O^i _,ff ,/V' ^^>'^ 311 Let Knowledge grow fuom more to more." — Tennyson. 03^ MAGAZINE OF S€IENC^ PLAINUf WORDED -EMCTLlDESCRIBfi CONDUCTED BY RICHARD A. PROCTOR. ado^d VOLUME I. NOVEMBER, 1881, to JUNE, 1882. LONDON: WYMAN & SONS, 7 5, GllEAT QUEEN STREET, LIXCOLN'S-INN FIELDS, W.C. 1882. INDEX TO VOL. I. GENERAL. ACTlsirsi, » metal found in white zinc pigment, 227 Address lo " Our Header'," 3 Alien, Gr»nt :— The ori|!>u of Buttercurs, 85 ; wh«t is a grape? 1*>2; a winter weed, 217; hyacinth bulbs, 261 ; our Bocestors, the 8ton« age men, 351 ; our ancestors, the Cells, 402, 130 ; the beetle's ciew of life, 508 ; llbe Teutons, 660 Amalgams, 497 Amateur electrician, the. 511 (i lustrated), 568, 619 Amphorte at Pompeii, 169 Ancestor*, onr, 351. 402. 430. 650 Ancient Kgjpiians, we'e the/ acquainted with the earth's movements ? 379 Anec'otes of dogs. 138 Animal oolcnis. philosophy of, 21, 44 ,, vaccination, 439 Animals, change of habit in, 429 „ colours of, 193, 224 intelli-eno- of, 28, 46, 69, 108, 177, 196, 245, 251 , 269, 28«, 361 , 3S0 Antiquity ot man in u estern Europe, 463 Aqua ammoniie. explosion of, 32'^ Astronomy, Newoomb's Popular, 423 Authors and Publishers (review), 72 BiDOON. biogrsphv of a. 381 Babylonian discoveries, 268 sun. worship. 174 Ball, Dr., Astronomer Royal for Ireland : — Birth of the moon by tidal evolution, part i., 331 ; part li., 362; part in, f'lture of the earth and moon, 420 Barrett, W. F., F.R.S.E., ProfesKor of Experimental Physios in the Koyal College of SeiBnoe, Dublin :— Bote on ihe spheroidal state, 169 Baiendell, Joseph. F.R.A S. ;— The Great Pyramid measures aud the diameiers aud distances of the SUB, earth, and moon, 50 Beckett, Sir Edmund, on the laws of nature (re- view), 338 Beer, fermentation in, 257 Bees, are ihey s nuisance? 237 Beetle's view of life. 608 Betting and mathematics, 132 Birds, intelligence in, 499 ,, with tcetli, 30 Birmingham and Midland Institute, egotistical remi- niscences of the, ,('.; annivereary meeting, 81 Biting, relative to snakes, 367 Blooo. malanai organisms in the,379 Blowpipe chemistry, easy lessons in, 137, 295,359, 423, 471 Body, the human (review), 50 Roiling spring. 169 Brain troubles, 25, 45, 90. 175, 262, 291, 357, 427, 495 „ aud ils function, the (review), 378 „ aud skull (illustrated), 359 Brealhini!, 1»2 British ferns (review). HI Brothers, A., F.R.A.S. :— Photography for amateurs, 400; part ii., 466; part iii , 494 ; part iv., 647 ; part y., 669 ; part vi., 585 ; part vii., 602 ; part viii., 821 Browning, John, Vice-President of the Tricycle Association :— Tricycles in 18»2, 397, 450 Buckland, Miss A. W. :— Tr.e Wyandotte Indians, 158 ; Charles Darwin, 571 Buny, an electric, 213 Buttercups, origin of, 65 ButterQies and moths. 606, (illustrated) 624 CiiAiO •• Painter, " lh2 Cambridge and Oxford rowing styles, 633 Campbell, J. K. •.— Tbe principle of the vernier, 224 Canals on the Planet Mars. 619 Carbon, static caloric of, 237 Carnivorous parrot, the, 381, 471 Carpenter, Dr. W. B., F.B.8.:— The relation of food to muscular work, 6 ; part ii., 23 ; on the conser- vation of solar energy. 417 Cassiopeia, new star in, 227 Celestial objects for common telescopes (review) . 359 i-elu, the, 403 ChaloeiJony. as containing a liquid, 4S4 Change of habit in animals, 429 Chanie), a ride across the (review), 6«S Charbon, preventive inoculations of, 483 Chess Column, 19; Mephisto's notes, 20; general hints. 41; giving odds of queen, 41 ; two knights* defence, 63, lOJ, 216, 269; Mephisto, an "end game." 82; knights* opening, 82; game played at Leamington meeting. Oct., 1887, 127 ; game between Mr. Barnes and Mr. Gunaberg. 170; chess by correspondence, 396 ; the Giuoco piano, 4-11 ; Lowenthn'. problem tonrney, 461 ; the southern cross, 663; Vienna international tourna- ment. 614. 633 ; also see 239, 2>-'2, 308, 330, 360, 369. 415, 485. 605, 525, 642. 680, 697 Chloroforming during sleep, 3116 Clodd, Edward :— Dreams, 107 ; part ii., 130 ; the antiquity of man in Western Europe, 463 ; part ii., 667 Coal and iron industries of Great Britain, new work on, 328 Cod-sonnda and scientiflo privilege, 477, 620 "Cold-catching," 280 Cold week in May, the, 620 Collisions at sea, 610 Colour, curiosities of, 603 „ of Bunlieht, 18 Colours of animals, 183, 224 Comets (illustrated), 8, 26; comets' tails, 48. (iUustrs. ted) 86; the destroyed comet (illustrated), 135; the menacing comet, 3'20 ; (illustrated) 310, 311 ; the Specttitor'9 comet, 404 ; the comet of tlie SatarJii;/ Review, 450 : the comet, 608 Conic sections, an instrnment for dravring the (illus- trated!, 160 Consumption (review), 546 Copying drawings, 637 Crete, labyrinth at, 189 Crustaceans and light, 306 Crystnl Palace electrical exhibition, 318, 335, 354, 372, 401, 135. 447, 493, 651 Crystals, 683 ; (illustrated) 601 Cultivated fields, 173 Daffodil, the first, 443 Darwin, Charles R., 618. 671 Distracted attention, 176 Dog, Niagara Falls safely descended by a, 574 Dogs, intelligence of, 341 DoUsnd's sidereal watch, 183 Draper, Dr. J. W. (with a portrait), 263 Dreams, 107, 130 Dress, modern, 464 Duchess of Connaught, illness of, 451 Dunman, Mr. Thomas, 614, 630 EiBlH and mnon, future of the, 420 ,, tremors, ISl K. C. :— New mode of growing plants, 51 Ejho sign, the, 427 Eclipse, the, 663 (illustrated); see also, 619 Edwards, Amelia B., the Pyramid of Meydoom, Effluvia and health. 295 Egotistical reminiscences of Birmingham and Mid- land Institute. 16 Egyptians and the movement of earth in apace, 470 Electric fire alarms, 1129 „ lighting and fire risks, 629 „ telegraph, the, 198, 607 Electrical generators, 611, 568 „ machine, a simple, 189 Electrician, the amateur (illustrated), 511, 568, 619 Electro-magnetic repulsion. 629 I „ „ theory of light, 130 Electricity and magnetism (review), 377 Elements, the so-caUed, 161 I Klephants, 514 I Engineering, 629 English as the speech of tbe future, 139 Equinoxes, precession of the, 218, 312 Excessive drinking in Russia, 189 Eve, the, and the microscope, 311 i Fairt folk-lore of Shetland, 510 I Fallacies about lock, 322, 311, 353 1 Faure accumulator, 158 Fermentation in beer, 257 i Ferns, British (revie.v), 111 Fields, onr, 85 Fiji Islands, the, 31 Fire alarms, electric, 629 „ risks and electric liehti.ng, 629 Fish sounds, 295, 380, 429 Fleas, the use of, 295 Floors, a new plan to deaden them, 640 Flowers in May, 688 Fluids, properties and motions of (review), 634 Focal length of deep convex lenses, measurement of, 005 Fog-bow before sunrise, 393 Food we eat, the (review), 338 „ its relation to muscular work, 5, 26 Foot-racing, development in, .'i71 Fossils in meteoric stones, 227 Foster, Thomas, illusions, 10 ; 'part ii., 70 ; seeing through the hand, an optical illusion. 244 ; illu- sions of motion and strobic circles, 121 Found links, 195 223, 288, 164, 488, 632 Future of knowledge, the, 663 Gas, manufacture of from wood, 348 Oeikie, James, LL.D., F.B.S., natural rubbish heap; 318 Geometrical problem, a pretty, 380 „ exercises for beginners (review), 377 Germs of disease and death, 67, 89 Ghosts, 269 Glass, new variety of, 213 Glories of the starlit heavens, 607 Glycerine leather polish, 348 Granville, Dr. J. Mortimer, breathing, 132 Grape, what it is, 162 Gray on Anatomy, 640 Green-beam paper, the, 496. fiol Green light : is it made by the laminous mixture ol blue and yellow ? 496 Growing plants, new mode of, 51 Hair turning white, -439 Hanlan and Trickett, 570 He«lth studies (review), 60 Healthiest cities, the six American, 169 Heliometers, novel, 393 Hemispheres, the two (review), 470 Hieroglyphic inscriptions of the Sakara pyramids. 111 Higgins, tbe Rev. Henry H., chalcedony containing Liquid with a movable bubble, 151 Hints to local meteorological observers, 137 Holophote, an electric, 337 Honolulu, signal station at, 199 House martin, intelligence of, 289 Howie, Dr. Muir, the effects of tobacco, part )., 292 ; part ii., 313 Human body, the (review), 50 Huxley, Professor, on science and culture (review), 622 Hyacinth bulbs, 261 ICEBBBOS, 637 Illusions (illustrated), 10; (illustrated) 70; of motion and strobic circles, 421 Impaired memory, '15, 90 Inoigo, artificial, 270 Infinities around us, 663 Intelligence in animals. 29, 46, 69, 108, 177, 196, 245, 261, 269, 289, 361, 380 Irritability, 496 Jacko : a baboon's biography, 381 Jago, William, F.C.S., Assoc. Inst. Chem., crystals, 593 ; part ii., (iOl Jelly-fish. 499 Jupiter, changes on the surface of, 382 KsowLRDOB, the future of, 663 Lauson case, the, 558 Landauer's blowpipe analysis (review), 339 Land and water, 609 Laws of nature, 339 Life, duration of, 228 Light, electro-magnetic theory of, 430 London fog, earliest date of, 306 Luck, trusting to, 39 Lungs, capacity of, 327 Lynd, W., the'Fanie accumulator, 168 ; the electno telegraph, 19S ; the battery, 313 ; the wires and insulators, 371 , circuits and galvanometers, 607 Maoio wheel (illustrated), 179, (illustrated), 198, (illustrated), 247 Magnetic storm, the recent, 629 IV ♦ KNOWLEDGE [Mat 26, 1882. Ocnerti— cnnfiMKrJ. Malsnal uri:>niimt In th* blood, n7l> M>ll>t'i •xiimomrton (illuttra' ■■<)), lli7 Mao, aniiqoifj of. in Wo8t«ni Kuropp, M~ „ IhpoTolulion of, l.-,7 ,, ■ fruit-rmlor (roiiew), 01 Man's prop«r food, 1^2 Mu-l, ran>laon, Mil „ p>lh of, from 197^ lo 18R2, 463 M>t>ri>l«, tlrxngth n(, 304 Mathf^matioAl Column T—IntrodQC-torT, 10; LoRar* ithnii, 111; prarlioal nio of loxarlllima, HI, lllO; to cif. aluna Muck into Ihrox part*, li>3; the Wileh or Ai-nrai, 12H, l'k7; dilToronlJal oalculna, ItM; alia ol cotio, :;it; tortoiro prohirm, 2r>ll ; ut And Iho arra intrri-optod bctwprn a hTporbnIo and an aaymptoto, 30i ; laws or probabi'luw, -U3, 4:111, 4at presorTation, 635 Meroe, Kthiopio inacriptions at, 189 Meteoric oritaniaros, 'ITtl Meteors, no oreatiic matter in them, 267 Meteorology, l^rofcasor Grant OD, 294 Mfydoom, pyramid of. 228, 380 Microscopic vision and minute life, 332 Microscopical science, studies in (review), BOO Minnie life, a study in, 371, 4U, 627 Moon, birth of, by tidal evohitiou, 320, 331, 362 „ the, and the weather, 247 „ reproducing imitations of surface of, 439 ,, true story of the (review), 2(>S Momtne work. 4:10 Moths and butterflies (illnstrsted), 608, 024 Motion of the earth and the Egyptians, 510 Mould and worms (review). 14 Movement of the earth in space, and the Egyptians, 379, 470 Mumps, micrococci in, 439 Muybridge, Mr., and rowing, 609 Xabcotic indulgence, 673 >'atural ruhbish heaps, 318 Naval and submarine exhibition, 570 Nebula in Orion, 673 I^ewcomb's populac astronoiny, 423 Mew comet, the, 613 ,, moon in April, 613 Neptune, a planet outside, 62 Newton and Darwin, 615 „ as to a metiaoing comet, 404 Niauara Falla falely descended by a dog, 574 Jfight minima of Algol, 330 Nights with a three.inch tele*cope (illustrated), 201, (illustrated) 220, (illustrated) 20 ', (illustraled) 312, (illustrated) 371!, (illustrated) 445, (illus- trated) 611, (illustrated) 685 November, a mi.d, 02 Old May-day. 582 Origin of the laws rf nature (reriew), 333 Orion, nebula in, 572 Our ancestors, 351, 4I3, 118, 416, Ifll R'>val Academy, science nt the, 681, 599, 617 Ru'akin, Mr., on educa'ion, 119 Ruasiu, eiceasive drinking in, 1-9 ,, prebiatorio research in, 198 Safktt lamp. 180 -Sahara pyramids, hieroglyphic inac^iptious on the, 111 S.ilurilay Iti-rirw, comet 01 the, 1.W Saturn, the planet (illustrated), 178 ficienco and religion, 3, z7l „ and culture (review), 623 „ at the Royal Academy, 581, 699, 617 „ ladders (review). 292 „ plain words in (reviowl. 39 „ of the stars (review). 203 „ for all (review), 292, 330 ,, teaching, 367 Scientific ghoata, 183 paradox, 203 Seal fisberioa, f.71 Seeing through the hand, 241 Selenography, first steps in (review), 268 Seychelles, language of 'be. 303 Phaw, James, right-handedness, 130 Shetland, fairy-folk lore of, 6'10 Siemens, Dr., eolar energy, 623 Silvered gUss telescope, 498 Slack. Henry J.. F.fi.S., F.R. M.S., the eye tnd the microscope, 311 ; microscopic vision and minu'e life, 527, 332; a study in minute life, |371, 411, 527 ; silvered glass telescope, 498 ; curiosities of Colo , 603 Solar energy, the conservation of, 417, 665, 623 ,, motion and cometa from outside, 636 Solids, effects of compression of, 282 „ liquids, and gases, 43, 66, 87, 109, 166 Soot c. pollen, 439 Soun.l or swim bladder of fish, 439 South European volcanic system, 22 Southern hpmisphere, temp-rature of, 540 Speech, partial loss of, 262, 291 Spel ing and punctuation (review), 377 Suheroidal state, notes on the, 159 Solders, how they fly, .ilS Standard time, comparing the, 318 Slar-lit heavens, the glories of, 517 btars, science of the (revi-w). 292 „ the, and the earth (review), 553 Stature alarm, an electrical, 327 Stone age n,en, the, 351 Storms, new me hod of forecasting, 537 Stove.heal, 367 rtove-heated rooms, the air of, 285 StC'ibic circles, 421 Studies in life (review), 60 Sulphate of quinine, new method of manufacture, 169 Sulphuretted hydrogen, 367 Sulphuric acid, discovery of, in its natural state, 189 Sun, the, in April, 463 ; in Mav (illustrated), 657 „ Pro'essor Young on the, 211 Sunday Lecture Society, 267 Society, the, 189 Sunlight, colour of. 18 Sun wirship, Babylonian, 171 Sulfide, statist'cs of, (review), 134 Swallows, winter flight of, 213 Tape-wosm, the, 233 Telegraph, the electric, 108; the battery, 313; the wires and insulators. 371 Telescopes, lenses for, 610 Teutons, the, 550 Three cold davs of April, 612 Thre»-inch telescop»s, nighiswith a (illustrated), 201, 220, 2110. 312, 376, 4J5, 511, 680 Time signalling, 318 Toad in a hole, 136 Toads, Tilslity of, 203 Tobacco, the efl'ccts of, 292, 342 Total eclio-e, the, 610 Transit of Veona, 688 Train.ng, 102 Tribune riddle. 18 Tricycles in 1 882, 397, the use of, 420, tricycles in 18S2, part 2, -154 Tunnel worm, the, 202 I^NUKALTiiY houses (review), 39 Vaccinatiok. Dr. Carpenter on, 319 Vegetable poisons, 226 Ventilation bv open tire-places, 373 ,, domestic, 187, 636 Venus in April. 1832, 513 „ last transit of, 333 „ coming transit of, 686 Vernier, the principle of the, 224 View of life, a beetle's, 508 Vine growth and electricity, 169 Volcanic action, recent studi-s of, 129, 164 „ system, the Sonth Kuropean, 'it „ in Central Asia, 169 Volume, onr new, fll7 WAimiro rooms, 303 Water, iia ripausion by beat, 257 Water-pipes, bursting of, IMO Weather diagrams, 4li7, 619, 637, 5.S8, 673, 5^1. >•■ . 629 Webb, T. W., canals on the planet Mar«,tl» Weed, a winter. 217 Williams. W. M*ttien, some egotistical reminiscence*, the Dirn.ingbam and Mulland Inalilure, l« , solids, liquid., and ga>ea, part i., 4.'), IK), 87, Hf. U6 ; aiiniversary meeting of the Birmingbaio and Midland Inatilut« Union of teachers an1 „ in animals and plants, 143 ihe primarv, 96 Comet, the great, of 1861, 387 Comets, 65 Comets' tails, 99, 188 Coney of Scripture, the, 610 Conic section, figures of the, 55 Mat 26, 1882.] fr."Sl?."r,rrur.''.ford.,er,bi,>g the. 230 jDservation of solar enerRJ, o93 oiisoaiption, SlU, ISIO and tobacci, 830 orora, owner of the, 433 r«ui*l contour, vied : , 9t .poMles 13!t liBWIs and desirp, 160 i.rwin'« theort of eToluuon, ll» thede.centofma.. 2 9 and the microscope, -.7 )ay,'ihort»ni'g of the, 3I>1 )eBOent and Darouism, - >3 )iet, the perfect w«t in, WJ,oO- )oe, an intelllBent, 220 , in.elliBei.oe iu the. M7 an idiot. 179 log., the eyes.nht of, 3S9. 46/ 3onati'« cometa, li3 [IreaniP, 345 , Dnnman, the late Mr. Th'-ma". 6;0 liAUtH, heat ol the interior, 433 „ popnUtion of, 6(o Hfleminacy of appearance. 9& Klectric teleeraph. ■»"», 601 Electrical aorumulator, new form 01, i->i hells, 1«> image*, 273, 40^ P lecVro-platini;, 3t>3 Elementary eleclricitT, 143 Kncores at concerts, tiiO Eocr.i,it.B, 387 Kvemreens, onffin of, -/O Evolution, 1«4. 