanded, and very irregular in its outline. The figure is extremely variable, and some curious examples of its variations are given in Dr. Johnston's " British Zoophytes," 2nd edition, p. 231. Within the space of a single hour Bellis will present a great variety of shapes. This Protean mutability of form is effected in two ways. First, by distension of the body with water until it nearly equals the disk in diameter ; and, in the next place, by constricting itself in one part and constantly moving the position of this constriction. When extended to the utmost limit the stem is slender and perfectly cylindrical. Bellis is usually found in clusters of at least four or five individuals in each cluster, and crowded together in the same crevices or fissures, where their expanded disks press upon each other and form a continuous row of flower-like bodies. Cornwall is called the metropolis of the English species. In Mount's Bay and along the Cornish coast daisy is the commonest of its genus. It is a littoral dwelling animal, and seldom met with except between tidal limits. Mr. Cocks (Johnston lU supra) points out that pretty Daisy will sometimes forsake those " wells of pure water " — the tidal pools — for what he describes as little better than a Stygian bog. " I found the beach," he writes, "composed of mud, sand, and decomposed algie ; many of the stones when lifted presented a face as black as the skin of an African, and sent forth a rich aroma of sulphuretted hydrogen. In turning the stones over, I was astonished to find in this Pandorian locality herds of the Actinia bellis in prime condition — ^jackets as red as a Kentish cherry — tubercles on external portion of the disk, light neutral tint, and strongly marked — so pugnacious that, when touched, water issued in full streams from nearly all the ducts or apertures. The ground is literally covered with them. The oral disk and the tentacula present a variety of tints — dark Virown, light fawn, dark and light ochre, cream, etc. ; all the tentacula (one excepted) are annulated. Each individual (I have fourteen in my bottles) has the ochre-coloured or white tentaculum — nearly one-third larger than any of the others — making one of the central row ; and a white or liuff mark, or line, extends from it to the angle of the mouth on each side." Bellis is almost invariably stationary, rarely quitting its home or corner to which it has once become attached. Besides being able to produce the convolutions of calyx and peduncle, already described, it occasionally projects its disk and lips, which movement is called pouting, and it can retract completely both tentacles and disk when it appears in button form. A curious habit, through not peculiar to Daisy, is thus described by Mr. E. W. H. Wordsworth : — "I have seen the elongation of one of the tentacles of the first row in Bellis. The ordinary shape and proportions were retained, but the arm was stretched to more than twice its natural length, yet without any appearance of unnatural tension or straining ; it was constantly in motion, apparently feeling about for something, but assumed its usual size after a few hours." Another observer noticed a tentacle on each extremity of the disk's diameter thrown out until the two together commanded an area of fully six inches in length by four in width. The space within this area was minutely examined by moving each tentacle in numerous circles and various elegant curves. The object of this singular movement was tested by placing a scrap of meat within reach of one of the elongated tentacles, when it was immediately seized and conveyed to the mouth. (To he continued.) JACK KETCH. By Richard A. Proctor. WHAT a pleasing effect the newspaper references to the " conmion hangman " are calculated to produce. Formerly, the subject was not considered very suitable for re- spectable papers. We could take up our Tinu's, or Daily Nev;s, or Standard, with the assurance that, except in the accounts of executions, we should find no reference to the common hangman. Lately it has been dift'erent. One day we learned how the wretch who last held the office employed his leisure time ; another day we were told how he had been allowed to visit the Houses of Parliament, and how among the 66G (or whatever the actual number) who repre- sent the collective wisdom of our legislature, several showed marked attention to the degraded ruffian who had delibe- rately selected man-killing as part of the business of his life; next we hear of the details of his illness as if some great statesman or public benefactor were nearing his end ; and now, with atrocious ill taste several of our daily papers (papers which may be laid each morning on the tables round which our A^ives and daughters sit) repeat the ghastly communications sent in by the murderous brutes who wish to be the next of our common hangmen ! Truly those who provide matter for our journals are strangely Sept. 21, 1883.] ♦ KNOWLEDGE ♦ 189 ill acquainted with the tastes of British readers ; unless it is to be held that beneath a veneer of culture we have exceedinjily coarse and savage tastes. Are we to suppose that in cock-fighting, bull-baiting, public prize fights, and other noble " sports " with which a " sentimental law- making " has interfered our innate savagery found a wholesome vent, and that now, wanting these, our people require to be supplied with " gallows news " to satisfy their hankering for what is savage and brutal ? I fancy the leaders of public opinion (Heaven save the mark) might safely have credited us with better taste. It may be urged that as we must have executioners so long as capital punishment is in vogue, the holder of the office ought not to be held in contempt, or regarded as necessarily a cruel and brutal wretch. There is, however, no iimst in the case. In America for the last half century there have been no " common hangmen " though capital punishment is still awarded and occasionally inflicted. On the Continent where there are executioners, their identity is concealed. No one in Great Britain was ever driven by want to take the office. The letters published so cheerfully in the public journals may at least serve a useful purpose in showing what manner of men hangmen are, — though this might have been guessed without so ghastly and degrading an exhibition. As to the propriety of capital punishment, nothing need here be said. Taking the scientific view of the matter it may be noticed that Nature inflicts capital punishment relentlessly — if somewhat blindly — for less offences than those for which the law assigns the penalty of death. If there were no law for eliminating murderers from our midst they would be removed ere long without law ; and systematic elimination is better than irregular removal. But in these days a more seemly system of capital punish- ment ought to be adopted. Ciiitonal (Sosfsiip. A CORRESPONDENT is exercised in his mind because at a recent meeting of the Astronomical Society certain doubts were raised respecting a point in the Lunar Theory. He tells me tliat a certain Mr. W. H. Phillips has devised " a new theory of a serpentine course of the moon " to which I ought, it seems, to have long since alluded. Mr. Phillips " says plainly," writes my correspondent, " that your theory and all astronomers an: irrmvj, and that the Royal Astro- nomical Society had generously [acknowledged his new discovery " — " so you see," he adds, referring to a former communication, "I am not mistaken in what he says about the Royal Astronomical Society owning to their being wrong in this matter of a Lunar Theory." This is not the first time that a discussion in the Astronomical Society about some matter far beyond the range of the general student, has been mistaken for an expression of doubt about an elementary matter. I remember that the late Mr. Reddie, paradoxist and founder of the Victoria Institute, was convinced that the Astro- nomical Society and the Astronomer Royal in particular, were coming round to his views, becausi; Sir George Airy showed that the theory of the sun's proper motion in space was as yet by no means complete. Mr. Reddie had not the least idea what "the sun's propi^r motion in space" might mean ; but he had ventilated some wild ideas about elementary astronomical matters and especially about the sun's fixity of position, so he immediately jumped at the conclusion that Sir (icorge Airy had heard of these notions and was speaking of tluun. Now as a matter of fact Mr. Reddie's letters had long since found a place on the shelf which Sir George Airy had cruelly labelled, "MY LUNATIC ASYLUM FOR LUNATICS." It ought not to be necessary for me to explain that the douljts raised recently by Mr. Stone respecting the Lunar Acceleration have nothing whatever to do with the ordi- nary account given by astronomers respecting the moon's motion round the earth and (with her) round the sun. There never has been any doubt about this point since the Copernican theory was established, — and there never can be (that is, among astronomers). When astronomers speak of the Lunar Theory they do not refer to so elementary a matter as this ; but to the mathematical analysis of those multitudinous perturbations which the moon's movements undergo, by which she is now swayed a little on this side now a little on that side, now a little above anon a little below, the course she would pursue if undisturbed in her combined elliptical paths around earth and sun. This course would differ little from an ellipse around the sun at one focus ; for as Sir George Airy neatly put it (in a letter to Mr. Reddie) the moon may be regarded as a planet travelling around the sun but largely perturbed by the attractions of a neighbouring planet, the earth. The analysis of the other perturbations and of the constant fluctuations in the elements of the moon's apparent orbit round the earth, constitutes what is called the Lunar Theory, a subject which none but advanced mathematicians can hope thoroughly to grapple with, far less to deal with so as to advance our knowledge respecting it. The Dif- ferential and Integral Calculus is the A B C of the subject and of all kindred subjects. As we want to be a good deal Ijeyond the A B 0 to read profitably, so must the mathematician be far beyond his first acquaintance with the " Dif-Cal " to follow the complex reasonings involved in the Lunar Theory. P.\RTS of the Lunar Theory remain still to be more fully explored than as yet they have been. Among these must be mentioned the Lunar Acceleration, that slight but measurable hastening of the moon in her course, by which she would not gain her whole apparent diameter in many centuries. It was supposed at the beginning of the present century that Laplace had explained this phenomenon fully, by his masterly analysis of the efiect due to the gradual diminution in the eccentricity of the earth's orbit. But recently Professor Adams showed that when the analysis was carried somewhat farther half the acceleration remained still unaccounted for. After a long inquiry Adams' con- clusions seemed established, and Delaunay suggested that the part of the acceleration unaccounted for might be apparent only, the real change being a constant but slow retardation of the earth's rotation ; and he pointed to the tidal wave as capable of retarding the earth's rotation, though whether in suflicient degree to account for the estimated change, he could not say. And now further inquiry by Mr. Stone, Radcliffe Observer, indicates the probability that with further and deeper analysis the Lunar Theory may be able to account for the whole acceleration after all, without our having to assume any measurable retardation of the eartli's rotation. Yet retar- dation of terrestrial rotation is doubtless taking place all the time. The Delaunay mentioned in the preceding paragraph must not be confounded with the Delaunay wlio has ventilated absurd theories about the influence of tlie 190 ♦ KNOWLEDGE ♦ [Sept. 21, 1883. planets in producing earthquakes. The latter, Captain Delaunay, made a happy hit in j)redicting a great terres- trial disturbance within two days of the time of the Javan earthquake. But a dozen such coincidences would not establish a theory so preposterous. As M. Faye said, commenting on Captain Delaunay's ideas, nothing is more certain in science than that the influence of the planets on terrestrial phenomena is iiiL OUR AMERICAN COUSINS.* WE have read many books about America, books meant to be brilliant, witty, humorous, profound, entertaining, and so forth ; some meant to exhibit Americans as they are, others written to teach the Americans what they should be ; books laudatory, and books scathing in denunciation. Here is a book which treats a subject one might suppose to be well worn, yet as full of freshness as though no one had ever yet written about America. There is no effort at effect, yet the account is thoroughly effective. We find here what a thoughtful Englishman, kindly but honest and just, has to say of that great nation which has grown on the other side of the Atlantic from European and chiefly from British blood. Mr. Adams has done thoroughly well what he sought to do, he has " presented a fair and accurate picture of so much of American life and American manners as came within his own observa- tion." That there is much more of praise than of dis- approval in this book proves the fairness of the writer ; for no honest and intelligent Englishman can visit the United States without being impressed by the fact that in many most important matters, and espe- cially in those which touch the dignity of manhood, the conditions there are more favourable than on this side of the Atlantic. But in his admiration for what is good Mr. Adams does not lose siglit of less favourable con- ditions. He speaks plainly of what undoubtedly is the " rock ahead " for America, the readiness of Americans to suffer the control of aflkirs, — national government, state legislature, and civic administration, alike, — to be in the hands not of the best men, but of men who often are among the worst in the land. Because greedy and unprincipled men have grasped at power and wealth, the best men in America withdraw from politics, showing not true disinterestedness (though they are disinterested) but want of due interest in the welfare of city, State, and nation. Mr. Adams notes justly too one important cause of this — to wit, the unmeasured abuse poured by party papers in America (and what papers in America are not party papers 1) on every candidate for ofiice. With the certainty that however pure his motives, honest his zeal, and earnest his labours for his country's good, he will be abused by some if not most of the organs of public opinion as a scoundrel and a villain, the most patriotic American is apt to be deterred from the thought of giving his services to his country. The evil is deep-seated and affects the very life-blood of the nation. We can say emphatically and truthfully of Mr. Adams's book that it is by far the best work of its kind we have yet seen. Reading it will correct many false impressions which Englishmen entertain respecting the great nation * " Otit American Cousins " : being Personal Impressions of the People and Institutions of the United States. By W. E. Adams. (Walter Scott : London). which their cousins have formed on the other side of the Atlantic. We do not agree with all that Mr. Adams says. (For instance, liis love of freedom which we fully share, leads him to overlook, as it seems to us, the wrongdoings of those through whose action but against whose original intention, slavery was done away with.) But even his mistakes, or what appear to us as such, approve his fairness and justice. He presents throughout the facts as he sees them, and his insight is keen and true. From this small and cheap work more may be learned about the real character of America and the Americans than from any book we have seen. We may add that the substance of Mr. Adams's book appeared originally in a series of articles contributed to that excellent weekly paper, the Newcastle Weekly Chronicle. r^z.~.:r " Let Knowledge gi'ow from more to more." — Alfred Tennyson. Only a small proportion of Letters received can possibly he in- serted. Corresponde'its must not be offended, therefore, should their letters not appear. All Editorial commtmications should be addressed to the Editor of Knowledge; all Bnsiness cormnunications to the Pcblishers, at the Office, 74, Great Queen-street, W.C. If Tras is not attended to DELAYS ARISE FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should be made payable to Messrs. Wyman & Sons. The Editor is not responsible for the opinions of correspondents. No COMMUNICATIONS ARE ANSWERED BY POST, EVEN THOUGH STAMPED AND DIRECTED ENVELOPE BE ENCLOSED. VISUAL PHENOMENON; COLOUES OF FLOWERS; ERRATUM. [934] — The phenomenon seen by ilr. Leonard Brown (letter 906) has been investigated by Mr. John Aitken, of Darroch, Falkirk. An account of his experiments will be found in the Journal of Anatomy and Physiology, for 1S78 I believe; but as I have mislaid the author's copy which he kindly sent me, I am not sure as to date. No doubt, however, a letter on this subject sent by Mr. Brown to the above address would be courteously replied to. For an experimental investigation of the colours of flowers, Mr. G. G. Hardingham may be referred to Dr. Sorby's paper on " Com- parative (Vegetable Chromatology " ("Proceedings of the Royal Society," No. 14G, Vol. XXL, 1873). The paper is 41 pp. long, and cannot, therefore, be condensed into a paragi-aph. He confines his observations for the most part to colouring matters obtained from the leaves of the higher or the fronds of the lower classes of plants. I think, however, that Dr. Sorby would not undertake to say hoi" colour is formed in flowers, inasmuch as he winds up his paper with this remark, "The stoi-ing up of the energy of the sun's rays in the various compounds formed by plants is probably so intimately connected with the optical and chemical properties of some of their coloured constituents, that the further extension of such inquiries as I have described may possibly assist in clearing up this very difficult and yet most important problem." (On page 155, second column, line 5, for " ires" read " irises.") William Ackroyd. W^\JtT-CHARMING. [935] — Apart from any superstitious credulity, I beg I may be allowed to entirely upset the " simple explanation" of "Mephisto" regarding Wart-Charming. An old gardener lived many years in our family. He was unlettered, but might be called " one of Nature's gentlemen." He was gifted with great imagination, and often, as children, we would listen with intense delight to him. He possessed the power of wart-charming. [Would one not rather say the power of impressing the minds of the warty ones ? — R. P.] Brothers from school often applied to him for help in the cure of Sept. 21, 1883.] ♦ KNOWLEDGE ♦ 191 these annoyances. I myself have shared in the effects of his mystic powers. The number of warts were given and faithfully counted by liim in cntting notches on a stick. In strict secresy this stick was buried in the garden, [tlio gardener] uttering over it some charmed sentence, which no one was allowed to hear. The warts quickly vanished. A visitor in our family underwent the same treatment, ^vith the same happy result. The warts were neither touched with saliva, or even looked at. A Co.N'STA.NT Header of " Knowledge." [936] — As a subscriber to your excellent paper, Knowledge, I saw (in No. 81, for May 18, 1883, amongst " Letters to the Editor") a very interesting article under the heading of " Wart Charming." If you will kindly allow me, I will offer an experience of my own with regard to warts, which you are at liberty to insert in your paper if you think it of any interest. When I was a boy of about fourteen years of age I happened to have upon the back of my right hand three to four warts. One day a friend, happening to notice them, said that he would soon drive them away, and there and then told me what to do. Said he, "Next time you see a female dog, put something sweet over the warts and make the dog lick them, as long as you can over five minutes. I laughed, as I had a suspicion that the gentleman was making fun of me. However, I thought I would prove the gentleman's method any way. So for three days after was on the look-out, when at last I fell in with an old schoolmate who had a little bitch along with him. Immediately I made friends witli her and patted the animal on the head kindly; then I placed a few crumbs of biscuit (1 happened to be munching at the time) upon the warts, and offered them to the dog. She ate them up greedily and licked the place over and over again, when I would put more crumbs on the warts ; this kept her licking long over five minutes. Then I went home soon after and forgot all about the occun*enee, when, lo ! a few days after I was suddenly amazed to find the warts gone, but the place where they had been was visible for a little time after and then disappeared also. I can answer for the truth of this, and, as far I am able to understand it, it is, as you say, in some way influenced by the mind over the body, the attention being called towards them. Yokohama, July 12, 1883. Henby A. Vincent. [The case illustrates " Mephisto's " theory, which no doubt has an element of truth in it, though the mind influence theory is not overthrown or even shaken by it. — K. P.] DEAF CATS. [937]— R. S. T. (850) writes of a family of deaf cats, whose deaf- ness he attributes to in-and-in breeding. I, too, have some acquaintance with deaf cats. The first I met was given to me as a very small kitten, in Syria, by a gentleman who told me it would grow up deaf, adding as a fact in natural history, that all white cats with blue eyes are deaf. I took my kitteu to Malta, when in due time ho developed into a deaf cat. At Malta I lodged in a house where my landlady possessed a family of three wliite Persian cats, all of whom were deaf; of course, for anything I knew to the con- trary, in-and-in breeding may have been the cause in both cases, tliough certainly independently of each other, for my cat is not a Persian, and is like those belonging to my landlady only in colour. I may mention that my landlady is also acquainted with the quasi- jihysiological fact that white cats with blue eyes are invariably deaf. I can answer for these animals not being deaf mutes, liowever. What a comfort it would be if this could be achieved by iu-aud-in breeding or any other means. LETTERS RECEIVED, AND SHORT ANSWERS. C. W. B. Yes ; though your account is inexact, and your drawing, as you say, exaggerated. From the centre of whatever hemisphere of the earth is turned moonwards, a certain hemisphere of the moon is visible at any given moment ; from points round tho edge of that hemisphere of the earth, an observer can see a certain small distance beyond this hemisphere of the moon. The fringe of the moon's farther heuiisphere thus brought into view, is about one degree of are in breadth. — W. H. Bangall, B.A. Tho subject is excellent and Mr. Alien would treat it admirably ; but so many subjects are excellent, and he is admirably treating subjects of his own choosing. — J. A. R. Of course tho principle of such tricks is obvious; yet they interest many. — H. F. F. IF. I do not know how rain-water may be kept sweet in a large wine cask. — James Bukn. It is sad that none of tho seientilie con- tributors of the Newcastle Weeld]/ Chrnnidc noticed vour theory about tho way in which the earth receives her heat. You have " formed the opinion that the rays of light when coming in contact with the atmosphere, after having passed through the frigid zone which encircles the globe either by an electrical or chemical action, lets loose the latent fire which the region of the air holds, as it were, in solution : by this means the earth will always have a suificient supply of heat, and when it has done its duty it will again retm-n to its aeral home." I have formed the opinion that I know no more than you do yourself what you mean. Try this theory : — The molecules of aqueous vapour super- saturated (as it were) with carbonic acid pass either by polar or magnetic action (so to speak) athwart the torrid zone which encircles tho globe, and there bind the miasmatic emanations, which would otherwise pass away into the interplanetary a;ther ; thus there is no waste, but (as one might say) a constant regeneration of (what may be called) the mundane heat fuel. " I trust I make myself understood." — H. Price. Whether, your eyesight being such as you describe it, at present, you vrill be able twenty years hence to see as well, — your age being now 30 — I find myself unable to divine. I see as well now as I ever did in my life ; but whether I shall be able to do so when I am fifty, I cannot say. How then can I tell you what your eyesight will be like a score of years hence. — Ed. Sheppard. You take three digits, selected by A, B, and C, multiply A's, by 20 and add twice B's, then midtiply the sum by 30 and add 6 times C's ; dividing the sum by G you have the three digits. Well this is not very surprising. Your process gives you, — 1°, six times C's digit; 2°, twice B's multiplied by 30, or 60 times B's ; and 3°, 20 times A's multiplied by 30, i.e., 600 times A's : therefore naturally, dividing by six, you have C's digit, 10 times B's, and 100 times A's ; i.e., A's in the hundreds' place, B's in the tens' place ; and A C's in the units' place. — Phonos. Know of no work that explains and teaches the thousand and one games that can bo played with a pack of cards. Erratum.— In the last line of Letter 926 (p. 173) 17-8" E. of Greenwich should be 17'8 sees, (of time) E. of Greenwich. &nt Cbrss Column. By Mephisto, SOLUTION. Problem No. 96, by J. Berger, p. 160. 1. Q to R5 1. K to Kt4 2. B to Kt6 2. K moves 3. Q mates accordingly If 1. K to K6, 2. Q to K 8i (eh), anl 3. Q to Q2 mate; or >i 1. P to K5, 2. Kt to Kt6 (eh), and 3. Q to K sq mate. PROBLEM No. 99. Fourth Prize Three-mover in the Nuremberg Problem Tocknament. By J. Berger, Graz. Black. White to play and mate in three moves. (We shall be pleased if our solvers will institute a comparison between this problem and the lirst-prize three-mover in Knowledge, 192 ♦ KNOWLEDGE ♦ [Sept. 21, 1883. No. 89, p. 33. We think such a comparison will result favourably to the above composition). GAME PLAYED ON THE 30th OF JULY, 1883, IN THE NUEEMBERG INTERNATIONAL CHESS TOURNAMENT. Scotch Gambit. Black. Gunsberg. P toK4 Ktto QB3 P takes P B toB4 Q toB3 KKt to K2 Kt takes Kt (a) B to Kt3 P to KR3 (b) P to Q3 White. Blackburne. 14. QR to B sq 15. Kt to B4 16. P to QKt4 17. P to K5 (.») 18. P takes P 19. B takes P 20. B takes P 21. R to K7 (i) Q to Kt3 22. R takes B KR to Q sq 23. B to K5 (ch) Kt takes B 24. P takes Kt R takes R 25. Q takes R, and White won. Black. Gunsberf;. K to R sq (e) Q toR2 P to B4 (0 P to Kt4 (h) P takes Kt P takes P (0 B to Q2 0) White. Blackburne. 1. P to K4 2. Kt to KB3 3. P to Q4 4. Kt takes P 5. B to K3 6. P to QB3 7. Q to Q2 8. P takes Kt 9. Kt to B3 10. B to B4 11. Castles KR Kt toB3 (c) 12. Kt to Q5 Q to Kt3 13. KRtoKsq(c!)Castles NOTES. (a) This is incorrect, for it not only gives White a good centre position, bat also loses time, as the Black Bishop is forced to retire to Kt3. Stronger play than this is 7. B takes Kt. 8. P takes Kt (If 8. B takes Kt, Q to Kt3), P to Q4. 9. P to Q5, Q to Kt3, with an even game. (h) Loss of time. 11. Q to Kt3 would have been better, as it would have somewhat retarded White's development and taken the Q out of reach of the White QKt. (c) White's development is much superior to Black's. White threatened the dangerous move of P to B4, to be followed by P to K5, &c., wlien Black's game would soon become untenable. Kt to B3 obviously prevents P to B4 for the present. (d) Better than QR to K sq, for, as will be seen, the QR soon takes an active part in the game. P to B4 would not do, as Black could have repUed with Q takes KP. (e) B to Q2 instead would probably have been Black's safest course, as it would have enabled him to oppose the advance of White's centre by QR to K sq. It would have been bad to take the KP now, as White would obtain a winning attack, i.e., 14. Q takes KP 15. B takes P 16. Q to Kto (threatening B takes KtP, &c.) 17. K to R sq 18. R to B sq and White should win by B takes P, following by Kt checking, iSrc. (/) The move of B to Q2 would stUl have held good. ((/) A well-calculated move. By exchanging pieces Black could apparently win a P, but in reality he would lose, i.e., P takes P 18. P takes P Kt takes KP 19. B takes B Kt takes B 20. R takes Kt BP takes B 21. Q to Q6: and White should win. (/i) This is a veiy risky counter- attack, but Black had no satis- factory reply to the move of P to Ko, the result of Black's prema- turely playing P to B4, and de- laying to develop his QB and QR. (i) White has more than ample compensation for his piece in this interesting position. Black could not play B to Q2 on account of P to Kto, which would win. The terrible check with the B on Ko wins the day for White, i.e., 15. Q takes QP 16. Q takes P (ch) 17. B to Q5 ^^'k^'"- r ■# 1 1 1 t ^ k^t \ ;*i "^ 2 .2 19. B to Q2 20. B to R4 21. B takes R 22. Q to Kt3 B toE4 20. P to Kt5 21. Q to Kt2 22. P takes Kt 23. P takes B 24. P takes P, &c. (j) Black had to play all this under great pressure of time. R to Q sq seems stronger, but the nature of the position is such that White would have triumphed whatever Black played. White had three moves at his disposal in replv to R to Q sq, viz., (a) R to K7, or (6) P to Kt5, or B to B4, i.e., (a) 20. R to Q sq 21. R to K7 21. Q to Kt3 22. B to KB7 22. Q to Kt4 and we do not see any winning move for White ; Black threatens both the R and the B. If White plays P to B4, Black could safely retire Q to Kt3. The best move for White in this position is pro- bably 23. R takes Kt. Black obviously cannot take the Q, as White would mate in two moves by B checking and then B disc. ch. and mate, but Black would have a satisfactorv replv in 23. P takes B. For if 24. B to Ko (ch), K to R2. 25. B" to Kt6 (disc, ch.) (beat), for 25. Q takes Q, P takes Q. 26. B to Q5 (ch), K to R3. 27. B takes P, B takes P. 28. B takes R, B takes B, and Black wins, as he threatens R to Q8). 25. K takes B (best). 26. R to Kt7 (ch), K to E4. 27. Q to K2 (ch), Q to Kt5. 28. R takes Q, P takes Q, and we do not see anv immediate prospect of White winning (h). 20. E to Qsq 21. P to Kt5 With this move we think that White can force the game what- ever Black plays, i.e., 21. Q to Kt3 (best). 22. B to B4. B to R4. (If Kt to E4, then 23. E to K7, Kt takes B. 24. E takes Kt, B to K3. 25. B to K5 (ch), K to Kt sq. 26. R to B3, &c.) 23. Q to K3 B takes R 24. E takes B B to Q2 (If Kt to E4, then 25. Q to K7 wins.) 25. P takes Kt B takes P 26. P to Q5 B to K sq 27. Q to Q4 (ch) K to E2 28. E to K7 (ch) B to B2 29. P 10 Q6 R to KB sq 3U. P to Q7 (threatening B takes E, followed by P to Q8 (Q) QR to Q sq 31. B to B"! K to Kt sq 32. B takes B (ch) R takes B 33. B takes E, and wins. If in the foregoing variation Black on his 22nd move plays Kt takes QP instead of B to E4, White would continue with 23. Q to Kt2 ; if then R to Q2, 24. E to B3, and White will soon obtain a winning advantage. Returning again to the position in the diagram, we find that, in reply to 21. P to Kto, E takes B, can be played, but with similar unfavourable result, i.e., 20. E to Q sq 21. P to Kt5 E takes B 22. E to K8 (ch) K to Kt2 23. P takes Kt, and White must win. (i) This move brings about a winning end game. P to Kt5 would also have won, but by a more complicated and difiicidt method. ANSWERS TO COEEESPONDENTS. *»* Please address Chess Editor. W. Furnival, G. W. — Problems received with thanks. Correct solutions received : — Problem No. 96, G. W., W. Furnival. No. 97, W. Furnival, Schmucke, Warwick, John, W., G. W., Stettin. No. 98, Stettin, G. W., W., Warwick, Schmucke, W. Furnival, H. A. D. H. A. D., in Prob. £7, if 1. B to B 8, P to B4, and there is no COXTENTS OF No. 98. (Position after White's 20th move.) S" k' * # 1 1 ■& ^ f% : 1., t 1 ,j 1 V w ^ o ,...