252 Ei'Sight of dog», '388, *>' FlBTHlns, interest on a, -3- Faure accumulator, the, IIB Ferrier Dr., ana vivisection, o8 Fla.h of lightnine, duration ol a, 121, 187 Flesh food, 2!9, 3.'2, 33U Fleiure in planes, 362 Flowers of 1 he sky, IIB Fluorescence, 611 Food question, a, 186 Fossils in meteors, 388 in meteorites, 302 . " from London clay, their preservat.oi " Sc how to preserve them, 433 Four fours, 184, J2» > ox and guns, 229 Funei and lichens, 229 GiS, mannfacture of, from wood, .188 Gh'Sts, 233, 403, 501 ^^ Glacial epoch, time of the, -0- .,- Glimpse ihr'Ueh the corridors ot time, -oi Golden sa ids, 501 Grammar, 13D ; a question of, U Gran me machine, reversihill'y nl th Gravity, and Sir K Phillips b4 do comets obey n fVi ' what is the cause of, ost cause of, 99 irrr^:5^^(~«a,,52i Heads male and female, 209 Heatofthesnn, 74, 9«^ ,, from the sta'S, -o- High numbers, 478 Hints to correspondents, to Histiiloey, books on, 207 Horseradish, 303 '"•'tBe.'the'tn'Qreat Britain, 3il, (dlu.trated) 315 yachts, speed of, 3-1, „ can they sail Illusions, IH, 139 , „^ . .,rt "In Meiotiam," disputed passage in, 5r« Inclination, the earth's, 36 Insnlators earthenware, W4 Intelligence in animals ls7. 2o2, ./3 Interior of the earth, 296 „ heat of tne earth, 36i laterstellar space, temperature of, 25i Intoning in synasogues, 59 Intra-mercurial planet, 3.1 JuttTiBT, 1S32, the weather of 303 Jombo-iotelligence in amines, 611 Jnpiter, D.nnine's comet, IW in Cassiopeia, 1.8, o"l Ksowl.«I>GH and the scientiBc societies. 14.) for the yrung, 11/ technical t-rms, 78 I LiSKYank, the, 4-i7, 502 L Latin quo'aiions, 57 I Lectures, 3'i2 Life, duration of, 339 Light and heat waves, 2o4 .. and lanterns, 251 ,. the invisibility of, 93 „ velocity of, 164 ,, vibrations of, in ether, 163 lightning in November, 96 protecting houses from, 117 Link, the missing, 74, 93, HJ, 111, 429 Liquids and their vapours, L5- ♦ KNOWLEDGE ♦ Logarithms. 96 ^ table of, 207 Longevity in animals, '231 Luminous phenomenon, I'-l Lunar lUusions, 57, 93^230 Magic squares, 186, '^74 wheel, th.-, •2'29 Magnetic needle, the, 208. 263 Man, antiquity of. 18o. '2u7 descent of, 254 boilers, 253, 272 Marriaee and the death-rate, 139 „»,h» M«w*li; Professor Clerk, and the reversibility of the grainme michine. 113 Memory if language in a bear. 187 ^'-''.^"'^'■.'"theyamaUerth.uofyore? M. 78 M.-ne9','d«teof,207 Mental physiology, 16S Meridian.l (arts, tallies of, 94 Mesmerism, 301, 361 Meteorites, fossils in. 303 Metrical system, the. 99 Microscooical, 389 Mind-doolor«, 273 Minhocao, the. 302 Mock suns, '232 ikey, intelligence of a, 43S ,„. an «'-fi;'«J;;„'^j^ ti,, 233. 251, 277. 301 113 ill faster tha ' 16, 5t) diamete 501 of the i s 42 in. object glasi rioB of light round the, 233 tthe, 184 321 1 Everest, on of the, U4,: npntiog the, 55 [[ the, and the weather Moses, burial of. 431 Mountain, a, 3.000 feet higher tha NiJIBS of stars, 143 Natural philosopiiy, history ot, 3i>- Nautilus, the, 252 Navvies, health of, 251 Neolithic man, 456 Neptune, density of, 164 Newspaper science, 163 November meteors, 35 f o.^ Number 4, singular propertv of, 209 Nomerical eointidsnces, 2 9 Open lire-places, 603 OfS musions, 67, 95, 230, 341. 345, 339, 409 Ordnance maps, the 1-inch 9) survey, the 1-inch map, do Orrery, an. 164 Our unbidden guests, 208 PilsoiiiHic man, colour of, 4'8 Palizsch and Hallev s comet, 93 Papua, a high mountain in, 63J Parable for Paradorers, 139 Paradoi, a mathematical, 432 Pasteur's plates of germs, 143 Pendulum, possible daily vans variability of a, IM Periphery of ellipse, error in c Personal identity r tattoo marks, 20, .. illusion, 433, 521 Phillips, Sir Kichard, 161 Phrenology, 69, 96 and the brain, 209 Planet, retrogradation of », 164 Planet's movements, 59 Planets hid ng stars, 163 Plauetary riurs, 1.4 Plans for the New Vear, 16J Plants in bedrooms. 431 Plating, 363 alkaloids, 2o4 Pneumatic bell, 230 . Poisons, a new comparison ot, lib, aits, -i Polarsun, the, 362 Polarity r. Gravitation, 115 Pole at the north, 345 srar. the. and precession, 203 Popular electricity, 99 ,, fallacies, -231, 276 Population of the earth, o75 Potato the 431. 520, 611 Precesriona'l reeling of the earth. 139 Pressure an instance of, 188 Primary colours, the, 18 1 _ Prisma.io analysis, new fact in, 2/8 ProbabiUties, 301, 610 Problem, a pretty geometrical, 229 Problems geometrically insoluble. U5 Psycho, 207 Purple of the ancients. 387 Puzzle, the hog, 232, 363, 43- the three square, Ibb •• the fifteen, 37. 74, 101, 18.5, 230 Pvrimid. the, and paradoxera. 113 ' ,. the Great, 163 measures, 94, 114 .nntiquitvofthe, 168 „.. „ i'n Knowlibge, 184 loMETBE, the, 3=8, 457 baud, the, 433 naii.bow, a remarkable, 115 Rainfalls and forests, 122 Raf, why thev gnaw water-pipes, 140 Rattlesnakes. 231 Pyra QCBI R K Reflecting telescopes, 45« Richter'a dream. -Hi, iii Rowing, notes on, 4,9 „ „, .=7 SiluaN. physical appearance of. 4o7 Saturn's shadow, shape of, -33 Scent. 363 . Schoolgirls, the flfteen 186 Science and religion, 3•^9 true spirit of, 140 Scientillo paradox, 254 Borew-driver, 478 tubes, 693 Seagull, a clever. 67 Seeking after a sign 4i6 irx! irflu-e;:: ofTrn'mf,^, 35, 78, 230, 276. 321 Sexes, comparison of, 3-18 Shortening of the day, 361 Sidereal time, 612 Singular illusion, 118 Sirins and Orion, 164 Small telescopes, 209 Bocieties, reports on, liH „,;,„„f ..11 Sodom and .«mo.rab. destruction ol, 131 Solarheat. 96, 164 ,, waste ot, 06 illumioation. equality of, 144 puzzle, 276 „ storms, 165 Solution, cold saturated, ii ^ Sound, -208 „ Space, is it boundless r oa/ ,, paradox, 478 Spectral lines, 345 Speech, partial loss of, 38J Spherules, water, 1« ,.. Stamens, colours of, -o3, -/o Starch in potatoes, 50- _ Starfiih, the common, IbJ letters and numbers, Ibl ,, maps, 117 ,, names, 77 Stats, the, in their courses, 29b and the earth, 612 Stone on wheels, 115 Stove-warmed houses, 388 Sun distance of the, 99 ,. ' is the, hot ? 15, 35, 06 '„ constitution of, 209 Sunday art exhibitions, 113 Sun god festivals, 278 Sunlight on fires, 252, 277 Sunspots origin of, 209 Synagogiies, intonation in, 59, 116 T-ATTOO marks, 253, 275 Technical terms, 121 Telephone, 479 (Illustrated), 408 Telescope, 275, 296, 389, 431 a £5, 121 how to construct one 2/0 practical work with the. / / , 1 1 6 Telescopes,_^che^ap. 232^ years' system, 456 Telescopic images, brightness of, 433 Terraces in Dorset valleys, 301 Thawing ice (illustrated), 207 Three-square puzzle, 116, 184 Thunderstorms, action of, 3il Tides a new theory of, 68 Toads', 165, 231, 277 „ stuDg by insects, 207 Tobacco and consumption, b3J ,. and science, 3^8 Tricycles, 521, 559 T.-ioor'tin.' an ancle, 11/ ,,,., u"™htI of London, matric. exam., 432 Ursa Major, 230 ■Variable magic square,//* ^rs°arVa"'m'f 25°l,"55,'3'i2', 3.?2, 389. 407, «1, 479 Ventilation by'opeu fireplaces. 457 Ventriloquism, 387 Venus in sunshine, IBl Vermin, 209 .„ ■ . sa Vivisection and Dr. Ferner. 53^^_^^_ ^^^ Volcanic projectaes, -276, 298 'Zt:Z-.ZTIt.t:m. '^ "276, '296. 34,, 3B1 WindmUl illusion. -276 Woman, social influence ol, 46/ 11)5,466 Women : are they inferior to men .- /7, 9.,, , Word-choice. 165 Worms, 296 ANSWERS TO CORKESPCNDENTS. .icHROMATisixo tel»Bcopes. 577 Alcohol and work, 365 Altruism, 459 American humonr, 3Uo Apes tails of, 613 Apsides, motion of, 327 Archimedes and the cylinder, 213 Axial rotation of the earth, 481 Bateachiabs and reptJes. 281 Hell's line-writing. 437 rr^o'r;d/yraor.ir?h;m\\^bou.,6:a ♦ KNOWLEDGE ♦ [May 26, 1882. Aniwrrl to CnrrMpondenU— ad ih.- !•"• of n»lur«, ■W7 Clifford, Mr. .nd Iho cri..tion,4a7 CloudM. how foriDfd, 1A7 Coram" Kill, -Nnfton'i ihi-orj of, 4»> Coprrnicntlirorr, Ihc. 317 Co«iuic»l ••IrmpnH, and line cqaationl, IHI DlTi of thr wMk »«»ociat<-d "Uh colonra, 300 Dpciinal poinl, rule f.>r placnj th», 070 ll..,lol>mc(,t.r<>m.rl<»on,3W l).(r.-reiili«l cftlo..lu« and phy.ici, 237 Unfita how to eipreas in oontrBCt«d form, OJI DreanJa. pilra-ai ientiQo viewa of, tVi K vKTU rlootric currents, origin of, 631 Klociriu curreuu, fatal cITecu of, 677 KIwtricitT, tell-boona on, 677 Koi .on < a..a,len.», lino, by Broagb, 306 Ktbor of spac" and aciencp, ISS Krolution and fanntus, 522 KitraChrisiianandl'rofeMor Uniley.Snl __ Kvepitce of telescope, measuring the power of, 6/ < K\TR and evolut'On, 366 Keata of atreugth under mcmono inQucnce, 2o« FenoiDK, 603 Kixod stare, trembline of, 4'*2 Kocal image of a planet, 213 Koiis, 3»l Kound links, 391 KroK a spawn and tadpoles, 237 FudglnK. 491 , , ,.„ DiLll-KO noi blinded by use of telescope, 603 •• Genre psinters," 280 •Jeology and astronomy, 302 t»«om-tric»l scries, dellnition of, 481 Glacial period eanh not approaching another, 481 tJod, th- einteuc- of, inferable from His works, 169 Grove's cell, to make one, 622 Ouillemio's " heavens," remnrks on, o*7 HiSDWiillixo and character, 237 Heat and light waves, 213 Hutlon, Mr., and vegelariasism, 43( Hydrogen and balloons, 413 laisn curs. 3»3 . Ladies and scentific di»cnsBion, 212 Lightning coodnciors, how they act, 391 Logarithms, .W3 Logarithm of a negative quantity, 4S3 Loxodrod.ic curve, the, 250 Mas's teeth, and their eigoiflcance, 330 Slacaulay ano iho semicolon, 603 MUtakes, on making, 392 Moan's history and Saturn a rings, 431 imat;e and telescope, 3t>0 Moses, butial o', 4S1 Sewiox, Sir Isaac, reference to, 392 0*a, 'he, a lever of the second kind, 481 Open lire's, 317 Optical laws, inversion of image, 4S1 Orbit of thee-rth, and distance of fiiet stars, H2 •• PabaLlxx," a theory of the earth, 413 Parenthesis, use of, 503 Wane of toe earth's p«th, nnchacging, 411 Peraoecti.e, la«s of, 236 • ■, j,„ ci Photographs : pamtmg them on glass, m oil, Sc, bdl Phrenology, 393 „ remarks on, 280 Polygons, 213 fopolation of the ear'h, 631 Primary colours, 236 Probabilities, theory of, 318 Problem, the Petersburg, 3S<2 Pyramid bu Iding, a theory of. 436 builders, and the grand gallery, 432 curious theory respecting the, 301 ". measurement of great gallery, 436 Rainbow, curved shape of, 2l2 ,, theory of, 522 Rotatory motion in nebulous masses, 303 BAiBi-l-iias, theory of their eipuUionfrom primaries, 481 Bayce on Assyrian literaiure, 459 Segment of a sphere, attraction of, 521 Shape of the head, character shown by the, 623 Short whist, 257 Sirins and the sun, 412 Sliding-seat. in rowing. 2S0 j >, ,j Bounds, iroitalions of things described in sound by old poets, •492 Rmall-pox and vaccination, 320 Smoking, effects of, 365 Snakes swallowing their young, 347 Space, dimensions of, 212 Buontaneous generation, 320 _ , „ -on "^ , and Professor Tyndall, 639 Star m'ips, for whom intended, 280 Stars not seen where thev actuallv are, 327 refleciing same in water, IfJ Ftorms, and their warning from America, 230 Strala, thickne.aof, 481 Bun, aitiaction of, 437 and moon, siie of, near horizon eiplained, 237 S'linhglit tutting out Ure a fallacy, 305 Sun's restraining force on tbo eatlh 326 Swan's lamps, 622 TiH(iK»TiAi.i.T moving maaa, energy or, 3-; Telesoopaa, advioo ooncermiig ohttioe of, 67i 1 erro.tRal eompr-.ion, Se.t.n'a eslimat. of. 213 Ton at .arth's surface, how much attracted to the ElictrioBl coil, ♦'M Turning wheels, centrifugal tendency of, 612 Twinkling ol llied stars, to what due, 412 •Trpe-writer, the, 326 ViCCIlliTIo.x and small-pox, 459 pamphlet against, 481 Tegetaides and fruit, 481 Vegelarianis-n, 3110 Vernier, remarks on the, 366 Venlililion ol sick-rooms, 438 Venns, day of, 391 Vivi.colion, whether right or wrong, 301 vVABOAtifl as a river for rowing, '280 Worms, remarks on, 237 ZoDIACil. light, the, 491 QUERIES. AnsiBACT reasoning, 316 Actinium, 390 After-images, 167 Air-pump. 324 Algol, li'2, '278 Algoland M.ra.inj Almanacks and celestial maps, 234 Alpha Cassiopeia, 210 Aluminium,211 Ancestors, our, 410 Ancient man, 123 Angle, Irisection of, 101 Animals' food, 323 >\uimal Isnguage, 255 Aniline dyes, 303 Antarctic regions, 434 Anlipathv and sympathy, 1.2 Ants, industry of, 145 Aslr.nomieal slides, 101 Astro-phitography, 434 Atlaniic cable, 434 Atomic theory, the, 3"3 Axes of the planets, 167 Bahombieb. '324 Barometric oscillations, iis Bear, the great, ml, 188 Bedrooms, plants in, 410 Beer, fermentation of, 168 Bees! 234 Binocular microscope, 4.j-i Birds Md 'animals comparative anatomy of, 80 eg«s, colour of, 123 " a flight of, 38 BoUny,211,43t lectures, 101 „ works on, 279 Botanical, H* papers, 101 Blood analysis, 168 Blowpipe an.l^sis, 279 ; chemistry, 389 self-acting, 453 Braiu injuries, 123 Brewing, 210 Brick-clay, 231 Burni' e gas, smell from, 3UJ CALCVLrs, the, 255, 410 Calculating machines 4;8 Cambridee, scholarships at, 410 Cards, 480 . Ca-siopeia, new star in. 102 Centre of the earth. Ht> Cheap telescope, 183 Chemical, 210 analysis, 303 heating apparatus, 273 problem, a, 323 queries, 123 questions, 101 treatises, 60 Chemist, 323 the, 12' Cho , 234 Climbing plants, 435 Coal age and the earth's internal heat, 167 Coflee leal', the, 168 Colour-hearing, 278 Commercial tables, 304 j ■ i , Comparative anatomy of birds and animals, S" Compound pendulum, 378 Copper, engraving on, 101 Cotton, how to make it waterproof, 16« Creation, las „ vestiges of, 101 Daisiis, 323 Deep sea soundings, 80 Dout»le refraction, 168 Doubtful organisms, 310 Dreams, 80 Drying wild flowers, 364 KoiNBUBOH University, examinations «t, 210 KfHuvia, elTeots of, on health, 23* Electric, 3i3 , circuit, '234 , organ, 434 ricity, 3»J „ . jbUr, -TOa F.leclro-platiog. 168 RUclrophote,the, 30^ F.lhpae, ioatraiaent for deecnbing, «» KocnTtV; iTt axiom of Ih. flrst book of, 27^* F.uskarians, 458 Evoluiion and origin of rrergre«i», 2*» knd geologv, 435 E«ript)onal season, 410 Eye, the, a- one of the senses, 168 Kve'pitKe, 255 F.,e Lying to, cause ol, 33 Magic lasiebx, 410 Magnetic neeole, the, 123 Magnelscope, 101 Marine boiler, 167 id the death-rate, 8D ,. 210 Materials, strength of, 390 iphone, 323 Microscop.", lOl Moon, the, 234 influence of the, 122 atmosphere of the. 123 bright..efSof the, 324 rotation of the, 101 Milona of Mars and Saturn, 107 Moses, burial o', 410 Mosses, 435 Medieval, 323 Medical botany. 168 Mental physiology, 133 Mercury, revolution of, 102 Meteorological, 43-1 Name of star, 167 Natural history. Sfi ,, philosophy. 303 Nautilus, the, 231 Nebula;. 304 Neptune, densitv of. 101 Nickel-plating. 210 Obsbbtatioh of weather, 278 ilAY 20, 1882.] • KNOWLEDGE Qaeriei^eontinued. Old atlas, 361 Old pnnU of flowers, restoring the colours of, 316 Opium, 279 Optical illnaioiw, ICl, 167 Oreaoic compounds, tJS Orrerr, SO Paist, a DOQ-condnctor, 480 P»IiE'>notaDT, 279 ParaOio, 34U ParallelopipedoD, 167 PeDcil-point protectors, 3»3 Fnoto^rapbic, 3&0 studio, 410 Photography, 364 Physiography, 323 PigmcDts, 364 Planetary movements, 122 ring', 101 Pneumatic bell, 167 Pole, the, 234 Polar sun, the. 323 Preserraiion of zouphytea, 4o., 255 Probabilities, 123 ,, apparent paradox in, 410 Prose composition, 324 Psychology, 27S Puzzle, a fifteen. 33 Pyramids, aotiquitj of the, 1>2 r-yrologicl, -434 QciBlz in ct a', 410 Qaiclisands, 410 Quicksilver, noD>poisonous, 279 Quotation, 502 Radiometbb. the, 122 Railway collisions, 167 Bainbow, 123 Baior, 410 Eefrigerator, 273 Ketrogradation of a planet, 60 Bnsr, »s9 Saksibi tablet, 435 8aJt, 3ao Satelhtes, 273 Scent, what is a, 234 Scientitic terms. 390 Screw-propeller, 167 Seal lisbenes, 454 Seismometer, 122 Sertnlarias, the preservation of, 255 Shocking coil, 434 Shortest day, the, 234 Shorthand, 234 Sliver, 410 Singing voice, breaks in the, 459 Sinking Funds, 48 > Sinus and Orion, 102 Smelling salts, 390, 410 Sodom and Gomorrao, destruction of 410 Bolar heat, 101 „ ,, experiments en, 123 ,, storms, 122 „ system, illumination of, 101 Solids, illusory figures, 167 Solutions, cold saturated, 255 Sound, its penetrating force, 102 Sp.nisb botany. 323 Spectrum of Actinium, 346 Sphere, volume of, 38 Stamina, 390 Star letten and numbers, 102 ., catalognes, 234 Stars, the, in nonhem and southern latitudes, 193 „ heat from the, 211 Stone on rolling wheels, SO Stonebenge, 434 Strata, 364 Students' societies, 234 Sub-tegmine >>gi, 434 Sugar analvsis, 346 Sulphur cast, 364 Summer days and winter nights, 145 Bun at bis nea'eet, 234 „ diameter of the, 210 „ oial, 38 Sun's beat, cessation of, 210 Snnligbl on flres, 18s TlLiPHO»I, the, 303 lalescope, 323 ,» a cheap, 183 u a reflecting, 390 „ garden-stand lor, m Telewopes. pou-schromatic, 234 Tennyson, 279 Terrible dreams, 123 Tertiary f.ssils, 410 Thoracic integritv. 384 Thuniierstoroiii, action of. 255 Tune and teuperature, measures of, 390 Toads, 123 Tobacco and science, 278 _ ., eflVcts of, 410 Tortois.s, 211 Training, 80 Transparent sobds, ijluiory fignies of, 167 Three-handed chess, 101 Trichice, 278 Tncycles, 453 UtTUn Thcls, 38 Dniyene, the unseen, 14j University of London, B.So. Exam., 431 Uranus, sa'ellites ot 2"9 Vkgftablb food. 3t>4 Vegetarianism, 410. 434 Velocity of sound, 60 Ventriloquism, 364 Venus transit ol, 1883, 108 Vines, 316 Volt.io HlectricitT,279 Vulcan, the planet, 101 Wisp siiogs, 145 Warmth at night, 921 Wasted energy, 101 Watch jewels, 145 „ pivuta. 145 Water of Ayr stone. 1 15 „ spheroides, 64) Weight and pulley, 211 REPLIES TO aUEElES. Abstbact reasoning, 390 Algol, H« Almanacks and celestial maps, 279 Aluminium, 236, 25B Anatomy, comparative, of birds and animals, 102 123, 124 Ancient m.n, 146, 168, 279 Animal Unguaize, 324 Aniline dyes. 346 Antiquity of man shown in the Nile mud> 169 AsbestOB paint and the salety-lamp, 347 Atomic theory, the, 326, 346 Blowpifb. a self-acting, 521 „ chemistry, 435 Beer, fermentation in, 303 Biological — the ape and man, S46 Blue streaks in brick clay, toe, 303 Botanical, 48 J Botany, 480 Brain injuries, 146 „ troubles, 189 Brewing, 390 Burning gas. smell from, 436 Burial if Moses. 458 Cancbb, mortality from, 325 Cassiopeia, new star in, 146 Cheap microscope and telescope, 134 „ telescope, 211 Chemical, 235, 256 „ analysis, 325, 346, 410 ,, problem, 364 ,1 queries. 168 „ questions, 125, 146 treatises, 123 Chemist, exaii.ination for, 4c., 364 Chin, the, 211 Choaoites. 303 Climbing plants. 502 Coal age and imernal heat of the earth, 211 Cold in the head, care of a, 453 Colliery tpoil banks. 602 Collodion plates, 169 Creation, 211 Dbsigxs, Messrs. J. and E. Hall's, 324 DoUinger, the Eev. W. H., papers of the 235, 256 Doubtful organisms, 235, 279 Drawing, 4.58 Drying wild flowers, 410 Kabth. inclina'ion of ihe, 60, 80, 123 Keinburgh University, exaiuiuaiions at, 235 Electric, 435 Electric.l, 346 Klectricitv, 34«, 436, 458 Electro-metallurgy, the art of, 324 „ plaliog, 435 England and Wales, map rf.410 Equatorial adjnstment <>f, 538 Evergreens, origin of, 279 Eye, the, as one of the i-eii'cs. 211 PatTBK's accumuUtor, 124, 324, 435 Flight of birds, 60 Flowers, names of. 211 Food, forms of, 102 Foraminifera of chalk, 435, 458 Frogs, 235 Fungi and lichens, preservation of, 211, 235 Gabde.v tripod for telescope, 145 Geographical maps, 410 Geometry, descriptive, 430 German and Engiish, 123 Glacial epoch, time of, 212 Gold, 559 Grammar, a question of, 146 Greek fntnres, 235 „ verbs, 125 Haib, 435 „ turning white, 364 Heat, 324 Heating room, 430 High frrmenlalion, 235 Histology, IS^ Ho . 325 ible dreams, what due to, 146 Horseradith, 279 Hot winds, cans- of, 80 Humhie bees, 23i Ics,235 Ice age in Britain, 324 Iliad, the, 364 Inchoatiou of the earth, 60, 60 Indigo, preparation of, 211 Insects, use of some, accounted noxious, 236 Intensity coils, 435 Jonx Bull, originof the name, 235 Jordan Barometer, 303 K»ows languages, 256 LaKGrAGss of the earth, 279 Leases, 324 Lectures, 435 Lepidodendron, 365 Life, duration of, 436 Light andlantein, 279 Lightning, 3y0 Link. toemiiBinB,169 Logarithms, li<2 London University examinations, 145 Luminous paint, 411, 436 Magic la-. tern. 458 Magiietic needle, the, 211 Marriage and the death-rate, 124 135 Material, strength of, 435, 480 Meat, parasites in. 236 Mental Physiology, 146, 211 Meridional parts, tables of, 146 Mercury's revolution, 125 Microphone, the, 364, 435 Microscope. 146 Miuimaof Algiil, 324 Miscellaneous, 435 Moon, rotation of the, 189 Mosses, an excellent work on, 480 Navbs of flowers, 211, 255 Navvies, health of, 326, 411 Nautilus, the. 279, 303 Neptune. 124 Nick 1-plating, 235, 435 ,324 Optical illusion. Organic compounds, 325 Orrery, 168 PAEASiTBsiumeat, 236 Pencil-pjint protectors, 436 Phosphorescence of tish, 480 Photography, 390, 411, 480, 502 Photographic, bromide solution, 436 Pole, the, 27a Pular sun, the, 365 Prose composition, 435 Puzzle, a fifteen, 80 Pyramids, anfquityof, 168 Pyrological, 48o QcABiz iu coal, 480 Quicksilver, 361 „ non-poisonous, 324 Rabbit, experiments with a, 279 Railway collisions, a practical suggestion, 235 Razor, 453 Refrigerator, 278 Bust of iron, 411 Sakkasa tablet, 480 Salt, 436 Scientific terms, 411, 436. 458 Sea-blue bird of March, 335, 180 Seal fisheries, 430 Silver, 458 „ residues, treatment of, 4.53 Sirius and Orion, 146 SoUr heat, 146 Solutions, cold saturated. 30J S.'UDd, velocity of, 123 SmeUing ealf, 43li Sphere, volume of, 61, 123 Spinning top, 559 htamens, colour of, 303 Stars, names of, 212 Star numbers and letters, 2."5 Stone on rolling wheels. 124 Sulphur modiflcatioos, 146 Sunlight on fire, 211 Telbpeone, 502 Telescope, 364 Tennyson: " Bar of Michael Angel j," 325 Thoracic integrity, 410 Thnnderstorms, action of, 303 Tobacco and science, 436 Tortoises, 279, 303 Tortoise, longevity of the, 236, 324 Training, 124 Treatise on chemistry, 146 Triangle, trisection of, 125 Trichinae. 346 Ultima Thclb. 60, 80 Vallbt terraces, Dorsetshire, 490, 430 ^ egptable food, 4.35, 433 Vegetarianism, 458 Vegetarian bot'ks and pamphlets, 521 Ventriloquism, 39J Venus by daylight, 125 „ casting shadow, 168 Vestiges of creation, 124 Vulcan, the planet, 145 Wj ,411 Warmtn at night, 365, 435 Wasted energy, 145 Water of Ayr stone, 43S Weather guide, 212 KNO^A/'LEDGE [May 26, 1881;. B«pH«* lo (la»ri«i-««"»""'- I Wild flnw»r«, S90 7.orr»jri, tho, IM EEVIEWS- .-« PnaiiriTioH. a cnnone guiii* to l,.h,n« (Lon.1on • W,n,... * *- il.^j^, ,„„ ,h, rs„T«d n.'^'.Tral.'it.bxC.pUia Hugh A. K.ocdr. ?;.T,'r,c;v?':"d r.«o:nr;b;8. p. Tho»>p.oo.377 377 llBuispnEBBS. th« two, 470 Muro.copic.l >«.•..>-. "Od... .n, B09 Moald »nd worm,. D»7"VJV John Jon-,, 2(15 Mood, the tru. f'';;^ ,"' } i,' gir Edmund Beckett, l...Vrwora. in soienco. .n address by Dr. G. V. VopJla? «tr^n''o'y' br>-0? ^""st' ''''•''■' ''' i^e'Lr;;^/cLterb»nu™.b.5ss P^.%" and CoUure Projessor U l^e, ou. «.. Science for All (^ m i.'«„i!.r« •>»2 Spemn.':n^d;u;:;LUbruTnVrB\.dneU,W,n.an R„,i!;f?n^lr^byH.Siue,air^^i^;^^^, Suicide, staiisl.cs ot, by Henrr Morseui, w Star., the. •"4 '"j* "'"i'^^X j Pe.-oe. 292 X^-W.l"^n7,ts:i: • 'eciure b, Pro.c.or de Chau- moit, 39 Whist for beginners, 698 ILLUSTRATIONS. BlSDi's comet in 1946 (3 figs-). 133 Botanical contrivance. 2o3 Batterme..ndmo.h,.6j4 ii9. lU. 161. 201, romef 'thfmenJnc iUaitr.t\on. of. 310. 341 ^ret;on?n(2fig;.).86.87 fanciful Tieits of. 9 ;; (-1 BBS.). 21. 27 Comet paths. 572 Oomets'^t.ils. 48. 49 ?>7,'J:iVfand perforated sholls, 360 Donatt's comet (?.fl8»- "f'^'^V ■?«! Sir'a?d'oitr^:h:ffirl-r.of.533 Eastern skies in Notember, U, ir«rri«i!;!'.h"".n,.t.ar : electric gon.rator., 669 f??;":';rpe";::"'a™;L,',r.::.nrof .an,.,, sa. 535 1 Kound link.. l».-.l.kcl.-tnn,nl.it.nol bird.). «88 1 OLiCIATKD hm-.ton« lieb-.le, ■iH j iallary oVllie'gra.t pyramid, pwsptctire Tie", "317 IUlo ronnd the moon. 621 IllCbioiib. a nest of, 71 ■ 1 . ini iff of miition and slrob'C circlet. 421. \i- Kaivojiboo. haunch-bone of, I>32 I.0OPIB path or » planet. 4S2 Maoio wheel, 179. 19i, 199. 247 mal.?; wi'.h'the 3.ioch leleacope. 20). 22 V290. 312, 37«. 44.'>, 611, 695 I Bhouldep-hones of. 5)3 PvMot.i.cu a comnonnil. 455 Xe;:;:tJi;;r'"^i:r:irn^£3 .i'r/-orti.%5:::'''^r.':;:'i^-A''"'' pyramid o.,erT.t..ry,.howu,g the object-end of tboTre.t ohserriDB tube, 399 ; vertical section of {be pyrliJ ob.erJ.tory. 399 : diagrams of «itro- loKical .ch.-me and of pyramid, 0J8, oi9 Satlb.v. the planet, 17rt Sun in April. 469 ' Tei.epho.vb, 409 Toothed tiir.1, .keleton of, 33 j Transit of 1883, chart of, 699 Waibr-moik. Australian. o32 1 ZoDliCil. map. 235, 406 Fowls, speech among. 499 Fol atory, a. 3.>9 . Fniil. in preservation for '"°t'%]\» Ois iranufactare of, from wood. 240 Gift' to the New York Museum of Art, len Uo.U lo protect sheep. :W5 (iraphite. new nso (or. 53.. Graves nesr Pratigorst. 167 llBAIandsunlmhi. 19 Heath. Mr. Franci. George, and the J01 Fur„lry.nH Holy wrll ol Z-ro«m, water ol. l<» MISCELLANEOUS. AcCCHTI-iTlTEsinkinEfand, 514 Americ.u asriculture ti. hogl.sh 609 Ancient tablets from Sippara, 008 Animal instiuols, 381 Animals. intellit!enc»in, 337, 409, 430 reasming in. 430 rights of. .421 Ant town. Bu. 570 Asbestos ttre.proof paint, 2/ 1 ^ Asteroids. 53S Asthma and tobacci, 419 Bear and ragaed stafT. sign of the. 4W Bulldog, a generoOB. 358 Cedars of Leb«oon. 40 Chalcedony enclo8i..g liquors, 609 Coal, fjrmation of, 513 Cod sound. 36S Collie, sense ofduty of a, 383 Colliery spoil banks. 47/ Cores, geography of. 188 _^ Crocodile's jaw, muscular force of, 0*8 Crow, reasoning power of J". I"f»°' **' DiPBiBEBiA communicated by cats, 500 X).)t.s, eye. sight of. 437 Dog.'curious freak of a. 216. 616 EcMPSB map of Egypt, 631 i'lec'trica'i eihi'bitions and the Government, 12 Electricify. application of, 14 Eiplo-ive paint, 493 Fevbb tree. the. 608 ^ • „ 1 ."ool-warmers, substitute for water in, 414 II pailime of a. 369 11 water. 303 cargo of. 39 India-rubber gathering in ColnmWa 6. Induction b.lance applied to surteiy. 4) Imitation Dowers. 72 ln«brietv. history of. a. a disease. 449 Inlellig'n=e in animals, 337, 409. 4W LlMSOK case. the. 47il Lightning, eff-ct. of on trees. 61 Light, its penetrative power in a L'ght of ine stATS, 169 Littri! and positivinm. 672 Luior. temjlo o». 513 », k» r.,-. Macaclat. description of smaU-poi by. oiJ N A'ii".:' HU?^y Society. Soith Middl««, 369 Nature's respirator, 90 Navvies, health of, 197, 455 Newton, Sir Isaac, light and colour, 505 NordenjWjold. Professor, 16. Notes on science. 479 Nutmegj. how they grow. 644 OSE wire, separate sounds on. i/1 Uyat«r<. effects of sewage on. 2j1 Poi80!i003 crayons, 601 Poisons, new comparison of, bO Police-court scionc in, 39 K'sio°n°arL.Uon^re»''.nd popular -tronomy. 41 Kbtoh:tio» in a herd of deer. 3oo BAtTBD pork, inspection of. 188 Science and religion. 427 Sippara, ancient tablets from, o;k9 8mall-pox described by MaCAUlay. 545 Social problem, the French. 2/1 Societies, reports of. 52 dolar apparatus. .>S9 „ physics, the future of. 306 „ spectrum, the. 470 a \. mr. Sound, the. or swim-bladder in Bsh. 4«o Spectroscopic analjsis of light. 9- storing electricity, new invei.tion for, 179 Structure of bodies, the ultiroate, 19 Studies in Venus' transits, 030 1 Sunlight and heat. 19 . 1 Sussex arcbKological society. 497 Swans, intelligence in. 499 ,„ ,„ Svnchronizing electric clocks, 106, 137 . Tbi-bpho-ib the, and some meteorological phenomena. llV) .carrying. 375 Tortoises, wate TQbercle»ndit». -..,..- Ultimate structure of bodies. 19 ViCOlSiTioif, the protective eBect ol. las Vermilion. Chinese, method of manufacturing, . Vivisection. 451 Wbatbeb forecasts. 40 Weights of human body and brain, 3B» Welsh "W." the. 600 Whale, plaster cast of, 199 I Wordy science, 138 Wliw « Boot. Pri«(.r., 74-6. G«" , MAGAZINE o?5l^IENCE P UlNLy^ORDED-EXACTlVPESCRIBED LOXDOX: FRIDAY, NOVEMBER 4, 1881. CONTENTS. FAGS. I ToOmREiDKxs 3 Science and Relieion. By the Editor 3 Tho Relation of Food to Muscular Work.— Part I. By Dr. W. B. Carpenter, F.R.S. 5 Aro Women Inferior to Men ? 6 Cometx.— ilUuttrated) 8 lUusiona. By Thomas Foster— (IHin- traltd) 10 The Eastern Skies in Kovember — {nluttrated) 13 rAGB. Darwin on Mould and Worms 14 CoRRBSPONDBNCB. — Introductory — Hints to Correspondents — Is tho Sun Hot ?— Can Ice- Yachts sail faster than the Wind? 15 The Birmingham and Midland Insti- tute. Bv W. Mattieu Williams ... 16 Colour of Sunlight 18 The rwjiiiif Riddle 18 Our Mathematical Column 19 Our Chess Column 19 TO OUR READERS. " T^ ^'-^^-'-'^^^'^ ' *^ ^ weekly magazine intent^ed to -l\- bring the truths, discoveries, and inventions of Science before the public in simple but correct terms — to be, Ln fact, the minister and interpreter of Science for tliose wlio have not time to master technicalities (whether of Science generally or of special departments). KvowLEDGE will contain Original Articles by the ablest exponents of Science ; Serial Papers explaining scientific methods and principles ; Scientific News translated into the language of ordinary life; a Correspondence Section (including columns of Notes and Queries) for free and full discussion, and especially for inquiry into matters whicli the readers of original articles may find tliiEcult or per- plexing; and Reviews of all scientific treatises suitable for general reading. In addition to these portions, there ■will be a section for Mathematics, and columns for Chess and Wliist (regarded as scientific games), conducted on a novel plan intended to render these portions at once useful to learners and interesting to proficients. I have long regai'ded the material benefits derived from Science, great though these unquestionably are, as small by comparison with those to be derived from Science as a means of mental and moral culture. Nearly ten years have passed since, recognising this, I pointed out the necessity for such a journal as the present. We have none doing the work which Knowledge is mtended to perform. But I felt that before attempting to conduct such a Journal, I should obtain as wide an experience as possible of the wants of the class of readers for which it is in- tended. During the last ten years I have come in contact as lecturer and writer, with tons of thousands belonging to that class. The experience I have thus gained is altogether exceptional. From letters addressed to me during my lecture- tours in Great Britain, the United States, Canada, Aus- tralia, Tasmania, and New Zealand, as well as those almost equally numerous written to me from other countries, T have learned the nature of the difiiculties which commonly perplex scientific students and the readers of scientific treatises. 1 believe this experience must prove of great value to me in conducting Knowledge. The tone of the articles will be that which I have found most useful in lecturing and writing. The general public do not want Science to be presented to them as if they were of intelligence inferior to their teacher's. But they cannot be expected to take interest in state- ments couclicd in absti-use or technical terms. Nor is Science degraded when plain untechnical language, such as we propose to use in Knowldge, is employed; when, for instance, instead of speaking about the " mean equa- torial horizontal solar parallax," a writer refers to the sun's distance ; or when a race of men is not described as "microseme and dolichocephalic," but as small-faced and long-headed. Discoveries and inventions communicaied to scientific societies at home and abroad will not be presented until they have been translated from technical language which to the general reader is mere jargon. The price of Knowledge is lower than that which has heretofore been assigned to periodicals of the same class. It is trusted that those who approve of the plan above sketched, and wish to see the Magazine firmly established, will help to " Let knowlctlgc c^ow from more to more," by making its existence known to their friends. In this and other matters cordial co-operation from all quarters is invited. Rich.4RD A. Proctor, SCIENCE AND RELIGION. By the Editor. MANY seem to imagine that the tendency of Science, especially in its more recent developments, is irre- ligious. Some give a special reason for tliis strange opinion, namely, the inconsistency which they conceive to exist between some of the results to which modem Science \mmistakably points, and ideas which have been derived from poetical descriptions found in the Bible. So far as this particular form of objection is concerned. Science need be at no pains to formulate a reply. It would be as reasonable to do sof I conceive, as it would be seriously to answer such a question as this : " How can the Dar- winian theorj' of the remote cousinship of man and monkeys be reconciled with Job's statement (Job, xxx. 29), 'I am a brother to dragons'^" or this: "How can thej views of modern medical men sCljout the intestines be reconciled with Job's assertion (Job, xxx. 27), ' My bowels boiled and rested not'1" Moreover, the world is not interested (or should not be) in hearing the views of Science as to the real meaning of words which theologians, after much time and trouble given to a matter lying • KNOWLEDGE • [Nov. i, 16H\. 