„i AJ> ,:'':> M FAGB A Natorahst's Year. The Bam Owl FUea. By Grant Allen 161 Pleasant Hours with the Microscope. (Illus.) By H. J. Slack 162 The Harvest Moon. (/«im.) By R. A. Proctor 164 The Chemistry of Cookery. XTIII. By W. Mattiea Williams 165 The Morality of Happiness. By Thomas Foster 166 Evolution of Human Physiognomy. lIUus.) By E. D. Cope 168 I FAGB Tricycles 169 ■Winds as Projectiles 170 Dangers of Sea Bathing 171 Editorial Gossip 171 Face of the Sky 172 Correspondence : The Bennett Batterv — Small Wheels for Tricycles — A Curious Pheno- menon—The Comma, ic 173 Our Mathematical Column 175 Our Whist Column 176 Our Chess Column 176 TEEMS OF SUBSCRIPTION. The t«rmB of Annual Subscriptien to the weekly numbers of Knowledge are fi follows ; — 8. d. To any address in the United Kingdom 10 10 Te the Continent, Australia, New Zealand, South Aincs 4 Canada 13 0 To the United Slates of Amenca J3.26. or 13 0 To the Bast Indies, China, ic. (ria Brindisi) 16 i) All subscriptions are payable in advance. OFFICE : 74-76, GEEAT QUEEN STEEET, LONDON, W.C. Sept. 28, 1883.] KNOWLEDGE ♦ 193 MAGAZINE OF SqENCE PLAINLT:VyORDED -£XACTLYDESCRIB£D LONDON: FRIDAY, SEPT. 28, 1883. Contents of No. 100. PAGE A Naturalist's Year. Blackberries are Ripe. By Grant AUen 193 The Chemistry of Cookery. SIX. By W. Matt"ieu WiUiams 194 The Antiquity of Man, By W. Pen- gelly 193 The Sun's Distance. By Professor E.S. Ball, LL.D 197 The Morality of Happiness. IV. — Right and Wrong. By Thomas Foster 199 Vast Sun Spots. (lUus.) 201 ByW. Chemistry of the Cereals. Jaso, F.C.S Poker Principles 203 The Philosophy of Mathematics. Part I. By Professor A. Cayley 201 Commas and Colons 205 The Face of the Sky. ByF.R.A.S. 205 Editorial Gossip 203 Correspondence ; High - Wheeled Tricycles v. Low Wheels — The " Sun and Planet " Bicycle, &c... 806 Our Chess Coliinm 208 A NATURALIST'S YEAR. By Grant Allen. BLACKBEEEIES AEE RIPE. IN all the hedgerows and on all the commons, now, the village children are eagerly filling crocks and baskets with the one great fruit of the year to them, poor little souls, the common wild blackberries. There is no bush more familiar in overgrown spots in England than the bramble, and yet there are few others the story of whose evolution is more interesting than that of this universally distributed British shrub. We can trace the entire history of the blackberry through its various grada- tions almost without transgressing beyond the limits of our own little native flora. The bramble kind are a special oll'shoot of the rose family, distinguished chiefly by their peculiar granulated berries, each of which consists of several tiny one seeded, succulent fruitlets, united round the common receptacle into a single compound fruit. The origin of the race from the original central rosaceous stock, represented by the cinquefoil and other potentillas, is so clear and oVjvioua that it well repays a few minutes' careful attention. In their simplest existing forms, the rosaceous plants are low perennial herbs, with small yellow flowers, and tiny dry nut-like seeds, crowded together on a large flat or conical reccjitacle. This is the type familiar to all of us in the English cinquefoils, silverweeds, and tormentils ; and from some such form, the whole of the widely varj'ing rose family lias slowly diverged in one direction or another. But it is not often that we can trace the steps of the divergence among surviving plants so clearly as in the case of tlu! British blackberries. The lowest existing members of th(! blackberry genus are small creeping herbs, of simple habit, hardly diU'ering at all from the potentillas except in the peculiar character of their granulated fruit. Of tlicse very primitive kinds, the cloudberry of Northern Europe may be taken as an excel- lent example. It is a little unol)trusive plant, growing abundantly in the turfy bogs and tundras of Scandinavia, Russia, and Siberia, and still found in quantities in Scotland, though rare in Northern England and the Welsli hills. Like many other early forms, in fact, the cloudberry has now been stranded in Arctic or Alpine situations, while both it and its relatives have been driven entirely from more favoured southern climates by its own more advanced cousins, the raspberry, the black- berry, and the dewberry. The stem bears no prickles, and the leaves are simple and rounded in outline, or at most slightly lobed, instead of being deeply di\-ided into separate leaflets, as in all the more advanced bramble types. Its flowers are large, as is often the case with Arctic blossoms, so as to attract the eyes of the rare noi'thern butterflies or moths ; and in this respect the cloudberry is just abreast of some higher potentillas, like the barren strawberry and the true strawberry, which have also progressed from yellow to white petals: while it is ahead of some other rather more developed members of its own genus, which, though in most respects superior to it, have not yet got beyond the primitive stage of yellow flowers. But it is the possession of the peculiar berry which at once marks off the cloudberry from the potentilla group, and points at its true place as an early embodiment of the blackberry type. This berry has been formed from the numerous hard dry carpels or nutlets of the potentillas through the selective agency of the northern birds, in whose scanty diet they form as important a part as they do in the usual stores of Arctic travellers. The outer coat of each little nut has grown soft and succulent, and has at the same time acquired a bright orange-red colour, to attract the attention of the friendly birds by whose aid its seeds are dispersed. The device is exactly analogous to that adopted unconsciously by the strawberry, only that in the strawberry it is the receptacle that becomes sweet and brightly-coloured, while the individual " seeds " or car- pels (really small nuts) remain hard and unobtrusive : whereas in the cloudberry the receptacle is inconspicuous and dry, while the outer coat of the carpels has become succulent and ruddy. The mulberry (a tree belonging to a widely diflerent family — that of the figs and nettles) has a granulated fruit even closer in some respects to that of the bramble : but each granule of the mulberry is produced from the carpels of a separate flower, while in the black- berry the whole set of carpels belong to a single V>lossom. There are other little herbaceous bramble kinds besides the cloudberry, such as the pretty little Ruhus arciicus, a very northern form, whose flowers have become pink, while its leaves are divided into three leaflets, like those of the strawberry ; but these are of less importance in the genealogical order than our own British stone-bramble, a mountain plant of central and northern Europe, found pretty frequently in Scotland, in Yorkshire, and in the Welsh hills. In this ugly but interesting little plant, the buried rootstock sends up short greenish stems, very slightly armed with the first beginnings of prickles in the shape of small swollen and pointed projections. Some- times, indeed, these rudimentary defences are altogether wanting ; at other times they as.sume the form of fairly developed sharp spines. This is just what one would expect from the nature of the spots which the stone- bramble inhabits : a low, spreading herb, like the cloud- berry, growing in broad northern bogs and tundras, has little need of protection against browsing herbivores ; but comparatively tall and juicy stems, like those of the stone- brambles, growing in open woods or on broken mountain sides in the great backbone ridges of Europe and Asia, would soon get eaten down entirely by chamois, sheep, or other wild and domesticated ru- minants, unless they were well protected by thorns or prickles from their herbivorous foes. How quickly the weeding action of the animals can produce the survival of protected specimens only is well seen on all the suburban 194 * KNOWLEDGE ♦ [Sept. 28, 1883. commons of Kent and Surrey, where the prickly variety of common rest-harrow alone can thrive ; the more ordinary armed variety is all eaten down wherever it appears by the ubiquitous London donkey. The leaves of the stone- bramble are divided into three leaflets, after a fashion which runs more or less throughout the whole genus ; and the flowers are in a sort of intermediate stage between dirty greenish-yellow and dingy yellowish-white. The red berries do not difl'er much, except in the fewness of the carpels, from those of the raspberry. In the higher brambles — the raspberry, blackberry, and dewberry — we get the same type still further developed into a straggling woody bush. This growth in woodiness depends, of course, merely on the thickening and length- ening of certain cells and cell-walls in the stem, and it is everywhere readily produced by natural selection, W'herever the circumstances are favourable to its evolu- tion. Yet the difference between the stone bramble and the raspberry in this respect is far less than one might at first imagine ; both have perennial creeping root-stocks as reserves of material ; but that of the stone-bramble only sends up green annual shoots, herbaceous in character ; while that of the raspberry sends up rather stouter and woodier biennial stems, which seldom outlive the second year. In the blackberry, they sometimes continue for three or four years together. Such gradual intermediate stages are almost universal in nature. At the same time that the higher brambles have acquired their woody and creeping habits, they have also acquired sharp prickles, rather weak in the raspberry, stout and usually hooked in the blackberry. These prickles not only serve to defend the plants against the cattle that browse (or the deer that once browsed) among the thickets where they love to grow, but also aid them in clambering over the bushes, hedges, or heaps of stones over whose top they usually straggle. The raspberry flowers are white ; but the blackberry often shows a tinge of pink in its much larger petals which reminds us of such bigger and more developed rose-flowers as apple blossom, cherry blossom, and the true roses. Side by side with these changes, the leaves, now growing out into the open by the aid of the woody stems, can afford to expand more freely and widely ; and so, instead of the simple lobed leaf of the cloudberry, or the trefoil leaf of the stone-bramble, these higher types have usually leaves of five leaflets, though the gradation from the three-leaved to the five-leaved form can almost always be observed upon the same plant. In the wild raspberry, as everybody knows, the fruit is still red, like that of most other brambles, but the blackberry seems to suit our native birds better, with its dark purplish-blue tinge, than any of these brilliant northern kinds. Indeed, it is noticeable that very dark-blue and black, which are extremely rare colours in flowers, are extremely common in wild fruits — for example in sloes, privet, whortleberries, wild madder, elderberries, dogwood, and wayfaring-trees. This seems to suggest a diflerence of taste in colour between birds and insects. The true blackberry has no bloom on the fruit, but in the variety known as the dewberry, and commonly accounted a species, the berry is covered with a delicate blue-black mealiness which makes it a very pretty object indeed. Blackberry brambles in fact, show an immense tendency towards variation — so much so, that while Mr. Bentham makes two British species, and Sir W. Hooker six. Professor Babington actually distinguishes as many as forty. As yet, however, it does not seem to me that any special selective action has been exerted upon these numerous varying forms, and, therefore, from the evolutionary point of view, they must te regarded as mere accidental sports, not as true botanical species. THE CHEMISTRY OF COOKERY. By W. Mattied Williams. XIX. REFERRING to No. 17 of this series, August 1, a correspondent who has just returned from Norway, where he followed the route of my last trip there, reminds me of the marvellous congregation of sea-birds that assembles on some of the headlands of the Arctic Ocean, and suggests that egg-oil might be obtained in large quan- tities there. He quotes from the work of P. L. Sim- monds on " Waste Products " the following : — " In the Exhibition of 1862 the Russian Commission showed egg- oil in large quantities and of various qualities, the best so fine as to far excel olive oil for cooking purposes ; " but it was not sufficiently cheap for general use. Among the places indicated by Mr. Grimwood Taylor, the most remarkable is Sverholt Klubben, a grand head- land between the North Cape and Nord Kyn, rising pre- cipitously from the sea to a height of above 1,000 feet. The face of the rock weathers perpendicularly, forming a number of ledges about two or three feet above each other, and extending laterally for more than a mile. On the two occasions when I passed it, the whole of this amphitheatre was occupied by a species of gull, the " kittiwake," perched on the ledges, their white breasts showing like the shirt- fronts of an audience of a million or two of male pigmies in evening dress. On blowing the steam-whistle, the rock appeared to advance, and presently the sky was darkened by a living cloud, and every other sound was extinguished by a roar of wings and the harsh wailing screams of a number of birds that I dare not estimate. The celebrated bird colony on the Bass Rock is but a covey compared with this. The inhabitants of the little human settlement in the Bay of S\erholt derive much of their subsistence from the eggs of these birds ; but wliether they could gather a few millions for oil-making without repeating the story of the goose and the golden eggs, is questionable. The eider- ducks that inhabit some of the low mossy islands there- abouts, are guarded by strict legislative regulations during their incubation period, lest they should emigrate, and the down-harvest be sacrificed. I now come to the subject of stewing, more e.speciaUy the stewing of flesh food. Some of my readers may think that I ought to have treated this in connection with the boiling of meat, as boiling and stewing are commonly regarded as mere modifications of the same process. According to my mode of regarding the subject, i.e., with reference to the object to be attained, these are opposite processes. The object in the so-called "boiling" of, say, a leg of mutton is to raise the temperature of the meat throughout just up to the cooking temperature (see Nos. 3 and 4) in such a manner that it shall as nearly as possible retain all its juices ; the hot water merely operating as a vehicle or medium for conveying the heat. In stewing nearly all this is reversed. The juices are to be extracted more or less completely, and the water is required to act as a solvent as well as a heat-conveyor. Instead of the meat itself surrounding and enveloping the juices as it should when boiled, roasted, grilled, or fried, we demand in a stew that the juices shall surround or envelope the meat. In some cases the separation of the juices is the sole object, as in the preparation of certain soups and gravies, of which " beef-tea " may be taken as a typical example. Extractum Carnis, or " Liebig's Sept. 28, 1883.] • KNOWLEDGE • 105 Extract of Meat " is beef-tea (or mutton-tea) concentrated by evaporation. The juices of lean meat may be extracted very com- pletely without cooking the meat at all, merely by mincing it and then placing it in cold water. 2[aceration is the proper name for this treatment. The philosophy of this is interesting, and so little understood in the kitchen that I must explain its rudiments. If two liquids capable of mixing together, but of different densities, be placed in the same vessel, the denser at the bottom, they will mix together in defiance of gravitation, the heavy liquid rising and spreading itself throughout the lighter, and the lighter descending and diffusing itself through the heavier. Thus, concentrated sulphuric acid (oil of vitriol) which has nearly double the density of water, may be placed under water by pouring water in a tall glass jar, and then carefully pouring the acid down a funnel with a long tube, the bottom end of which touches the bottom of the jar. At fir^t the heavy liquid pushes up the lighter, and its upper surface may be distinctly seen with that of the lighter resting upon it. This is better shown if the water be coloured by a blue tincture of litmus, which is reddened by the acid. A red stratum indicates the boundaries of the two liquids. Gradually the reddening proceeds up- wards and downwards, the whole of the water changes from blue to red, and the acid becomes tinged. Graham worked for many years upon the determination of the laws of this diffusion and the rates at which different liquids diffused into each other. His method was to till small jars of uniform size and shape (about 4 oz. capacity) with the saline or other dense solution, place upon the ground mouth of the jar a plate-glass cover, then immerse it, when tilled, in a cylindrical glass vessel containing about 20 oz. of distilled water. The cover being very carefully removed, diffusion was allowed to proceed for a given time, and then by analysis the amount of transfer into the dis- tilled water was determined. I must resist the temptation to expound the very in- teresting results of these researches, merely stating that they prove this diffusion to be no mere accidental mLxing, but an action that proceeds with a regularity reducible to simple mathematical laws. One curious fact I must men- tion— viz., that on comparing the solutions of a number of different salts, those which crystallise in the same forms have similar rates of diflusion. The law that bears the most directly upon cookery is that " the quantity of any substance diffused from a solution of uniform strength increases as the temperature rises." The application of this will be seen presently. It may be supposed that if the jar used in Graham's diffusion experiments were tied over with a mechanically air-tight and water-tight membrane, that brine or otliL-r saline solution thus confined in the jar could not difluse itself into the pure water above and around it ; people who are satisfied with anything that " stands to reason " would be quite sure that a bladder which resists the passage of water even when the water is pressed up to the bursting- point, cannot be permeable to a most gentle and sponta- neous fiow of the same water. The; true philosopher, however, never trusts to any reasoning, not even mathe- matical demonstration, until its conclusions are verified by observations and experiment. In this case all rational pre- conceptions or mathematical calculations based upon the amount of attrartix-c fon'c exerted between the particles of the dillerent liiiuids are outraged by the facts. If a stout, well-tied bladder that would burst rather than allow a drop of water to be squeezed mechanically through it bo partially filled with a solution of common washing soda, and then immersed in distilled water, the soda will make its way out of the bladder by passing through its walls, and the pure water will go in at the same time ; for if, after some time is allowed, the outer water be tested by dipping into it a strip of red litmus paper, it will be turned blue, showing the presence of the alkali therein, and if the contents of the bladder be weighed or measured, they will be found to have increased by the inflow of fresh water. This inflow is called endosmosis, and the outflow of the solution is called exosnwsis. If an india-rubber bottle be filled with water and immersed in alcohol or ether, the endosmosis of the spirit will be so powerfully exerted as to distend the bottle considerably. If the bottle be filled with alcohol or ether and surrounded by water it will nearly empty itself. The force exerted by 'this action is displayed Ijy the rising of the sap from the rootlets of a forest giant to the cells of its topmost leaves. Not only plants, but animals also, are complex osmotic machines. There is scarcely any vital function — if any at all — in which this osmosis does not play an important part. I have no doubt that the mental effort I am at this moment exerting is largely dependent upon the endosmosis and exosmosis that is proceeding through the delicate membranes of some of the manj' miles of blood-vessels that ramify throughout the grey matter of my brain. But I must wander no further beyond the kitchen, having already said enough to indicate that exosmosis is fundamental to the philosophy of beef-tea extraction, and reserve further particulars for my next paper. Postscript. — I feel bound to step aside from the proper subject of these papers to make public acknowledgment of an act of honourable generosity, especially as many hard things have been said concerning American plagiarism of the work of British authors. As everybody knows, we have no legal rights in America, and any publisher there may appropriate as much of our work as he chooses. American leyislalors are responsible for this. Neverthe- less, I received, a short time since, a letter from Mr. E. L. Youmans, of New York, enclosing a cheque for £'20, as an honorarium in consideration of the fact that these papers are being reprinted in the Fojmlar Science Magazine. Shortly before this, a similar remittance was sent from another publisher (Messrs. Funk it Wagnalls), who have reprinted " Science in Short Chapters." These facts indicate that some American publishers have larger organs of conscientiousness than the present majority of American legislators. I am told that another American publisher has issued another reprint of " Chemistry of Cookery " without making any remittance ; but, as Mr. Proctor would say, " this is a detail." THE ANTIQUITY OF MAX.* By W. Pexgelly. PREVIOUS to 1858 all geological evidence respecting the antiquity of man was received with apathy and indillerence. Early in the present century the Rev. J. M'Enery discovered flint implements beneath a thick continuous sheet of stalagmite in Kent's Cavern, Torquay, but when he submitted these specimens to Dr. Buckland, then the leading geologist of the day, the latter refused to regard them as evidences of the antiquity of man, but was of opinion they belonged to the ancient Britons, who "had scooped out ovens in the stalagmite," thus * Abstract of au adiU-ess delivered at the Bi-itisli Association. 196 ♦ KNOWLEDGE ♦ [Sept. 28, 1883. accounting for their presence in the diluvium. This opinion Dr. Buckland held notwithstanding Mr. M'Enery's statement that in no instance had he discovered evidence of breaches or ovens in the floor, but one continuous plate of stalagmite diffused uniformly over the loam. In justification of Dr. Buckland's conduct, it should be mentioned that he himself had explored Kent's Cavern previously to Mr. ^M'Enery's researches therein, and, while doing so, had discovered a flint implement. This, how- ever, he found under such circumstances as did not con- flict with his published opinion on the low antiquity of man. But it is doubtful whether even Dr. Buckland's faith in his early convictions remained unshaken to the end, for when pressed by an intimate friend, a Professor at Oxford, to prepare a new edition of his " Reliquas Dilu- viana' " and his " Bridgewater Treatise," he excused him- self on the ground that the work would not be editing " but rewriting." In 1840 Mr. Godwin Austen, F.G.S,, read a paper before the Geological Society of London on the Bone Caves of Devonshire. Speaking of Kent's Cavern, Mr. Austin said that human remains and works of art, such as arrow-heads and knives of flint, occurred in all parts of the cave, and throughout the entire thickness of the clay, and no distinction founded on condition, distribu- tion, or relative position, could be observed, whereby the human could be separated from the other reliqua. He also expressed the opinion that the bones and works of art must have been introduced into the cave before the flooring of stalagmite had been formed. These state- ments, however, attracted little or no attention at the time. In 1846 the Torquay Natural History Society appointed a committee, consisting of Dr. Battersby, Mr. Vivian, and Mr. Pengelly, to make a few diggings in Kent's Cavern for the purpose of obtaining specimens for their museum. In the report of their investigations this committee stated that they had established the important point that relics of human art were found beneath the unbroken floor of stalagmite. After taking every precaution by sweeping the surface and examining most minutely whether there were any traces of the floor having been previously dis- turbed, they broke through the solid stalagmite in three difl'erent parts of the cavern, and in each instance found flint knives. In the spot where the most highly finished specimen was found, the passage was so low that it was extremely difticult with quarrymen's tools and good work- men to break throiigh the crust, so that the supposition that it had been previously disturbed was impossible. But such was the incredulity with which the inferences deducible from these facts were received that when the report was printed in the "Quarterly Journal" of the Geological Society, it was formally announced that the authors alone were responsible for the facts and opinions contained in their respective papers. This state of incredulity and apathy lasted until 1858, when some workmen engaged in a limestone quarry on Windmill-hill, near the fishing town of Brixham, in South Devon, unexpectedly broke a hole through what proved to be the roof of an unknown and unsuspected cavern. A committee of exploration was immediately appointed and placed under the superintendence of Professor Prestwich and Mr. Pengelly. The facts which mainly contributed to the decision to have this cave systematically exploretl were that it was a virgin cave which had been hermetically sealed during an incalculably long period, the last previous event in its history being the introduction of a reindeer antler found attached to the upper surface of the stalagmite floor, and therefore it was free from the objection sometimes urged against Kent's Cavern — namely, that, having been known from time immemorial, and up to 1825 always open to all comers, it had perhaps been ransacked again and again : secondly, it was believed and proved to be a com- paratively small cavern, so that its complete exploration was not likely to require a large expenditure of time or money. At the end of a period of twelve months, during which time the cave had been subjected to a thorough and searching investigation, the committee were able to report that eight flint tools had been found in various parts of the cavern, all of them inosculating with bones of mam- malia, at depths varying from nine to forty-two inches in the cave earth, on which lay a sheet of stalagmite from three to eight inches thick, and having within it and on it, relics of lion, hyaena, bear, mammoth, rhino- ceros, and reindeer. The results of these explorations at Brixham had an enormous influence in impressing the scientific world generally with the value and importance of the geological evidence of man's antiquity. Among the first fruits of the awakening was a paper by Professor Prestwich, read to the Royal Society, May 26, 1859, on the occurrence of flint implements associated with the remains of animal of extinct species in beds of a late geological period in France at Ameins and Abbeville, and in England at Hoxne. In this paper Professor Prest- wich distinctly stated that it was the discoveries which he had witnessed at Brixham which first fully impressed him with the validity of the doubts thrown upon the previously prevailing opinions with respect to such remains in caves. Sir Charles Lyell, too, in his address to the Geological Section of the British Association at Aberdeen, September, 1859, stated that the facts brought to light in connection with the explorations in the Brixham Cave had prepared geo- logists to admit that scepticism in regard to the cave evidence in favour of the antiquity of man had been pushed to an extreme. But probably the greatest proof of the change of opinion which began to take place in the scientific world in regard to this subject was that no less than three editions of Sir Charles Lyell's bulky work on the " Anti- quity of Man," which first appeared in February, 1863, were published in the course of ten months. The result of the researches at Brixham quickened a desire to re-examine the Kent's Cavern evidence, and, accordingly, in 1864, a committee was formed, and received a grant of money from the British Association for that pur- pose. The investigation was begun on March 28, 1865. The committee was annually reappointed, and the work con- tinued without intermission to June 19, 1880. The total money grants amounted to £1,900, together with £63 re- ceived from various private sources. In M'Enery's work was a diagram of three remarkable canine teeth, belonging to a group of carnivorre to which in 1846 Professor Owen gave the name of Machairodus lalidens. A considerable amount of scepticism existed for many years as to whether these specimens were really found in Kent's Cavern, it being contended that, from its zoological aflinities, Machairodus latidens must have be- longed to an earlier fauna than that represented by the ordinary cave mammals. It was therefore naturally hoped that the re-exploration of the cavern would set this question at rest. However, it was not until after the lapse of seven years and four months that the President, while engaged in washing a " find," discovered a well-marked incisor of Machairodus latidens with a left ramus of lower jaw of Sept. 28, ItS?.] ♦ KNOWLEDGE ♦ 197 bear, in wliich was one molar tooth. This at once esta- blished M'Enery's accuracy, left no doubt that J/ac/(«2Vo(7»s latidens was a member of the cave earth fauna — whatever the zoological aflinitifs might say to the contrary — and proved that man and Machuirodus were contemporaries in Devonshire. When their exploration began, and for some time after- wards, the committee had no reason to suspect that the cavern contained anything older than cave earth. At the end of the first five months, however, facts pointing ap- parently to earlier deposits began to present themselves, and when, after the expiration of three years, a vertical section was cut, there was shown in clear, undisturbed succession, not only the cave earth with the granular stalagmite lying on it, but under, and apparently support- ing the cave earth, another thicker and continuous sheet of stalagmite called crystalline, and below this, again, an older detrital accumulation known as the Breccia, made up of materials utterly unlike those of cave earth. The Breccia was just as rich as the cave earth in osseous remains, but the lists of species represented by the two deposits were very different. The remains of the hy»na prevailed numerically very far above those of any other mammal in the cave earth, his presence being attested by his teeth-marks on a vast number of bones, by lower jaws — including those of his own kith and kin — of which he had eaten ofithe lower borders as well as the condyles, by long bones broken obliquely just as hya-nas of the present day break them, and by surprising quantities of his coprolites. In the Breccia, however, there was not a single indication of his presence, the crowd of bones and teeth belonging almost entirely to bears. No trace of man was found in the Breccia until March, 1870, when a flint fiake was met with in the third-foot level, which was believed to be not only a tool, but to bear evidence of having been used as such. Two massive flint implements were discovered in the same deposit in May, 1872. At various times other tools were found, until at the close of the exploration the Breccia had yielded upwards seventy implements of flint and chert. All the stone tools, both of cave earth and Breccia, were Palaeolithic, and were found inosculating with the remains of extinct mammals, but a cursory inspection showed them to belong to two distinct categories. Those found in the Breccia, the more ancient series, were formed by chipping a flint nodule or pebble into a tool, while those from the cave earth were formed by first detaching a suitable flake from the nodule, or pebble, and then trimming the flake — not the nodule — into a tool. The fact, however, most significant of time and physical change was the presence of the hyrena in the cave earth or less ancient, but not in the Breccia or more ancient of the two deposits. This fact rendered it almost im- possible to avoid the conclusion that the liyana was not an occupant of Britain during the earlier period. The acceptance of such a belief, however, would necessitate the adoption of the view that man was resident in Britain long before the hya'na, and also that it was possible for the hyiena to reach Britain some time between the deposition of the Breccia and the deposition of the cave eartli. In other words, that Britain was part of the continent during this interval. In support of this argument, it is to be remembered that Sir Charles Lyell recognised the following geographical changes within the British area between the newer pliocene and historical times — firstly, a pre-glacial continental period, towards the close of which the Forest of Cromer flourished and the climate was somewhat milder than at present ; secondly, a period of submergence, when the land north of the Thames and Bristol Channel and that of Ireland was reduced to an archipelago. This was part of the glacial age, when icebergs flrated in our waters. Thirdly, a secoiid continental period, when there were glaciers in the hiol.er mountains of Scotland and Wales. Fourthly, the breaking up of the land through submergence and a gradual change of temperature, resulting in the pre- sent geographical and climatal conditions. The fact that neither in the Kent's Cavern Breccia, nor in the Forest of Cromer were any remains of hycena found, and that the list of mammalian remains found in the one does not clash with those found in the other, renders legitimate the inferences that the hyaena did not reach Britain until its last continental period, and that the men who made the Pakeolithio nodule tools found in the oldest-known deposit in Kent's Cavern arrived either during the previous great submergence, or, what is more probable, unless they were navigators, during the first con- tinental period. There was little doubt, therefore, but that the earliest Devonians were either of glacial or pre-glacial age. Of course, the discovery of remains of hya'na in the forest bed of Cromer, or any other con- temporary deposit, would be fatal to the argument, but it would leave intact all other evidence in support of the doctrine of British glacial or pre-glacial man. THE SUN'S DISTANCE.* Br Professor E. S. Ball, LL.D., As1 ronomer-Royal for Ireland. THE problem which is to engage our attention has been justly regarded as one of exceptional interest and importance. It seems not unlikely that in early ages the distance of the sun was one of the very first astronomical problems which ever attracted speculation. In modern times, as the problem has gradually approached solution, the interest attached to it has gradually increased until it has culminated in the last few months by the occurrence of the transit of Venus. The importance of this problem arises from the fact that the distance of the sun is the base line in terms of which almost every other linear magnitude in astronomy is to be expressed. An accurate measurement of this base will infuse accuracy into all the other astronomical quantities which spring from it. When we have learnt the distance of the sun we can measure the bulk of the sun and his diameter, we can measure the great planet Jupiter or the rings of Saturn, and the scale of the whole solar system becomes known to us. Again, when we attack the loftiest problem in practical astronomy, and seek to stretch a sounding line over the vast abyss which divides our system from the stars, it is the distance of the sun wliich we must use as our measuring rod. Ko pains should be spared to give to so fundamental a unit all the precision of which it is capable. Let us define accurately the magnitude to be measured. The actual distance from the earth to the sun is not con- stant. In these autumnal months the distance is rajiidly decreasing. We are at this moment drawing nearer and nearer to the sun at the rate of a thousand miles an hour. Next Christmas we shall be about a million and-a half miles closer to the sun than we are to-night At the com- mencement of the new year we shall begin to recede. Next mid.^ummtr will find us as far from the sun as possible ; then we shall draw in again, arrive next autumn * A discourse delivered nt the second general meeting of the British Association at Sonthport. 