8p««cially within thoir province, arc not at one in inter- preting. Hilt whon thr tpii'Htion i.s of tlio trutli of tlio.sn si-inntitic vi<>ws wliicli aro oj>|)U(;noJ, or a.s to tlu> licariii^ of Scifm-f (fciioraiiy on llclijfion, tlii^ ca-so is dift'croiit. rtoiimco may roa.sonalily an.swcr quo.stion.s relating to tho infliinnco of .sciontitio di.sc'ovi-ric.s on tlin human mind. Tho groat olijcction raised against modoni .science appears to be in tho rnaii\ this, that it enlargas unduly our ideas of the Tastne.ss of CJotl's domain in space, of tho immensity of the time periods during whicli lleact.s, and in fine, of Ilia inconceivaMo power and wi.sdoni. We may admire the wi.sdom of the Almighty, aa .shown in the pebble, or the rock, in the flower or in the tree, in tho in.sect or the ■animal, nay, we may even .so far ext<"nd our vision as to iivognise th<" laws under which a stratum, or a forest, or a race of animals, p(>rhaps even a continent, or a flora, or a fauna, had their origin and passed through their various stages of development But we must not e.\tend owr survey further. To see Ood's hand in these. His wisdom in the laws by whicli they are formed, is to be religious and good, but to trace His power and wi.sdoni on a largiT scale is to be irreligious and wicked. Evolution on the small scale we may atlniit without harm ; but to see evolution in the dov lopnient of a world or a world-.system, and still more tooseo evolution throughout the entire universe as revealed to man, this is " to set God on one side in the name of Universal Evolution." It is unfortunate that those who take this view of the general scope of modern scientific research had not been careful at an earlier date to explain, when admitting the growth of a tree, a forest, or a flora — of an animal, a race, or a fauna, according to natural laws, and even explaining (a3 many of them did) the wonderful nature of the laws according to which such growths took place, that they wished it to be clearly understood that in thus recognising the action of law tliey were rejecting the idea that the Almighty fashioned the plant or the animal, the forest or the race, the flora or the fauna, or indeed, aught| (animate or inanimate) the development of which man is able to study through all its stages. Because, if it Jiad been clearly understood that wherever they recognised growth and development as the results of law, they were assured such results could not possibly be attributed to the Almighty, Science might perhaps, (though it seems un- likely) have been deterred from researches leading to the distressing conclusion that there is development according to law on the greater scale as well as on the less ; nay, that to all appearance law prevails throughout the entire domain of the Almighty in space and during the entire period of time in which he acts — that is, throughout infinity of space, and during eternity of time. As regards the actual evidence of the vastness of space and the immensity of time tliroughout which the action of law extends, it may suffice to say that only the very ignorant or the \'ery dull can for a monu^nt entertain doubt. Unless tlie evidence given by earth and heaven has been specially devised to mislead man, or unless the reasoning powers be- stowed on man by God have been given but to lead him astray (conceptions alike blasphemous and unreasonalile), there can be no manner of doubt that on the one hand the universe is infinitely larger than it was suppo.sed to be before the days of Copernicus and Kepler, Galileo and Newton ; or that, on the other hand, our earth has lasted, and will last, thousands of times as long as had been sup- posed liefore its structure had been examined ; the solar system millions of times as long as had been supposed before its movements had been studied ; the galaxy of stars yet longer ; the higher order of systems to which that "alaxv belongs for periods so vast, that to all intents and purposes they extend (in our conception) to absolute eternity — in tho paat as in tho future. As to the influence which a result such as this should have upon men's minds, it should perhaps suffice to say that those who believe that the Almighty is all-wise eis well as all- powerful ought not to fear le.st tho discovery of truth from the study of His universe should produce evil effects. But I go much further than thi.s, and .say that of all possible forms of teaching, those derived from or based upon science must be most Itenoficial in the religious .sense, not using the words science and religion in their ordinary narrow significance, but in their wide,st and noblest. " Doubtless," as Herbert Spencer has well said, " science is antagonistic to tho superstitions that pass under the name of religion ; but not to the essential religion which these superstitions merely hide. Doubtless, too, in much of the science that is current there is a pervading spirit of irreligion ; but not in the true science which has passed beyond the superficial into the profound." Or, as Huxley has even more pointedly remarked, " True Science and true Religion are twin-sisters, and the separation of either from the other is sure to prove the death of both. Science prospers exactly in proportion as it is religious, and religion flourishes in exact proportion to the scientific depth and firmness of its basi.s. The great deeds of philo- sophers have been less the fruit of their intellect than of the direction of that intellect by an eminently religious tone of mind. Truth has yielded herself rather to their patience, their single-heartedness, and their self-denial, than to their logical acumen." To which may be added the noble saying of Carlyle, that " to know the Divine laws and harmonies of this universe must always be the highest glory of a man, and not to know them the greatest disgrace for a man." But we may fairly go even further than this. We need not be content to defend, or merely to justify, or even to laud. Science in its relation to Religion. W^e may assert without fear of valid contradiction that the neglect of science is irreligious. For what is such neglect (where men have time and leisure for the work) but the refusal to study the works of the Creator ? And ia what position, logically, does a man stand who praises the Creator in words, but declines to study His creation ? " Suppose," says Spencer, " a writer were daily saluted with praises couched in superlative language. Suppose the wisdom, the grandeur, the beauty of his works were the constant topics of the eulogies addressed to him. Suppose those who un- ceasingly uttered these eulogies on his works were content with looking at the outside of them, and had never opened them, much less tried to understand them. What value should we put upon their praises 1 \Miat should we think of their sincerity 1 Yet, comparing small things to great, such is the conduct of mankind in general in reference to the universe and its cause." The study of science implies the surest belief that God's works are worth study, the fullest recognition that the author of those works is worthy of our reverence. It is the truest kind of homage, in that it is not homage expressed merely in words, l)ut homage shown in work, in service, in sacri- fice. The man of science, in fine, refuses to ofler to the Almighty "the unclean sacrifice of a lie." He oflers him instead (in the search for truth) the sacrifice of time, of labour, and of thought. His very questions imply the fulness of his faith : — This is his homage to the niiKhtior powers. To ask his boldest question, undismayed By muttered threats that some hysteric sense Of wrong or insult will convulse the throne Where Wisdozi reigns supreme. Nov. 4, 1861.] • KNOWLEDGE THE RELATION OF FOOD TO MUSCULAR WORK. Bv Dr. W. B. C.«iPEN-TER, F.R.S. [In an article on the " Use and Abuse of Food," repnblished in my '■ Pleasant Ways in Science," tliere is a passage in which Liebi;;'s mistake abont the relation between nitrogenous or flesh-torming food and work is quoted without being corrected. I was not aware when the article was written ,(1867) that scientific experiments were in progress which were eventually to completely expose the fallacy of Liebig's position. When the article was republished these experiments had long since been brought to a satisfactory issue. Although the point does not importantly affect my ess.iy regarded as a whole (for the material of a machine, as well as tlie source of its working energj' must be kept in repair, and the work- man does not get less good from his food because he takes it under a misapprehension as to the particular benefit it will do him), the mistake is one which should hare been corrected. The interpreter of scieotific statements, too technical for general comprehension, must not be content with presenting correctly and intelligibly the accepted teaching of an authority in any special branch of science. He must assure himself, as time passes, that the teaching which was regarded as sound when the subject was first dealt with, has not undergone correction in the mean time. If I had done this in the present case (as I have in general been careful to do), the error in question would not have appeared in the pages of " Pleasant Ways in Science." The following exceedingly interesting paper, by Dr. Carpenter, puts the matter in the proper light. He speaks, I need hardly say, "as one having authority." I may point out that it is one of the great advantages of a journal like the present that errors into which even the most careful will fall from time to time, will here be corrected at once. In the columns of a monthly magazine correspondence would be inconvenient, even if permitted. Here the freest ((uestioning and discussion is invited, and it is par- ticularly desired that those having special knowledge of a subject will call attention to, and correct, any statements which may appear to them erroneous. — Ed.] PART I. THAT " the evil which men do Uves after them,"' is often exemplified by the continued prevalence of scientific doctrines accredited by the authority of great names, long after their fallacy has been demonstrated by the subsequent researches of other inquirers to the satisfaction of all competent judges. For, if these demonstrations be not presented to the world under the sanction of a like authority, tlie old errors are continually reproduced by popular expositors, and unquestioningly accepted by ordi- nary readers. Having met with a notable instance of this kind not long ago, in the reproduction, as an accepted physiological verity, of the doctrine of Liebig as to the direct depend- ence of muscular energy on the expenditure of nitrogenous food, I think that a journal which aims to communicate positive " knowledge " to its readers may be an appro- priate medium for a brief statement of what are now accepted by all scientific Physiologists as the facts of the case. It is no derogation to the well-established fame of Liebig as one of the greatest Chemists of his day,* to aflirm that when he passed out of his own domain into that of Biology, he made many and flagrant mistakes. Looking back after an interval of nearly forty years, at his " Organic Chemistry in its Relations to Physiology and Pathology," I am really astonished at the reckless audacity of some of his assertions; as, for instance (1st edit 1842, p. 219), that " we know with certainty that the nerves are the con- ductors of mechanical effects, and that by means of them motion is propagated in all directions ; " and that "the heart and intestines do not generate the moving power in themselves, but receive it from other quarters." He might • See "The Life-Work of Liebig," by Prof. Hofmann, the " Faraday Lecturer" for 1875. just as well have said that " we know with certainty that when a charge of gunpowder or dynamite is exploded by an electric spark, it is the conducting wire that supplies the energy which rends asunder the rock." For nothing was even then more certain, than tliat the heart, intestines, and all other muscles fumisli, in virtue of their own con- tractility, the power (or, as it would now be called, the " potential energy ") which protluces their mechanical effects, this being simply called into action by the nervous stimulus. Another most noteworthy example presents itself in Liebigs denunciation of the " germ-doctrine " of fermen- tation and contagion, which was then being built-up on the basis supplied liy the microscopic discoveries of Cagniard de la Tour on the fungoid nature of yeast, and of Audouin and Milne-Edwards on the like character of the ^Muscardine-disease of silkworms. " A theory," he says (3rd edit. 1846, p. 212), "of the cause of fermentation and putrefaction, which is utterly fallacious in its fundamental principles, has hitherto furnished the cliief .support of the parasitic theory of contagion. The advocates of this theory regard putrefaction as a decomposition of organic beings caused by infusoria and fungi, and consider every putrefying body as a breeding-place for infusoria or a nursery for fungi ; and where organic bodies putrefy over a large surface, the whole atmosphere, according to this view, must be filled with the germs of these infusoria and fungi. The germs of these organised beings are, in this theory, the germs of disease or of the causes of disease." Yet it is this very doctrine, the complete estab- lishment of which by the admirable researches of Pasteur, and of those who have followed in the line of inquiry which he so clearly marked out, has not only given the true interpretation of the phenomena of Fermentation, but, in its application to Pathology, is now serving as the basis for " preventive " medicine and " antiseptic " surgery. And I feel sure that Liebig himself, had he lived into the present era, would have been quite ready to admit its truth ; for he was the last man to persist in views no longer tenable, merely because he had himself advanced them. " There is no harm in a man's making mistakes," he used to say, " but great harm in his making none, for he is sure not to have worked." And Professor Hofmann records ha%'ing been exhorted by Liebig " not to keep in your house from night till morning an error you liave become cognisant of." Now Liebig's chemical diWsion of food-materials into plastic, or "tissue-forming," and respiratory, or "heat- producing," was unquestionably an immense advance ; and the basis of it is still universally recognised as sound. I can myself remember the time when it was a question whether the nitrogenous components of the blood, and the tissues formed at their expense, can be built-up in the animal body, with the aid of atmospheric nitrogen, out of starch, sugar, fat, and other non-nitrogenous h^'drocarbons. Chemistry had not then shown the almost e.xact conformity of many Vegetable compounds to the albumen which was regarded as the fundamental constituent of Animal food ; and while it was by Mulder that the doctrine of the /(ro/t'in-compounds was worked out, which, with some modifications, is now generally accepted, it was by Liebig that the impossibility of supposing that animals can form their tissues out of anything else than the "proteids" originally generated by Plants, was first definitely insisted on. He was not aware, however, that the formation of " protoplasm " requires fat as well as proteids ; and that thus fat is to some extent a tissue-food. But he was unquestionably right in affirming that animal tissues cannot be manufactured out of sacchariiie compounds (as starch and sugar), unless these have been pre\'iously • KNOWLEDGE ♦ [Nov. 4, 1881. ilmnRod into fat — a cli.-ui),"" wliosc possiMlity In- went fur to iirovc, — ami thrn only in tlio sanio iiicusun- iis fnt itsi'lf. .Vnd lie (|uito oorrpctly nssi|,'nccl BR tliP ultiiniit p-cat l>ulk of the non-nitrogenous toin- pononts of food, the beini^ (so to speak) " Imrned " within the liody, l>y couiliinatiiin with oxygen taken in through tiie lungs ; their liyilrocarlions lieing exhaled t>y these organs in the form of water and carlionic acid. But he assiimrtl that the only purpose served liy this o.xidation was the protluction of h^iit ; alKruiing that all the me- rhnnicnl force, exerted I'y the Animal Uody is the product of a transformation of liriit'j muscular til>re into (had, the " vital force " which was possessed by the living tissue heing " expended in the shape of motion." The oxidation of the dead material he seems to liave regarded as only a consequence of its loss of power to resist chemical agencies, and as a means of its removal, — serving, at the same time, as an additional source of heat. And riglitly judging that this chemical metamorphosis should show itself by the increased excretion of urea in the urine (the kidneys fur- nishing the channel through whicli most of the nitrogenous "waste" is carried out of the body), he appealed, in support of his doctrine, to what he supposed to lie the fact of such increase, and its proportion to the amount of work done. Notwithstanding the general acceptance of Liebig's doctrine among the Physiologists of that time, there were those who saw that it was attended with considerable diffi- culties, notably as regards the amount of work done by man and animals upon a very small allowance of nitro- genous food. It was well known, for instance, that Bengalee labourers (who, for their size, are very fair workers*) live all but exclusively on rice, which consists almost entirely of starcli ; a pound of this, with a little ghee (butter), or a small bit of fish, constituting their ordinary diet. And it appeared from the carefully conducted experiments of Mr. Joule, of Manchester, that the quantity of work done by a grass- or hay -fed ox (taking into account that done by its heart vnthin its body, as well as that done outside its body) was more than could be accounted-for by the metamorphosis of the nitrogenous constituents of its food. Mr. Joule was at that time engaged upon an inquiry into the Mechanical equivalent of Heat, which led him to suspect that the combustive oxidation of the non-nitrogenous coiistituents of food might be a source of mechanical poiver, as well as of heat. But this doctrine was first definitely stated, and shown to be one expression of the great general fact (or law) now known as the Conservation of Energy, in the " epoch- making " treatise published in 1845, by Mayer; who urged (1) tliat the chemical force contained in the ingested food and in the inhaled oxygen, is the source of the motion and heat which are the two products of animal life ; and (2) that the production of these forces varies in amount with the chemical changes to which it is due. The animal body, he maintained, is comparable, in these respects, to a steam- engine, in wliich work is being done, and heat produced, by the combustion of fuel ; and he calculated that the quantity of carbon burnt off by the Ijody in a day (as measured by the amount of carbonic acid given off in the expired air) is far more than sufficient for the whole day's work, — about four- fifths of it being used in the production of heat, while the remaining fifth suffices for the prodiiction of the muscular force ordinarily exerted within and without the l»ody. He affirmc'd that " the muscle is the instrument by wliich clieniical change is transformed into mechanical effect, not the material wliicli is itself transformed ; ' and he regardi;d the blood-stream that flows through the capillaries of the muscle, as bringing both the fuel and the oxygen needed to burn it. With the prevision which marks true geniii-:, Mayer asserted that as soon as experimental motliods should become sufficiently perfect to render it possible to deter- mine with precision the amount of chemical change, either in the whole animal body or in a single mu.scle, during a given period, and to measure the production of heat and the work done during the .same period, the result would show a definite correlation between them. This (as will be shown hereafter) has been completely verified by subsequent research ; the only point in which ^Mayor's doctrine has been found to need correction, being one of secondary importance. [To he continued.) • I have been informed by an engineer who superintended the construction of part of the Bengal system of railways, that the average quantity of earthwork done by a native labourer on the above diet is about two-thirds that of a higlily-fed English " navvy." ARE WOMEN INFERIOR TO MEN ? A FRENCHMAN named Delaunay has recently pul>- lished a pamphlet, the object of which is to show that women are intellectually and physically inferior to men. At the outset it should be noticed that this M. Delaunay must not be mistaken for the great French astronomer Delaunay, (who died some nine years ago). The point requires noting, because the present Delaunay has ere this dealt with sta- tistical evidence relating to astronomical matters, en- deavouring to prove therefrom that the planets Jupiter and Saturn exercise a marked influence on the phenomena of earthquakes. It is hardly necessary, perhaps, to say that the proof was hardly so perfect as M. Delaunay imagined. In fact, his reasoning would not have at- tracted attention if his name had not sounded like that of a very eminent astronomer, of whose death many had not heard. M. Delaunay now devotes himself to the task of showing that those who regard the two sexes as intellectually or morally equal, are absurdly sentimentaL He seeks to show that women are in a lower stage of development than men, on grounds wliich he describes as purely anthropological, though he should rather, it would seem, have described them as biological, since his inferences respecting the tests of development are derived quite as much from the study of other animals as of men. He admits that among certain lower forms of life, as insects, some fishes, and reptiles, the females show a superiority to the males ; but among the higher races of vertebrates (backboned animals) it is dif- ferent. Among birds and mammals (he might have added marsupials, or pouched animals, as kangaroos, opossums, kc), the male is nearly always superior to the female. The inference is, that whereas in lower races the female is superior to the male, the male is equal to the female in races more advanced, and superior to the female in all the superior species. "The supremacy of the female is there- fore," he says, " the first form of the evolution undergone by sexuality, while the supremacy of the male is the last form." The conclusion is calculated to be so satisfactory to men that they may be permitted, perhaps, to pass over the manifest weakness of the reasoning. The law, which should be universal to be of avail, is admitted to be only general ; and it is noteworthy that the reasoning really points to the conclusion that the higher the race, the lower relatively is the female : so that it would seem tkat the first Nov. 4, 1881.] K N C W LEDGE point to be established by one who would prove his nation in advance of others, should be the inferiority of the women of his race. If this were really so, we imagine that there are some races of men, not supposed to be far from the very forefront of human progi-ess, who would not care, at such a cost, to establish their claims to a high position. M. Delaunay is caref\d to show why he thinks the female inferior to the male in the higher races. First, we find that among birds and mammals, including man (who shares with the pig, the monkey, the dog, itc, the privilege of breast nourishment), the nutritive phenomena are more intense than in the female. Man eats more than woman ; and he is, therefore, incontestably her superior. " Yet, although she eats less, the woman is more of a (jonrmande, and eats more frequently." (This may be proved by com- paring aldermanic feasts and club dijmers with the favourite forms of feminine gourmandism.) " Xe.xt we observe that the breathing of men is more intense than that of women. For an equal height he has a greater capacity of chest, and a larger thoracic index than the woman" (a greater breathing capacity). " He also absorbs more oxygen, though his breathing is slower." (Why should not this be regarded as a proof of inferiority 1 Suppose a woman were writing, and should put it this way, Woman requires less oxygen than man, and is therefore superior to him ; how then f) " The temperature is higher in man than in woman,' and the pressure of the blood greater, though the pulse is less frequent." This, again, might be quoted the other way by women. It would be almost as logical to say, Man is superior to woman because he wears a beard, and the hair on his head is shorter than hers. It appears that the frame of man, as compared with that of woman, proves incontestably his superiority. He has a heavier skeleton, absolutely as well as relatively. " The woman in all the physical characteristics of her skeleton is intermediate betweenjthe child and the man, according to Topinaud." Must we then rank the elephant as man's superior ? his skeleton is certainly heavier than man's, not only absolutely Init relatively. " The woman is not so right-handed as the man ; the pre-eminence of the right side over the left is not so marked with her as with the male." Charles Reade would probably regard this as e%'idence of superiority rather than inferiority ; and many men who have not been thought inferior to their fellows, but the reverse, have been at no small pains to train the left side to equality, or as near equality as they could attain, with the right side. Worse remains, however, to be told. " The male ex- ternally is always larger than the female. The woman is not so heavy as the man, although she would often appear larger on account of the development of the adipose system, which in her is greater than the man." The next point, if established satisfactorily, would bo rather more to tlie purpose. " In all our Hindo-European races," says Topinaud, "the woman is more prognathous than the man," that is, her jaws are relatively more pro- jecting than those of man. This would be a strong point, because there really appears to be a correlation between the position of the jaws in animals and the capacity (relative, of course,) of their brains. But it would be desirable to have all the particulars liy which the pecu- liarity referred to has been established. It would be easy to select classes either of men or of women who would be very unfair representatives of their sex taken as a whole ; and though I would be far from saying that anything of this sort has been done, I would note that it is a much more difficult matter than many would suppose (who have not tried) to obtain a large number of either sex who could be regarded as absolutely free from class influences. The task would be easier if men and women pursued similar avocations. As they do not, the statistics collected by Toi-pinaud may, for aught that appears, have tended, if rightly interpreted, to show that such and such a\ ocations either affected intellectual develojunent, or were selected by persons of inferior intellect, rather than anything speci- fically distinguishing men from women." A similar objection applies, but yet more strongly, to M. Delaunay's next point. He says that, " according to his o\^^l researches, woman is more flat-footed than man, and has a foot less ai-clied — a sign of inferiority — hence tlie preference of women for high-heeled boots." It is a rather bold assumption that the form of the feet thus indicates intellectual development. But assuming that it were so, I apprehend that the statistics of feet-forms would show very diflerent results according to the classes that might be selected. Supposing, for instance, M. Delaunay had measured the feet of a few hundred waiters, and com pared them with those of a few hundred opera-dancers, he might, perhaps, have inferred either that opera-dancing conduced far more than waiting at table to intellectual development, or else that women were far superior to men. 1 do not say that a selection so unlikely to lead to a correct result as this has actually been made: but we require to know much more than we do about M. Delaunay's statistics before we can accept his conclusion, even if we admit that the mental and moral qualities can be deduced from the shape of the feet. The fancy for wearing high- heeled boots may reasonably be regarded as showing that women regard a high instep as a natural feminir.e beauty, to be enhanced where present or imitated where wanting ; that, in fact, women are more particular in this respect than men. So viewed, it would no more prove that women are commonly flat-footed than their weai-ing chignons or switches would show that they commonly have shorter hair than men. In fact, M. Delaunay's argument here is decidedly unfavourable to his theory, if a high instep really is a proof of intellectual superiority ; for women try more to enliance those qualities which they regard as feminine, and therefore attractive, than those which they share with men. "The female voice is sharper than that of the male. Both in wild and domesticated animals the male has the muscular system more developed than the female." All this may be granted ; but it proves nothing to tlie purpose. The bull has a deeper voice than man, and the gorilla has the muscular system far more developed ; but we do not infer that the bull or the gorilla stands higher iji develop- ment on either account than man. " The movements are more precise in man than in woman." (What movements 1) "Among pianists of the two sexes the mechanism reaches a much higher degree of perfection in men." As musicians, whether we consider composition or execution, women certainly are surpassed by men ; and I may note among the absurdities of our system of education that almost every girl in the middle and upper classes " learns the piano" (save the mark !) though not one in a hundred has any natural aptitude for music, while among boys music is comparatively neglected. There is little, however, in feminine execution to justify the statement that their movements are less precise. On the contrary, numbers of girls acquire wonderful pre- cision in playing ; only, unfortunately, most of them want that aptitude for music which can alone make mere per- fection of digital mechanism of any account. It is not easy, however, to see why musical skill should be regarded as a test of mental or moral qualities. I am disposed, on the contrary, to consider that women in our day are handicapped by their musical education ; and that pro- 8 KNOWLEDGE • [Nov. 4, 1881. )«il>ly, if so many w(>ro not conipollfd (without niUKical talent to help them) to waste many years of their life ill the weary work of " practi.sing," we might have liettor opportunities of learning wliut WDmen are capalile of in other ways than wt- are actually allbrdetl. Music, at any rate, is one of the weak points of modern femi- nine education, if not its worst feature. Even as musi- cians, women would be far likelier to show power, if only those who possessed aptitude for music received a musical training. How can the ri-ul musician among tifty girls get any chance, when she has to go through, with the forty-nine who are not musicians the weary music-killing work of our present system of so-called musical train- ing i (Is not this matched, however, liy the existing systems of classical and mathematical training for boys, irrespective altogether of any aptitude for clas- sical or mathematical work ?) We come next, in M. Delaunay's paper, to the more important question of cranial capacity and form ; for certainly (setting aside, of course, i)hrenological absurdi- ties), the shape and size of the brain are more likely to indicate mental and moral capacity correctly, than are the shape of the feet, the tone of tlie voice, and the muscular development As, however, my limits are already exceeded, I leave the rest of M. Delaunay's paper to another occasion. So far as we liave gone, M. Delaunay's arguments remind us, more than we should have thought possible in a scientific brochure, of the reasoning in a humorous article which appeared a year or two ago in the Ifew York Times, wherein it was gravely argued that the inferiority of woman to man is proved conclusively by women's habit of sitting on the ground to take off, or to put on, their shoes and stockings. In fact, I am not sure that M. Delaunay might not find more in favour of his theory ill this argument than in any of his own that have thus far been considered. COMETS. THE year which was to have seen