198 ♦ KNO^A^LIl:DGE ♦ [Sept. 28, 1883. where we are this autumn, and commence anew the cycle of changes I have indicated. Though these changes amount to millions of miles, yet they are at the utmost only a small fraction of the sun's distance. To superficial observation the sun always seems the same size, and hence there can be no great relative changes in its distance. There is no difficulty is understanding what is meant by the average distance of the sun. To express the idea with precision we may borrow the language of mathematics, and say that the distance from the earth to the sun consists of two parts — a large constant part and a small periodical part. The important problem, and the difficult problem, is the measurement of the large constant part. The early history of the subject is as easy to sketch as the latter part is difficult. For fourteen centuries the doctrines of Ptolemy were adopted on the distance of the sun as on all other astronomical problems. The method of Ptolemy might have succeeded if the sun's distance could have been measured by thousands of miles instead of by tens of millions. As matters stands, Ptolemy's method was utterly inadequate to cope with the real difficulties of the question. It led him to a conclusion which we now know to have fallen far short of the truth. The real dis- tance of the sun is twenty times as great as that which Ptolemy deduced from his observations. But Ptolemy's result was a great step in advance, notwithstanding the tremendous error by which it was vitiated. It was, at all events, an honest attempt to solve the problem by a direct appeal to nature, and he succeeded so far as to demonstrate the great truth that the sun is larger than the earth. It is somewhat remarkable that the first reasonable approximation to the sun's distance was obtained by what can only be described as a well-considered guess. The illustrious Huyghens, in the seventeenth century, hazarded a speculation, which seemed plausible at the time, and which we now know to have been reasonably correct. Huyghens compared the diameter of the planet Mars with the sun. He compared the diameter of Venus with the sun. The primitive instruments used were capable of making these measures with some accuracy. Huyghens knew that the earth was also a planet revolving outside the path of Venus and inside that of Mars. Was it not reasonable to assume that the bulk of the earth might be comparable with that of its fellow planets, and inter- mediate between the bulk of Venus and that of Mars 1 This assumption — and, of course, it was no more than an assumption — gave the means of guessing the distance of the sun, which was concluded to be about 100 million miles. When guesswork came to be replaced liy measurement, this estimate of the sun's distance was corrected. It was found to be too large. It was amended first to 95,000,000 miles, then to 91,000,000 miles. This was subsequently found rather too small, and it is now generally thought that the sun's distance must be more than 92,000,000 miles but hardly so much as 9.3,000,000 miles. We have here a range of one million miles. The problem in its present condition can now be dis- tinctly stated. We require to determine the sun's dis- tance accurately to within 100,000 miles, or, to speak in round numbers, we desire to determine the distance of the sun accurately to one-thousandth part of its total amount. Is such a degree of accuracy obtainable ? I believe that it is. I do not say that the problem has already been solved with this precision, but an approach has been made, and enough has been done to show that the accuracy I have indicated may be attained. But this margin is not really large when we reflect on the stupendous magnitude of the sun's distance. A favourite illustration in books of astronomy states that a journey to the sun in an express train running night and day without stopping would consume about 300 years. Before entering on such a journey it would, however, be well to recall to mind a very interesting lecture on railway accidents delivered by Sir F. Bramwell to this association a few years ago. From the figures available he showed that supposing a man made up his mind to be killed by a rail- way accident it would usually be necessary for him to travel day and night by express trains for 900 years before he could be quite certain of achieving his purpose. One or two return trips to the sun would no doubt suffice. There are certain conditions which any method of mea- suring the sun's distance must fulfil. In the first place, it is obvious that we cannot measure the distance directly. We cannot take a tape and measure it as we would the length of a field. We are compelled to resort to indirect methods. In other words, instead of measuring the sun's distance directly, we measure something else, from which we derive the sun's distance by calculation. Whatever that something else may be, there is one obvious condition which must be fulfilled. The method by which the calcu- lation is to be made must be absolutely unimpeachable. The measurable quantity and the sun's distance must be connected together by inexorable logic. The theory may be difficult, but it must contain no trace of ambiguity or of indefiniteness. No question of mere judgment or of estimation should be admissible. The connection between the two results must be as tight as a demonstration in geometry. Another condition, alike obvious and important, must be specified. Whatever be the measurable quantity, be it the displacement of a planet, a lunar inequality, or the co-efficient of aberration, our measurements are subject to error. Sometimes the measured quantity will be too large, sometimes it will lie too small. It is necessary to have an organised plan of symmetrical measurement, so that the number of measurements which are too great shall be as nearly as possible equal to the number of measurements which are too small. This condition is secured by forethought in arranging the details, and by vigilant suspicion of error from every conceivable source. The observations or measurements can then be purged from error by the well-known method of taking the mean. The success of this operation depends upon the number of observations that have been accumulated. It is, therefore, desirable that any proposed method of finding the sun's distance should admit of repeated application. Once we are assured that the observations contain no pre- disposition to be all too large or all too small, the mean will afford a result vastly more accurate than the original observations. It will do more than this — it will tell us not only what the result is, but how far that result is entitled to our confidence. Let me venture on an illustration to show how accu- racy may be obtained from the mean of inaccurate results. Suppose the question were to be asked this evening — What o'clock is it 1 and suppose that every lady and gentle- man were at the same moment to look at their watches, we should have, I suppose, a thousand watches or so brought to bear on the question. Perhaps I am not wrong in supposing that, if the trial were made, the thousand watches would exhibit some degree of variety. Some, no doubt, would be right, some would be a minute or two wrong, some, perhaps, would be five minutes wrong, or even more. But though there may be a general tendency in watches to be wrong, I believe no one can assert that as a whole they exhibit any particular preference to being fast rather than slow. There are, perhaps, some hundreds of watches in the Sept. 28, 1883.] ♦ KNOWLEDGE • 199 room more or less fast, and there are probably an equal number of hundreds more or less slow. This is precisely the state of affairs that every astronomer likes. He would, under such circumstances, tolerate even watches that were very far wrong. It is quite possible that one or two of the watches present may have stopped altogether ; they were not wound last night, or the spring is broken. Shall we then exclude such watches when we proceed to take the mean 1 It is unnecessary to do so. Even if a •watch were five or six hours behind time it would only make the mean slow by about one-third of a minute, and in all probability this would be compensated liy some other watch several hours too fast. The principle is sufficiently obvious. Each watch represents a more or less accurate attempt to tell the time. There is no particular bias for the watches to be fast rather than to be slow, and the greater the number the more accurate will the mean be. The moral is obvious. If we wish to determine the sun's distance the method employed must admit of a very large number of measures being made. [About] half will be too large, [about] half will be too small, and the mean of all will afford a result which may be relied on. The various considerations I have brought forward may be considered to merge in tlie general condition that any proposed method must admit of the determination being made to within a thousandth part of its total amount. With this canon of criticism I shall briefly review the various methods in use, and in doing so I am glad to acknowledge how much I have profited by the labours of Mr. Gill, her Majesty's Astronomer at the Cape of Good Hope, who has, with characteristic energy, devoted himself to the discussion of this problem. (To he continued.) THE MORALITY OF HAPPINESS. By Thomas Foster. CHAPTER IV.— RIGHT AND WRONG. (Continued from page 167.) IN its scientific aspect, then, as indicated by processes of evolution, conduct is good in proportion as it tends to increase the quantity and the fulness of life, bad in pro- portion as it exerts a contrary influence. Conduct may tend to increase life in its fulness directly or indirectly, proximately or remotely ; and again conduct may in one aspect increase while in another aspect it may diminish the fulness and quantity of life : but our definition of good and bad conduct is not aflected by such considera- tion.s. Just as a knife may be a good knife for cutting bread and a bad knife for cutting wood, just as a business transaction may be good in relation to some immediate purpose yet bad when remoter eflects are considered, so can we truly apply to conduct the terms i/ood and bad in reference to one sot of considerations even though wo may have to invert the terms when conduct is considered in reference to another set of considerations. But always, in its scientific aspect, conduct is to be regarded as good where it increases life or the fulness of life, and bad where it tends the contrary way. When we separate conduct ethically indifferent from conduct in its strict ethical aspect, it is convenient to sub- stitute for the words tjood and bad the words riy/it and ivronij. But the change is slighter than at first sight it appears. Indeed the more carefully the question of Tightness or wrongness, — the question of dutij., — is con- sidered, the more thoroughly does the kind of conduct judged to be morally indifterent merge into that which we regard as praiseworthy or censurable. Taking first those parts of conduct which relate directly to the quantity or to the fulness of individual life, we find that while the terms good and bad are freely applied to them, and even the terms right and wrong, they are for the most part regarded as morally indifi'erent. When we say you ouijld to do this or to refrain from that, the idea of duty is often not really present, so long as the act in question relates to a man's own life or its fulness. Even when we use words of praise or censure in relation to such acts, they do not imply that a moral obligation has been discharged or neglected. The reason doubtless is that, as a rule, men need little encouragement to look after those parts of their conduct which affect themselves and their own interests. For it may be observed that where it is likely there may be want of due care or wisdom in such matters, there we find distinct ex- ceptions to the general rule just indicated. So far as quantity and fulness of life are concerned, the man who crosses a crowded thoroughfare carelessly, he who neglects his business, and he who wears insufficient or unsuitable clothes in cold and wet weather, act with as little pro- priety iu their adjustments, as is shown by the man who steadily drinks intoxicating liqior?. But while none preach such duties as caution in street crossing, prudence and energy in business, and care about clothing, at least as duties morally obligatory, quite a number of persons preach against steady and heavy drinking as against a moral offence. The Bible indeed does not, though it has many a word of advice against wine-bibbing ; yet even in the Bible we find evidence of the early existence of total abstainers, and it is altogether unlikely that those ancient Blue-Ribbonists omitted to recognise sinfulness in all who did not share their views and follow their practices. Here we find evidence of the law of moral philosophy that a system of ethics, with recognition of moral rightness and wrongness, only begins to be formed where the best conduct (so far as fulness of life is concerned) runs the chance, for whatever reason, of being neglected, and inferior conduct followed. In this case, the best conduct is apt to be neglected because the increased fulness of life to which it conduces is more remote than the temporary increase of life fulness to which inferior conduct tends. Yet speaking generally it may be said that as Mr. Herbert Spencer puts it, — "The ethical judgments we pass on self-regarding acts are ordinarily little emphasised ; partly because the promptings of the self-regarding desires, generally strong enough, do not need moral enforcement, and partly because the promptings of the other self-regard- ing desires, less strong, and often over-ridden, do need moral enforcement." When we turn to the life-regarding actions of the second class, those which relate to the rearing of offspring, we no longer find the words good and bad, right and wrong, used with doubtful meaning. Here the question of duty is clearly recognised. The conduct of parents who by neglecting to" provide for their children's wants in infancy, diminish their chances of full and active life, or of life itself, is called Ijad and wrong not solely or chiefly because it is not favourable to the increase of life, but as open to moral censure. In like manner, men blame as really wrong, not merely unwise or ill-adjusted, such conduct as tends to make the physical and mental training of children imperfect or inadequate. Still clearer, however, is the use of the words right and wrong as applied to conduct by which men influence in various ways the lives of their fellows. Here the adjust- ments suitalile for increasing the fulness of individual life 200 KNOWLEDGE • [Sept. 28, 1883. VAST SUN - SPOTS, &c. {See opposite page.) L^ Transit of Venus, 1882. Apparent Size and General Appearance of Venu3, as seen projected on a Screen. Aperture, 3 inches. Focal length, 45 inches. Power 80. (The " Ligament " was glimpsed as a dusky band. Did not obeerye any central bright spot.) April 10, 1S82, 3.30 p.m. 03 COMPARATIVE^ SIZE OF THEfARTH i AND THi ^g^SoiAPSPOTS ! Vast Solar Spot of April, 1882 (accompanied with an intense Magnetic Storm). Extreme length, 2' 0". Mean breadth, C 45". .'. Area = ± 1,0'J3, 500,000 square miles. Nov. 15, 1882, 10.47 .\.M 30^ r Nov. 19, 1882, 10.20 a.m. Nov. 21, 1882, 10-50 A.M. 30" I Huge Solar Spot of November, 18.^2 (accompanied with an intense Magnetic Storm). Extreme length, 2' 12" Extreme length, 3' 10" Mean breadth, 1' 30" Mean breadth, 1' 30" .•. Area = ± 2,405,700,000 square miles. Area ± 3,462,750,000 square miles ! Extreme length, 2' 0" Mean breadth, 1' 30" Area ± 2,187,000,000 square miles. or for fostering the lives of offspring (alike in quantity and fulness), are often inconsistent with the corresponding adjustments of others. The development by evolution of conduct tending to the advancement of individual lives or lives of offspring would of itself tend constantly to acts inconsistent with the wellbeing or even with the existence of others, were it not for the development (also brought about, as we have seen, by processes of evolution) of con- duct tending to the increase of the quantity and fulness of life in the community. But there arises a constant conflict between tendencies to opposite lines of conduct. It is so essential for the welfare of the community that tendencies to advance the life interests of self and children should be in due subordination (which is not the same thing be it noticed, as complete subordination) to tendencies leading to the furtherance of the fulness of life in others, that rules of conduct towards others than self or children have to be emphatic and peremptory in tone. Hence it is, as Mr. Spencer justly remarks, that the words good and bad have come to be specially associated with acts which [respectively] further the complete living of others and acts which obstruct their complete living. (To be continued.) During fourteen days, recently, five accident; witb hydraulic lifts occurred in the City, by which four persons- lost their lives. Sept. 28, 1883.] KNOWLEDGE ♦ 201 •Thne 25, 1883. 7''45"aM. y 7° 35"" A M .June 29, 1883. 8 a" d" A M June 29, 1883 y. s" lo" A.M. June 30, 188.3. Ti s" 5 " A M • Notice above the .absence of the usual sharp listinction between Umbra and Penumbra. VAST SUN-SPOTS. THE Rev. Mr. F. Howlctt, whose skill and success in drawing spots, shown by the method of projection described in last week's Knowi.eiice, is well known, has favoured the editor with photographs of the great spots visible in April and November, 1882, and in June, 1883; also of the Transit of Venus, December, lScS2. From his photographs the accompanying engravings have been made. CHEMISTRY OF THE CEREALS. By William Jagg, F.O.S. No. VI.— BEEAD-MAKIXG (Co„linued). THE fact that there is such a thing as bad oread comes home to us at times in too pertinent a fashion to permit of any doubt of its existence. Since writing the last of these articles, I have eaten, during a stay in Liver- pool, some of the best bread I ever tasted — an article far 202 ♦ KNOWLEDGE . [Sept. 28, 1883. superior to any bread I have ever obtained in the South. The particular bread referred to was obtained from an ordinary baker's shop, and was light, white, of most deli- cious flavour, and even after keeping some days, showed not the slightest taste or smell of acidity. Without a greater knowledge of local facts, it is difficult to give the reasons for this superiority. Without doubt, in the first place, the baker must be a master of his trade. But in addition to this, flour of the best quality must be used ; it is possible that Liverpool, being one of the principal English ports to which flour and grain are shipped, and these from some of the best wheat-growing countries, that better flour can be there obtained for the same price as that asked for an inferior quality where aji additional •charge for carriage is incurred. Be this as it may, for reasons laid down in oiu- last article, good flour is an indis- pensable requisite for the production of good bread. Unfortunately nature, in yielding us the fruits of the earth, does not always yield them in the best possible condition ; rain and want of adequate sunshine may cause the wheat crop to be poor and the grain damp and not thoroughly ripened. Under these adverse circumstances the problem to be faced is how to make the best bread possible from the unsound flour obtainable. The great difficulty with such flour is the tendency of the gluten to convert the starch into sugar ; there is further the danger of lactic fermentation and consequent sourness. Certain mineral substances possess the power of arrest- ing the action of the gluten of damp flour on its starch ; among these alum has been long employed by the bakers. Alum is a double sulphate of alumina and potash, having the formida ALK„(S0j)4. A flour which, under ordi- nary circumstances, produces a bread unfit for consump- tion can be made by the addition of a small quantity of alum to yield a white bread of fair quality. If an infu- sion of bran be made and added to some boiled starch, the starch is rapidly converted into dextrin and sugar, and the mixture gives no colouration with iodine tincture ; but if to a second quantity of boiled starch a little alum is added before the infusion of bran, the conversion is either altogether stopped or proceeds very slowly. In the same way the alum prevents the decomposition of starch in the operation of bread-making. It is also claimed for alum that it prevents bread becoming sour or mouldy. Both these changes, in common with ■ordinary fermentation, are produced by the growth of organisms, and the action of alum may be explained by stating that its presence is injurious to these bodies ; that it is, in fact, to them, a poison. Hence alum also tends to prevent fermentation proper (or alcoholic fermentation), but its presence is not so inimical to these particular germs as to those producing lactic acid and ordinary mould. So far we have been dealing with the advantages resulting from the use of alum ; and there is no doubt that in many ways its action is beneficial. There is, however, another side to this question, and that relates to the conse- quences resulting from a continual absorption into the system of alum, even in small quantities. Opinion is here divided, but an undoubted result is the production of con- stipation and the symptoms of ill-health following in its train. It acts in yet another manner ; in very much the same fashion as it prevents the decomposition of starch during the time the bread is " put to soak," so, too, it tends to retard the digestive action of the fluids of the stomach on the bread ; much of the nutriment contained in the flour being thereby wasted. It has also been asserted that bread which has been alumed retains a much larger quantity of water than it otherwise would do. Chemical analysis does not, however, bear out this state- ment, for on examination some alumed loaves were found to contain 43 68, and others without alum 42 78 per cent, of water. This diflerence is less than the variation between the limits of percentage of water in loaves of the one class only. Other substances are or have been suggested as substi- tutes for alum. Among these, the least injurious is lime- water. This substance is stated to be equally efficacious in preventing the decomposition of starch ; while, as the yeast fermentation proceeds, the carbon dioxide gas that is evolved combines with the lime and produces chalk (car- bonate of lime), a substance having but little action on the organs of digestion. Among other proposed substitutes for alum, sulphate of copper is said to have been used. This body is so poisonous that its employment in even the smallest quantities is extremely reprehensible. Hitherto, the only means considered for the production of carbon dioxide within the bread has been the use of yeast or leaven for the purpose of causing fermentation. The employment of alum and other substances of similar properties is simply to prevent injurious changes pro- ceeding simultaneously with the fermentation, unsound flour being particularly liable to such alteration. Although it is still almost universally the custom for dough to be raised by the use of yeast or leaven, there have been from time to time other methods devised than that which depends on the production of carbon dioxide gas by the decomposition of a part of the flour itself. Among these other methods the use of " baking powder " is the best known. This substance consists essentially of bi- carbonate of soda and tartaric acid. If a pinch of the powder is put into some water, the same reaction takes place as when water is added to " sherbet " or " citrate of magnesia." All these mixtures contain the two bodies above-mentioned, and when moistened the tartaric acid immediately combines with the soda and liberates the carbon dioxide : — H0C4H4O6 + 2NaHC03 = Na.,CjH406 -H 2H2O + 2C0- Tartaric Bicarbonate Tartrate of Carbon acid. of soda. soda. Dioxide. The baking powder in making bread is mixed with the dry flour, which is then made into a dough with water, cut into loaves and then baked in a quick oven. The bicar- bonate of soda is sometimes used alone, as the heat of the oven is competent to eflect its decomposition into normal carbonate of soda and carbon dioxide thus : — 2NaHC03 Na.CQj -H CO. -1- HjO bicarbonate Normal Carbonate Carbon of soda. of soda. Dioxide. Although not strictly connected with our present subject, it may be of service to mention, in passing, the diflerence between the bicarbonate and normal carbonate of soda. The above formuhe show that the carbonate contains twice as much sodium. Carbonic acid, H,CO;„ contains two atoms of hydrogen, which require two atoms of sodium in order to displace them ; when only the one atom is displaced, a bi- or half- salt is formed. Carbonate of soda is but little used for domestic purposes, as it is more powerfully alkaline and exerts an injurious action on the coats of the stomach. Our next article will deal specially with the properties of aerated bread. Life of the Edison Lamp. — It is stated, says the Electrician, that some Edison lamps in a mill at Phila- delphia have lasted on an average 3,886 hours, and are still going. Sept. 28, 1883.] KNOWLEDGE ♦ 203 POKER PRINCIPLES. ri'^HE following specimen of American humour will amuse X our readers : — " It is a long way from the stars to poker," says the Chicac/o Tribune, " but Richard A. Proctor has made the jump, and in the Septembernumber of Lon//inan's M^agazine he discusses learnedly the topic, ' Poker Principles and Chance Laws.' It might be expected of a man whose turn of mifld is scientific, who reasons on hard facts and cold deductions, that he would treat even a game of poker in the same cold, calculating manner, and Mr. Proctor does this. After describing the game, for it is not yet fairly acclimatised in England, he calculates in a cold-blooded manner the chances for each diflfei-ent hand at poker. He finds that the total number of poker hands is 2, -598,960. He then enters into an exact mathematical calculation, and finds that in these hands there may be 40 flush sequences, 624 fours, 3,744 full hands, 5,108 common flushes, 10,200 common sequences, 54,912 triplets, 123,552 two pairs, 1,098,240 pairs, and 1,302,540 other hands. With these data for starting points, he devotes page after page to abstruse calculations of chances on given hands, and finally winds up by saying that ' poker-playing generally, as a process for making money more quickly, is much improved and enlivened by a slight degree of intoxication ' — a condition which seems highly problematical if the player is expected to remember the involved mathematical processes which he lays down, and certainly implies a moral laxity which makes one shudder at the mere thought. If Professor Proctor really believes that intoxication is an aid in perfecting and applying mathematical deduction, it is easy to understand why he has so often slipped up in his celestial mathe- matics." [My Chicagoan friend should have shown when and where ; since, however, the remark about intoxica- tion was not mine, but was made by an American writer on Poker Principles, the Chicagoan's \ague idea about errors in my calculations may be taken for what it is worth —nothing.— R. P.] " The most startling feature of Prof. Proctor's discussion is the manner in which he treats blutling. He gravely recommends intoxication as a prime condition for playing a good or poor hand, and regards it as mathematically moral — but ' bluffing should be omitted, as practice in this department of the game is really practice in the art of lying with unchanging face, and this is an undesirable art, whatever rogues may think. The gain which can be made by skill in lying is more than matched by the loss which a reputation for such skill is sure to bring.' This, it need not l)e said, is a narrow English view of a purely American institution. It is not poker as Minister Schenck taught it to the court and people to which he was accredited — a boon which has made his name famous in the annals of diplomacy. It is not the kind of game played by Clay and Webster, which Mr. Proctor cites, in which after each had §2,000 on the board, Clay called Webster on an ace-high, and found his opponent had a pair of deuces, in comment- ing upon which the astronioner learnedly says : ' The strange part of the story is that Clay should have called, for, apart from any question whether AVebster were lilulUng or not, ace-high is not a hand on which to call.' Mr. Proctor will never induce those who have once come under the fascination of the game to a\oid lilulUng. To play the game on such a condition involves about the same degree of thrilling interest one would experience in sitting down to calculate a table of logarithms or to work out an endless lennth of sines and cosines." " Unwittingly, perhaps, he has stripped the game of all that has made it so dear to the American heart. By his methods it loses all its airiness of contour, its mysterious glamour of illusion, its dashing assaults, its leadings of forlorn hopes, its thrilling surprises, its ruthless blights of expectation, its oscillations from hope to defeat, and is reduced to a mere dry, hard, cold mathematical computa- tion, which is not even mitigated by his recommendation that the players get intoxicated. It plucks the very heart out of the game, and slaughters the mystical sphinx whose riddle at poker no man has ever yet read. If a full hand must always be beaten by fours, or two pairs by a triplet, what inducement is there to play poker 1 Better casino and old maid than this game emasculated of that mysterious, subtle, always-appearing-when-least-expected quality which makes it possible for a jack high to sweep the board against three kings or an ace full. No ! Mr. Astronomer. Poker knows no laws and spurns all conditions. The man is its measure, and he who has the genuine poker afilatus, though he were a clown and had but a pair of deuces, would be dangerous to Mr. Proctor with a straight flush, even were he to follow his own recommendation and get as drunk as a lord. Let Mr. Proctor take his heaps of calculations and come into these Western wilds, if he wants to know the legions of possibilities that lurk in this noble game." [As I never took a hand at poker and am not likely to, the legions of possibilities in poker will for ever remain unknown to me, except as indicated by mathematics. — R. P.] The American Telegraph System. — A correspondent of the Daily Telegraph recently wired as follows from Washington : — " The Committee of the United States Senate appointed to inquire into the American telegraph system and the advisability of its acquirement by the State on the English plan met to day. The principal witness examined was Mr. Jay Gould, the eminent financier and president of the Western Union Telegraph Company, who emphatically denounced the scheme for placing the tele- gi-aphs under the control of the Government. He affirmed that Government telegraphs must always be ineflicient, unstable, and subject to political influence." Anthracene and Light. — The substance known as anthracene has been found by Dr. Tommasi to possess a new property, namely, a sensitiveness to light, which will doubtless prove of value. Anthracene on exposure to light acquires different physical and chemical properties without any change in its composition. If a cold clear saturated solution of anthracene in benzol is exposed to the direct rays of the sun, it becomes turbid and deposits crystals, which have received the name of paranthracene. — E)igineei-ing. A NEW mountain railway — Territet Montreux-Glion — has been constructed on the shores of the Lake of Geneva. No locomotive is used, but the weight of the descending carriage is used to bring the ascending vehicle up the incline. The necessary increase of weight required is pro- vided for by water ballast. The line is only about 750 yards long, and the height attained is 327 yards above the spot where the railway connnences. The lower portion of the line has a gradient of 300 in 1,000, and the upper por- tion 570 in 1,000. An automatic brake has been provided, which acts in case a breakage of the rope takes place. The carriages are specially built in consideration of the gradients referred to, and are constructed to hold twenty persons each. — Enghieer. 204 • KNOV\^LEDGE ♦ [Sept. 28, 1883. THE PHILOSOPHY OF MATHEMATICS.* By Pkofessor A. Cayley. IN TWO PARTS.— PART I. MATHEMATICS connect themselves on the one side with common life and the physical sciences ; on the other side, with philosophy, in regard to our notions of space and time, and in the questions which have arisen as to the univeisality and necessity of the truths of mathe- matics and the foundation of our knowledge of them. As to the former side, I am not making before you a defence of mathematics. Still less would I speak of its utility before, I trusf, a friendly audience, interested or willing to appreciate an interest in mathematics in itself and for its own sake. On the other side, the general opinion lias been, and is, that it is indeed by experience that we arrive at the truths of mathematics, but that e.xperience is not their proper foundation ; the mind itself contributes something. But it is maintained by John Stuart Mill that the truths of mathematics, in particular those of geometry, rest on experience ;t and, as regards geometry, the same view is on very different grounds maintained by the mathematician Riemann. * Abstract of that portion of Professor Cayley's Address before the British Association at Southport, which relates to the philo- sophy of Mathematics and to certain recent ideas respecting non- Euclidian Geometry and space of more than three dimensions. t " It remains to inquire what is the ground of our belief in axioms, what is the evidence on which they rest. I answer, they are experimental truths, genei-alisations from experience. The pro- position ■ Two straight lines cannot enclose a space,' or, in other words, two straight lines which have once met cannot meet again, is an induction from the evidence of our senses." But I cannot help considering a previous argument (p. 259) as very materially modifying this absolute contradiction. After inquiring, " Why are mathematics by almost all philosophers . . . considered to be independent of the evidence of experience and observation, and characterised as systems of necessary truth r " Mill proceeds as follows : — " The answer I conceive to be that this character of necessity ascribed to the truths of mathematics, and even (with some reservations to be hereafter made) the peculiar certainty ascribed to them, is a delusion, in order to sustain which it is necessary to suppose that those truths relate to and express the properties of purely imaginary objects. It is acknowledged that the conclusions of geometi-y are derived partly at least from the so-called definitions, and that these definitions are assumed to be correct representations, as far as they go, of the objects with which geometry is conversant. Now, we have pointed out that from a definition as such, no proposition, unless it be one concern- ing the meaning of a word, can ever follow, and that what appa- rently follows from a definition follows in reality from an implied assumption that there exists a real thing conformable thereto. This assumption in the case of the definitions of geometry is not strictly true ; there exist no real things exactly conformable to the definitions. There exist no real points without magnitude, no lines without breadth, nor perfectly straight, no circles with all their radii exactly equal, nor squares with all their angles perfectly right. It will be said that the assumption does not extend to the actual but only to the possible existence of such things. I answer that, according to every test we have of possibility, they are not even possible. Their existence, so far as we can form any judg- ment, would seem to be inconsistent with the physical constitution of onr planet at least, if not of the universal (sir). To get rid of this difiicnlty and at the same time to save the credit of the sup- posed system of necessary truth, it is customary to say that the points, lines, circles, and squares which are the subjects of geometry exist in our conceptions merely, and are parts of our minds, which minds, by working on their own materials, construct an « priori science the evidence of which is purely mental and has nothing to do with outward experience. By howsoever high authority this doctrine has been sanctioned, it appears to me psychologically incorrect. The points, lines, and squares which any one has in his mind are (as I appre- hend) simply copies of the points, lines, and squares which he has known in his experience. Our idea of a point I apprehend to be simply onr idea of the minimum visible— the small portion of surface I think it may be at once conceded that the truths of geometry are truths precisely because they relate to and express the properties of what Mill calls "purely imaginary oVijects." That these objects do not exist in Mill's sense, that they do not exist in nature, may also be granted; that they are "not even possible," if this means not possible in an existing nature, may also be granted. That we cannot " conceive " them depends on the meaning which we attach to the word conceive. I would myself say that the purely imaginary objects are the only realities, the oirwc oiTfi, in regard to which the corresponding phy- sical objects are as the shadows in the cave ; ai d it is only by means of them that we are able to deny the existence of a corresponding physical object. If there is no con- ception of straightness, then it is meaningless to deny the existence of a perfectly straight line. But, at any rate, the objects of geometrical truth are the so-called imaginary objects of Mill, and the truths of geometry are only true, and a furtiori are only necessarily true, in regard to these so-called imaginary objects ; and these objects, points, lines, circles, itc, in the mathematical sense of the terms, have a likeness to, and are represented more or less imper- fectly, and from a geometer's point of view, no matter how imperfectly, by corresponding physical points, lines, circles, etc. I shall have to return to geometry, and will then speak of Riemann, but I will first refer to another passage of the " Logic." Speaking of the truths of arithmetic, MiU says (p. 297) that even here there is one hypothetical element : — " In all propositions concerning numbers a condition is implied without which none of them would be true, and that condition is an assumption which may be false. The condition is that 1 = 1; that all the numbers are numbers of the same or of equal units." Here, at least the assump- tion may be absolutely true ; one shilling = one shilling in purchasing power, although they may not be absolutely of the same weight and fineness, but it is hardly necessary ; one coin -f one coin = two coins, even if the one be a shilling and the other a half-crown. In fact, whatever difliculty be raisable as to geometry, it seems to me that no similar difficulty applies to arithmetic ; mathematicians or not, we have each of us, in its most abstract form, the idea of a number ; we can each of us appreciate the truth of a proposition in regard to numbers, and we cannot but see that a truth in regard to numbers is something different in kind from an experimental truth generalised from expe- rience. Compare, for instance, the proposition that the sun, having already risen so many times, will rise to-morrow, and the next day, and the day after that, and so on, and the propo.sition that even and odd numbers succeed each other alternately ad iiifinitum, the latter, at least, seems to have the characters of universality and necessity. Or, again, suppose a proposition observed to hold good for a long series of numbers, 1,000 numbers, 2,000 numbers, as the case may be, this is not only no proof, but it is abso- lutely no evidence, that the proposition is a true proposi- tion holding good for all numbers whatever ; there are in which we can see. We can reason about a line as if it had no breadth because we have a power which we can exercise over the operations of our minds — the power, when perception is present to our senses or a conception to our intellects, of attending to a part only of that perception or conception instead of the whole. But we cannot conceive a line without