the end of the world, because of planetary conjunctions and perihelion passages, because Mother Shipton had said so (or was said to have said so), and because the ascending gallery in the Great Pyramid is 1882 inches long (so that the year 1882 is to introduce a new era), has been remarkable in astro- nomical annals for the number of comets which have been seen. Already six hare been numbered, and the year is not over yet. Something still remaining — more, indeed, than we are always ready to admit — of old superstitions respecting comets, has led many to regard the coincidence as full of meaning. Others, not quite so credulous, have supposed that though comets may not come in flights of half-a-dozen together to portend the end of the world, they may yet affect our weather in some way ; perhaps directly, as the moon is supposed to do (with very little reason) ; perhaps indirectly, by acting on the sun. To the astro- nomer the appearance of so many comets — some of them large ones — has been full of interest, because he hopes by the application of the new methods of research discovered within the last quarter of a century to solve some of the mystodi(^s revolving around the sun in nearly circular orbits, nearly in one plane, and all in the same direction ; we find that these globes rotate upon their axis — still in the same direction ; they have, apparently, atmospheres proportioned to their dimensions ; and many of them are attt^nded upon by bodies resembling our own moon. And therefore, without enti-ring upon the vexed question of the plurality of worlds, we are alilc to pronounce that, i/' these globes are inhabited, dwellers upon them have, like us, their years, their days, their sea.sons ; a sun — rising in the east and .setting in thi; west ; twilight and moonlight ; air and vapour ; winds and rain ; all things, in fact, as it would seem, necessary to their comfort and convenience. Here and there — as in the zone of asteroids and the rings of Satuni — we meet with novelty of arrangement or configuration ; but even then we find a stability, either of figure or motion, which renders such objects comparable, so to speak, with those we are accustomed to. I'lUt with comets the case is wholly different When we have said that these objects obey the law of gravity, we have mentioned the only circumstance — as it would appeatr — in which they conform to the relations observed in terrestrial and planetary arrangements. And even this law— thi- widest yet revealed to man — they seem to obey half un willingly. We see the head of a comet tracing out systematically enough its proper orbit, while the comet i tail is all unruly and disobedient The paths followed by comets show no resemblance either to the planetary orbits or to each other. Here we see a comet travelling in a path of moderate extent and not ^ery eccentric ; there another which rushes from a distance of two or three thousand millions of miles, ap- proaches the sun with ever-increasing velocity until nearer to him than parts of his own corona (as seen in eclipses), sweeps around him with inconceivable rapidity, and makes off again to where the aphelion of its orbit lies far out in space beyond the most distant known planet, Neptune. Some comets travel in a direct, others in a retrograde, path ; a few near the plane of the earth's orbit, many in planes showing every variety of inclination. Some comets regu- larly return after intervals of a few years ; some after hundreds of years ; others are only seen once or twice, and then unaccountably vanish ; and not a few show by 'tht; paths they follow that they have come from interstellar space to pay our system but a single visit, passing out again to traverse we know not what other systems or regions. The ancients believed comets to be of the same nature as meteors, or shooting stars — either in the earth's atmo- sphere, not far above the clouds, or, at all events, much lower than the moon. These views are, liowever, much less ancient than the more correct views maintained by the Pythagoreans. Their doctrine was that comets are planetary objects, having long periods of revolution. From whom this opinion was derived is uncertain. Like other opinions attributed to Pythagoras, it was doubtless ob- tained froin Eastern philosophers ; but of what country — whether Egyptian, Persian, Indian, or Chakhean — we have no means of learning. Apollonius, the Myndian, ascribe.; the opinion to the Chalda?ans. He says they spoke of comets as of travellers penetrating far into the upper (or most distant) celestial spacer Seneca and Pliny held similar views, exhibiting in this respect says Humboldt, the imitative facultv of the Romans. But the Greek Nov. 4, 1881.] KNOWLEDGE philosopher preferred to look for a theory of the universe in the conceptions of his own brilliant and imacrinative mind. As if to show future ages how little was likely to be achieved by the highest mental powers without the habit of patient obscn'ation, he endeavoured to educe a system of philosophy from fancies, and to found it upon syllogisms. Aristotle — who may be considered the typical philosopher of the Greek school — included comets iu the wide range of phenomena which he claimed the privilege firming Newton's views by results founded on actual obser- vation, he collected all tlic records of comets which seemed entitled to contidence, and attempted — as well as his meagre materials would allow him — to calculate the elements of their orbits. In this way he computed the paths of no less than twenty-four. Among these, three presented a remarkable similarity. One appeared in 1531, and was described by Appian ; another appeared in 1607, and was oliserved l>y Kepler ; the third was traced by Halley him- of e.xplaining. To him was due the opinion men- i self in 1G82. The equality of the intervals between these tioned above — an opinion confidently maintained during the many centuries in which the philosophy of Aristotle held sway over men's minds. To him, also, was due a yet more remarkable opinion, the view, namely, that the !Milky Way is a vast comet which continually reproduces itself ! Xenophanes and Theon, in the fifth century, adojited a rather singular view of the Aristotelian theory of comets, when they spoke of these objects as " travelling light-clouds." To these fancies the ancients added the idea that the shapes of comets indicated their character as portents. Thus in Fig. 1 five views of comets are shown, as an arrow- head, a sea monster, a sword, a lance, and in flames. -Various fanciful views ■ L'o.i.ets, ajcorJing to Pliny. From the CometojraiMa of Hevelins. Tycho Brahe was the first to express doubts respecting the ^-iews of Aristotle. From a careful series of observa- tions, he demonstrated that the orbits of comets are cer- tainly situated beyond the moon's orbit. He thought the orbits must be circular, for he lived at a time when none but circular orbits were conceded to the celestial bodies. Diirfel, a native of Upper Saxony, proved that the orbits of comets are either very elongated ovals, or parabolas, and that the sun occupies a focus of the curve. It happens, singularly enough, that this discovery was effected Viut a year or two before Newton propounded the theory of gravi- tation. Newton himself examined the orbit of the great comet of 1680 (known as " Newton's comet") and others : and he found that they all accord with the law of gravity. But before long, Ne\six)n's friend and pupil, Halley, effected a yet more remarkable discovery. In hopes of con- epochs led to the suspicion that the same comet had apjieared three times. And Halley found, on searching historical [records, that a comet appeared in 1305, another in 1380, and a third in 1456. Combining these appearances with those mentioned before, he tliought he had satisfactory evidence of identity. For he was sufficiently familiar with the results which might be expected to flow from the law of gravity, to be aware tliat absolute regularity of motion was not to be expected in a body traversing the solar system in an eccentric orbit, and swayed from its proper path by the attraction of such giant planets as Jupiter and Saturn. Indeed it happens, singularly enough — one out of many remarkable coincidences in the history of comets — that the comet of 1830 was not Halley s comet, which really appeared in 1378, a date bringing in a yet greater dis- cordance in tiie intervals than Halley had suspected and accounted for With remarkable acumen — since no means existed in his day for anything like accurate computation — he not only pointed out the possible influ- ence of the great planets in disturb- ing the comet in past revolutions, but he made a rough approach to an estimate of the eflect that they would have on the period of its next visit. " Instead of appearing in August, 1757, as it would if its period re- mained unaltered, it will not appear," he said, "until the end of 1758, or the beginning of 1759, for it will be retarded by the action of Jupiter. Wherefore," he adds, with a pardon- alile anxiety to secure the credit of his ingenious investigations, " if it should return, according to our pre- diction, impartial posterity will not refuse to acknowledge that this was discovered by an Englishman." As the time for the fulfilment of the prediction approached, an intense interest was excited in the minds of astronomers. In 1757, Clairut, Lalande, and Madame Lepaute under- took the comi)utation of the epoch at whicli the comet might be expected to"" return. They applied methods of investigation invented by Clairaut himself. It resulted fi'om their laliorious computations that April 13, 1759, was fixed on for the epoch at which the comet should attain its closest approach to the sun, or, as it is teclmically e.xpressed, should pass its perilielion. But Clairaut was careful to allow a month either way, on account of un- avoidaVile omissions in tlie calculation, and for the efiects of unknown forces, "such as the action of some planet too far oS" to be seen " (a happy anticipation of modem discoveries). And now the heavens were swept diligently by all the telescopists of Europe, each eager to be the first to 10 KNOWLEDGE • [Nov. 1, 1881. announcu the discovery of an o1)jii- aiil, by u i^uxun fiirnuT, Geor;;e I'alitscli, on Cliri.stiiiius iliiy, 17r>8 It reuched its pl^rih(■iion on March Hi, IT.'i'J, eontiniiin;,' at once the accuracy of (Jlaimut's coni- putution.s and tiie justice of hi.s caution in assigning rather wide limits of error. It was now evident tliut comets travel, like the planets, in iletermined patlis ; and also, tliat the investij^ation of their motions is a suliject worthy the study of tiie alilcst niathi? maticians, and sufficient to tax tli«r highest powers. An account of their labours would be out of place in such an article as the present ; but we recommend the subject to the notice of the agricultural student, as one of the most interesting chapters in the history of modern science. One comet, however, discovered not long after astronomy had achieved this triumpli, seemed at first to teach a difl'erent lesson. In 1770 a comet appeared whose path turned out to Ijc — not a long oval or parabola, as had been the case with all the orbits yet examined — but an ellipse of moderate extent, and not very eccentric. The orbit lay also much closer than usual to that thin sUce of space (so to speak) within which the planets are observed to move. Lexell, who computed the path, found that the period of the comet was about fiveand-a-half years. Its return was carefully watched for, Iml no oiie has ever seen the comet since. The cause of its disappearance, and also of its sudden appearance— for tliis was equally remarkable, when we remember that so conspicuous a comet could not have been circidating long in its small orbit without discovery — was carefully inquired into. The result was singxilar. On tracing back the path of the comet, it was found that it must have passed very near to the gi-eat planet Jupiter. " It had intruded," saj's Herschel, '• an uninvited guest into his family circle — actually nearer to him than his fourth satellite." Accord- ingly, the comet's path, originally a long oval, had been bent into a cirrve of less extent. Having once entered on this new path, the comet was free to follow it — always returning, be it noticed, to the point at wliich it had started on it — so long as Jupiter was not interfered with. But it happened, unfortunately for the stability of the comet's motions, that, after going twice round the new path, it again presented itself near Jupiter's track, when the planet (which had meanwhile gone once round his orbit) was not very far from the scene of his former encounter. He accordingly again exei-ted his influence upon the luifortunate comet, and this time dismissed it on a path wliich will not admit of its approaching the earth near enough to be seen.* Let us return, however, to Halley's comet. It so chances that the comet which was the first to show full obedience to the law of gravitation, was one which exhibited in a very remarkable and significant manner the characteristics which distinguish comets from other heavenly bodies, and make them so mysterious to the student of science. At the return of Halley's comet, in 1836, all that had signali.sed the return in 1759 was repeated, but the mathematical triumph was far greater. Damoiseau, Rosenberger, and Pontecoulant calculated the comet's return to perihelion within two or three days, instead of a month, and the time when it passed this point of its orbit corresponded, within a few hours, to the mean • It must be noticed, however, that Lovorrier, who very carefully rc-cxamincd the question, was led to es upon tlie sky. When it had pa.ss<-d from our northern skies, it was carriwl (aft'-r a short interval, during which it was lo.st to view in the sun's rays) to the soutliem lieavens. Sir John Herschel, and Maclear (A.s- tronomer Royal at th<; Caj)e), were prepared to receive it ; but when first observed l>y them it showed none of the features which made it .so remarkable in our skii^ It had no tail and scarely any head. In fact. Sir John Herschel, in one account, says, that as first s(«n it could only l>e dis- tingui.shed from a fixed star liy its motion. The study of its gradual change of aspect from that time threw so much light on the nature of comets' tails and other appendages (or at any rate of that particular comet's tail) that Sir John Herscliel, not accustomed to be over confident, said there could be no doubt as to the true interpretation of the observed phenomena. What these phenomena were shall be considered further on. ILLUSIONS. By Tuomas Foster. THE senses are the means by which, directly or indirecth', all observations are made, and science can oidy make real advance in so far as it is based on observi- tion and experiment. It is most important, therefoi-e, that either our senses should be trustworthy in their action, that is should give us true information, or (if they neither ai!e absolutely trustworthy originally nor can be so trained as to become so) that we should be able to test and to correct their indications. Now it very soon appears, when we put the matter to the test, that the direct evidence of the senses is not to be accepted without careful cross-examination. The science of our day may be regarded as having been established in opposition to the apparently obvious evidence of the sensefe. Take, for in.stance, astronomy. Nearly everything that the eyes tell us about the heavenly bodies, and nearly all that the sight and touch tell us about the eartli (so far as astronomy has to deal with the earth as one of the planets) is false. Not one of all the stars we see in the skies is really where we see it. The earth seems flat, large, and fixed ; it is really a globe, small compared -n-ith the seemingly small stars, and it is moving in many ways, not one of which the senses correctly appreciate. It is the same with otlier sciences. W'e are not concerned, however, to discuss here how far the apparent teaching of the senses has to be analysed before its real meaning can be understood. The examples illustrating this would cover the whole range of science. For instance, to sliow how the real place of a star can be determined — more or less exactly — from its apparent place in the sky, we require to discuss the laws of refrac- tion, aberration, the proper motion of stars, and a number of other matters. In sucli cases as this, though what the eye tells us is in a sense incorrect, the eye is supposed to do its work correctly. The eye tells us truly that the rays received from the star by it have come in such and such a direction, and what science has really to do is to determine in what direction those rays must have set out in order after various changes of direction, due to the various media through which they passed, to reach the eye situate on a moving and rotating body like the earth, in the direc- tion which they had, or at least seemed to have — or, more Nov. 4, 18S1.] KNOV/LEDGE * 11 strictly, in order to produce an image of the star on sucli and such precise pait of the retina. But there are many cases in which the senses seem actually to convey false information, the eye telling us wrongly about the shape, size, position, ;. 