breadth — we can form no mental picture of such a line ; all the lines which we have in our mind are lines possessing breadth. If any one doubts this, we may refer him to his own experience. I much question if any one who fancies that he can conceive of a mathematical line thinks so from the evi- dence of his own consciousness. I suspect it is rather because he supposes that unless such a perception be possible, mathematics could not exist as a science — a supposition which there will be no difficulty in showing to be groundless." Sept. 28, 1883.] ♦ KNOWLEDGE ♦ 205 the Theory of Numbers very remarkable instances of pro- jjositions observed to hold good for very long series of numbers, and which are nevertheless untrue. ,. I pass in review certain mathematical theories. In arithmetic and algebra, or say in analysis, the numbers or magnitudes which we represent by symbols are, in the first instance, ordinary (that is, positive) numbers or magni- tudes. We have also in analysis and in analytical geometry negative magnitudes ; there has been in regard to these plenty of philosophical discussion, and I might refer to Kant's paper, " Ueber die negativen Grossen in die Welt- weisheit" (1763) ; but the notion of a negative magnitude has become quite a familiar one, and has extended itself into common phraseology. I may remark that it is used in a very refined manner in bookkeeping by double entry. But it is far otherwise with the notion which is really the fundamental one (and I cannot too strongly emphasize the assertion) underlying and pervading the whole of modern analysis and geometry — that of imaginary magni- tude in analysis and of imaginary space (or space as a locvs in quo of imaginary points and figures) in geometry. I use in each case the word "imaginary " as including real. This has not been, so far as I am aware, a subject of philo- sophical discussion or inquiry. As regards the older meta- physical writers this would be quite accounted for by saying that they knew nothing, and were not bound to know anything, about it ; but at present, and considering the prominent position which the notion occupies, say even that the conclusion were that the notion belongs to mere technical mathematics, or has reference to nonentities in regard to which no science is possible, still it seems to nie that (as a subject of phOosophical discussion) the notion ■ought not to be thus ignored ; it should at least be shown that there is a right to ignore it. Although in logical order I should perhaps now speak of the notion just referred to, it will be convenient to speak first of some other quasi-geometrical notions ; those of more-thanthreedimensional space, and of non-Euclidian two- and three-dimensional space, and also of the generalised notion of distance. It is in connection with these that Eiemann considered that our notion of space is founded on experience, or rather that it is only by experience that we know that our space is Euclidian space. It is well known that Euclid's twelfth axiom, even in Playfair's form of it, has been considered as needing demonstration ; and that Lobatschewsky constructed a perfectly consistent theory, wherein this axiom was assumed not to hold good, or say a system of non-Euclidian plane geometry. There is a like system of non-Euclidian solid geometry. My own view is that Euclid's twelfth axiom in Playfair's form of it does not need demonstration ; that it is part of our notion of sp.ace, of the physical space of our experience — the space, that is, which we become acquainted with by experience, but which is the representation lying at the foundation of all external experience. Kiemann's view before referred to may, I think, be said to be that, having in intel/eclii a more general notion of space — in fact, a notion of non-Eucludian space, we learn by experience that space (the physical space of our experience) is, if not exactly, at least to the highest degree of approximation, Euclidian space. But suppose the physical space of our experience to lie thus only approximately Euclidian space, what is the consequence which follows'! Not that the propositions of geometry are only approximately true, but that they remain absolutely true in regard to that Euclidian space which has been so long regarded as being the physical space of our experience. COMMAS AND COLONS. THERE is a further argument against the Brighton theory of parenthetic commas round adverbs, which will reveal itself if you merely write instead of " He insulted me, and therefore I went away," " He insulted me, and I went away in consequence," or " therefore." Who would think of putting a comma before " therefore " Ln that case 1 And in either position who would think of speaking it commaticalli/, which is often, if not always, the best rule for punctuation 1 I by no means disregard the distinction between colons and semicolons myself ; but I cannot shut my eyes to the fact that much better writers than I am are far from consistent in their use of them ; and I cannot find, or hardly imagine, a case where the substitution of one for the other would make any difTerence in either the real or the apparent sense. On the other hand, cases are con- stantly occurring where one would like a smaller comma — or a larger one, as the case may be. I thank you for your protection as to the e^■idently missing comma in my former letter, which I was sure that some " F. R." would be down upon. His criticism on my ambiguous " it " proves that he is one of those who think that if you can put a wrong or absurd meaning into some- body else's writing the somebody else must have meant it. Edm. Beckett. THE FACE OF THE SKY. Feom Sept. 28 to Oct. 12. By F.E.A.S. THE sun will be examined, as usual, for indications of disturb- ance on every clear day, and the Zodiacal liglit may be looked for in tbe East before sunrise. Map X. of "The Stars in their Seasons," gives a picture of the Kight Sky during our prescribed period. Mercury sets after the sun to-night, but comes into inferior conjunction with him on October 7, after which Mercury is a morning star. He is most indifferently placed for the observer. Venus is practically invisible. Mars still souths during the morning hours, but sooner and sooner every night, between the X.E. and tho E.N.E. points of the horizon. He still presents the appearance of an exaggerated red star. Jupiter now rises before midnight. He is pretty close to Mars in the sky. No phenomena of his satellites occur at times suited to the ordinary observer during the next four- teen days. Saturn, some 3° or -4° North of Aldebaran, rises soon after 8 p.m., and is getting nightly into a more favourable position for the observer. "The remarks which we made a fortnight ago with regard to Uranus and Neptune are still applicable. The moon is -09 days old at noon to-day (September 28), and 03 days old on October 1 ; her age being quite evidently 11'3 days at the same hour on October 12. Hence she will be fairly weU placed for the observer during a good deal of tho time to which these notes refer. No occultations of stars happen during the period which they cover. The moon is in Sextans at noon to-day, re-entering Leo about midnight. She quits this constellation for Virgo about 4 a.m. on tho 30th. She occupies until about 2 p.m. on Oct. 3 in crossing Virgo, and at that hour enters Libra, which she takes until between 5 and 6 p.m. on the 5th to traverse. Then she arrives at the narrow northern part of Scorpio, over which she jiasses before -1 o'clock the ne.^t morning. From that hour until nearly midnight on tho 7th she is traversing the southern part of Ophiuchus ; but she then crosses its boundary into Sagittarius. Her path through the last-named constellation takes her until 11 a.m. on tho 10th to describe. About 3 o'clock on the morniug of the 4th sho crosses into Aquarius. There we leave her. {rurt 11. in OKI- r(.) NouTu American Indians as Railway Navvies. — From fifty to seventy Winnebago Indians are employed on the Omaha Railway as labourers. They are eager to obtain the work, to which they consider they have a claim, and make excellent labourers, doing a better day's work than the Chinese. — Engineering. 206 KNOWLEDGE ♦ [Sept. 28, 1883. Oitorinl (Soetsip. The British Association meeting makes large claims upon our space this week, and will do so for the next two or three weeks. We propose, when the rest of Professor Cayley's address has appeared, with its amusing references to non-Euclidian space and fourth, fifth, and yet higher dimensions in space, to comment on these conceptions, which certain non-mathematical writers, in their amaze- ment at such profundities, have described in the daily press in terms which would be scarcely justified if applied to Newton's greatest discovery. In writing my " Gossip " for last week I referred to that part of Sir George Airy's library which he assigned to paradoxists, — Reddie, Parallax, Hampden, et hoc genus omne. I was in doubt as to the actual title that he gave to this part of his library, and having written " My Lunatic Asylum," changed the title into " My Asylum for Lunatics," but suppose I failed to delete the first " Lunatic," for the rather tautological title "My Lunatic Asylum for Lunatics " appeared instead of what I intended. Truth gives me comfort. Several reviewers found my article on Poker Principles in Longman's Magazine too abstruse. Truth says it only shows that two and two make four. Yet Truth condescends to borrow my table of poker hands as " curious." As a considerable part of the article is occupied with the reasoning by which the table was established, this is rather incongruous on Mr. Labou- chere's part. Perhaps he oTijected to some remarks of mine on the Bishop-Labouchere row, — in which, however, I take no manner of interest personally. I only objected to a writer, whose authority on actors and princes and dukes and actresses and circuses may very likely be high, undertaking to define the limits of mental influence, where men like Dr. Carpenter and Professor Barrett have been unable to formulate an opinion. Hk goes on to ridicule my remark that "bluffing" at Poker is not desirable, — he makes me say " immoral " which is unnecessary, — because " the gain which can be made by skill in lying is more than matched by the loss which reputation for such skill is sure to bring." "This is about as ridiculous," he says, " as [it would be] to suggest that whist should be played without even finessing because it is a deception practised upon the adversary." My critic appears to confound "finessing" with "underplay," — a very diflerent thing. For in the great majority of cases, "finessing" is not adeception practised upon the adversary; " underplay " is. However, his argument is not afiected by his blunder. But no one would think of regarding " undei-play " as wrong, any more than he would regard feints in fencing or single-stick as immoral. Blufiing which is lying for money is a difl^erent kind of trick alto- gether ; yet not immoral if gross and greedy gambling" is not immoral. But my point was the inexpediency of frequent bluffing, regarded with direct reference to the game itself. To be effective, bluffing should only be re- sorted to occasionally. As to the expediency of "under- play," Clay has spoken pretty stronglj', objecting to it for the very reason indicated by myself in regard to bluffing, that in the long run it does not pay. Probably Clay knew as much about whist as Mr. Labouchere : at any rate I do not find that Clay ever confounded " finessing" with " underplay " (excepting in reference to those special cases where a finesse involves underplay). " Let Knowledge grow from more to more." — Alfred Tennyson. Only a small proportion of Letters received can possibly he in- serted. Correspoiidents must not be offended, there/ore, should their letters not appear. All Editorial communications should be addressed to the Editob of Knowledge; all Business commmiications to the Publishers, at the Office, 74, Oreat Queen-street, W.C. If this is not attended to DELAYS ARISE FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should be made payable to Messrs. Wtman & Sons. The Editor is not responsible for the opinions of correspondents. No COMMUNICATIONS are answered by POST, EVEN THOUGH STAMPEr AND DIRECTED ENVELOPE BE ENCLOSED. HIGH WHEELED TRICYCLES r. LOW WHEELS. [938] — In spite of what Mr. Browning says further in last week's Knowledge upon this question, I still hold the conviction that high wheels, i.e., wheels of 50 in. diameter, and when geared up ranging down to say 46 in. with ordinary machines must, and do, give better results as regards general ease of propulsion, and easily acquired and maintained speed, than wheels of the diminutive size he advocates. It must he remembered that Mr. Browning says he now rides a 38-in. wheeled tricycle, and proposes to have a 36-in. wheel next year. There are, I venture to say, very few practical riders of any powers that will not agree with me that so small a wheel is a mistake. In the first place the pedalling must be very rapid to get up any speed at all, and there is a limit to gearing up. Mr. Browning quotes Mr. Nixon as one of his supporters, but I believe I am right in stating that Mr. Nixon rides machines of 48-in. wheels. At any rate, I should be very glad to "take him on " if he wiU ride a machine with 36-in., or even 38-in. wheels of any ordinary pattern. I should then prefer to have a muddy or rough Macadam road, and although Mr. Nixon is undoubtedly a more highly-trained rider than I should ever take the trouble to be, I have very little fear of the result. I should ride my 50-in. Imperial Club light roadster that I have now ridden over 3,000 miles, geared up to 60 inches. I should bar the '' Humber," which is for some reason an excep- tion, but even the "Humber" will, not, I imagine, produce such good results if the wheels fall below, say, 42 in. Mr. Marriott, who is a remarkable rider, is said to have ridden a 40-in. in the recent tifty miles championship. He did not, however, make such fast time as Lowndes did last year with 48-in. wheels. At hill-riding, I am satisfied that small wheels are at a decided disadvantage, and as I live at the foot of Muswell-hill, I am in a good position to speak from practical experience. I have ridden this hill from bottom to top without stopping, in all over 50 times, and always with a 50-in. or 52-in. wheeled machine. I once tried hard witli a 44-in. machine, but could not get up, but directly after- wards I mounted the hill with a machine of exactly the same make — a Cheylesmore — weighing about the same, with 52-in. wheels. I believe the reason for this is that the small wheels have to go round so much more frequently that the influence of the dead point comes in so often as to im])ede progression. I have now in my stable a Sociable with 40-in. wheels, and the riding of this machine, although it is geared up to 47 in., is torture as compared with my 50-in. geared up to 60 in. It is harder work, even with a strong rider in company, and to get up a pace equal to that I can keep up without effort on the 50-in., the pedalling has to be so fast as soon to become fatiguing. It is only by dint of very rapid pedalling that a speed of some eight miles an hour can be attained, while with the 50-in., very slow, easy pedalling will achieve this very moderate pace. I have recently been riding an "Otto" with 56-in. wheels, and the roll of these big wheels was truly delightful, carrying one over the rough roads without noticing the loose places. An " Otto " with 60-in. wheels, geared level, was ridden up Muswell Hill the other Sept. 28, 1883.] * KNOWLEDGE ♦ 207 day, and I will venture to Bay that it ivould be a task of no little difficnlty to get a 36-in. or 38-in. wheeled geared-np machine up this gradient. Exceptionally small wlieels may do very well on the smooth cinder racinr;-track, but they will certainly not answer bo well as reasonably high wheels for ordinary road riding. I should like to see two men of equal powers who have never been on a tricycle mounted — the one on Ifr. Browning's pet machine, and the other on my pet machine — and I would " bet my bottom dollar" on the result, but for the fact that I never bet at all. Fancy the appearance of a tall man on a very small Shetland pony ! Verb. sat. sap. ! Sigma. [930] — As one deriving much enjoyment in the use of the tricycle, permit me to say that I think the advocates for high, as also for low wheels, are endeavouring to prove too much. As with horses, so with tricycles, there is no particular height suited to every weight and build of rider. There is much room for the exer- cise of judgment in the matter of height of wheel and kind of machine suited to each individual rider. There are, however, a few simple rules which may, and certainly should, be applied to the selection and use of tricycles, whether of high or low wheels. (1) To economise power it is essential that the saddle-seats, being only suited to invalids, should be well over, or even somewhat in advance of the pedals. (2) The centre of gravity should be as low as possible. This is obtained by fixing the pedals as near the ground as may be suffi- cient to clear inequalities and loose stones on the surface of the road. I find 4 in. sufficient clearance. (3) The weight should be pretty evenly distributed on all the wheels. I could add to the list, but I spare yon, and with the foregoing secured the novice would be started on the right "track," and would soon learn to ride with ease and elegance — both at present conspicuously absent from the great majority of tricycle riders. W. H. Feance. [940] — It has been with interest that I have read these articles, especially as they seem to have been written for people like myself, who are far from strong. To those who object to small wheels and have not the power to propel the large ones up hill, I would recom- mend the omnieycle. Its wheels are 50 in. It has three gears. Speed for ordinary work, medium for rough or heavy roads, and power for up-hill work ; balance gear and free running wheel.?, both of which are an immense blessing. It runs smoothly and evenly, and, being a lever action, it has no dead points and can be started with ease, even half way up a hill. I run mine in hilly country, and find it everything that can be desired. John Alex. Olt..\ed. [941] — "Sigma's" article on tricycles, in No. 98 of Know- ledge, is valuable, as recording the opinion of a rider — and one of our best riders too — of a 50 in. wheeled tricycle geared up to 60in. But has "Sigma" ever thorouijhiy h-ied a small wheel (say 40 in.) geared up to the same figure ? I fancy not. One paragraph of the article under question would almost lead any one who did not know the writer to imagine that he was not a rider at all. I refer to where he says : " Nothing wearies so much as rapid pedalling, and nothing looks so ungraceful j and it is obvious that with small wheels the pedalling must be very rapid indeed to get any pace at all." Now, even the greatest novice at tricycling knows that a small wheel can bo geared up to any size, and that, consequently, the feet revolve slower proportionately as the size increases. For myself, I very much prefer a small wheel, and this after experience with eleven or twelve machines, varying in size from 54 inches to 40 inches, geared in different ways. My present mount — a 40-inch " Shadow," geared to 52 inches, and weighing only 4G lb. — I ride with ease with 4J-Uic/i cranks, the usual length of a tricycle crank being 5^ inches. The advocates of large wheels talk about the loss of power and bumping on bad macadam roads which the riders of small wheels have to put up with, but it is my experience that for evex-y mile of bad — really had — road mot with in the course of a year, I get hundreds of miles of good road, so we don't lose much there. I believe I am right in saying that Mr. Browning does not attempt to advise on machines for racing men, but for those who rido for p?en,si«i'e, and wish to do their forty or fifty miles a day with comfort and ease ; hence his advice to gear low. Thanking you for opening your valuable coIumn,s for the discus- sion of the construction of the " Coming Tricycle," I am, &c., S. U. R. Sai,.mon-, Hon. Sec. London Tricycle Club, T.U. THE "SUN AND PLANET" BICYCLE. [942] — In reply to Mi\ Browning, my machine weighs 45 lb. exactly. It is heavier than it should be, the forks and backbone being very wide. But I suppose, as the difference in weight of bicycles can only amount to a few pounds, it does not affect the speed much, as it must with tricycles when it comes to 30 lb. or so. I find the machine goes much easier than the Cheylesmore and other tricycles I have been in the habit of riding. I get a beau- tiful pace out of it, and it is curious that the slow motion of the seat made me feel at first that I must be on a " 50-inch " — this was rather unpleasant until I overcame the illusion. When dangers thicken around you, on a small machine nothing is easier than to drop back at once to the ground, in a position of per- fect safety, and ready to run the machine anywhere. This could not be done with a tricycle. The machines are very neat and well made — like engine work — and I can recommend them as the farthest advance I know of in the direction of speed and safety. Eeally the fallacies in " Sigma's" remarks seem too plsiin to need pointing out, but one is that he seems to have an idea Mr. Browning is speaking of geared-up wheels. S. J. NAKED-ETE SUN-SPOT. [943] — Once more I take np my pen to record the appearance of another spot on the snn, so large as to be easily visible to the naked eye. The first time I saw it in that way was on Wednesday evening last, September 12, when the sun was setting like a great ball of copper through the mist of the horizon, the spot being very distinct, situated a little below the centre of the disc ; and each day since then I have seen it several times through smoked glass. It is a spot that I first saw with my telescope on Saturday last, September 8, when it was just coming on at the eastern edge of the sun's disc, and consequently appeared very much elongated and foreshortened, and, as far as I could then judge, it was only one spot, but on examining it again with the telescope yesterday, I found it was really composed of two almost entirely distinct spots, of about equal size, placed so close together that the extreme edges of their penumbras at one point appeared to just touch each other. Each spot individually is very large, and so taken together they constitute a tremendous disturbance ; and then there are several other smaller spots scattered about the sun's disc, so that I think we may safely say that there is some very great agitation going on there again now, as there has been so many times during the last twelve months. Excelsior. A CURIOUS PHENOMENON. [944] — The remarkable phenomenon which Mr. Noble described in No. 98 of Knowledge was also witnessed by me in Liverpool on Aug. 29, at 12 h. 40 m. a.m. I had just been looking at Saturn, when, for the first time, I saw a bright divergent cone of light about 7° above the horizon ; the entire length of the cone was about 5°. The apex or nucleus displayed such a degree of concentration that I thought it was the planet Jupiter. I turned my telescope, a 2-inch, armed with a power of 30, on the point where the apex should be (it was now obscured bj- a cloud), with the expectation of being able to unravel the mystery, but was disappointed, as the cloud was too dense. I then ran my telescope along the major axis of the cone, and the field of view was so faintly illuminated that the brightest part could hardly be said to equal the Uimicre cendriSe seen under similar conditions. It gradually faded from view, after having been visible for thirteen minutes. I continued watching the part of the heavens where it had disappeared, with the con- fident hope that it would return, but was at last obliged to give it up, as a great bank of clouds precluded all further observation. It could hardly have been an auroral streamer, as the point where it appeared is 67° east of North. W. K. Bradgate. Sept. 15. [945]— The phenomenon seen by Captain Noble may have been the inverted cone of light proceeding from an ironfounders' cupola, visible in slight haze. A line drawn from the observatory in an E.N.E. direction passes nearly through Ashford, in Kent. I do not know that place, but my map" of Kent shows it to be an important railway junction, with an " engine depot." It is probable that at such a' place there is a cupola, and that melting might be going on as lato as 10.35 p.m. The light is intensely brilliant during the latter part of the operation of' melting, when the white-hot metal or slag is left at the bottom of the furnace, and might, I think, bo seen, under favourable circumstances, as far off as Ashford (tweiity- six miles). That it was a distant object is evident from the sketch. Various causes might account for the sudden extinction. J. II. Coaxes. 208 ♦ KNOWLEDGE ♦ [Sept. 28, 1883. THE " HUMBLE SOLDIERS." [946] — May I (perhaps in atonement, being one of the " point- pepperers") give what seems to me to be a good reason for the elimination of the commas in the sentence, " He called for help ; and, therefore, I went to him." I would submit to the ivriter in the Brighton Herald that the word " therefore " is here used as equivalent in sense to the words " that was why," or " for that reason ; " and surely he would not insert the commas in either of the following sentences : — " He called for help ; and that was why I went to him." " He called for help ; and lor that reason I went to him." Compositor. LETTERS RECEIVED, AND SHORT ANSWERS. F. M. DiPLOCK. I do not see, cither, that the comma is out of place. But it is well to note that the word " Why," in the sentence, is not a question per se, as many imagine. — W. B. All the planets turn the same way round as the sun does, except Uranus, and probably Neptune. This way round is that also in which they all, without any exception at all, travel round the sun.— W. 0. Dawson. Article in type.— W. Lawrenxe. If Mr. John Hampden had dictated your letter you could not more completely have caught his style. Permit me to congratulate you. I thought him unique : now I see I was mistaken. If I have " failed to convince a single individual who was in doubt about it" ("it" being the earth's rotundity) I have failed in what I have never attempted to do. Mr. Browning makes excellent spectacles, but he has failed to make a single individual see who chanced to be born blind. (He has not tried, that I am aware, but that only makes the parable better ; for neither have I tried to make those see with the mental eye who are mentally blind.) — A. M. Those passages are given in a little volume, published by Messrs. Appleton, New York, containing the speeches (made and not made) at the dinner given in honour of Mr. Herbert Spencer's visit to America. By the way, I am inclined to wonder what would be Mr. Spencer's deliberate opinion on the subject of dinner-giving as a way of indicating esteem and admiration. — D. C. S. (1.) Pro- bably a harmless, but still more probably a useless recipe. You would have to buy of the person who seems so generously to offer the recipe. Note his prices, and recognise rascality. (2.) Yes; smoke-abatement an important subject ; ex fumo darelucem — if it could but be managed. — Sexex (1.) Not that '' silent lightning" is never seen ''n daytime, but why it is not so often seen in daytime as at night (your note on this subject slightly shortened, will appear). (2.) One cannot dii-ectly comj)are the intensity of waves of light, sound, and water. (3.) Reflection of rainbow can be seen. — Co-sMos. Neither the longitude of perihelion nor the inclination of major axis is assumed. The initial assumptions are at once less simple and more tentative. The subject is one for an article, not for a Short Answer. — J. W. WiLso.x. If we were certain the mass of the two stars together equalled the mass of the sun and earth, we could infer from the period of revolution the precise distance. But in every case yet dealt with we have either had no such knowledge, or have known that the case is quite other- wise. In my " Other Worlds than Ours " the points involved in the problem are fuUy discussed.— E. T. L. The papers on the Moon began with Vol. III., and the reference map appeared with the first of them.— W. S. Bosc.wex. I do not know where the rising and setting of stars visible in Babylonia as early as 2,000 B.C. can be obtained. In my library star atlas, and in the maps of my gnomoiiic atlas, are the longitude and lati- tude lines, by which correction can he made in the case of any star, for the effects of precession. The star must be carried westwards along its latitude parallel at the rate of 5' for about 359 yenrs of past time. This serves for the vernal equiiiox also. — M. J. Harding. I am sorry more copies of the Index were not printed. But a copy was sent to every subscriber (as distinguished from buyers). I myself much prefer the plan of issuing the index with the paper. But the publishers saw reasons for adopting a dif- ferent plan.— D. E. Samuel. The nasal twang of the true Yankee or New Englander has been derived from Puritan ancestors. The Roundheads so spoke. But chronic catarrh may now have some- thing to do with the matter.— E. S. B. Thanks for kmd letter. Hints noted. With regard to the " sneak " as you justly call him referred to in article on " Social Dynamite," I have never been in doubt who he was, since Mr. Lockyer disclaimed all knowledge of the matter. I have no doubt either, that after reading what I there wrote, Mr. Lockyer himself could form a tolerably shrewd guess on the subject. He has not however thanked me yet for enabling him to see what a treacherous '' friend" that particular person was. — E. F. T. La Xature might suit you. — M. C. I think the flat earth folk would deny the validity of the spu-it-level proof. — W. G. Knowles. Read Darwin's book on " Mould and Worms." — George Jordan. Cannot further try to explain matters to one unfamiliar with even the elements of science. Have already given to you much more time and attention than you could expect. — W. W. F. The whole column of water. — H. Askew. (1) Some nonsense about the holy numbers three and seven. I forget what. (2). It is difficult to get in all desirable subjects. — J. G. Fisher. The printers arrange that matter of month, day, year. Your letter sent to printers. — Inqvirer. If you will state in a letter the rules for the four possible cases, will publish : but a single case out of four would only perplex readers. — T. Maude. There are differences of atmospheric pressure in different latitudes, and these differences obviously depend on latitude ; but they are certainly not proportional to the rate of terrestrial rotation. The pressure and density are greatest in the sub-tropical zones. — W. B. No one would think of extracting square root by logarithms, when only two or three digits are wanted. — Uncertain. I fear those metaphysical speculations would have no interest for readers. As to your swearing, / can have no manner of objection. It may be as you suggest, " an unco' reUef to a body." I fancy it is like dram.di-inking though, and that the round oath which relieves your feelings now vrill reqm're to be replaced by a stronger one hereafter. My own personal objection to swearing is that no matter what form of oath one adopts, one becomes conscious of temporary misuse of reason in employing it. Whether you swear by " thunder," or wish you may be *' dad- slapped," or call what offends you a "dodgasted" noun of some sort, or prefer something more genuinely profane, comes to much the same ; there is idiocy in the thing, in every aspect of it. &m Cftesis Column. By Mephisto. PROBLEM No. 100. Bv G. Woodcock. Whiib. White to play and self-mate in five moves. SOLUTIONS. Problem No. 97, by C. Planck, p. 176. 1. Q to Kt4 If K to B6, Kt to K2 mate. K to B4, Kt to Q3 mate. K to K4, Kt to R5 mate. K to K6, Kt to Kt2 mate. P to B4, Kt takes P mate. B moves, Kt to K6 mate. No. 98, BY J. C. S., p. 176. 1 R to Q, sq. K moves, or B to Kt4 2. B to QKt4 (ch) K to K4 2. B to Kt4 (ch) Kt takes B 3. Kt to B4mate. 3. P to B4 mate. ANSWERS TO CORRESPONDENTS. *^* Please address Chess Editor. W. R. Edwards.— In Problem 97, if 1. Kt to Q3, K to B6, and there is no mate next move. Correct solutions received. Problem 97, Borrow, John Watson, B. Gleam, M. T. Hooton. No. 98, John Watson. No. 99, Berrow, W., I H. Sewaid. Oct. 5, 1883.] ♦ KNOWLEDGE ♦ 209 AN ILLUSYRATED \Jt MAGAZINE OF SCIENCE ^ ^PLAINIXVfdRDED-£XACTl)f DESCRIBED LONDON : FRIDAY, OCT. 5, 1883. Contents of No. 101. PiQE British Association Scraps 309 The Birth and Growth of Myth. XVII. By Edward Clodd 210 The Elements. By Dr. Gladstone... 211 Two-speed Tricycles. By John PAQS Evolution of Conduct. By John Fiske 213 Pleasant Hours with the Microscope. [Illus.) By H.J. Slack 211! Editorial Gossip 217 COBHKSPONDENCB : Hull-dowU Ship (;;/».».)— Totemism, &c 219 Our Mathematical Column 220 Our Chess Column 222 Sea - Anemones. V. The Daisy {conlinued) . By Thomas Kimljer 2U Truth and Poker. By Richard A. Proctor 215 BRITISH ASSOCIATION SCRAPS. N a paper read before the JSIatheniatical and Physical section, Professor Chandler Roberts remarked on the rapid diil'tision of molten metals. The two metals chosen were lead and gold enclosed in a U-shaped tube, the lead occupying the lower portion of the tube, and the gold beiug put in at the top of one limb. After about forty minutes Professor Roberts found that the two metals had been thoroughly mixed. Sir \V. Thomson called attention to the extreme importance of this, with reference to metallic alloys, and remarked that it resembled the difl'usion of gases or of heat in a gas rather than of a solid in a liquid. Salt would take years to dill'iise in a similar manner through water. A PAPER was read which had been received from two American gentlemen, Messrs. W. B. Scott and 11. F. Osborne, upon the " Origin and Development of the Rhi- noceros Group." These gentlemen have made careful re- searches in the extensive series of tertiary lake deposits in the North- Western United States, in which specimens of very many animals have been discovered, which render it possible satisfactorily to trace the genealogy of several im- portant groups of mammals. These gentlemen have dis- covered the remains of the ancestor of the ihinoceros group — an ancestry from which it is found that both the rhinoceros and the tapir groups are descended. This animal has been named Orthocynodon. A somewhat do- tailed account of the anatomy of the skull and form of dentition was given, bearing out the auth 'rs' views. The committee on ^Meteoric Dust state that Mr. Pope Ilennossy had obtained a quantity of ice and snow from the Himalayas. After lieing melted and boiled down the residue was sent to England for examination. In most specimens of the dust arc^ a number of small spherical bodies of magnetic matter, the surfaces of which are generally highly polished. Dr. Schuster showed several of these particles, the largest being perhaps one-twentieth of a millimetre in diameter, which had been obtained from a Gpot in the Himalayas about 3,400 ft. high and It miles from any human habitation. Sir R. W. Rawson stated that, according to the obser- vations of the Anthropometric Committee, it appeared that from the top of the social scale to the bottom there was a gradual descent in stature, weight, chestrgirth, and all the elements of strength. It was therefore of the utmost importance that by nurture and improvement of sanitary conditions the lowest should be raised to the level of the highest. Dr. Schuster read an interesting paper on the motion of the Swiss glaciers. It has been known for some time that there are long periods of time during which the Swiss glaciers advance down or recede up their beds. Thus, in 1741, they were advancing, but it was reported that in 1700 it was possible to walk from Chamounix to Cour- meyer over the Col de Gt-ant without touching ice. They advanced all last century as far as is known and up to 1817, then went back until 1840, advanced till 18-59, and have since been receding till the present year, when many, including the Mer de Glace and the Kosenlaui glacier, have begun to advance. Dr. Schuster has made ob- servations this summer on the Glacier des Boissons, at Chamounix, and has arrived at the important con- clusion that the rate of motion of the same point on a glacier changes greatly from day to day. Thus he showed that while during the day the hourly rate of motion of one point observed was only G centimetres, during the next night it advanced at the rate of 5 .5 centi- metres per hour. The rate of other points examined varied, but not so greatly. Dr. Schuster also noticed the change occurring at the foot of the glacier when it comes into the valley. The downward motion of this point is determined by the fact that the parts above advance more quickly than the ice at the foot melts away. He found tliat on one side of the glacier, where it rested against a boulder, there was no apparent change in the outline of the ice or in the position of the boulder during the day, while at the other side the end had moved in the same time four or five feet. A PAPER was read by Mr. E. B. Poulton on heredity in cats with an abnormal number of toes. The peculiarity appeared in the third generation and in succeeding genera- tions. All varieties between the normal four and the extreme seven toes had been observed. The females most frequently possessed the abnormal number of toes. They were very clever at catching mice, and readily learnt to shake hands. The President said the importance of such observations lay in their bearing on heredity. Reasons had been advanced to show that man was descended from a six-fingered animaL Miss Buckland said she had seen in Bath a cat with seven toes on each foot. Professor Marshall remarked on the importance of such observations in relation to investigations as to the origin of species. Mr. Adam Sedgwick gave an account of the Periodatus — a slug-like animal which he found in South Africa, and of which he exhibited specimens. The animal, he said, had only recently been discovered, and he made a special visit to the Cape to obtain specimens. Special interest attached to it, as it had no living relations in the animal kingdom. It was a survival of a type of animal which at some ancient time in tlie world's history was represented by a greater number of forms. The animal lived in the roots of rotten trees, and it had probably survived on account of its habit.