1 is coininiiiily repirded (l)ut without sufficient reiuson, or, inileed, any as-signed reason) a-s belonging to the clas.s of illu.sions illustrated in Fig. 4 (first noticed liy ZUllner). Here the lines AB, CD, EF, (HI, itc, which are really parallel, appear to converge alter- nately towards AC', 1)F, Ed, IIL, and KM. This illusion is ditierciit from that of Fig 1, as affecting the apparent directions of lines, whilst the other does not (parallel lines are regarded liy geometricians as in the same direction). Fig. 4. Tlie illusion of Fig. 4 appears to result from the attention being drawn unduly to the circumstance that the vertical lines pass athwart the other sets at an angle, so that the angle is, as it were, exag- gerated. The eye notices, for instance, that AB passes the parallels in order from right to left, the uppermost parallel crossed by AB l>eing farther to the right than the lowest, and thus the idea is conveyed that B, instead of being a point vertically below A, is to the left of such a point. So D seems to the right of a point vertically below C, and so on. The illusion of Fig. 4 admits of being varied and, in some cases, strengthened by substituting wairdng lines of various forms for the diagonal hatching. Several cases of this kind will be shown m the ne.\t number. I conclude this paper with a few simple illusions, afiecting not only the direction and position of lines really straight, but also their straightness, making them appear as curved lines. The lines AB, CD of Fig. 5 appear to be curved so as to be nearer at the middle than at either end ; while the lines EF, (JH, in the same figure, appear to be so curved as to be farther apart in the middle than at either end. Obviously, the eye un- consciously notes the varying distance be- tween the really curved lines and the straight lines, and attribute* part of the change of distance to a curvature of the really straight line-s. This form of illusion may he modified, as Bhown in Fig. 6. Some find the apy)arei]t curvature produced by the arrange- ment of Fig. G stronger than the other. For my own part, I find the apparent curvature of the lines AB, CD strongest in Fig. 5, that of the lines EF, GH Btrongest in Fig. 6. 'I"he illusion seems intensified in the case of lines AB (Fig 7), which seem to be convex towards each other ; the symmetry of the pair of curves lying V)etween these parallels ought theo- retically to restore the idea of parallelism. The lines EF and («H in the same figure may be made to seem either parallel or concare toward each other, according as the eye takes together the cur\'es which approach EF and GH (re- spectively) nearest, or the concentric pairs ; for the two curves which lie between EF and GH produce opposite elTects on each of the line'; EF, GH. Kit'. C. Kext week I shall consider other cases of apparent curvature, but in the meantime I may note that I shall be glad to hear from readers who have noticed illusions akin to these, or may have been led to other explanations than those I hare suggested. What is a man, If his chief good, and market of his time, Be but to sleep and feed ? A beast, no more. Sure, He that made us with such large discourse. Lookin;; before and after, gave us not That capability and godlike reason To fust in us unused. — Shakespeare. Electiuc.^l ExniPiTioxs axd the Govek.xmeut. — Our corre- spondent probably reflects the general opinion of British cxliibitors in Paris when he says that " the conduct of oui- Government has prevented our country from holding the place it deserved to hold among European nations in an industry which promises before long to be one of the utmost importance." But it is perfectly well known to foreigners, and also to ourselves, that the British exhibi- tor, so to sjieak. must swim without corks, lie m.iy not make so large a show as some of his rivals ; but what lie does show is evem more likely to be over-estimated, as being the result of his unaided efforts, than to bo undervalued in consequence of any unfair com- parison with those who have enjoyed advantages which he does not possess. The difference between the conditions which surround British and foreign exhibitors is thoroughly understood by all who are interested in understanding it ; and we do not believe that a steady adherence to the general rule of Government non-interven- tion, although it may detract from the prettiness or completeness of a display, will ever be really detrimental to the interests of a national manufacture. — rimes. Nov. 4, 1881. J KNO\VLEDGE 13 14 KNOWLEDGE [Nov. 4, 1881. DARWIN- ON MOULD AND WORMS.* No man of si-ionco of our clay uiKK'r.stancts l)ettt'r, or applies iiioro tliorouglily, than Darwin, the principle laid clown by Lord Bacon, that " Man, as the minister and intorprotcr of nature, does and understands as much as his observations on the order of nature permit hiui, and neither knows nor is capable of more. " To one who rightly apprehends this, the fundamental principle of modem scientific research, small things and great, so only that they illustrate the order of nature, are alike worthy of study. He may carry iiis survey over the depths of space, or into the^structure of a microscopic creature ; he may e.xtond liis view into the remote past and the distant future, or he may limit the range of his vision to phenomena taking place in a second or in a yet shorter time : but only in so far as liis pui-pose is to determine tlic order of nature's works, is he the true minister and interpreter of nature. The modern student of science, following this principle, is in strong contrast with the pliilosophers of the Greek school, who, little disposed to pursue observations, evinced, as Humboldt has said, " inexhaustible fertility in giving the most varied interpretation of half-perceived facts;" and, as Bacon himself said, " Laid theii- whole stress upon intense meditation, and a continual exercise and perpetual agitation of the mind ;" and so were led to frame systems on insufficent knowledge, and to explain false systems by false hypotheses. Doubtless, a philosopher of that school would have looked with contempt on a Darwin studying the movements of plants, the ways of bees, the breeds of pigeons, and analysing the plaj- of features in joy or in sorrow, in anger or in pleasure. It would have seemed to him far worthier to educe from his moral consciousness ideas as to the true position of worms in the scale of being, than to devote years to the actual study of their ways and works. But by the humbler and more lal)orious method the student of science in our day manages to attain, or at least approach, the truth ; the more brilliant philosopher of the olden school educed from his active mind multitudinous errors. Darwin's latest treatise, on Vegetable Mould and Earthworms, alFords perhaps the best illustration of his method of all the works that he has yet published. His "Origin of Species" and "Descent of Man" mark an epoch in science ; but such a work as the present illustrates the way by which the new paths have been entered. It is true no one can road those epoch-making works without recognising in every page the kind of work on which their author's mind has been engaged while establishing his theories, or the tone of modern scientific thought. But results have there to be touched on which, in a work like his " Monograph on the Cirripedia," " The Movements and Habits of Climbing Plants," and, above all, the present treatise, are e.xhibited in detail. Forty- four years ago Darwiu announced the first results of his study of the formation of vegetable mould, in a paper read before the Geological Society of London. In the interval which has elapsed since then he h.as been accumulating tlie stores of knowledge al>out mould and mould-makers which are presented in the work now before us. Perhaps the most remarkable results of Darsvin's observa- tions is the " stupendous work " accomplished by creatures so small and weak. It was objected against the views which he published in 1837, that worms could not possibly bury to • " Tho Formation of Vegetable Mould through the Action of Worms, with Observations on their Habits." By CnABLEs Dabwin LL.D., F.R.S. (London : John Murray, 1881.) a depth of several inches fragments of cinders, burnt marl, itc, which had been strewn over the surface of mcaidow land. But now Darwin is able to speak confidently of their liurial of the remains of Roman villas and pavements. He shows also how ancient encampments and tumuli have been gradually lowered bj' the agency of wonn.s. Grass-covered slopes undergoporpetual denudation through theirjoperations, th(' covering of grass remaimng all the time intact, and even the inclination of the slope remaining unchanged It may well seem incredible to the superficial reasoner, that creatures like worms, — small, weak, and soft-bodied — should produce such results ; nay, results far greater in the course of time, changing as they do the entire aspect of a country. It is this inability, as Darwin well remarks, " to sum up the effects of a continually-recurring cause, which has often retarded the progress of science, as formerly in the case of geologj', and more recently in that of the principle of evolution." When men like Sir John Herschel or Sir Charles Lyell have spoken of the efTects of slowly-acting causes in modifying continents and seas, they have been ridiculed by the thoughtless, who cannot see how the downfall of rain, the slow movement of rivers, the play of waves on shore-lines, can produce such results. In like manner the biologist is ridiculed who, noting small changes in various races in short periods (or even in periods which to our conceptions seem long), points to the effect of such changes when multiplied during the lapse of tliose long periods of time of which the earth's crust tells us. But our author has shown how even creatures so tiny and weak as the coral animal have made large islands and long lines of sea-resisting reef, by constant labour^'; and now he shows how under our very feet the despised cairth- worm is changing the form and nature of the land we live on. When wc learn that the rich dark mould in which vegetation thrives best, is matle by wonns, we see that not only the aspect of a country, but the condition of its inhabitants, and even its history, have been modified by their work. So that we may accept in its widest signifi- cance his remark that "it may be doubted whether there are many other animals which have played so important a part in the history of the world as have these lowly creatures." The study of the habits of worms in this work is full of interest As in nearly all the author's books, the language is clear and simple. It may be said indeed of this treatise, presenting the fruit of observations so long continued on a subject apparently so little promising, that great though its scientific value unquestionably is, it is better fitted than ' nine-tenths of our works of fiction to while away a weary hour. It merits, however, more than mere reading. It is a work not to be tasted merely, but to be cJiewed and digested. We shall hereafter return to this work, to consider more at length some of the interesting results of Mr. Darwin's researches. AprLU'ATioKs OK ELECTKiriTY. — Tlic public hardly realise, as yet, a tenth part of the uses to which electricity can bo readily and con- veniently adapted ; and exhibitions will furnish tho best possible means of rendering them familiar with these uses, wliich, in many | cases, are of an essentially domestic character. Electric bells, for I example, although almost universal in large hotels, offices, and i public buildings, make way but slowly in private houses, notwith- ' standing their many advantages. Telephones, in like manner, are > far lo-ss numerous than they ought to be ; and many forms of electrical arrangement ciuitc common in tho United States, and ' found to have great value in saving labour, are scarcely at all in use among ourselves. The electric light is not yet employed in many places for which it is eminently suitable; and its cmplny- mont is still impeded by ditEcuItics of detail which a larger demand would set aside. — Timea. Nov. 1, 1881.] ♦ KNOWLEDGE 15 ifttn'si to tt)t ©Jjitor, [2Tk* Editor doet not hold him$elf rerporttitU/br the opinion* of kit correspondents. He cannot undertake to return manuscriptf or to correitpoiid tcilh their leritert. All communicationa should be as short a* possible, co/ttistently vith full and clear state' nents of the writer's meaning.'] Alt Editorial communications should be addrested to the Editor qf Ks'OWLKDGB; all Business communiculions to the Putli^hert, at the OJice, 74, Great Queen- ttreet, W.C. All Semittances, Cheques, and Post-Office Orders should he made payable to Messrs. Wyman if Sons. •,* All letters to the Editor trill be Numbered. For convenience of reference^ correspondents, when referring to any letter, kHI oblige by mentioning its number and the page on which it appears. AU Letters or Queries to the Editor which require attt^ntion in the current issue of KxoynsvGV, should reach the Publishing OJice not later than the Saturday preceding (Atf day qf publication. ^^^_^ "In knowledge, that man only is to be contemned and despised who is not in a state of transition Xor is there anything more adverse to accuracy than fiiitT of opinion." — Faraday. ** There' is no harm in making a mistake, bnt preat harm in making none. Show me a man who makes no miitakes, and I will show yon a man who has done BOthing." — Liebig. _ urposes, and incidentally remarks that the arguments of Professor Veranda Brown are fallacious, inasmuch as he forgot to include the coal-cellar in his calculations, and the coal-cellar cannot possibly be brought into any intelligible relation with the Jewish comuionwcalth. — A'etc Yorfc rimes. Ultimate STRrcTUKE of Bodie.s. — "As matters now stand," says Mr. U. C. Sorby, "we are about as far from a knowledge (by vision) of the ultimate structure of organic bodies as we should be of a newsyiaper seen with tho naked eye at a distance of one-third of a mile." Poxd's Extract is a certain cure for Khcnmatisin and Oi>ut. Pond's Eitract is a certain cnre for Hieniorrhoids. Pond's Extract is a certain cure for Nouralpic pains. Pond's Extract nill heal Bums and Wounds. Pood's Extract will cure Sprains and Bruises. Sold by all Chemists. Qet the geouine.' f Adtt. Nov. 4, 1881.] ♦ KNOWLEDGE • 19 #ur i¥latl)fmatiral Column. MATHEMATICAL columns in magazines arc too apt to de- generate into puzzledom corners, collections of problems of considerable difficulty, but having no real interest, and not valuable as illustrating principles. We wish ours to be of real use to the student of mathematics, but still more to those who, when studying other branches of science, find that rightly to understand their subject they require to be familiar with certain special departments of mathematics. It must be confessed that most of our treatises on mathematical subjects pay Uttlc attention to the requirements of students of this kind. They are