-* and the dilliculty of finding it. Since its iirst discovery the animal had lieen found in New Zealand, South America, and other parts of the world. 210 ♦ KNOWLEDGE ♦ [Oct. 5, 1883. THE BIRTH AND GROWTH OF MYTH. By Edwabd Clodd. BEFORE bringing this series of papers to an end, it may be well to give an illustration or two of the survival of myth in historical narrative. For proofs of the emergence of the higher out of the lower in philosophy and religion, to say nothing of less exalted matters, whether the beast-fable or the nursery rhyme as holding barbaric thought in solution, examples have necessarily been drawn from the mythology of past and present savage races. But these are too remote in time or standpoint to stir other than a languid interest in the reader's mind ; their purpose is served when they are cited and classified as specimens. Not thus is it with examples drawn nearer home from sources at which our young thirst for the stirring and romantic was slaked. When we learn that famous names and striking episodes are in some instances only transformed and per- sonified natural phenomena, or, as occurring everywhere, possibly variants of a common legend, the far-reaching influence of primitive thought comes to us in more vivid and exciting form. And although one takes in hand this work of disenchantment in no eager fashion, the loss is more seeming than real. Whether the particular tale of bravery, of selflessness, of faithfulness, has truth of detail, matters little compared with the fact that its reception the wide world over witnesses to human belief, even at low levels, in the qualities which have given man empire over himself and ever raised the moral standard of the race. Moreover, in times like these, when criticism is testing without fear or favour the trustworthiness of records of the past, whether of Jew or Gentile, the knowledge of the legendary origin of events woven into sober history pre- pares us to recognise how the imagination has fed the stream of tradition, itself no mean tributary of that larger stream of history, the purity of which is now subject of analysis. As a familiar and interesting example let us take the story of William Tell. Everybody has heard how, in the year 1307 (or, as some say, 1296) Gessler, Togt (or governor) of the Emperor Albert of Hapsburg, set a hat on a pole as symbol of the Imperial power, and ordered every one who passed by to do obeisance to it ; and how a mountaineer named Wilhelm Tell, who hated Gessler and the tyranny which the symbol expressed, passed by without saluting the hat, and was at once seized and brought before Gessler, who ordered that as punishment, Tell should shoot an apple ofi" the head of his own son. As resistance was vain, the apple was placed on the boy's head, when Tell bent his bow, and the arrow, piercing the apple, fell with it to the ground. Gessler saw that Tell, before shooting, had stuck a second arrow in his belt, and, asking the reason, received this for answer : " It was for you ; had I shot my child, know that this would have pierced your heart." Now, this story first occurs in the chronicle of !Melchior Russ, who wrote at the end of the fifteenth century, i.e., about one hundred and seventy years after its reputed occurrence. The absence of any reference to it in con- temporary records caused doubt to be thrown upon it three centuries ago. Guillimann, the author of a work on Swiss Antiquities, published in 1-598, calls it a fable, but subscribes to the current belief in it, because the tale is so popular ! The race to which he belonged is not yet extinct A century and a half later, a more fearless sceptic, who said that the story was of Danish origin, was condemned by the Canton of Uri to be burnt alive, and in the well-timed absence of the oflender, his book was ordered to be burnt by the common hangman. But the truth is great, and prevails. G. von Wyss, the Swiss historian, has pointed out that the name of Wilhelm Tell does not occur even once in the history of the three cantons, neither is there any trace that a " Vogt " named Gessler, ever served the house of Hapsburg there. Moreover, the legend does not correspond to any fact of a period of oppression of the Swiss at the hands of their Austrian rulers. " There exist in contemporary records no instances of wanton outrage and insolence on the Hapsburg side. It was the object of that power to obtain political ascendancy, not to indulge its representatives in lust or wanton insidt," and, where records of disputes between particular persons occur, " the symptoms of violence, as is natural enough, appear rather on the side of the Swiss than on that of the aggrandising imperial house."* t^^ Candour, however, requires that the evidence in support of the legend should be stated, although it may have little weight with the readers of Knowledge. There is the fountain on the supposed site of the lime-tree in the market-place at Altdorf by which young Tell stood, as wel) as the colossal plaster statue of the hero himself which confronts us as we enter the quaint village. But more than this, the veritable cross-bow itself is preserved ih the arsenal at Zurich ! However, although the little Tell's chapel, as restored, "was opened with a national /?)i Bei-iew, January, 1869, p. ] 3-1. Article on Rilliet's " Origines de la Confederation Suisse : Histoire et Legende." ■)• Times' telegram from Geneva, June 25. OoT. 5, 1883.] ♦ KNOWLEDGE ♦ 211 " That I might avenge on thee the swerving of the first by the points of the others, lest perchance my innosence might have been punished, while your violence escaped scot-free.' " * Going further northward we find tales corresponding in their main features to the above, in the Icelandic Saga, the Vilkina ; in the Norse Saga of Saint Olaf or Thidrik ; and in the story of Harold, son of Sigurd. In the Olaf Saga it is said that the saint or king, desiring the conversion of a brave heathen, named Eindridi, competed with him in various athletic sports, swam with him, wrestled with him, and then shot with him. Olaf then dared Eindridi to strike a writing-tablet from o& his son's head with an arrow, and bade two men bind the eyes of the child and hold the napkin so that the boy might not move when he heard the whizz of the arrow. Olaf aimed first, aaid the arrow grazed the lad's head. Eindridi then prepared to shoot, but the mother of the boy interfered and persuaded the king to abandon this dangerous test of skill. The story adds that had the boy been injured, Eindridi would have revenged himself on the king.f Somewhat like this, as from the locality might be expected, is the Faroe Isles variant. King Harold chal- lenges Geyti, son of Aslak, and, vexed at being beaten in a swimming match, bids Geyti shoot a hazel-nut from oft' his brother's head. He consents, and the king witnesses the feat, when Geyti " Shot the httle nut away, Xor hurt the lad a hair." Next day Harold sends for the archer, and says : — " List thee, Geyti, Aslak's son, And truly tell to me, Wherefore hadst thou arrows twain In the wood yestreen with thee ?" To which Geyti answers : — " Therefore had I arrows twain Yestreen in the wood with me. Had I but hurt my brother dear The other had piei'ced thee." With ourselves it is the burden of the ballad of William of Cloudeslee, where the brave archer says : — " I have a sonne seven years old ; Hee is to me full deere ; I will tye him to a stake — All shall see liim that bee here — And lay an apple upon his head. And goe six paces him froe ; And I myself with a broad arroe Shall cleave the apple in towe." In the Malleus Maleficarum, Puncher, a magician on the Upper Rhine, is required to shoot a coin from off a lad's head ; while travelling eastwards, as far as Persia, we find the Tell myth as an incident in the poem " Mantic Ultrair," a work of the twelfth century. Thus far I have spoken of the variants of the legend found among Aryan peoples, and it is tempting to base upon this dilt'usion of a common incident a theory of its origin among the Central Asian ancestors of the Swiss and the Norseman, the Persian and the Icelander, iiut it is found among non-Aryans also. The ethnologist, Castren, whose researches in Finland liave secured a valuable mass of fast-perishing materials, obtained this tale in the village Ultuwa. " A fight took place between some frceliooters and the inhabitants of the village of Alajarai. The robbers plundered every house, and carried oil' amongst their captives an old man. As they proceeded with their spoils along the * Bk. X., p. 160. Cf. Baring Gould's " Curious Myths," p. 117; and Fisko's " Myths and Myth-raakers," p. 4. t Baring Rould, p. 119. strand of the lake, a lad of twelve years old appeared from among the reeds on the opposite bank, armed with a bow and amply provided with arrows ; he threatened to shoot down the captors, unless the old man, his father was restored to him. The robbers mockingly replied that the aged man would be given to him, if he could shoot an apple off his head. The boy accepted the challenge, pierced the apple, and freed his father." Among a people in close contact with an Aryan race as the Finns are in contact with both Swedes and Russians, the main incident of the Tell story may easily have been woven into their native tales. But in reference to other non-Aryan races Sir George Dasent, who has treated of the diflusion of the Tell story very fully in tho Introduction to his " Popular Tales from the Norse " (a reprint of which would be a boon to students of folk-lore), says that it is common to the Turks and Mon- golians, and a legend of the wild Samoyedes, who never heard of Tell or saw a book in their lives, relates it, chapter and verse, of one of their marksmen. What shall we say, then, but that the story of this bold master- shot was prominent amongst many tribes and races, and that it only crystallised itself round the great name of Tell by that process of attraction which invariably leads a grateful people to throw such mythic wreaths, such gar- lands of bold deeds of precious memory, around the brow of its darling champion.'* Of course the solar mytho- logists see in Tell the sun or cloud deity ; in his bow the storm-cloud or the iris ; and in his arrows the sun-rays or lightning darts. This is a question which we may leave to the champions concerned to settle. Apart from the evidence of the survival of legend in history, and the lesson of caution in accepting any ancient record as gospel which we should learn therefrom, it is the human element in the venerable tale which interests us most. Remote in time, far away in place, as is its origin, it moves us yet. The ennobling qualities incarnated in some hero (whether he be real or ideal matters not) meet with admiring response in the primitive listeners to the story, else it would have been speedily forgotten. Thus does it retain for us witness to the underlying oneness of the human heart beneath all surface differences. Note. — The totemic illustration in the previons paper was copied from Dorman's " Primitive Superstitions," p 238, and Lubbock's " Origin of Civilisation," p. 52. THE ELEMENTS. t rpHOUG H theoretical and practical chemistry are now X intertwined, with manifest advantage to each, they appear to have been far apart in their origin. Practical chemistry arose from the arts of life, the knowledge em- pirically and laboriously acquired by the miner and metal- lurgist, the potter and the glass-worker, the cook and the perfumer. Theoretical chemistry derived its origin from cosmogony. In tlie childliood of the human race the question was eagerly put, " By what process were all things made 1 " And some of the answers given started the doctrine of elements. The earliest documentary evidence of the idea is probably contained in the " Shoo King," the most esteemed of the Chinese classics for its antiquity — probably older than Solomon's writings. The elements named are — water, fire, wood, metal, earth. A similar idea of five elements, • Introd. XXXV. t From Dr. Gladstone's Address, Chemical Section of British Association. 212 KNOWLEDGE ♦ [Oct. 5, 1883. differently named, was also common among the Indian races Viefore the fifteenth century B.C. The five are curiously correlated -nith the five senses, and they are not looked upon as independent material existences, but as derived from one another. This philosophy was accepted alike by Hindoos and Buddhists. It was largely extended over Asia, and found its way into Europe. It was best known to us in the writings of the Greeks. Among these people, however, the elements were reduced to four — fire, air, earth, and water — though Aristotle endeavoured to restore the " blue ether " to its position as the most subtle and divine of them all. For the modern idea we must again travel back to China. In the sixth century b c. the great philosopher Lao-tse and his disciples founded the religion of Taou. They held that the souls of the five elements — water, metal, fire, wood, and earth — arose and became the five planets. At the begin- ning of the seventh century the doctrine of Lao-tse was in great favour at the Chinese court. The disciples of Mahomed carried their arms and his doctrines to the Flowery Land. In the eighth century there were frequent embassies between East and West, wars with Caliphs, and a matrimonial alliance. The teachings of the Taouist alchemists penetrated to Arabia. Geber, a Saba?an, started what to the west was a new philosophy about the transmutation of metals. The idea became gradually clearer that all material bodies were made up of certain constituents, which could not be de- composed any further, and which, therefore, should be con- sidered as elementary. The introduction of quantitative methods compelled the overthrow of mediteval chemistry, and led to the placing of the conception of simple and compound bodies upon the foundation of scientific fact. Lavoisier, perhaps, deserves the greatest credit in this matter, while the labours of the other great chemists of the eighteenth and the Ijeginning of the nineteenth cen- turies were in a great measure directed to the analysis of every conceivable material, whether solid, liquid, or gaseous. These have resulted in the table of so-called elements, now nearly seventy in number, to which fresh additions are constantly being made. Of this ever-growing list of ele- ments not one has been resolved into simpler bodies for three quarters of a century ; and we who are removed by two or three generations from the great builders of our science are tempted to look upon these bodies as though they were really simple forms of matter, not only un- resolved, but unresolvable. The notation we employ favours this view and stamps it upon our minds. Is it, however, a fact that these reputed elements are really simple bodies ? Or indeed, are they widely different in the nature of their constitution from those bodies which we know to be chemical compounds 1 Thus, to take a par- ticular instance, are fluorine, chlorine, bromine, and iodine essentially distinct in their nature from the compounds halogen, cyanogen, sulphocj-anogen, ferricyanogen, Arc. 1 Are the metals lithium, sodium, and potassium essentially distinct from such alkaline bases as ammonium, ethylamine, diethylamine, &c 1 Ko philosophical chemist would pro- bably venture to ask this question categorically with either "Yes" or "No." It was at first hoped that the spectroscope might throw much light upon the nature of elements, and might reveal a common constituent in two or more of them. Thus, for instance, it was conceivable that the spectrum line of bromine or iodine vapour might consist of the rays given by chlorine ^)/?/s some others. All expectations of this have hitherto been disappointed ; yet, on the other hand, it must not be supposed that such a result disproves the compound nature of elements, for as investigation proceeds it becomes more and more clear that the spectrum of a compound is not made up of the spectra of its com- ponent parts. The general tendency of the arguments is to show that the elementary radicals are essentially dif- ferent from the compound radicals, though their chemical functions are similar. There remains still the hypothesis that there is a " pri- mordial element " from which the others are derived by transmutation. With the sages of Asia it was the " blue ether " ; with Thales, water ; with Dr. Prout, hydrogen. The earlier views have passed away, and the claims of hydrogen are being fought out on the battlefield of atomic weights and their rigorous determination. There does not appear to be any argument which is fatal to the idea that two or more of our supposed elements may differ from one another rather in form than in substance, or even that the whole 70 are only modifications of a prime element ; but chemical analogies seem wanting. The closest analogy would be if we could prepare two allotropic conditions of some body, such as phosphorus or cyanogen, which should carry their allotropism into all their respective compounds, no compound of the one form being capable of change into a compound of the other. Our present knowledge of allotropism and of variations in atomicity affords little, if any, promise of this. The remarkable relations between the atomic weights of the elements, and many peculiarities of their grouping, force upon us the conviction that they are not separate bodies created without reference to one another, but that they have been fashioned or built up from one another according to some general plan. This plan we may hope gradually to understand better ; but if we are ever to transform one of these supposed elements into another, or to split up one of them into two or three dissimilar forms of matter, it will probably be by the application of some method of analysis hitherto unknown. TWO-SPEED TRICYCLES. By John Browsing, Chairman of the London Tricycle Chii. I TRUST I shall be excused for the delay which has occurred in the appearance of this article, but I have withheld the paper until I could give my experience of each machine to which I have to refer. The two speed gearings I shall mention in the order in which I have tested them. First, then, I must name the Crypto-Dynamic. This elegant contrivance I know less of than any of the rest. I tried it once only on good roads. The gearing for hill riding was equal to 2.3 in., and there was not a steep hill in the neighbourhood. The hill I tried it on I ran up easily, of course. This was more than a year ago, and I have not been able to hear much about the contrivance since ; but it will, I believe, be purchasable by the public next month. It is compact, and easily applied to almost any machine ; but I fear it will work with considerable friction if it has to rotate at any great velocity. Should this prove to be the case, it will not be well adapted for tricycles with small wheels. Next I tested Burdess's two-speed Sterling tricycle. This is the simplest contrivance yet introduced. By pedal- ling forward you drive the machine, which has -IG-in wheels, for speed, and it runs as though it were 56 in. By pedalling backward you drive the machine for power, and it runs as though it were 38 in. The motion can be re- Oct. 5, 1883. ♦ KNOWLEDGE ♦ 213 versed easily, tliree or four times in a minute, while going. Tliere are no levers to move, nor anything to think of. So soon as driving forward becomes harder work than you like you have only to pedal backwards to gain power. One great advantage of this arrangement is tliat in driving the slow-speed gearing to ride up-hill, you bring another set of muscles into play, which, of course, act more vigorously ; and, meanwhile, those used for riding over the level roads are being rested. The machine is too liighly geared for my own riding. Some strong riders would prefer it so. It is excellent in workmanship, and very strongly made. It would be improved if the wheels were smaller and the weight reduced by 10 or 20 lb. ; but, even as it is, after trying it for weeks over all conditions of roads, and in all kinds of wind and weather, I can say that I have not been able to get it out of order, and that it runs easily and well. Lloyd Brothers' two-speed Quadrant Tricycle was the next machine I tested. This is a very ingenious con- trivance. The gearing-down of the machine for hill-riding is effected by pressing a lever. This causes the upper chain-wheel to expand, and so carry the driving-wheels round slower than the cranks are turning. The machine is a double - driver and front- steerer, central-geared. I tried it up steep hills, over roads rotten with rain, and against a strong wind, and none of these unfavourable conditions stopped me. The machine I tried was the first experimental machine, and so was unnecessarily heavy, but as the makers have pi'oduced the lightest " Sociable " yet made, I suppose that future machines of this kind will be proportionably light. Thanks to the kindness of Mr. Grace, I next tried the "Diana." This machine has two pairs of chain wheels, and two chains. Either of these can be thrown in or out of gear, and the other one allowed to run freely. One chain drives for speed and the other for power. When the high speed is on the wheels are level-geared — that is, 40-in. wheels run as 40 in., 50 in. as 50 in., kc. ; in other words, the greatest speed depends on the size of your driv- ing wheels. Pulling back a small lever gears the machine down for hill riding. In an intermediate position of the lever, both chains are out of gear and run free. On long, slight downward inclines this is advantageous. The machine tried was built specially for Mr. Grace, who kindly consulted me before he had it put in hand. The wheels are 46 inches, because that was the smallest size the makers could supply. This, as I have explained, determined the high speed for th(! level. When geared down the machine ran as 32 inches. I have ridden it on several occasions, once for half-a-day over muddy roads, up-hill, nearly all the way against a wind so high that I had to drive hard even down a long steep hill at the end of my trial. The machine is a great success, but it could be made 20 lb. lighter with great advantage. Making the wheels 40 in., and gearing them up to 4 8 in. or 50 in. for high speed would facilitate this reduction of weight. As a proof of the power of the machine, I may say that I have seen Mr. Grace ride it up the steep rough hill which leads from Ktdliill to Blctchingley — the road at the time being covered with mud which buried the tires and rims, and in this mud there was a quantity of loose stones. This iiill is a severe task for a first-rate rider in tine weather when the road surface is in tlu! best condition. Mr. Grace will, I am sure, agree with me that if the " Diana " were made with 40-in. wheels, and were geared so that the speed- gearing ran as iifty inches and the power-gearing as thirty inches, and the weight were reduced about 20 lb., as it might easily be, we should then have a n-olel two-speed machine. The last two-speed machine I have tried is Grout's " Adroit" tricycle. This is a lever machine in which the fulcrum of the levers can be changed by turning the holding handle on the left-hand side — that is, on the opposite side to the steering handle. There is so wide a range of adjustment that the machine may be altered while running to equal any gearing from 20 in. to GO in., and stopped at any point between at pleasure. It is a front steerer and double driver, and the Ijand brake will stop it dead. The machine is light, and the maker will construct it with wheels of any diameter from 40 in. to 50 in. I tried it on rough wet roads and it performed well. With those who do not object to a lever machine I should think the " Adroit " multi-speed tricycle will be a favourite next season. On a single tricycle the two-speed gearing will be valuable in many ways. A beginner who commences with a two-speed machine may ride with the power-gearing until his muscles become accustomed to the unusual action, and put en the speed- gearing as he acquires strength in riding. A man who uses a tricycle for the purpose of carrying a heavy weight will ride with the power-gearing while he is carrying the weight, and with the speed-gearing as soon as he is relieved from it. Thus, a rider who carries a set of photographic apparatus of the largest size, to take pictures 12 in. by 10 in., which will weigh from 30 lb. to 40 lb,, will use his power-gearing only, and will ride with the same ease with a reduction in his speed. A " Sociable " with a two-speed gearing, when used by a gentleman with an unpractised or weak lady rider, would, as a rule, be ridden geared down, that is, with the power- gearing ; but when ridden by another gentleman as strong or stronger than himself, the same machine would be ridden geared-up, that is, with the speed-gearing, and a much higher speed attained without undue exertion. Dr. Richardson, in his admirably-suggestive essay, just published in Lomjman's Magazine, has protested against cycling being treated simply as a sport, and has pointed out in weighty words the evils that must ensue from pursuing such a course. I look forward to the adoption of the " Sociable " tri- cycle as the most likely means of elevating tricycling as a healthful pastime and an intellectual recreation. The suc- cessful application of changeable speed-gearing is a new era in cycling. BuRNii.\M Beeches. — Mr. F. G. Heath is issuing, through Messrs. Rider it Son, at the cilice of Forestry, a shilling edition (illustrated) of his little work " Burnhani Beeches." It will appear opportunely in connection with the public dedication of Burnham Beeches, next week, by the Cor- poration of London. Ev.\i'OK.\TiON .\ND Electkicitv. — Dr. L. J. Blake has been investigating the statements of Pouillet and others to the eli'ect that electricity is produced by the simple eva- poration of a liquid. He worked with sea-water, sulphate of copper solution, chloride of sodium solution, kc, but in every case the results went to show that electricity is not produced in this way, and that seme other means must be found of explaining the production of atmospheric elec- tricity. Dr. Blake also negatives the hypothesis of Franklin and others to the effect that electricity is con- veyed by still evaporation from an electrilied liquid. The experiments were conducted with a quadrant electrometer of M. Yoss, Berlin. — Emixnceriny. "^o 214 • KNOV^^LEDGE ♦ [Oct. 5, 1883. SEA ANEMONES AT THE FISHERIES EXHIBITION. By Thomas Kimber. v.— THE DAISY. (^Continued jrom page 188.) " Hail, holy liglit, offspring of Heaven fii'st-born." — Hilton. BEND and distort any plant as we may, the strongest proof that it is wrested from its original and inherent nature will be in the ceaseless efforts which it evinces to raise its struggling branches to the skies. In like manner sea anemones follow this law of vegetable life, though feeble, indeed, must be the ray in those sea-depths where some of the largest and brightest species flourish and bloom. Darken the top of the aquarium, and Daisy bends her stem that the disk may face the lighter side of her home, and though some actinia' are impatient of a strong light, it would seem that utter and continued darkness are incom- patible with full health in any species, and the free ex- pansion of their flower. The daisy — as before pointed out — differs from all other anemones in having comparatively a very slender column, whose average diameter is not more than one-fourth that of the disk ; she is prolific, and in many cases both viviparous and oviparous. The fully-formed young are discharged from the gonidal grooves, whence the ova also make their appear- ance. The shape and marking of the newly-born daisy are readily recognised, the chief distinction between the young and their parent being, apart from size, the small number of tentacles — not more than a baker's dozen — and these are larger in proportion in the young than in the adult. It has been frequently noticed in anemones generally that a large animal has large offspring, the reason being, it is very naturally concluded, that a large body allows more space for the fuller development of the young before they are brought into the world than it is possible in the case of a small parent that is equally productive. The mature ova, however, are observed to be of the same size in the same species. Bellis is sometimes obtained from deep water, but its favourite resorts are pools, crannies, rock fissures, and other similar hiding-places between tidal limits. In many such cases daisy is difficult to get at, for when the disk can be seen and reached, the base is found to be fixed in some crevice which the animal has chosen for safety. A hammer, steel chisel, and great patience are then necessary, as with- out these three requisites there is a strong probability that in tearing away the animal the central portion of the Ijase will be left behind. The creature so mutilated will after- wards occasionally expand its bloom and look healthy for a time, but seldom survives its proper period. Cases, how- ever, are met with in many species in which immoderate wounds and lacerations heal, and lost parts are restored. The safest way, and the most satisfactory to both parties — daisy and her captor — is to cut ofl' a piece of the con- glomerate to which she is usually attached. Still colonies are not unfrequently met with in situa- tions more favourable to the collector, as in superficial fissures, and shallow hollows of coarse sand, or pudding- stone, where, at ebb tide, only a few inches of water cover them. In these situations they are frequently so crowded that their disks pressing upon each other lose their circular shape. The flower is puckered and frilled, filling all the interstices, and presenting a continuous surface of distorted disks. The amount of bright colour thus displayed is in- considerable, but the effect upon close inspection of the convoluted and fringe - like pattern is pleasing for its novelty. Mr. Gosse mentions a variety of this species (" Actinologia," p. 3.3), at Weymouth, which he names Sordida. These anemones are met with on fetid mud, and are dingy in appearance. Tlieir bases simply rest on the slime, but when removed to a vessel of clear sea-water, they very soon become attached to the bottom or side. They differ widely from the Cornish mud-dwelling variety described on page 188. The Daisy is a hungry creature, and will eat varaciously bits of meat, fish, oysters, worms, or almost any animal substance. For the most part bellis is stationary, and when in sound health is nearly always open. She is essentially a southern beauty, more of a French than an English belle, somewhat Irish, and very little Scotch. Daisy has been found on the south-west shores of Scot- land, in EatHin Island, Dublin Bay, and the south and west coasts of England and Ireland. She is constantly being captured at Boulogne and in the Channel Islands ; she is also found by myriads near Oporto. The older writers, Lamark and Blainville, give the shores of the Mediterranean as her chief habitat, but pre-eminently the Bay of Naples. In Dana's great American work there are three brilliant anemones named and described, which have some of the leading traits and habits of Bellis — Actinia decorata from a Lagoon of Honden Island, A. Fuegiensis, and A. Iin- patiais from crevices of rocks and tide-pools in Orange Harbour, Terra del Fuego. The examples of daisy in the Fisheries are not numerous, and are scattered in various small vases and tanks, but amongst them are a few very good specimens. By the way, all the tanks now (Sept. 21), are in excellent condition, the water in them is bright, and the greater part of, if not all, their denizens appear in vigorous health and are seen to great advantage. Only a week or two ago this was not the case, and just criticisms were beginning to make their appearance in the daily press. The improvement, however, has been prompt and so far very complete and eflectual. This department continues to be one of the most attrac- tive in the Exhibition — more particularly when illuminated in the evening, and all the tanks, in consequence, are then excessively interviewed, without regard for the comfort or welfare of their occupants. Frequent renewals of the less hardy are therefore indispensable under the present pres- sure of visitors. Where practicable, the anemone and other tanks should be looked at during the early part of the day, as by the electric light anything like a careful and quiet examination of them is impossible. Electric Lighting in Mills. — A mill situate on the banks of the Doria, near Turin, is lighted by means of sixty-four Swan lamps. The current is supplied by a Gramme dynamo, driven by the water-wheels of the mill. The speed of the dynamo does not exceed eight hundred revolutions per minute. The installation is reported to give great satisfaction. The Swan lamps have replaced colza oil.- — Electrician. Edison System in the House. — Mr. Shaw Lefevre has purchased the Edison plant which has been in use at the House of Commons during the past Session. He intends, owing to the success attending the existing installation, to adopt the light as a permanency, and to considerably extend its \ise. The existing plant consists of 2.50-light dynamos, and 276 lamps, with all necessary fittings. The new plant will comprise an Armington and Sim's high-speed engine, and two L (250-light) dynamos. The total number of fresh lamps to be employed will be 214. Oct. 5, 1883.] ♦ KNOWLEDGE ♦ 215 TRUTH AND POKER. By Riciiaed A. Proctor. AN angry man is apt to appear unfavourably in a fencing bout. He aims wildly at a seemingly exposed but really well guarded spot, leaving himself open to a riposte which, but for his wild attack, might easily have been foiled. I fear Mr. Labouchere must be angry with me, he has twice attacked me so thoughtlessly. (Yet have I given him no just cause for anger.) Truth need not have a bad memory, though untruth we arc told should have a good one. One week it rushes out with upraised cudgel, to fell me to earth by calling my article on Poker in Longman's Magazine a silly paper which proves too lengthily that two and two make four, yet (strangely) quoting as "curious" my enumeration of poker hands: next week another way of hitting at Proctor's Poker is tried (any stroke seems right to the blindly angry). " A correspondent writes " (says Mr. Labonchere) " to point ont the inaccuracy of Mr. Proctor's ' Poker Fissures/ which I cited last week. ' There can,' ho says, ' bo only 78 possible pairs in an ordinary pack of cards, and not 1,098,240, if any two cards of the same denomination constitute "a pair." So, too, in regard to " triplets ; " he thinks there can be 54,912 ; I contend there can only be 52. Again: lie makes "fours" produce 624, whilst I can only make them produce 13. It appears to me that your authority (whom you did not appear to deem much of an authority) considers any two cards to be "a pair," instead of two cards of the same denomination.' I merely quoted the calculations from an article on Poker, by Mr. Proctor, in Longman' s Magazine, quantum laleant." Yes ; but, my good sir, you should have a better memory : you accompanied your quotation with the re- mark that my article proved only that "two and two make four, with other such matters of universal cognition." (I quote from memory, but I can trust mg memory.) It would seem that now you are in doulit whether two and two make four, and not (perhaps) five, or (it may be) three. After showing your familiarity with whist by confounding " finessing " with " underplay," you further illustrate your " universal cognition " by inserting preposterous comments as possibly valid criticism, — but possibly not, you cannot for the life of you .say which. Permit me to remark (I will not say " explain," lest you should remind me then of your " universal cognition ") that though there are only 78 possible " paiis " in an ordinary pack of cards, there are 1,098,240 "pair hands" at poker; though there are only fifty-two possible " threes," yet there are 54,912 "triplet hands"; though there are but thirteen " fours," yet are there (as I have said and shown) G24 " four hands ; " and lastly if (becoming tempor.arily idiotic) I liad supposed amj two cards to be a " pair," I should still not have arrived at the number 1,098,240, the total numlier of two-card combinations in a pack being only 1,32G. [Tlieso and similar relations in card games I may shortly discuss in these columns — at the risk, even, of 1 icing told (by, but not with, Truth) that I am dealing with matters of universal cognition.] EVOLUTION OF CONDUCT. ^T/'lI-'^T says the doctrine of evolution with regard to VV the ethical side of this twofold assertion that lies at the bottom of all religion] Though we cannot fathom the nature of the inscrutable Power that ani- mates the world, wo know, nevertheless, a great many things that it does. Does this eternal Power, then, work for righteousness 1 Is" there a divine sanction for holiness and a divine condemnation for sin 1 Are the principles of right living really connected with the intimate constitution of the universe 1 If the answer of science to these questions be affirmative, then the agreement with religion is complete, both on the speculative and on the practical sides ; and that phantom which has been the abiding terror of timid and superficial minds — that phantom of the hostility between religion and science^is exorcised now and for ever. Now, science began to return a de- cisively affirmative answer to such questions as these, when it began, with Mr. Spencer, to explain moral beliefs and moral sentiments as products of evolution. For clearly, when you say of a moral belief or a moral sentiment that it is a product of evolution you imply that it is something which the universe through untold ages has been labouring to bring forth, and you ascribe to it a \'alue proportionate to the enormous efibrt that it has cost to produce it. Still more, when with Mr. Spencer we study the principles of right living as part and parcel of the whole doctrine of the development of life upon the earth ; when we see that, in an ultimate analysis, that is right which tends to enhance fulness of life, and that is wrong which tends to detract from fulness of life, — we then see that the distinction between right and wrong is rooted in the deepest foundations of the universe ; we see that the very same forces, subtle and exquisite and profound, which brought upon the scene the primal germs of life and caused them to unfold, which through countless ages of struggle and death have cherished the life that could live more perfectly and destroyed the life that could only live less perfectly, until humanity, with all its hopes and fears and aspirations, has come into being as the crown of all this stupendous work — -we see that these very same subtle and exquisite forces have wrought into the very fibres of the universe those principles of right living which it is man's highest function to put into practice. The theoretical sanction thus given to right living is incomparably the most powerful that has ever been assigned in any philosophy of ethics. Human responsibility is made more strict and solemn than ever, when the eternal Power that lives in every event of the universe is thus seen to be in the deepest possible sense the author of the moral law that should guide our lives, and in obedience to which lies our only guarantee of the happiness which is incorruptible — which neither inevitable misfortune nor unmerited obloquy can ever take away. — John Fiske. RELIEF OF SEA-SICKNESS. IN spite of the fact that much has been written on the suliject, people still continue to suffer from sea-sick- ness, which proves the unreliability of our therapeutic resources. Therefore the following experience of Dr. T. M. Kendall, who has recently had 200 cases under his charge, may prove interesting : — jiany people, as soon as seasickness commences, have recourse to oranges, lemons, kc. Now oranges are very much to be avoided, on account of their bilious tendency, and even the juice of a lemon should only be allowed in cases of extreme nausea. Cliaiiipagne, too, is a very common remedy, and, with- out doubt, in many cases does good ; but this appears to be chieiiy due to its exhilarating effects, as if it be dis- continued, tlie result is bad, and a great amount of prostra- tion follows. Creosote is a very old but still very good remedy, and, in cases accompanied by great prostration, is very useful ; 216 KNOWLEDGE ♦ [Oct. 5, 1883. but if given in the early stages of sea-sickness, it is often followed by very bad results, and even increases the nausea. Bicarbonate of soda is useful in slight cases, as it relieves nausea, and checks the frequent eructations which often follow attacks of sea-sickness ; but in severe cases it is absolutely useless, and, in fact, it very often prolongs the retching. A very good remedy in the earlier stages of sea-sickness is a teaspoonful of Worcester Sauce. How this acts I can- not say ; but it without doubt relieves the symptoms and renders the patient easier. Its action is probably of a stimulant nature. Jli/drocyanic acid is of very little service, and most acid mixtures are to be avoided, except that, perhaps, for drink- ing purposes, when it is best to acidulate the water with a small quantity of hydrochloric acid. Of all the drugs used, I found the most effectual was bromide of sodiit?n. When bromide of sodium is given in doses of ten grains three times a day, the attacks entirely subside, the appetite improves, and the patient is able to walk about with comfort. In all cases of sea-sickness, it is very desirable that the patient should take sufficient food, so that at all times the stomach may be comfortably full, for by this means over- straining during fits of retching is prevented, and the amount of nausea diminished. The practice of taking small pieces of dry biscuit is not of much use ; as, although the biscuit is retained by the stomach, yet the amount taken is never sulEcient to comfortably till the stomach. Soups, milk pi ddings, and sweets are to be avoided, as they increase the desii'e to be sick and are followed by sickening eructations. Fat bacon is easily borne, and does much good, if only the patient can conquer his aversion to it. When taken in moderate quantity, it acts like a charm, and is followed by very good results. But of all food, curry is the most useful in sea sickness, and is retained by the stomach when all other food has been rejected. Kext to curry, I would place small sand- wiches of cold beef, as they look nice on the plate, and are usually retained by the stomach. In conclusion, I would advise that brandy should be used very sparingly, as in many cases it induces sea sick- ness ; and its chief use is confined to those cases where the prostration is very great, and even then champagne is more effectual. — Scientific American. PLEASANT HOUES WITH THE MICROSCOPE. By Henry J. Slack, F.G.S., F.R.M.S. GOETHE anticipated the mode of studying nature now generally admitted to be right, when he said to Eel ermann, "The utility teachers say that oxen have horns to c'efend themselves, but I ask, why is the sheep without any 'i If, on the other hand, I say the ox defends himself with his horns because he has them, it is quite a different matter." Some shallow thinkers have regarded this mode of reasoning as opposed to a recognition of design in nature, but it is not so. Sciences of observation and ex- periment have to do only with how and what. The iclnj remains for philosophical consideration, and as the old design argument fades away on account of its narrowness and insutBcency a much grander one arises, showing that the adaptation of organisms to their surroundings arises cut of general laws, and cannot be rightly viewed as so many disconnected exhibi- tions of creative skill. Let us examine two insects belonging to the great Order Hymenoptera, and notice how importantly their mouth organs help to determine their way of living. If the head of a wasp is looked at with » hand magnifier, immediately below its upper lip two re- markalily powerful mandibles are seen. They work — as insects' jaws generally do — horizontally, and are furnishecJ with strong, pointed teeth. Look in the same way at a honey bee. Its mandibles are much smaller, its face looks more innocent ; quite mild as compared with the tiger-like countenance of the wasp. Its jaws inform us at once by their aspect that the creature will not be engaged, as the wasp will, in hard biting woik. Extending a little beyond the mandibles, the pocket lens will show, in the wasp, a short, squarish, three-cleft organ of gauzy texture, the centre portion being the biggest, with a yellow spot at each tip, and similar spots, one each at the tips of the side divisions. This is a lapping tongue. The bee's tongue is also a lapping one, but constitutes a much larger and more powerful-feeding machine. It lies between two labial palpi and two maxilla;, which all join to form a tubular sort of sheath for it. A good way to know something of this remarkable appa- ratus is to catch a bee in a bottle, and see it feed. For this purpose a wide-mouthed bottle, of thin glass and about one inch in diameter, will do ; or, still better, a wide- mouthed test-tube, which can be bought for one penny, and which should be fitted with a cork not tight enough to exclude fresh air. The bee is easily caged while busied with a flower. Let it have a little time to recover from its astonishment and alarm, and then, while it is in the bottom of the tube, withdraw the cork, and put a little syrup of sugar and water upon it before replacing it. Previous to commencing dinner, the bee's tongue and adjacent mouth-organs look like a brown flattened tube of gutta-percha, curved — if one may so speak — under its chin, and towards its breast. As soon as it finds the syrup, the jaws open, the tongue is thrust for- ward between them, and an unexpected piece is shot out beyond the maxilla;. The pocket lens will indicate that this portion is very hairy, especially towards its tip. It may, in fact, be likened to a long-haired flexible broom, and the insect uses it accordingly. The long hairs all point downwards, so that, when the creature bends the end of the tongue backwards, lays it along the cork, and then draws it forwards, it acts exactly as we should do if we were using a flexible brush to wipe up a slop. Every now and then the creature draws the tongue between its hairy fore-legs, as if to clean it, but the action may also bring the fluid down to an orifice through which, I think, it is tucked up. Another curious motion may also be seen, that of thrusting the tip of the tongue backwards towards its body. Is this only another cleaning process] or does the bee propose to carry otl some of the f'Vrup sticking to its hairs 1 Let the reader catch some bees, feed them well, and pay attention to their ways. In a former number will be found figures of the mouth organs of the biting breeze flies. Their maxillre are carving-knives, very unpleasant when used upon ourselves. The bees' maxilLT? serve quite another purpose ; they are not cutting implements at all, but combine with the next inner organs, the hairy labial palpi, to cover the tongue, and stroke down the fluid it laps up, when the insect rapidly withdraws the extended pait up into the tube-like sheath which they form. This is the interpretation of their use which watching the feeding process suggests. It is evident that the wasp's very different tongue could not do such effective lapping, and its shortness would prevent its gathering the nectir of many tubular flowers, as Oct. 5, 1883.] ♦ KNOWLEDGE <► 217 the bee can do. But the wasp can bring his jaws to aid ; and a little while ago, when Redhot Pokers {Tritomauvaria) were in bloom, numbers of wasps might be seen biting holes round the bottom of the tubular flowers, and thus enabling their short tongues to get at the coveted nectar. It may be incidentally mentioned that the Redhot Poker was introduced from Africa no great while ago, and English wasps must have contemplated it as a strange plant, which neither they nor their grandfathers had ever fed upon. The first wasp who tapped its corolla must have been an adven- turous experimenter — in his way a reasoner from analogy, and a benefactor to his race. ,1/1 r\^ (0 \ Fig. 1. — Mouth-organs of Honey .Bee. A. Tongue extended. BB. Labial palpi. CC. Maxilltc. DD. Maudibles, depressed to show other organs more plainly. When the bee sucks the tongne, &c., are raised and protruded between them. (Dra-i\-n from the objects uncompressed by Mrs. Slack.) x 20. We shall proceed in another paper to a minute examina- tion of the bee's mouth organs, but will now further consider what more the e.xamination with a pocket lens suggests. Having regard to the si/c of the two insects, and to the small quantity of food required for a creature that com- pletes its growth at the time of its emergence from its pupa state, the liee's mouth organs suggest that it might gatlu^r much more food than its own needs require, whilii the wasp's mouth organs suggest that a more varied food and a smaller quantity may suit its habits. This is the case. The bco has not only to feed a host of young during the warm months, but to lay up a store of food for a largo population to live upon atwaking times during the winter. The wasp has also to feed its young, but when the cold weather comes the bulk of the colony dies, leaving only some females to lay eggs and found a fresh city of paper houses when spring returns. The l)ee, making its comb and cells of wax, needs to eat the right food for this substance to be secreted. The wasp, to create its paper, has to bite wood and other substances' which its big strong jaws make easy work, but which the bee's jaws are not fit for. A bee could make no impres- sion upon a firm apple, but a wasp soon gnaws a great hole- in one, chiefly to suck its juices, as its small waist would forbid the passage of solid particles, unless of very minute dimensions. Fig. 2. -Wasp's tongue and labial palpi. (Copied from Westwood.) x 10. The mandibles, or jaws, of the bee come into special use in forming the comb. The wax is secreted in thin plates between the segments of the abdomen. This substance is kneaded by the mandibles, and added layer by layer to form the comb. In its early stage this consists of shape- less blocks, which the mandibles mould into shape. The mandibles serve a great number of other purposes. They are the insects hands as well as cutting tools. The subject will be continued in the next paper. Fig. 3. — Tip of Bee's tongue, underside uppermost. (Drawn fronu preparation in Canada balsam by Mrs. Slack.) x COO. €tittortaI (Sosisfip. A GREAT deal has been said about newspaper science, which is often spoken of as if it were uniformly valueless. That this view cannot bo altogether correct is shown by the circumstance that many of our most distinguished men of science have written newspaper articles on their own special subjects, and that such articles have not unfre- quently been embodied subsequently in scientific works of high standing. I am myself somewhat unwilling to see newspaper science systematically abused and ridiculed. For I have written many hundreds of newspaper articles — not all, by the way, on subjects which belong to my own special lines of research. I have always strictly limiteil 218 « KNOW^LEDGE [Oct. 5, 1883. what I Lave said to what I knew and understood, not thereby always escaping error (for this none can do) but escaping the blunders which necessarily arise when the blind undertake to lead the blind. This rule, carefully and honestly followed, should be all that is necessary to keep newspaper science above reproacli. But unfortunately many who write for our daily and weekly papers are not troubled with much fear of bringing reproach upon newspaper science or on the particular news- papers to which they are good enough to contribute. The editor of a newspaper cannot be familiar with every de- partment of science, if even with any. He cannot always be able even to distinguish those who are competent to write on any subject from those who are not. If a man known to have done good work in one department of a particular science offers to write on any matter connected with the subject, and possesses a tolerably effective literary style, an editor can hardly be blamed if he accepts and inserts the proffered contribution, even though it should turn out to be in reality utterly valueless and full of egregious blunders. The dishonesty of the writer is the real trouble, not the editor's want of scientific knowledge — a kind of knowledge not to be expected in a man who has to give his attention to other and very different matters. These remarks have been suggested by the reading of a leading article in the Times of Saturday, September 22, on the subject of Dr. Ball's excellent discourse on the Sun's Distance now appearing in these pages. Who may be the author of the article, I have no means of knowing. That it has appeared in such a paper as the Times is sufficient evidence that the writer has done some good work, or has the general credit of having done such work, in astronomy ; for otherwise the article would never have been accepted. But that the writer is hopelessly ignorant of the elemen- tary mathematics of astronomy is equally obvious. It becomes very ditficult, therefore, to explain how, without dishonesty, this article came to be written for the Times. If there is a less unpleasant explanation, let us hope that before long it will be given ; for, while the occurrence of occasional errors or even blunders in newspaper science may cause no great harm in the long run, the display of deliberate dishonesty such as has in this case, I fear, been shown, would be a serious misfortune. It is not to correct the errors in the article in question that I point them out, but because they are part of the evidence of what appears to me deplorable want of prin- ciple in some writer unknown. Here is an article on astronomy in a tone implying right to speak " as having authority." The writer talks condescendingly about " the mind of the average man," about " non-scientific persons," and so forth, and about the enlarged conceptions which such folk should form of " the laborious and patient accuracy of scientific work." But while, in the whole article, there is no trace of original thought or of any real grasp of what Dr. Ball himself had clearly explained in his lecture, there are blunders such as none liut a charlatan writing of what he knew nothing about could possibly have made. We are told that Neptune was " looked for in the position from which its disturbance was exercised," which is preposterous ; that the " larger of the asteroids, under favourable conditions, come within " such and such distances of the earth, as if size had anything to do with the matter ; and that Dr. Ball saw Venus (at Dunsink) in the middle of her transit last December, the middle of the transit occurring long after the sun had set at Dr. Ball's station. But these are only blunders, showing indeed the ignorance and inaccuracy of the writer, and otherwise insignificant. What, however, is to be said or thought of the deliberate statement that, " in consequence of the motion of the earth round an elliptical orbit, the distance which separates us from the sun is variable, being greatest when our planet is on the major axis, smallest when it is on the minor axis of the ellipse " 1 If the statement had been less precise in its nature, we might have supposed that the error had arisen from mere carelessness ; but in the sentence as it stands the writer deliberately expresses and even emphasises his ignorance. Xobody who knew, as every one familiar with the elements of astronomy must know, that the earth is nearest to the sun when passing one extremity of the major axis of her orbit, farthest from him when passing the other, and at his mean distance when on the minor axis, could possibly have made such a state- ment as we have quoted. One would only too willingly ascribe it to mere carelessness on the part of one who really knew better ; for by so doing the evidence of dis- honesty might be overlooked. But unfortunately no such interpretation seems possible. Completion of Second Million Issues at Mitchell LiBEARY, Glasgow. — This library has now completed the second million in the number of volumes issued to readers, and advantage .may be taken of this circumstance to draw attention to the very remarkable degree in which Mr. Mitchell's benefaction has been appreciated and made use of by all classes of the citizens — artisans, clerks, students, and professional men. The first book, " Liber Officialis Sancti Andree " (Abbotsford Club), was issued at ten o'clock in the morning of Nov. 5, 1877 ; the first million issues were completed Jan. 14, 1881, being 982 working days from the opening ; the second million issues were completed at 6.4.5 p.m. on Saturday last, Sept. 1, 1883, and occupied 808 working days. It is be- lieved that there is no previous instance on record of the issue of two million volumes within so short a period of the opening of a public library. As will be seen from the statistics below, the reading of fiction forms but a small proportion. It should be stated, too, that in addition to this large number of volumes asked for at the counter there has been a very great use made of the current periodicals — literary, artistic, scientific, technical, profes- sional, and other — which, to the number of more than. 200, lie openly upon the tables. The following is a statement of the number of volumes issued in each of the classes in which the library is arranged, with relative proportion of the whole issue: — Per Cent. Theology and pHlosophy 184,681 (9-23) History, biography, &c 435,326 (21-77) Law, politics, and commerce ... 51,094 (2'73) Arts and sciences 402,485 (20-12) Poetry and the drama 147,115 (7-36) Language 54,971 (275) Prose iiction 1-15,605 (7 73) Miscellaneous literature 566,123 (2831) Total 2,000,000 (10000) Of the whole issue, no more than 10,481 volumes have been issued to ladies, or only 5 per cent. This small attendance of ladies is regretted, but is probably due to the absence of separate accommodation of a suitable character. Oct. 5, 1883.] ♦ KNOV\^LEDGE ♦ 219 " Let Knowledge gi-ow from more to more." — Alfeed Tennyson. Only a small proportion of Letters received can possibly he in- serted. Corresponde-xts must not be offended, therefore, should their letters not appear. All Editorial communications should be addressed to the Editor of Knowledge; all Business communications to the Publishers, at the Office, 74, Oreat Queen-street, W.C. If this is not attended to DELAYS arise FOR WHICH THE EDITOR IS NOT RESPONSIBLE. All Remittances, Cheques, and Post Office Orders should be made payable to Messes. Wyman & Sons. The Editor is not responsible for the opinions of correspondents. No commonications are answered bt post, even thoogh stamped and directed envelope be enclosed. SIE WILLIAM HERSCHEL. [947] — I shall feel obliged if your contributor " A Fellow of the Royal Astronomical Society" — the one, I mean, who wrote "The Sun in a Three-inch Telescope " — will communicate his authority for the statement that " Sir William Hershel lost an eye " in an attempt to look at the sun without suitable protection. It may be true ; but to the best of my recollection I never heard of it before. Collingwood, Sept. 28, 1883. J. Herschel. ASTRONOMY OP THE TIMES. [948] — The Times of September 22nd, in its leader on Professor Ball's address to the British Association, informs us, in reference to the Earth's Orbit, that " the distance that separates ua from the sun is variable, being greatest when our planet is on the major axis, smallest when it is on the minor axis of the ellipse," so that, putting a for the semi-major axis of the earth's orbit, and c for the eccentricity (when, of course. e avl — e'-, and therefore, that ^/l^e > \^T+~e. which is, &c. J. R. C. CURIOUS PHENOMENON. [949] — In your number of September 14 last, page 173, is an account of a curious phenomenon, which is illustrated by an en- graving. This evening, Sept. 21, at 8.30 p.m., I observed just such a phenomenon also in the E.N.E., about 20° above the horizon. Tlio sky was cloudy at the time, and in the very words of the article mentioned, '* For a moment I imagined that I was view- ing the apparition of a new and glorious comet," the light was too white to have an artificial terrestrial origin ; it remained well in view for five minutes, but before I could bring a telescope to bear upon it, it slowly faded. Mrs. Harbin. Preston Hoase, Yeovil. THE "SUN AND PLANET" BICYCLE. [950] — There aro two misprints in my letter (942). In line 9, the word " seat " should be " feet " ;'and about " Sigma," I said that lie seemed to have «o idea that Mr. Browning spoke of geared-vp wheels. As to appearance, I should think a man looked better on a small, neat machine than inside such a squirrel-cage as a GO-incli " Otto." S. J. HULL-DOWN SHIP. [951] — Your interesting articles called "Pretty Proofs of the Earth's Rotundity" have caused mo to take a new interest in the visible sea-horizon, and I have been observing it while on the south coast recently with a 3i-incli telescope, of the kind recommended in Knowledge. But a phonomeaon I do not understand at all has presented itself : to a ship, hull-down there have seemed to be two horizons, a nearer one clear and distinct, on which the rise and fall of the waves could be seen, and a farther one which really concealed the ship and gave it the appearance of floating in the air ; and still more oddly a kind of reflection of the ship's sails connected the more distant with the nearer horizon, something as in this sketch, which I hope you can make out. Is this usual ? Would you kindly explain it for the benefit of myself and a few friends who saw but could not understand it, and you will greatly oblige H.A.L.S. [Doubtless there was a layer of still air above the distant water surface, of density greater than that of layer of air next above it ; and the ship was reflected in that as in a horizontal mirror. R. P.] TOTEMISM. [952]— Mr. Edward Clodd, in the fifteenth chapter of his in- teresting series of articles on " The Birth and Growth of Myth," touches on the customs and prohibitions which totemism has imposed upon savage and barbaric peoples ; he quotes as instances the American-Indians and Australian tribes. He also speaks of a form of salutation common to a certain province in China, but he has omitted to notice a singular custom of the same type which prevails in the native States of Cochin and Travancore in the Southern part of the Indian peninsula. These States cannot be styled savage or barbaric. One-third of the whole native population is Christian ; of the native castes, the so-called Namburi Brahmins rank first ; after them come the Nairs. It is of these we would speak. The rulers of these States are them- selves of Nair descent. When they succeed to the throne they are made Brahmins. They are "new-born" by passing through a golden cow, or vessel of that metal, which then becomes the pro- perty of the Brahmin priests. The females of the Royal families in these States invariably marry Brahmins, but all Nair women have the privilege of choosing their own husbands; bylaw they may change them as often as they will, but this, it is said, is going out of fashion. Obviously, this custom led to great confusion in the matter of inheritance ; therefore amongst the Nair caste a man's heirs are not his own children— his property descends to the children of his sisters or of his female cousins, however remote. With regard to polyandry, wo think it will generally be found to exist in mountainous districts, and where the soil is very poor and can only support a very small population. Snch, at least, are the conditions in Ladakh, or Western Thibet, where this custom pre- vails. Certain lOuropeans, who closely watched them for some years with that object, could never discover that its inhabitants practised infanticide. Co.smopolitan. LETTERS RECEIVED AND SHORT ANSWERS. E. D. Giroleston'e. — Imprimis, let me remark that I only object to the waste of time over the study of formal logic, especially by those who aro capable of reasoning correctly. I would not in the slightest degree object to your studying logic. And now to your illogical defence of Jack Ketch. You "argue correctly enough about a suppositious Jack Ketch, who never existed save in your imagi- nation. If the legislature had to select an executioner from among 220 ♦ KNOWLEDGE ♦ [Oct. 5, 1883. a number of citizens, all nuwilliiig to take the office, but ready to do so as a duty when actually called to the work, no one would think of calling the executioner a murderous ruffian. I apply that term to each one of those who have been in the past, are now, or will hereafter be (so long as our present sj'stem continues) eager can- didates for an office which none but a murderous ruffian would accept, if he could avoid it without failing in duty to his country- men. If you can believe that the numerous applicants who have come forward for the office within the past few weeks have done so with a feeling of repugnance against taking life, but a feeling also that it was theii' clear duty to offer themselves for the work, a painful duty which they could not conscientiously avoid, — why then, you can believe anything, and reasoning would be thrown away on j-ou. Every one knows that the actual case is very different, that every one of the applicants (every man Jack or Jack Ketch of them) has deliberately sought to adopt man-killing as the business or part of the business of his life. It is well, in the horror which the presence of so many brutally-minded wretches amongst us must excite in every rightly-constituted mind, to find that some of the " hangman knaves" are ashamed to let their names be known, until sure of the oj^ce. To compare soldiers with hangmen is sheer nonsense. A soldier is primarily a man who takes as his office a part in the work of defending his country at the risk of his own life and limbs. His country may engage in wicked wars, and the necessities of the service, the rules of its discipline, and so forth, may make him one of the number of those employed in wars of that particular kind. During the course of such wars his hand may take away the lives of other men. But no soldier ever gets enUsted with the thought that it would be a pleasant thing to him to take away life ; whereas there never yet was an applicant for the office of common hangman who was without this hideous incentive. It would not be a bad thing for the future of this country if every man who had publicly announced his readiness to take away life, his eager hankering for the hangman's office, were removed, along with his children and his nearest kinsfolk, to a place where they could be kept apart from their fellow men till the lot had in due course of nature died out. I say it would not be a bad thing for the country, not that it would be just, especially to the kinsfolk ; for in many cases these murderous folk are sports of nature, their kinsfolk being often gently-minded, worthy people. But it is terrible to think of these slaughter-loving men marrying and multiplying their kind in our midst. — J. Terry Patch. I think no such statement of the plan and pur- pose of Knowledge at all necessary, after what has been so clearly said (and so often) already. It seems to me unreasonable to insinuate that Mr. Clodd intended " a sneer at the faith of Christians" in speaking of the injunction to the Hebrews against eating pork as not actually a revelation of God's will. (You misun- derstand Mr. Clodd's use of "pseudo" in combination with the word revelation ; he does not mean either a false revelation or the state- ment of something false as if it were a revelation, but simply that a certain statement has mistakenly been regarded as a revelation.) Yoa might as reasonably accuse your neighbour at breakfast or dinner of intending a covert insinuation against the faith of Christen- dom when he takes ham with his eggs or bacon with his chicken ! Eead what the reverend head-master of Clifton has said about inspiration, and you will find abundant evidence that the ablest and most learned theologians reject the idea of inspiration of the kind you imagine, while the fiercest enemies of the faith you fancy you are defending find in the doctrine of such inspiration the readiest and most effective weapon of attack. No wonder with such views as yours you think Knowledge not always neutral. How could it be with such neutrality-laws as you woifld enjoin ? — W.J. Bkindle. Your man-servant mistook a dark part of the moon for an eclipse shadow. The mistake has been made before when the moon has been five or six days past the full. " Whitakers Almanac " naturally did not predict the occurrence, nor as you say did " F.B.A.S." in " The Face of the Sky." The sympathetic inks you describe hardly fulfil Mr. Wood's requirements.— Ja.s. Walker. We do not undertake to work sums. But here is a general way of working out such problems. Let h be the height of a right cone, V its volume, and v the volume you want to cut olf by a plane parallel to the base. (In your case c is V/3 for one section and 2V/3 for the other.) Let .r be the distance of the required section from the vertex. Then we have the proportion y -.V.-.h': ,r' whence you find ,r at once, because Y, r, and h are known.— D. Maver. Your mathematical papers received, and kept for future use. But other matter received earlier awaits insertion. Much obliged to you for it.