excellently adapted to prepare students for examination ; because at an examination a student of algebra must not be surprised if he be asked questions relating to infinite series, a student of trigonometry if he be asked to establish Dr. Moivre's Theorem, and so forth. But they do not meet the wants of one who requires to know the methods and principles of algebraical, trigonometrical, or other forms of calculation. There is bttle in such works to show the use and value of the processes con- sidered in them. Many a ready student has passed a fair examina- tion in the differential calculus, who had not the remotest idea of the practical value of its methods, or that in hundreds of simple subjects of inquiry the calculus can be employed easily and advan- tageously. There is no occasion for mystery respecting the use of mathematical methods; but it would really seem, to read some mathematical treatises, as though the last idea in the world the student should associate with any mathematical subject was the idea that it may actually be useful. Even the problems which are given for solution are, for the most part, either useless or absurd. This is not the way to render mathematical subjects inviting, or to encourage the student to master the difficulties which are inherent in them. Of course, we cannot here give mathematical essays which can render the student independent of systematic treatises. Such treatises ho must have, and must carefully study. But we hope to show that a number of departments of mathematical research, supposed to be either too profound, or of too little practical value to be worth taking up, can be readily and usefully studied. In every case we wish to come as quickly as possible to the practical application of the various methods we shall successively deal with. We shall probably begin with a simple paper on the use of loga- rithms, seeking to show that, instead of being regarded as a mere mysterious collection of numerals, a book of logarithms should be considered the great simjjlifier of all forms of calculation. Scarcely anyone who has much to deal with figures, otherwise than in mere processes of addition or stibtraction, should be without such a book ; and a very brief study of the subject will suffice to enable anyone to make ready and intelligent use of the tables which a book of logarithms contains. We may then discuss the Laws of Chance, the simple applications of Trigonometry, and other such matters, avoiding, as far as possible, those parts of a sr.bject which a student can readily study in set treatises. We shall be glad to receive problems of interest, either for solu- tion or discussion, preferring, he never, those which illnstrato general principles to those which are merely, as it were, casual. In many cases where problems are sent to us for solution, wc shaU only give hints, not complete solutions, believing that, so dealt with, they are likely to be of more use to the student than if a complete solution were at once given. We need hardly say that this is not a suitable place for the dis- cussion of very difficult mathematical problems, albeit those of our readers who do not take interest in mathematics must not be angry with ns if from time to time we devote a column, or even a page or two, to matters of no interest, or even absolutely unintelligible to them. They must remember that each of our lighter essays here may be equally interesting to proficients in the subject dealt with ; that, in fact, no one can expect all the contents of snch a journal as the present to be interesting to himself individually. Wo shall endeavour, however, to keep within close limits all matter likely to be " caviare to the general." Sunlight a-.-o Heat.— The intensity of sunlight at the sun's surface is calculated to be 190,000 times that of a candle-flame ; 5,,30O times that of the glowing metal in a Bessemer converter ; 146 times that of the limelight ; 3'4 times that of the electric arc at the brightest yet obtained. The heat emitted by the sun in a single second would suffice to melt a shell of ice covering the entire surface of the earth to a depth of 1 mile 1,457 yards, or to burn a layer of anthracite coal 17'7 yards thick over the earth's entire surface. This would be equivalent to a consumption of about 16,436 millions of millions of tons of such coal per second. (Bur Cftrss Column. MANY weekly and monthly periodicals in this country and in others now contain a chess column, but it may be a question how far any general knowledge of the game is encouraged in this way. Usually these chess contributions are limited to problems, games between first-class proficients, and replies to queries, with occasional items of chess news. The problems are such as only good players can readily solve, so that the learner, unable to master them without an expenditure of time which he can ill spare, is rather deterred from the study of chess than otherwise by these masterpieces of chess strategy. The games, again, even when they are sufficiently annotated, are generally too profound to have much interest for the learner. He cannot see the purpose of moves whose real significance depends generally on results five or six moves at least in advance, and almost always on moves which are not played on either side. The chess expert recognises the beautiful positions, the brilliant attacks, the complex defences, and so forth, which would result if a particular move were not met in that way in which, in the game itself, it actually is met. A volume would be required to show all such results of each move played on either side by two first-class players ; and the beauty of a game between two such players can only be properly appreciated by those who, as each move is played, can follow oat the various consequences, according to the way in which the move may be met. We wish to cater for a wider circle of chess players — for those who enjoy the game and can appreciate its beauties, while they have no ambition to be able to meet a Steinitz, a Blackbume, or a Zukertort without receiving odds. It must be admitted that nine out of ten who call themselves chess-players know very little about the game. They move their pieces without any adequate idea of the value of position, or of the manner in which the powers of the various pieces can best be brought out. Of the importance of time, again, in chess strategy, they seem to have scarcely any conception. A player of this class will move his Queen out to some square where she can be attacked by a piece which in attacking her will take up a strong position, then to some other square where she can be similarly attacked by another piece, and, perhaps, after four or five such moves, be fortu- nate in being able to return her to her own square. He will then complacently remark that he must try some other way of opening his attack, utterly overlooking the fact that his opponent has gained four or five moves, and that even a single move early in the game often makes all the difference between a strong attack and an unsatisfactory defence. If such a player moves his Knight from King's Bishop's third to King's Knight's fifth, and on the opponent moving Fawn to King's Rook's third (attacking the Knight), finds no better move than to return him to his former position, he would be incredulous if told that he had thus lost all chance of winning against correct plaj'. Yet there is scarcely an imaginable case, in the early stage of a game, where, if the game had been equal before this had happened, it would not afterwards have been seriously compromised. The opponent, be it observed, has made a move of great utility (though often too slow, except as in this case when a move is given away), while it is now his turn to play instead of the first player's, who stands just where he did before he rashly moved forth his Knight. (The opening, of wliich the accompanying game is an illustration, shows that, even when by venturing forth the Knight to the square in question a Pawn is gained, the counter attack, after the Knight has been driven back, compensates the second player fully for the loss. It also presents at move 33, a case in which loss of time is equivalent to loss of a game which might probably have been drawni.) It seems to us that we may do something to encourage sound chess play by giving our readers chess material of a different kind from that which has usually been presented in chess columns. We propose to explain in a scries of short papers the principal open- ings, discussing their advantages for attack and defence, and show- ing how the opening moves illustrate the general princijiles on which sound play depends. We shall illustrate these openings by games played by good players, but not played with quite so much study (and, therefore, not needing .such skUl for their interpretation) as the match games commonly selected for these columns. For this purpose we have made arrangements with the proprietor of the mechanical chess-player, Mephisto, to have games played with Mephisto specially for our chess columns. By an extension of Mr. Giimpel's kindness, the guiding spirit of that mysterious player has been persuaded to make his own comments on the game. It need hardly be said that only such games will be selected as have real chess interest. The multitudinous contests in which tyros have succumbed to Mephisto (and would have succeeded at the odds of a Queen) would be quite as much out of place here as in the 20 • KNOWLEDGE ♦ [Nov. 4, 1831. rolumna of tho Chess Chrnniclc, Immbler though our aim may sconi. Wc shall luiinmo on tho part of our readers a knowledge of tlic olemonta of chess play — tho moves, laws, and so forth ; and suffi- oiont familiarity with tho notation employed by Knglish-spcakinf^ players, accordinp; to which tho King (K), tho Quoon (Q.), the Bishops (K.B. and Q.H.), tho Knights (K.Kn. and g.Kn.), and tho Rooks (K.R. and Q.K.) are regarded as standing severally on tho first sipiare of a file, tho other squares of which are numbered in onier, the 2nd, 3rd, Ith, 5th, Cth, 7th, and 8th. For onr chess readers' amusement wc give an illustration of weak chess play, which occurred within tho last few days over our own chess-bonrd. Tho first player had the idea that, knowing little of tho usual openings, ho might equalise matters by playing on a line ontirely unrecognised by the books : — CHESSIKIX. Remove Black's Q.Ii Whit*. Amatbcb. 1. P. to K.4. 2. I', to K.R.4 (?) :!. Kt. to Q.B.3. ■I. R. to K.K.3. (?) .'•.. U. to Q.3. (?) (J. P. to K.B.3. 7. Q.Kt. to K.2. (■) «. P. to K.Kt. 3. !». Kt. takes Kt. 10. K. to K.2. Black. Chess Kditob. P. to K.4. Kt. to K.B.3. B. to Q.B.-l. P. to Q.3. B. to K.Kt.5. Kt. to K.R.4. Q. takes P. (ch.). Kt. takes P. Q. takes Kt. (ch.). Q. to K.B.7. mate. a The game was still defensible, by — „ P. take B. g P. to K.Kt.3. g Q. to K.B.3 . '■ Q. to K.R.5. (ch.). ■ Q.Kt. takes P. ' B. take Kt.^ GAME No. 1. Played between the Mechanical Chessplayer, " Mephisto," and an Amateur. Two KxiGHTs' P. to K.4. Kt. to K.B.3. B. to B.4. Kt. to Kt.5. P. takes P. P. to Q.3 C). Kt. to K.B.3. Q. to K.2. P. takes Kt. P. to B.3 {'). P. to K.R. 3. P. takes B. P. to Kt.4. P. to B.4. B. to K.3. (8). P. takes P. (>■). Kt. to Q.3. Kt. to Kt.3. Castles K.B. K. to K.2. Q. to Q.2. Kt. to Q. 4. B. takes B. Q. takes Q. Kt. to Kt.5. Kt. takes P. P. to Q.6. K.R. to K.sq. R. to K.2. Kt. to Kt.5. P. to B.3. C) R. to K.7. R. to K.Kt. sq. (I) R. to K.B. sq. P. to R.3. P. takes P. R. from B. sq. to K. sq. R. to K.8. (ch.)(») R. takes R. (ch.) B. to K.7. (ch.) K. to Kt.2. K. to B.sq. Besigna (") Defe.vce. Black. Mephisto. P. to K.4. Kt. to Q.B.3. Kt. to B.3 (•). P. to Q.4. Kt. to Q.R.4. P. to K.R.3. P. to K.5. Kt. takes B. B. to Q.B.4. B. to K.Kt.5 (•'). B. takes Kt. (<■). Castles. R. to K.sq. ('). B. to Q.3. P. to Q.R.4. R. takes P. R. to Q.R.6. Q. to R.sq. (1). Q. to B.sq. ('). Q. to B.4. Kt. to R.4. B. takes P. (ch.) Q. takes B. (ch.) Kt. takes Q. R. to R..5. R. to Q.B.sq. R. takes B.P. Kt. to Q.G. R. to Q.sq. P. to B.4. P. takes P. Kt. to B.4. P. to Kt.4. R. to R.5. (">) P. to Kt.5. P. takes P. P. to B.7. R. takes R. K. to B.2. K. to B. sq. R. to K.B.5. P. to Kt.G. MEPUISTO'S NOTES. (•) This move constitntcs tho Two Knights' Defence. C") This move gives White if not a ba/l, at least a difficult, game to play ; the continuation C.B. to Kt.5. (ch.) is to \>o preferred. (') This move is stronger than the usual move P. to K.R. 3. White threatens an attack with his Pawns on the hostile Bishop, thereby developing also his strong Queen's wing. P. to B.3. also provides u refuge for White's Knight onQ.4. incase Black should Caatic, whicli would leave the Knight en prise. C) This certainly seems tho most attacking lino of play, in addition to which Black could also play P. to Q.R.4. to prevent tho advance of the Queen's Pawns or P. to Q.Kt.4., or Castles. (■) This is better than B. to E.4., which would result to the advantage of White, e.g. 11. -5 10 • ... 12.. 13. Kt. to K.5. with the better game. (') Threatening to win the Queen. («) This is the right move to stop any advance of tho Black King's Pawn. Thus, for instance, 15. — — — '■ — instead, would not be B. takes P. fo, 15. PtoQ.B.5 P. to K.6 16. t»i....B^ ._ ^^^^jj ^j^g better B. takes K.B.P- game. White could not take the Bishop, for then Black would win his Queen by P. takes P. (ch.). C") Black has played P. to Q.B.4, with the intention of breaking up the Pawns on White's Queen's wing. If instead of P. takes P.. as actually occurred. White should play P. to Kt.5, then P. to Kt.3 would stop White's Queen's Pawns. Black might, perhaps, also reply with P. to B.3. The variations arising out of this move are very numerous. The idea is the same as in 15. p to Q K 4 namely to separate White's Pawns, and then attack them singly, e-0- 16. P. to Kt. 5 17. P. to B.5 (or see A) P. to K.6 19, P. to B. 3 ^'- B. to Kt. sq. Q. takes P. QJ^sQ. Kt.toQ.2 Q. toQ.2 -"• Kt. takes Q^ ^^- B. to B.2 with the better game. A. It would be disadvantageous to take with the Queen's Pawn, thereby opening the tile commanded by the Black Queen ; therefore, Kt.P. takes P. 17.1 P. takes P. If now White should play P. takes P., then Q. to B.2 would give Black a very good game, or if White should play, P. to B.5 „ P. to Q.6 „„ Kt. to Q.2 18. 5-r~ir^ — 19- s-~r^.\> 20. , . ^ ^r — with the object of B. to Kt.sq. B. to Kt.2 Q. to B.sq. •■ playing Q. to B.4, followed, perhaps, by Kt. to Q.2., Black should again get a good game. (') Threatening the capture of the Knight. (1) By 19 Castles, White thought to evade Black's attack en tho Queen's side, but only to exchange it for an attack on the King's side, the chance of which Black at once follows up by Q. to B.sq. C') White hopes to be compensated by his attack of R. to K.7 for this move. (') This is loss of time, as Black thereby advances his Pa\vn3 in support of the Bishop's Pawn. White cannot venture upon any- thing tor fear of P. to B.7 ; if K. to K.3, then Black wins the Wliito King's Pawn by Kt. to K.5 (ch.) ! therefore, 33 R. to K.B.sq. at once was White's best play. ("') This is hardly necessary ; the object was to make tlio T.k k available for support of the other Rook liil R. to R. sq. (") This is weak again. R. to B.7 would have given Wliito :•. _ i game; for, in reply to jj— r — jTv White would play K. to Kt.3 with a fair chance of drawing. (") Black threatens to Queen his Pawn by P. to Kt.7 (ch.), which White cannot prevent. KXOWI.KI'CI: AMI hiSORANXK. '• Ignorance is the curse of God, Knowledge the wing on which we tiy to Heaven." — ShakeifeaTe. *,• WuisT CoLCMN. — Our papers ou Whist will be comnicucod in No. 2. !sov. 11, 1881.] KNO^A^LEDGE 21 AN ,li LTRATED MAGAZINE OF SCIENCE plainlyWorbed -ExactMescribej LONDOX. FRIDAY, XOVEMBER 11, ISSl. CONTENTS. FAGR i The Fiji Islands 31 CoREEspoNBENCB. — Th© One -inch Map of the Ordnance Surrej— Is the Sun Hot ?— Influence of Sei on Mind— November Meteors, &c. ... 35 PAGE The Philosophy of Animal Colours. By Dr. Andrew Wilson, P.E.S.E . 21 The South European Volcanic System 32 The Relation of Food to Muscular Work.— Part II. By Dr. W. B. Carpenter, F.H.S 23 i Queries Jo Brain Troul.les 2.5 Unhealthy Houses 39 Comets. Part \l.— (Illutlr