— E. G. S. So-called spiritualism is associated with so much rascality that I would not care for papers explaining how the tricks are usually done. — H. Jones. (1.) The telescopes are different ; but not having seen one of them can express no opinion as to their relative merits. (2.) "The Stars in their Seasons " quite different from " Xew Star Atlas " : the former is constructed especially for England and places in about same north latitude ; the latter is an atlas of tho whole star sphere, and as well suited for any latitude, north or south, as for the latitude of London. ■ — A New Header. Thanks for magic square, which I will insert with description. I hope it is not one of those which have already appeared in Knowledge ; but really have not time to hunt them all up. This must be the last for the present of magic squaredom. — W. H. MiLNEs. I am no authority in matters classical ; but it seems to me there is a rather abrupt change of mood in the motto Aut nunquam tentes aut perfice, and that two subjunctives or two imperatives would be better. But I may be quite wrong. — C. H. Marriott. Do not know who is the publisher of Mr. Chimmo's book. A bookseller would be able to tell you. — A. G. Grenfell. Scarcely. Should say advertising might be of use. — Naggdeibb. Thanks for cutting with Capt. Delauney's nonsense. Hope the spelling of name correct, and that he is not really a namesake of the eminent Delaunay. — A. Hlbble. Thanks, but seldom have room for translations, and when I do I translate them myself. — Perplexed. Probably the difference arises from the way of blowing. The correctness of the law for closed pipes, even with the comparatively rough test you indicate shows that the law is sound enough. — W. N. Huddy. Probably long continued pressure on the eye during sleep had produced a temporary change of shape in the lenses. — A Wellwisher. Very glad the notice led you to a useful little book. — Welshman. Unfortunately do not know how bones may be melted so as to be moulded into any required shape. Should have thought it impossible. — ZER-rBBA-BEL. Know abso- lutely nothing about masonic keys, and am therefore unable to explain how the Tau figure is used in measuring the celestial globe. — J. D. Am away from Nautical Almanack, but for your purpose you should use that excellent work. It gives the K. A. of Polaris, and for each day in October (or any other month) you can readily find the time when Polaris is on the meridian either above or below the pole. If we were to solve every such problem which occurs to our numerous readers, we should find time running rather short. — A Subscriber. The question is momentous, and quite in my line as a student of mathematics, astronomy, and so forth : — " Cu7i horses breathe with their nosebags on them, filled with chaff and corn ?" Your humble opinion is, " that they are then in a state of suffocation " ; and " for the last seven years" you have "brought out a ventilating nosebag." (Brought it out where and how ?) My humble opinion is that horses, whether full of chaff and corn or not, can breathe and do breathe, with their nosebags on them. I have a curious theory that if they could not breathe they would cease to exist. But perhaps if I had brought out a ventilating nosebag for seven years I should think differently. Are not you rather full of chaff, by the way ? — W. S. — I quite agree with you that it is a circumstance full of terrible meaning that so many should have applied for that horrible office. #ur iHattjcmatiral Column. MATHEMATICS IN OUR SCHOOLS.* By Professor Henrici. PURE geometry seems to me to be of the greatest educational value, and almost indispensable in many applications ; but it has scarcely ever been introduced at Cambridge, the centre of mathematics and mathematical education in England. Geometry and geometrical drawing, which teach how to represent figures on a plane or other surface have been treated as arts un- known at English Universities, and relegated to the drawing office. Instead of this, they ought to be an essential and integral part of the teaching of geometry in connection with the purely geometrical methods. As far as the jirogress of science is concerned, this neglect of pure geometry in England has been of little consequence — perhaps it has rather been a gain. For science itself it is often an advantage that a centre of learning becomes one-sided, neglects many parts in order to concentrate all its energy on some particu- lar points, and make rapid progress in the directions in which these lie. But what may suffer, if one side of a science is not cultivated in is the industry which would have gained by its applications. In considering the teaching of any mathematical or other scientific subject, we cannot at the present time neglect the wants of the ever-increasing class of men who require what has been called * From Prof. Henrici's opening address to the section of Mathe- matical and Physical Science, British Association. Oct. 5, 1883,] - KNOWLEDGE 221 technical education. Among these, the large number who want mathematics at all require geometry much more than algebra and analysis, and geometry as applied to drawing and mensuration. The teaching of geometry especially, as judged by the text-books which have come before me, is somewhat deplorable. And this is so, principally, because the spirit of Euclid and the methods of the ancient Egyptians and Greeks, rather than the fundamentally differc-nt ideas and methods of modern geoinetry, still rule supreme ; though the latter have had their origin partly in technical wants. In wiiat is called geometrical drawing, or practical geometry, for instance, there are first given a number of elementary con- structions— such as drawing parallels and perpendiculars, or bisecting the distance between two given points. They are solved by aid of those instruments onlj' which Euclid knew — viz., the pair of compasses for drawing circles, and the straight-edge for drawing straight lines. Bnt there is no draughts- man who would not, as a matter of course, use set squares for tlie former problem, and solve the latter by trial rather than by construction. Then again, there come constructions like the division of the circumference of the circle into seven parts, which cannot be solved accurately, but which is very easily solved bj- trial. Instead of that, a construction is given which takes much more time, and is by no means more accurate. For, after all, our lines drawn on the paper are not without thickness, so that, for this reason alone, every part of the construction is affected by .some small error ; and it is absurd to employ a construction, though theoretically true for ideal figures as conceived in our mind, in preference to a much simpler one which, within our prac- tical limits, is equally', or perhaps more, correct. This is very much like the manner in which I found problems on decimal fractions treated by the candidates ior the matriculation oxamin.ation at the London University, and which reflected little credit on the manner in which the important subject of decimals is handled at our schools. It is so characteristic that I may be ex- cused for giving it here. The problem, for instance, being to give the product of two decimal fractions, exact to, say, four decimals, each nf the factors having the same number of places, this was almost regularly performed as follows : — First, the decimals are converted into vulgar fractions, then these are duly multiplied, nnmerator by numerator, and denominator by denominator, and then tliC resulting fraction is again converted to a decimal, with as many places as it may yield ; and, lastly, of these the first four -are taken and put down, duly marked " Answer ! " Or a candidate (standing, however, on a far higher level) multiplies both decimals out in the proper fashion, but to eight places, and cuts off four places at the end. No wonder that the public at large will hear nothing of the decimal system of weights and measures if the very essence of the decimal system of numbers is so little understood by the men who have to train the minds of the young generation. It is by the neglect of pure geometry and of its applications to geometrical drawing that Cambridge has lost, or rather has never had, contact with the practical needs of the nation. All the marvels of modern engineering have sprung into existence without its help. The great engineers have had to depend to a degree now unheard of upon costly experiments, until they themselves gra- dually discovered mathematical methods adapted to tlieir purposes. Only the electrical engineer found ready to his hands a complete theoiT of which the mathematical part has been to a very great extent developed at Cambridge, or by men who liave had their mathematical training there. This theory is, however, in its very nature less geometrical. The engineer will always prefer geometrical methods to analysis, and has invented for himself a great variety of them. Originally these are disjointed, being invented for special purposes. It is the business of the mathematician afterwards to connect, simplify, and extend them, as has been done to a great extent by Culmann in Zurich, and by Cremona at the Polytechnic School at Rome. Of these methods a few may bo mentioned. First of all the geographi- cal determination of stresses in certain girders invented both by mathematicians and by engineers. Its application i.s so simple that jio engineer will ever use any other method if once he knows this one. It is so well adapted to its purpose, that I venture to say that a simpler method is impossible, being fully aware how dangerous euch a statement is. Nay, if I were asked to give the formula" to obtain the stresses by calculation, I should write these down from a sketch of the diagram, this being the simplest way of obtaining them. Another problem which occurs again and again is the deter- mination of the area of a figure representing perhaps a plot of land, y immersion in cold water. On removing and straining such minced meat it will be found to have lost its colour, and if it is now cooked it is insipid, and even nauseous if eaten in any quantity. It has been given to dogs and cats and pigs ; these, after eating a little, refuse to take more, and when supplied with this juiceless meat alone, they languish, become ema- ciated, and die of starvation if the experiment is continued. Experiments of this kind contributed to the fallacious conclusions described in No. 6 of this series. Although the meat from which the juices are thus com- pletely extracted is quite worthless alone, and meat from which they are partially extracted is nearly worthless alone, either of them becomes valuable when eaten with the juices. The stewed beef of the Frenchman would deserve the con- tempt bestowed upon it by the prejudiced Englishman if it were eaten as the Englishman eats his roast beef ,; but when preceded by a potage containing the juices of the beef it is quite as nutritious as if roasted, and more easily digested. Graham found that increase of temperature increased the rate of diffusion of liquids, and in accordance with this the extraction of the juices of meat is eflected more rapidly by warm than by cold water, but there is a limit to this advantage, as will be easily understood by referring back to No. 3, in which is described the conditions of coagulation of one of these juices — viz., the albumen, which at the tem- perature of 134° Fahr. begins to show signs of losing its fluidit}- ; at 1 G0° becomes a semi-opaque jelly ; and at the boiling-point of water is a rather tough solid, which, if kept at this temperature, shrinks, and becomes harder and harder, tougher and tougher, till it attains a consistence comparable to that of horn tempered with gutta-percha. I have spoken of beef-tea, or Extractum Carnis (Liebig's Extract of Meat), as an extreme case of extracting the juices of meat, and must now explain the difference between this and the juices of an ordinary stew. Supposing the juices of the meat to be extracted by maceration in cold water, and the broth thus obtained to be heated in order to alter its raw flavour, a scum will be seen to rise upon the surface ; this is carefully removed in the manufac- ture of Liebig's extract or the preparation of beef-tea for an inxalid, but in thus skimming we remove a highly- nutritious constituent — viz., the albumen, which has coagulated during the heating. ^The pure beef -tea, or Extractum Carnis, contains only the kreatine, krea- tinine, the soluble phosphates, the lactic acid, and other non-coagulable saline constituents, that are rather stimulating than nutritious, and which, properly speaking, are not digested at all — i.e., they are not converted into chyme in the stomach, do not pass through the pylorus into the duodenum, &c., but, instead of this, their dilute solution passes like the water we drink directly into the 22G - KNOWLEDGE ♦ [Oct. 12, 1883. blood by endosmosis through the delicate membrane of that marvellous network of microscopic blood-vessels which is spread over the surface of every one of the myriads of little upstanding filaments which, by their aggregation, constitute the villous or velvet coat of the ston^ch. In some states of prostration, where the blood is insiiRciently supplied with these juices, this endosmosis is like pouring new life into the body, but it is not what is required for the normal sustenance of the healthy body. For ordinary food, all the nutritious constituents should be retained, either in the meat itself or in its liquid surrounding. Regarding it theoretically, I should demand the retention of the albumen in the meat, and insist upon its remaining there in the condition of tender semi-solidity, corresponding to the white of an egg when perfectly cooked, as described in No. 4. Also that the gelatine and fibrin be softened by sufficient digestion in hot water, and that the saline juices (those constituting beef-tea) be fartialhj extracted. I say "partially," because their complete extraction, as in the case of the macerated minoed-meat, would too completely rob the meat of its sapidity. How, then, may these theoretical desiderata be attained ? It is evident from the principles already expounded that cold extraction takes out the albumen, therefore this must be avoided ; also that boiling water will harden the albu- men to leathery consistence. This may be shown experi- mentally by subjecting an ordinary beef-steak to the action of boiling water for about half an hour. It will come out in the abominable condition too often obtained by English cooks when they make an attempt at stewing; an unknown art to the majority of th <^ //^y// ^■^ (2^:' ■'■ ^' ■ ^7^ //r) Scc i 4b 4h ^/%} •:/.■■ '■'} ii> X^ <^><^ d (-?- (QXf^' 4> s/ ■ ^^? • SJ> '^h <^ <^ XX ^^h<^ ■.o-> c^v . 57,; l'^) 4^ (^7} v^ (7^}l>EXCB : HtUl-down Ship (iZ?u».)— Totemism, ic 219 Ou -- ■ Ou TERMS OF SUBSCRIPTION. The terms of Annual Subscription to the weekly ntimbers of Knowledge are aa follows:— B. d. To any address in the United Kingdom 10 10 To the Continent, Austraha, >'ew Zealand, South Africa & Canada 13 0 To the United States of America $3.26. or 13 0 To the East Indies, China, &c. (iia Brindisi) 16 2 All subscriptions are payable in advance. OFFICE : 74-76, GEEAT QUEEN STEEET, LONDON, W.C. Oct. 19, 1883.] ♦ KNOWLEDGE ♦ 237 ^ ^ AN ILLUSTRATED MAGAZINE o?SGIENCE PLAmLVl/fORDED -EXACigDESCRIBED LONDON: FRIDAY, OCT. 19, 1883. Contents op No. 103. PAGB British Association Scraps %i7 The Birth and Growth of Myth. XVIII. BvEdward Clodd 239 The Hinialaras and the Alps. I. By Colonel Godivin Austen 2» Flames. By W. M. Williams 242 Pleasant Hours with the Microscope. ByH. J. Slack 242 Krao 243 fiea-Anemones. VI. {Illtt*.) By Thomas Kimber 241 FAOB Sun-Views of the Earth. By E. A. Proctor 245 Fish and Phosphorus. By W. Mattieu Williams 24G Locusts 247 Correspondence : Green Sun and India — Great ' Snn-Spots — Moon's Surface— Small Wheels for Tri- cycles— Short Answers and Letters Received 247 Our Chess Column 248 BRITISH ASSOCIATION SCRAPS. Mr. B. H. Inglis Palgrave, President of the Section of Economic Science, made the following suggestive remarks at the close of his address : The old age of the honest working man should be made secure against dis- tressing want or degrading relief, and the power of obtaining rational pleasures should be provided for him within reasonable bounds. The question for the economist to consider is — How far can it be granted without impairing the great principle of self-help 1 This is a point too fre- •quently ignored ; but, considering the condition of mauy of our working classes, their prospects in this country, and the openings which our colonies and the United States pro- mise to energetic industry, we must be prepared to otl'er 'better terms than we liitherto have done to those who con- tinue to dwell here. Legislation, conceived in a somewhat similar spirit, has recently been determined on in the •German Empire ; and if the iron spirit of Prince Bis- marck has felt it needful to yield this concession to popular feeling, it would not seem improbable that other .statesmen may have, willingly or otherwise, to travel in the same road. There are limits, however, to the application of this class of payments by the State which must be borne in mind. ]\[r. Fawcett is careful to enforce this warning. The real incentive to labour and economy is individual interest. Self-help is the best help. The ques- tion how far the principles usually included under the de- nomin.ition of Socialism should be taken into consideration by the State is one economists would do well to con- sider. The economist who sees that the happiness of the community can only be secured by causing individuals to submit to restraints which arc irksome and perhaps painful should not l)e termed cruel for pointing out what is essen- tial to the general well-being. A community which is not prosperous can scarcely piossesa all the elements essential for happiness. Economic science, like all other branches of science, is governed by certain laws. These laws must be adhered to, though it may not be possible to atlirm of them that they are always more than relative)}' true. Economic teaching is the natural utterance of the most fervent patriotism, and possesses the sanction even of a more serious authority. Mr. Litton Forbes stated that the territory of Arizona is now practically opened up for the first time in its history by the completion of the new Atlantic and Pacific Railway. The port of Guaymas, on the Gulf of California, probably in the not far distant future will be the port of arrival at least for mails and passengers bound eastward from Australia, China, and Japan. At present Guaymas is a small Mexican town, consisting of adobe houses. Its harbour is excellent — one with deep water up to the very shore, and well sheltered from every -wind. It is the only possible mail station on the Gulf of California, and is some 500 miles, or nearly two days' steaming, nearer Australia than San Francisco. Of all the western territories, Arizona has long been the most remote and inaccessible, and, there- fore, the least known of all the territories. The aridity of the climate and the presence of hostile Apache Indians have had much to do with this. Arizona is a country of extraordinary mineral wealth. In many parts of its exten- sive territory it offers large tracts of excellent land to the farmer and the stock-raiser. Its chief drawback is a want of water, but this can be supplied by irrigation works and by artesian wells. Coal, salt, and the precious metals exist in larger quantities probably than in any of the Western mining territories. The copper mines are even now the richest known. The area of the territory is about 114,900 square miles, or approximately 73,000,000 acres — in other words, three times the size of the State of New York. The general topography of the country is that of a plateau, sloping towards the south and west from an altitude of 7,000 feet to the sea-level. The surface of Arizona is much diversified, and contains some of the finest scenery in North America. In no country in the world can the evidences of past geological action be better studied. The canon of the Colorado is a stupendous waterwork chasm, 400 miles long and from a quarter of a mile to a mile and a quarter in depth, and the scenery in many parts is grand and impressive. A NOTE on some recent astronomical experiments at high elevations on the Andes was contributed by Mr. Ralph Copeland. At La Paz (elevation 12,000 ft), he saw stars with the naked eye, when the moon was full, that are with difficulty seen in Europe without artificial aid. At Puno (12,500 ft.), Canopus, Sirius, and Jupiter were visible to unaided vision from one to twenty-five minutes before sunset. A number of small planetary nebuhe and stars, with very remarkable spectra, were found in the southern part of the Milky Way, by searching with a prism attached to a 6 in. telescope on Professor Pickering's plan. The most remarkable stars showed spectra of little more than two bright lines, one near D, and one beyond F, with a wave length of 4(57 ninim., which the author, in conjunction with Jlr. Lohse, had observed in the spectra of various nebulae ; -/ Argus is a star of this type, with the addition that the line near D is threefold. Several close double stars were discovered. At Vincocaya (14,3G0 ft.) the solar spectrum was very much increased in brightness at the violet end. The solar prominences were seen with nearly equal ease in C, D^, F, and H-y. With a small spectroscope a number of lines were visible beyond II and 11^. The solar corona was not seen, nor were any lines discernible in the spectrum of the zodiacal light, although that light was sufficiently bright to be very obvious when the moon was eight days old. Dn. CoPELAXi) made also several interesting meteoro- logical observations. Black-bulb temperatures up to 205 '5 deg. F. were recorded, this being the limit of the tube of the instrument, and not the actual maximnm. 238 ♦ KNOWLEDGE [Oct. 19, 1883. With the black-bulb thermometer more than 13deg. above the local boiling-point, the wet-bulb was below the freezing- point. At Arequipa (7,500 ft.), the relative humidity of the air was as low as 20 per cent., and not much higher at other stations. The author believed that an observatory might be maintained with great facility at a height of between 9,000 ft. and 12,000 ft., the night temperature being little below the freezing-point at any season. Beyond that height an increased elevation of 150 ft. roughly corre- sponded to a fall of the thermometer of 1 deg. F., and a depression of the barometer of 1-lOth in., so that at 15,000 ft. very arduous winter conditions were encountered. Mr. Codtts Trotter, F.E.G.S., sketched the physical geography, natural resources, and character of the inhabi- tants of New Guinea, in the belief that the interest at present felt in that country is, partly at least, due to the prospect of its becoming a field for European enterprise. The author attributes the prevailing ignorance about Kew Guinea to causes which have ceased to operate, as the difficulties of the navigation, now minimised by steam, the exclusive system of the Dutch in the Spice Islands, and latterly the diversion of the stream of enterprise towards Australia. After a short summary of discovery and exploration, he traces the geological relations of New Guinea and Australia, showing the date of their separation to be recent, while the pah^^ozoic rocks of the inner ranges are identical with those of the Australian gold-fields. Densely - woodtd mountain ranges make the interior difficult of access, though possibly some large rivers as yet unexplored may lead thither. The forests contain magni- ficent timber, fruits, barks, and gums. The sago palm Professor Janssen gave an account of his observations on the solar corona, made at Caroline Island during the recent solar eclipse. He stated that in 1870 he had seen, for the first time, dark lines in the spectrum of the corona — indicating, probably, the existence of matter capable of reflecting the solar light. This observation had been con- firmed by some observers, while others had failed to obtain evidence of it. He thought that the failure was due to the fact that the telescopes used by most observers had too small an aperture compared with their focal length, so that the amount of light received by the slit of the spectroscope was very small ; the luminosity of the corona being very feeble. Dr. Janssen used a lens of 50 centimetres aper- ture, with a focal length of 150 centimetres to form the image on the slit of the .'spectroscope, which was one which admitted a large quantity of light. By means of an in- genious arrangement, it was possible to observe with one eye at the spectroscope, while the other noted through the finder the part of the corona examined. Dr. Janssen found a complicated spectrum with many dark lines. In the course of his pap^r he referred to the measurement by photographic means of the intensity of light, and stated that the corona was about as bright as the full moon. Dr. Schuster thought that the differences observed at different eclipses, as to the existence of dark lines, might be real, and not due to want of illumination. During the eclipse in Egypt he had succeeded in photographing G as a dark line. He agreed with Dr. Janssen in attributing the re- flection of the solar light to meteoric matter, and pointed out that near the sun there were no lines, so that there the matter was self-luminous. Professor Stokes was inclined to refer the reflection to the action of small particles of matter shot out from the sun in the form of vapour, but condensed at a distance from its surface, forming, as it were, clouds of minute particles. (about which statistics are given) and sugar may become great staples. There are tracts of land suited for cattle raising and for tropical cultivation ; but it is a question how far such lands are unoccupied. The natives have a keen sense of rights in the soil, and probably would not work regularly for Europeans. Perhaps confidence might be created first by establishing trading depots. An active trade is now carried on between the hill and coast villages, but their requirements as yet are very few. Thus, though the resources of the country are great, the chances of imme- diate profit from their development are doubtful. The mass of the people are Papuans, a negroid race which, variously modified, extends throughout Melanesia. Their religion consists mainly of reverence for ancestors, and a fear of the spirits of the dead. They show marked artistic taste in the decoration of their houses, weapons, ic. The eastern peninsula of New Guinea is partly occupied by a wilder race, with Polynesian affinities. Their relations with English explorers have been exceptionally good, and it is hoped that steps will be taken to regulate their intercourse with the whites before serious collisions occur. ^Yith our great experience much might be done in this respect, and the protection thus afforded to the people would more than compensate for interference with individual liberty. The Dutch claims over Western New Guinea are vaguely based on those of their dependent, the Malay Sultan of Tidore. His rights have been enforced mainly by periodical raids for tribute and slaves, and it would seem that civilisation has thereby been not only checked, but has retrograded. Disclaiming controversy, the author points out that with the present tendency of matters in the Pacific, and the cer- tainty that the development of New Guinea must be the work of English hands and capital, its separation from the Australian system, to which it naturally belongs, would be a grave political inconvenience. Mr. Wilfred Powell added a number of facts from his own experience. The people were horribly frightened at looking-glasses, thought them a sort of fetish, and threw them away. Sago grew at all known parts of the island. It produced a vegetable fibre which in this country he was offered £35 a ton for. It grew upon a tree in shoots, which were cut when they were about to touch the ground. The cotton of the island was not of much iise, as the staple was short and it was filled with small seeds. There were rice and great quantities of rough cinnamon. Eventually there would be a large pearl- fishery. There had been brought from the interior solid blocks of copper ore, and there were precious stones, opals being quite common. The natives were favourably im- pressed by missionaries, particularly Mr. Charles and Mrs. Laws, and, not knowing anything about convicts, accepted with open arms the French convicts who escaped from New Caledonia. The consequences might be imagined. Torres Straits were almost of as much importance to Australia as the Straits of Dover were to us, but they were filled with islands which would be formidable in the hands of an oppo- nent. It was extraordinary that we had as yet learnt so little about New Guinea, and he hoped that an English expedition would soon explore this terra incognita. Mr. H. 0. Forbes said the natives were friendly if they were well treated, as they had been by the Dutch, but not by others who were not of that nationality. Mr. Sclater said the island was the home of birds of paradise, of which Count Salvadori had discovered 700 species. *^* The papers on " How to Get Strong," by Mr, Thomas Foster, "Mathematics," and "Whist," will shortly be resumed in these pages. Oct. 19, 1883.] ♦ KNOWLEDGE ♦ 239 THE BIRTH AND GROWTH OF MYTH. By Edwabd Clodd. ITTIDESPREAD as a myth may be, it takes depth of VV root according to the more or less congenial soil where it is dropped. That about Tell found favourable home in the uplands and the free air of Switzerland ; with us, S. George, falling on times of chivalry, had abiding place, as also, less rugged of type than the Swiss marks- man, had Arthur, the " Blameless King," who, if he ever existed, is smothered in overgrowth of legends both native and imported. For such cycle of tales as gathered round the name of Arthur, and on which our youthhood was nourished, is as mythical as the wolf that suckled Romulus and Remus. Modern criticism and research have thoroughly sifted the legendary from the true, and if the past remains vague and shadowy, we at least know how far the horizon of certainty extends. The criticism has made short work of the romancing chronicles which so long did duty for sober history, and has shown that no accurate knowledge of the sequence of events is obtainable until late in the period of the English invasions. Save in scattered hints here and there, we are quite in the dark as to the condition of this island during the Roman occupation, whilst for anything that is known of times prior to this, called for convenience " prehistoric," we are dependent upon unwritten records preserved in tomb.s and mounds. The information gathered from these has given us some clue to what manner of men they were who con- fronted the first Aryan immigrants, and, enriched by researches of the ethnologist and philologist, enabled us to trace the movements of races westwards, until we find old and new commingled as one English-speaking folk. All or any of which could not be known to the earlier chroniclers. When Geoffry of Monmouth set forth the glory and renown of Arthur and his court, he recorded and embellished traditions six hundred years old, without thought of weighing the evidence or questioning the credi- bility of the transmitters. Whether there was a king of that name who ruled over the Silures, and around whom the remnant of brave Kelts rallied in their final struggle against the invading hordes, and who, wounded in battle, died at Glastonbury, and was buried, or rather sleeps, as the legend has it, in the Vale of Avilion, " hath been," as Milton says, " doubted heretofore, and may again, with good reason, for the Monk of Malmesbury and others, whose credit hath swayed most with the learned sort, we may well perceive to have known no more of this Arthur nor of his doings than we now living." Tlie comparative mythologists say that he is a myth pure and simple ; a variant of Sigurd and Perseus ; the winning of his famous sword but a repetition of the story of the Teutonic and Greek heroes; the gift of Guinevere as fatal to him as Helen to Menelaus ; his knights but reproductions of the Achaian hosts. Much of wliich is doubtless true. But the romance corresponded to some probable event ; it fitted iu with the national traditions. There were struggles between the Kelts and subsequent invaders — Romans, Angles, Saxons, Jutes. There were brave chieftains who led forlorn hopes or fought to the death in their fastnesses. There were, in the numerous tribal divisions, petty kings and queens ruling over mimic courts, with retinues of knights bent on chivalrous, unselfish service. Tliese were the nuclei of stories which were the (larly annals of the tribe, the glad theme of bards and minstrels, and from whicli a long line of poets, to the latest singer of the " Idylls of the King," have drawn the materials of their epics. The fascination which such a cycle of tales had for the people, especially in days when the ballad was history and poetry and all literature rolled into one, was so strong, that the Church wisely im- ported an element which gave loftier meaning to the knightly life, and infused religious ardour into the camp and court. To the stories of Tristram and Gawayne already woven into the old romance, she added the half-Christian, half-pagan, legend of the knights who left the feast at the Round Table to travel across land and sea that they might free the enslaved, remove the spell from the enchanted, and deliver fair women from the monsters of tyranny and lust, set forth on what in her eyes was a nobler quest — to seek and look upon the San Graal, or Holy Vessel used by Jesus at the Last Supper, and into which Joseph of Arimathea collected the blood and water that streamed from the side of the crucified Jesus. This mystic cup, in which we have probably a sacrificial relic of the old British religion imported into the Christian incident with which it blended so well, floated, according to Arthurian legend, suddenly into the presence of the King and his Round Table knights at Camelot as they sat at supper, and was as suddenly borne away, to be henceforth the coveted object of knightly endeavour. Only the baptised could hope to behold it ; to the unchaste it was veiled ; hence only they among the knights who were pure in heart and life vowed to go in quest of the San Graal, and return not until they had seen it. So to Sir Galahad, the "just and faithful," Tennyson sings how the sacred cup appeared, " Sometimes on lonely mountain meres I find a magic bark ; I leap on board : no helmsman steers : I float till all is dark. A gentle sound, an awful light ! Three angels bear the holy Grail ; With folded feet, in stoles of white, On sleeping wings they sail. Ah, blessed vision! blood of God I My spirit beats her mortal bars, As down dark tides the glory slides, And, star-like, mingles with the stars." Whilst in such legends as the Arthurian group the grain of truth, if it exists, is so imbedded as to be out of reach, there are others concerning actual personages, notably Cyrus and Charlemagne, not to quote other names from both "profane" and sacred history, in which the fable can be separated from the fact without difficulty. Enough is known of the life and times of such men to detach the certain from the doubtful, as, e.t/., when Charlemagne is spoken of as a Frenchman and as a Crusader before there was a French nation, or the idea of Crusades liad entered the heads of Most Christian Kings; and as in the legends of the infancy of Cyrus, which are of a type related to like legends of the wonderful round the early years of the famous. This, however, by the way, since, leaving illustration of the fabulous in heroic story, it will be interesting to trace it through such a tale of pathos and domestic life as the well-known one of Llewellyn and his faithful hound, Gellert. Whose emotions have not been stirred by the story of Llewellyn the Groat going out hunting, and missing his favourite dog ; of his return, to bo greeted by the creature with more than usual pleasure in his eye, but with jaws besmeared with blood ; of the anxiety with which Llewellyn rushed into the house, to find the cradle where had lain his beautiful boy upset, and the ground around it soaked with blood ; of his thereupon killing the dog, and then seeing the child lying unharmed beneath the cradle, 240 ♦ KNOWLEDGE ♦ [Oct. 19, 1883. and sleeping by the side of a dead •wolf, from whose ravenous maw the faithful Gellert had delivered it 1 Most of us, in our visits to North Wales, have stood \>y Gellert's grave at Beddgelert, little suspecting that the afl'ecting story occurs in the folk-lore of nearly every Aryan people, and of several non- Aryan races, as the Egyptians and Chinese. Probably it comes to us as many other tales have come, through collections like the well-known " Gesta Romano- rum," compiled by mediivval monks for popular entertain- ment. In the version given in that book, the knight who corresponds to Llewellyn, after slaying his dog, discovers that it had saved his child from a serpent, and thereupon breaks his sword and departs on a pilgrimage to the Holy Land. But the monks were no inventors of such tales ; they recorded those that came to them through the pil- grims, students, traders, and warriors who travelled from West to East and from East to West in the Middle Ages, and it is in the native home of fable and imagery, the storied Orient, that we must seek for the earliest forms of the Gellert legend. In the Panchatantra, the oldest and most celebrated Sanskrit fable Ijook, the story takes this form : — An infirm child is left by its mother while she goes to fetch water, and she charges the father, who is a Brahman, to watch over it. But he leaves the house to collect alms, and soon after this a snake crawls towards the child. In the house was an ichneumon, a creature often cherished as a house pet, who sprang at the snake and throttled it. When the mother came back, the ichneu- mon went gladly to meet her, his jaws and face smeared with the snake's blood. The horrified mother, thinking it had killed her child, threw her water-jar at it, and killed it ; then seeing the child safe beside the mangled body of the snake, she lieat her breast and face with grief, and scolded her husband for leaving the house. We find the same story, with the slight difference that the animal is an otter, in a later Sanskrit collection, the Hitopadesa, but we can track it to that fertile source of classic and medieval fable, the Buddhist Jatakas, or Birth Stories, a very ancient collection of fables, which, professing to have been told by Buddha, narrates his ex- ploits in the -5-50 births through -nhich he passed before attaining Buddhahood. In the Vinaya Pitaka of the Chinese Buddhist collection, which, according to Mr. Beal, dates from the fifth century a.d., and is translated from original scriptures supposed to have existed near the time of Asoka's council in the third century b c, we have the earliest extant form of the tale. That in the Panchatantra is obviously borrowed from it, the differences being in un- important detail, as, for example, the nakula, or mon- goose, is killed by the Brahman on his return home, the wife having neglected to take the child with her as bidden by him. He is filled with sorrow, and then a Deva con- tinues the strain : — Let there be due thought and consideration, Give not way to hasty impulse, By forgetting the claims of true friendship Ton may heedlessly injure a kind heart (person) As the Brahman killed the nakula. The several versions of the story which could be cited from German, Russian, Persian, and other Aryan folk- lore, would merely present certain variations due to local colouring and to the inventiveness of the narrators or transcribers ; and, omitting these at the demand of space, it will suffice to give the Egyptian variant or corresponding form, in which the tragical has given place to the amusing, save, perhaps, in the opinion of the Wall. This luckless person "once smashed a pot full of herbs which a cook had prepared. The exasperated cook thrashed the well-inten- tioned but unfortunate Wali within an inch of his life, and when he returned, exhausted with his efforts at belabouring the man, he discovered among the herbs a poisonous snake." In pointing to the venerable Buddhist Birth Stories as the earliest extant source of Aryan fables, it should be added that these were with Buddha and his disciples the favourite vehicle of carrying to the hearts of men those lessons of gentleness and tenderness towards all living things which are a distinctive feature of that non-persecuting religion, and thus of diflusing a spirit which would have us Never to blend our pleasure or our pride With sorrow of the meanest thing that lives. THE HIMALAYAS AND THE ALPS.* IX TWO PARTS.— PART I. "YT/^E can, in a measure, exemplify the structure of the T I Himalayas by that of the bones of the right hand, with fingers much elongated and stretched wide apart, of which the wrist and back may represent the broader belt of granitic rocks of the eastern area, the thumb and fingers the more or less continuous ridges of the N.W., some less prolonged than others to the north-west, such as the Chor axis, which may be represented by the thumb, terminating on the southern margin near the Sutlej. The left hand placed opposite will represent the same features to the west of the Indus. We may further suppose the intervals or long basins between the fingers to be filled with sedi- mentary deposits, and the fingers then to be brought closer together, producing a crushing and crumpling of the strata. Conceive at the same time that an elevation or depression, first of one or more of the fingers, then of another or of the whole hand has taken place, and you are presented with very much what has gone on upon a grand scale over this vast area. As these changes of level have not taken place along the whole range from east to west in an equal extent, but upon certain transverse or diagonal lines, undulations more or less great liave been the result, and some formations have attained a higher position in some places than in others, producing, very early in the history of these mountains, a transverse system of drainage lines, leading through the long axial ridges. The last eflbrts of these rising, sinking, and lateral crushing, and very slowly acting forces, are to be seen at the southern face of these mountains in the ter- tiary strata that make up the sub-Himalayan axis (Sivalik), a topographical feature which is most striking by reason of its persistence and uniformity for some 1,600 miles ; for, although a similar and synchronal elevation of the Alps has taken place, the same regularity of oro- graphical features has not been the result, most probably from the difference in the original outline of deposition in the latter area. From Assam on the east to the Punjab en the west, bending round and extending to Scinde, this fringing line of parallel ridges is found at the base of the Himalayas, sometimes higher sometimes wider, often form- ing elliptical valleys. Only in one part of the belt east of the Teetsa are they absent altogether, and for a distance of fifty miles the metamorphic rocks rise directly from the plains of India, a feature representing a great break — the correct interpretation of which will tell us very much of the past history of these mountains. These formations are of vast thickness, and in the Punjab, where they attain * From the address by Col. Godwin Austen, president of the Geological section, British Association. Oct. 19, 1883.] ♦ KNOWLEDGE ♦ 241 their greatest width and elevation l)etween the Chenab and the Indus, cover an area of 1.3,000 square miles. The whole of this material has been derived from the adjacent Himalayas, representing many feet of the older and higher mountain ranges, and has travelled down valleys that had been excavated in pre-tertiary times. This points to a slow subsidence of the whole southern side of the mountain mass, deposition generally keeping pace with it, broken off by recurring long intervals of re- elevation. Many long and instructive pages of its history are written on these rocks. These sub-Himalayan forma- tions arc fresh-water or torrential, showing that since nummulitic or eocene times the sea has never washed the base of the Himalayas. In fact, there is no evidence of this from the gorge where the Ganges leaves the mountains up to the base of the Garo Hills ; pointing to an extension northward at that early age of the Arabian Sea, separated from the Bay of Bengal by peninsular India. From Assam to Scinde there probably once existed one con- tinuous drainage line, a great river receiving its tributaries from the Himalayas, partly a land of lakes and marshes, the home of that wonderful mammalian and reptilian fauna which Cautley and Falconer were the first to bring to light. The Kashmir basin drained at the north-west end into the Kasliingunga Valley to Mozutferabad, and that of Hundes and Ladak trended towards the same direction vid Dras. The southern boundary of this long alluvial plain was formed by the present peninsula of India, and probably of the extension of the Garo and Kliasi Hills westward to the Rajmahal Hills. Depression has been considerable in the neighbourhood of Calcutta, nearly 500 ft. We know, probably, only a portion of the alluvial deposits. At 3S0 ft. beds of peat were passed through in boring, and the lowest beds contained fresh-water shells ; the beds also were of such a gravelly nature as to indicate the neighbourhood of hills, now buried beneath the Ganges alluvium. This is precisely the appearance of the country above Calcutta on approaching the present valley of the Brahmaputra. The western termination of the Garo Hills sinks into these later alluvial deposits, and along the southern face of the range up to Sylhet, the waters of the marshes, during the rainy season, wash the nummulitic rocks like an inland sea, and point to the very recent depression of all this area. The isolated granite hill- tops jutting up out of the marshy country from Dhoobri to Gwalpara and on to Tezpur all testify to the same continuous depression here. It is exactly north of this that we find the Sivalik formations absent at the base of the Himalayas, and we have the evi- dence of exclusively marine conditions in pliocene times at the base of the Garo Hills. \Vc find also a large development of marine beds above the nummulitic limestone in the Jaintia country, passing up conformably into a great thickness of upper miocene sandstone of the Burrail range. In such sandstone, north of the IVIunipur valley, the only fossils found were marine forms. This Ljiiulual depression of the delta of the (ianges, the relati\e liighcr level of the water-parting and shifting of the Punjab rivers westward, appear to be only the last phase of that post-pliocene disturbance which broke up the Assam sub-Himalayan lucustrine system draining into the Arabian Sea. Zoological evidence is also in favour of this former connection of the now-separated waters of the Ganges and Indus basins, and the hill tracks of the Garo and Khasi Hills with pcsninsular India. The ground where the miocene rocks are absent is not where any de- nuding force from the north could have acted with any abnormal intensity. It lies under the hills, where no great tributary enters the plain, and might have removed the above formation. All the evidence is in favour of the axis line of depression in the Ganges delta between Rajmahal and the Garo Hills extending thus far, and that the miocene beds, once continuous, are li-, re thus lost to sight beneath the more recent yet extensi\e graveis and conglomerates that here occur, and have partaken also of a last slight elevation of the mountain cliain. Great lateral rolls or waves of the stratified rocks occur at intervals all along the southern line of the chain, and apparently have a connection with the transverse drainage lines. Within the mountains in the old rock basins — and these are analogous to the valleys of the Alps — are pliocene and post-pliocene beds of great thickness, but of fresh- water origin ; the remnants of which are to be seen in Kashmir and Scardo at intervals, along the valley of the Indus, and that large — now elevated — accumulation at the head of the Sutlej River in Hundes, first brought to notice by the labours of Captain (now General) R. Strachey. The remnants of these deposits in Kashmir and Scardo are found preserved in the more sheltered portions of the valley basins, untouched by the denuding action during the glacial period — the exponents presented to us of the enormous denudation that went on during the post-pliocene times, of which the glacial period formed a part. The extent and displacement of the upper pliocene beds is in North Italy and here very similar. Often abutting horizontally against the mountains, they are in other places found tilted at a considerable angle on the margin of their original extension. When we examine their contents, we find that the fauna of that time in Asia, as well as in Europe, was more African in character, and genera now confined to that continent were abundant far to the north. The sluggish rivers and lakes of Sivalik times in Asia and of the corre- sponding period in Europe were the home of the hippo- potamus, crocodiles, and tortoises, of which the common crocodile, the gavial or long-snouted species, and an emys have survived the many geological changes, and still inhabit the rivers and low grounds of India to-day. The fresh-water shells are still the same now as then. Many species of antelope lived in the neighbouring plains and uplands ; the elephant was there in the zenith of its existence, for no less than thirteen species have been found fossil in Northern India ; but it is impossible in a short address to enumerate the richness of this fauna, and the extreme interest that surrounds it. (To 5e continued.) Electricity for Picnic Parties. — It is stated that the Cumberland Valley Railway Company has built an electric light car, which will be used to supply the electric light to picnic parties along the line. Small-Wheeled Tricycles. — What can be done on small-wheeled bicycles has just been proved by the per- formance of Mr. Adams, who, riding a 4 1-inch " Facile " bicycle, started at midnight, Friday, Sept U, from a point one mile beyond Barnet, on the Hatfield-road, and rode through Ilitchin, Biggleswade, Bedford, St Neots, Cambridge, and Huntingdon, returning by the same road to Hitchin, and went on to Langford, which" he reached at midnight on the Saturday, having covered a distance of 2-11.', miles in the 'J I hours. The roads were in many places heavy with wet, and some time was lost on the way. Had it not been for these dillieulties over 250 miles would certainly have been accomplished. Messrs. Larrettc and Barrow, in accompanying Mr. Adams from Cambridge to St Neots, rode the It* miles in 25 minutes, a splendid piece of road-riding on a tricycle. 242 ♦ KNO\VLEDGE [Oct. 19, 1883. ; LAMES.* By W. Mattieu Williams. ■\"Tty"HAT are they 1 They are commonly described as VV merely heated or " incandescent " gas. In a note to Chapter VII. of " The Fuel of the Sun " I stated some reasons for questioning this definition and justifying "the conclusion that Hame should be classed as another and dis- tinct form of matter, in addition to those of the solid, liquid, and gaseous forms ; " thus reverting to the four elements of the ancients — fire, air, earth, and water — their real meaning being that matter existed in one or other of the four conditions of fire, gas, solid, or liquid, their use of the word "element " being to express the idea that we now represent by " state." I suggested further investigation of the difference between flame and incandescent gases, and Dr. W. Siemens has recently used the opportunities aflbrded by his rege- nerative glass furnaces for making such investigations. He finds that gases are not luminous at the temperature of molten steel (1,-500° to 2,000° C). At this high tempera- ture the air emitted no light to a darkened room, showing that gases cannot be made red-hot or white-hot as solids may. Further observations on the behaviour of flames them- selves disproved Davy's theory that their luminosity is due to the incandescence of precipitated particles of carbon or other solids. My experiments showing the transparency of luminous flames (described in the above-quoted chapter) led me to the same conclusion, as such transparency of the white portion of the flame would be impossible if it were loaded with solid particles of carbon packed so closely together as to display continuous luminosity by their incandescence. In the German Annalen of Chemistry and Physics, W. Hittorf now claims priority over Siemens in respect to demonstrating this non-luminosity of heated gases. He observed in 1879 that a layer of air surrounding electrodes of platinum, made white-hot by a battoi-y of 1,600 celLs, appeared perfectl}' dark, and that with iridium heated even up to fusion by a battery of 2,400 elements, the gas media whether nitrogen, hydrogen, or oxygen, remained perfectly dark, and that these gases, when thus heated, became good conductors of electricity, even when its potentiality or penetrating power was low. It appears that Wedgwood in 1792 made similar furnace observations to those of Siemens, and, like him, concluded that the heated air therein was not luminous. It appears, therefore, that flame is not white-hot gas, nor white-hot solid particles precipitated from the gas, but is matter in a fourth condition — i.e., in the act of vigorous combination, or what I will venture to call chemical vitalifi/. Animal and vegetable activities depend upon the chemical combinations proceeding in organic structures, and if we may apply to the sum of these activities the designation of vegetable and animal life, I am justified in describing flames as an intense manifestation of inorganic or mineral life. There is really no innovation in this, but the opposite ; it is a return to some very ancient con- ceptions. In excavating at Suresnes, at the extremity of the Bois de Boulogne, the remains of a lake, or rather river, dwelling have been found. They consist, according to a correspondent of the Jiappd, of piles and an enormous quantity and variety of bones, but at present no trace of iron or bronze has been discovered. * From the Cfentleman's Magazine. PLEASANT HOUES WITH THE MICROSCOPE. By Henry J. Slack, F.G.S., F.R.M.S. THE sketches of the mouth organs of the honey-bee given in Knowledge, October 5, show that the insect is provided with a licking, lapping, and sucking tongue of considerable length, while the wasp family have very much shorter tongues, and, except by biting a hole in tubular flowers, would not get at the nectar which the bee's tongue, like the long proboscis of the butterfly, makes it easy to reach. Various accounts are given in different books of the structure of the bee's tongue, and some of them are evi- dently founded upon imperfect observation. Such objects are by no means easy to see properly, and as many readers of Knowledge may be glad of a little help in making a microscopical examination, we may suggest how they had better proceed. First catch a bee, as directed in the last paper, and watch it feeding in the test-tube. As stated, the tongue makes a sweeping, backhanded motion. It is like putting the hand, knuckles all down, on the table, and then drawing it forwards, raising it a little, and finishing the sweeping motion at the finger-tips. To understand the meaning of these motions, cut off the head of a bee, stretch the tongue out with a needle stuck in a little wooden handle, and then with a droplet of gum fix the head on to a glass slide. These arrangements and ordinary dissections are easily made under a hand -magnifier, the object being placed on a piece of glass. Mr. Baker (High Holborn) sells hand-magnifiers for the pocket, which can also be attached to little brass stands to hold them,' at any height required, and they are good substitutes for a dissecting microscope. Mr. Browning also makes a cheap botanical dissecting microscope, which, with a larger piece of glass for a stage, answers for general purposes. Having prepared a bee's head as described, look at it with an inch power and reflected light. This enables it to be seen much as is represented in Fig. 1 in the last article, but the tip will, if the specimen is quite fresh and un- injured, look a little rounder. The mandibles, D D, are depressed in the figure to show the other parts better. After carefully looking at the bee's head in the way men- tioned, take another bee and carefully remove all the mouth organs from the head, operating with needles, while the object, or subject, is immersed in a drop or two of glycerine. This fluid prevents any shrinking of the parts, and gradually sinks in, making them transparent. As soon as the mouth organs have been well cleaned from any dirt or stray particles, place them in the little cavity of a " hollow glass slide " which opticians sell. This is an ordinary slide of thin plate-glass with a hollow ground out in the middle, and then polished. It forms a convenient cell in which to examine objects that must not be squeezed flat. In the case of the bee's mouth organs it is well to remove the mandibles, as they are in the way of seeing other parts. The hollow slide should be filled with glycerine diluted with a little water, and the tongue, labial palpi, and maxilla; neatly spread out. Then put on a glass cover. This most likely squeezes some of the fluid out, although the precaution has been taken of putting a drop of glycerine upon it before placing it over the object. If an inconveniently large air bubble is formed, slide the cover a little off the hollow, and put in a little more water or glycerine with a glass tube drawn out like a dropping tube, but with a rather finer point than usual. When Oct. 19, 1883.] * KNOWLEDGE ♦ 243 immersed in glycerine the tongue, with its appendages, becomes a singularly beautiful object, with dark ground illumination. A power of IJ in. is handy for a preliminary view, after which a half-inch will exhibit most of the important details. The hairs are exquisitely arranged in a series of whorls, and become very brush-like towards the tip. All through the tongue there runs a tubular hollow, and at the tip an opening may be discovered as shown in the arched part of Fig. 3 (Oct. 5). I made a mistake in describing this as iinderside uppermost. It is exactly the opposite. The opening into the tube is on the upper side, which the reader will please correct in p. 217. This sketch was made from a preparation in Canada balsam, which permits the use of much higher powers than can be employed wlien an object is in a cell with Huid, but it has the important disadvantage of pressing together parts that ought to be seen in their natural positions. The tip of the tongue is damaged by this squeezing. As seen in the glycerine it is not at all flat, but somewhat pufled out, and with a hollow like a spoon. Seen sideways the spoon shape is very plain. It is provided with peculiar short, sharp, curved spines. I imagine from an examination with high powers that at the base these spines may be provided with nerve filaments, and that they may be sense-organ appendages, like cat's whiskers. After the tongue has been kept a few days soaking in glycerine, its transparency is increased, and the tube which runs down it is seen to be connected at the base with a bladder-like pharynx. The act of extending the tongue causes the whorls of hairs to stand out a little, and this makes them very effective for the sweeping use made of them. The maxillffi, as seen with the half-inch objective, are not only hairy — which the knife-like maxilhe of biting insects are not — but liberally provided with respiratory tracheal tuVjes running across them. External organs freely supplied with these tubes are usually adapted to collect some information ; that is, receive and transmit some im- pressions. In the bee, the maxillre are tongue-helpers, and we may be sure that a supply of nerve-power secures the harmonious co-operation of the several parts of this com- plicated feeding apparatus. As it is not convenient for Knowledge to give much space in one number to a single subject, further elucidation of the bee's mouth organ must wait for the next paper. KRAO. AT the recent meeting of the British Association, Mr. J. Park Harrison introduced the subject of Krao, the so-called " missing link." He said that the idea that the hairy child lately exhibited at the Westminster Aquarium possessed ape-like peculiarities, which she liad inherited from wild parents in some remote forest in Laos, appeared to be so widely entertained that he thought it well to bring the; subject before the department. Ho quoted statements that had been made in advertisements, and in a circular issued at the Aquarium, and called attention to the guarded language of some of the daily papers, and lie then said it was unfortunate that an account by Dr. Garson, which had appeared in the Jlri/is// ifediral Journal, had not obtained a wider circulation. That account showed that there was nothing abnormal in Krao except hairiness, and since then a letter had been published from a resident in Siam which stated that her parents were !~!iamese, and were then living. Neither possessed any special peculiarities, nor did their other children. Siamese was Krao's native language, but she had picked up a little Laos. The joints of her arms and fingers were flexible, but not more so than those of other Siamese. Her power of grasping things with the toes was also possessed more or less by all the Siamese, who are a barefooted people. Her parents were in the habit of showing her, and they sold her for £60 — double the value of an ordinary child. The first letter of her name expressed whiskers. She was an intelli- gent Siamese child, with no peculiarity beyond hairiness, and she possessed rather a pathological than an anthropo- logical interest. Dr. Garson said that the child was a well-marked example of the yellow-coloured races found inhabiting the eastern parts of India. The cheeks were normal, there was no enlargement of the space between the gums and the cheeks, and the fulness of the cheeks was entirely due to their thickness. There were no double teeth ; the hands and feet exhibited mobility, the feet not having been deformed by boots. The direction in which hair grew could be studied from this child on account of the quantity. On the fore-arms the hair was directed outwards and upwards ; on the upper arms it was outwards and downwards. Such cases occurred in various races and in difierent parts of the world. In many the development had been greater than in this child. There w-ere no ape-like characters present, nor any that would indicate specific difference of any kind. As to the so-called rudimentary tail, there was no abnormality to be observed in that region. Cases of reported development of tail were ex- tremely doubtful. In some cases slight abnormalities did occur, but could not be regarded as tail developments. Every one had normally a homologue of a tail, but it had only in one or two cases been found to be enlarged in size. The explanation as to these abnormal developments of hair which seemed most reasonable was the atavistic theory. If we were able to trace back man to a primitive condition we should probably find that he was covered with hair The follicles in which the hair grew had not disappeared in ourselves, and an abnormal growth was simply the re- appearance of an old condition which was normal in the primitive race of man. Dr. Struthers, of Aberdeen, described Krao's ease as a special case of development of the hair which was normally rudimeutary on the human body. He had once in Aber- deen had to examine the case of a body reported to have a tail, but he found that it was simply a case of misdirection of the natural bones, and so the tail case broke down. The anthropologists were often jokingly asked when they were going to find a man with a tail. It should be remembered that even the higher apes had no tail, and tlierefore the question of tail or no tail was of no importance. To discuss the missing link was to tread on dangerous ground. Hair would never settle the question. The great point was the brain. The missing link w\as not a link, but a chain. The brain was one link, and the other was erect posture. If we could conceive a monkey having somehow got one day an abnormally superior brain, it would not remain up a tree. Then his limbs would commence to adapt them- selves to their new conditions. Given the larger brain and the larger intelligence, the other development would follow in the course of time. The missing link, in one of the most painful senses, could be seen any day in the idiot ward of an asylum. Mr. Hyde Clarke said he was one of the Council of Science of the Westminster Aquarium, but they had not been asked to see Krao. He classed the " missing link " with the tattooed Greek sailor and the whale that turned out to be a porpoise. 214 - KNOWLEDGE ♦ [O.T. 19, 1883. SEA ANEMONES AT THE FISHERIES EXHIBITION. By Thomas Kimber. VI.— THE CAVE-DWELLER. Actinia troglodytes (Johnston). Scolanthus sphcero'ides (Holds- worth.) BY the early writers this anemone was called riduata (widowed). Dr. Johnston adopted, after Mr. Price, the more distinctive term tro;/!odi/ies, cave-dweller (from rpwy\oci)Tiir, one who creeps into holes). Though abundant in many localities, and widely distributed all round our shores, it is not easily found by unpractised collectors, on account of its retiring habits. Its favourite custom is to hide itself in holes and crevices of rocks, in shallow- tidal pools, and on the floors of caves. When scores of them are expanding their flowers in profusion at the bottom of the bright water, they may easily be overlooked, since their mottled disks and barred tentacles resemble the sand and gravel in the pools where they live. They shrink on the slightest alarm, and hide themselves in the sand or mud, protruding only their tentacles perpendicu- larly, and sometimes barely the tips of these organs can be seen. When sand or mud is not available, their con- cealment is frequently secured by suckers on the column, to which fragments of shells and quantities of gravel be- come firmly attached, and even when placed in a tank they frequently retain these foreign bodies with great obstinacy for a considerable period. mf4\i^ Fig. 1. — Disk, with B mark on Tentacles. Fig. 1. The Disk, dx. — The chief characteristic feature of troglodytes is the black mark at the foot of each tentacle, which is nearly always relieved by two white curved spots, forming together a strong resemblance to the Roman capital B. The tentacles are numerous, in fine specimens between two and three hundred ; they are set in four or five rows, and, as usual, the largest are innermost. There is no species of British anemones that varies so •widely in colour of disk and tentacles. The general pattern of the disk is well described as resembling the pencilled pattern of a snipe's feather. The bright orange, grey, and blue black varieties are the handsomest, and there are fifteen or sixteen others derived from the admix- ture of these colours. The marking of the disk itself, apart from the tentacle, is pretty constant. Each radius is light grey from the B marking on the tentacle to half way to the mouth ; then there is a bright white spot, as shown in the figure, fol- lowed by a thin line of yellow, or drab edged with black, which is continued to the lip. The mouth is usually whitish. Generally there is no difficulty in determining this species. The B mark is the most certain distinction, and in the few instances where this is not discernible, the firm texture of the column and base, Mr. Holdsworth points out, is "a fair mark." Troglodytes is not so easily injured as most species are, and his adhesive power is compara- tively weak. Fig. 2. Fig. 2. The Column. — The general colour is green, with an admixture of brown, producing various shades of olive, and sometimes dark brown columns are met with. The lower half is marked with pale stripes, which are broader towards the base. Above these stripes the column is smooth, and the suckers are there marked by pale spots. In large specimens the column is from 2 inches to 4 inches in height, and from 1 inch to 1 .'. inches in dia- meter, while the disk has fully 2 inches in breadth of bloom. Morecambe Bay and Torquay give specimens with orange and rose-red tentacles and disks ; while from Boulogne they are obtained with rich full lake and light lilac colours displayed in their flower. Mr. Holdsworth met with examples of this species in deep sands or mud at Seaford, near Beachy Head, so peculiar is their habits, that for weeks in succession they kept retracted both disk and base so as thereby to assume the form of a flat bead or an onion, and evinced no dis- position to attach themselves by their bases after the- manner of their kind. From this circumstance he named them sphero'ides, believing them to be a distinct species, living entirely free from attachment ; but he has since seen reason to modify his views. On soiae occasions, in the glass tank or vase, examples of this peculiar type will attach themselves by the suckers on the upper part of the column, and then they appear in an almost inverted position, with their base uppermost, where their disk ought to be. Specimens of this class are called by difl'erent writers vagabond, homeless, restless, and, besides receiving other hard names, they are described in. this stage of their existence as " sowing their wild oats," after which period they settle down, lead a quiet life, and become respectable. They are then a credit and an orna- ment to any aquarium, and perhaps all the more cherished for being reformed characters. This roving free habit marks especially the mud-dwelling class of troglodytes. The disposition to be at all times less firmly attached by the base than other species, and the habit for lengthened periods of living quite detached, particularly distinguishes Troglodi/les as constituting an intermediate link between, the permanently free and the permanently attached forms. Oct. ly, 1«83.J ♦ KNOWLEDGE ♦ 245 One MoNTn before ArrrMXAr, Ecjrixox. At the Autumnal Equinox. One Month after Autumnal Equinox. SUN VIEWS OF THE EARTH; OR, "THE SEASONS ILLUSTRATED." By RicnARD A. Proctor. IGIVK this week the Sun Views for the month, showing the aspect of the earth as supposed to be seen from the slin at six in the niorniug, noon, six in tlie evening, and midnight, Greenwich solar time, a month after the autumnal equinox. For comparison, th& Suu Views for August and September are repeated. 246 ♦ KNOWLEDGE ♦ [Oct. 19, 1883. FISH AND PHOSPHORUS. By W. Mattieu Williams. A CURIOUS notion concerning fish diet is widely pre- valent. It is supposed to sup))ly special brain food. If this were true the Dogger Bank fishermen, who feed on cod-fish, should be intellectual giants. I sailed for two months in a schooner, the skipper, the mate, and half of the crew of which had for many years eaten cod-fish at every meal. They were by no means remarkable for cerebral activity, nor ai-e the rest of their class. The popular fallacy seems based on a series of other fallacies. First, that there is something very spiritual in phosphorus ; second, that phosphorus is a special and ■exclusive constituent of the brain ; and third, that fish contains more phosphorus than other food materials. The first is mere imaginative nonsense. The second is a half-truth. Phosphorus is a constituent of cerebral and other nervous matter, but it is also a constituent of bone, ■which contains aViout eleven per cent, of phosphorus, while brain matter contains less than one per cent. The third fallacy seems to have originated in that very common source of error — viz., dependence on mere words. Fishes are remarkably phosphorescent — ergo, says the word-slave, they must abound in phosphorus. The fact is that the chemical element named phosphorus has nothing whatever to do with the phosphorescence of fishes, nor with that of the multitude of other phosphores- cent animals. The glow-worms (of which there are many species in England alone) and the numerous insects in- cluded under the general name of fire flies are brilliantly phosphorescent without the aid of phosphorus. The minute jelly-like creatures that at certain times render the crest of every breaking wave a blaze of light, and mark the course of porpoises and bonettas with pale rocket-like trails, are animals in whose composition phosphorus is especially lacking. The true connection that exists between the luminosity of phosphorus and that of organic phosphorescence is that both are dependent on slow or languid chemical combi- nation, while vivid combustion is a manifestation of intense or vigorous chemical combination. Ordinary com- bustion is a vigorous combination of something with oxygen ; the phosphorescence of phosphorus is due to a slow oxidation of this element, and it is probable that the other cases of phosphorescence are due to the slow oxidation of something else. B. Radziszewski has recently investigated this subject, and concludes that the phosphorescence of organic bodies is produced by the action of active oxygen in alkaline solution. (Ozone is another name for active oxygen. ) He describes two kinds of organic phosphorescent matter, the first of which contains hydrocarbons, and the second aldehydes, or yields aldehydes when treated with alkalies. According to this, all phosphorescence is a result of slow combustion, like that which produces animal heat, or the heating of a damp haystack or other heap of vegetable matter and water. As heat and light are both due to internal activities of matter, differing only in a manner analogous to the diffe- rence of motions of the air produced by the difference of the vocalisation of Santley and Patti, the mystery of Will- o'-the-Wisp, of oceanic phosphorescence, glow-worm light,