ie we ee Se Se mn wa tale ee ere Awan Ere Oar ee Dee Oe A OO a reer Cie ee ee ee ee ce 2 0409.6 2-29 GOH 82608 4H PO e 1a ER bY? mn’ wera gas Par A oe re a) vent Pe ene Cen sumer aah Se wee ety 4 So nek Pee Pee fee ee eae eT RN DE wn , ot ‘ arene eer er he Meee Oe a I ee ee ' wee Creer ark We 0c Wc Ms Pa VOY Ae f cay eer es hk ea Oe ek ee be a tee Pir ere Deere ee ee Wee ern ee oe ee Ce ee oe pede ree Dae Ee es Oe ea eT aay Perce wire a tO eee ee . vee eee Pair err me TRE Me SO AU a ee ee ee ‘ ce ee ae Feed CONS RD ET PE RA GAM Fee Ny AOR ONE RO dN Par rok are) Sore ke A ‘ he Pare ieee De Os bebe eas eae ete Wate teee Cae SM A Ys had wr? ' ie rer Ot SC Oe ee a nd ‘ ‘ vrenly See ee eeere tok ep DO FG TE G8 1 08588 e fem} ey eid Fo anh eae Bloc gl it te OF thy eee rrnra a irae oe ee ee ee ee eR TT ee eee me ee Ce wo een i err Whee ried w glass bee Peer Cee Wen eC er ere ee ee ee a bebe bth eae Rape ee ee sane seine ba ea die Pere iy Ce Oe Ste Pec an We 7 rer toe gy CC eee » Ore he Rc Rr Me eee Perma Car Scie De ee De PMC he ee i ee ek Ae A ee ee ee wees se yan hywy et Pe oe ae eS Ce ee Ara hee re ee ar CO eS Oe ee a) PO re ee Cae eee) ‘ a uae Be Pe re ee ee ee hat ey bie ke ms Re Ray sere dateenae teed Pee Re re ee ey rm oe ‘ ’ ' ‘ Pr wie eee Se Mc a, GO ey etre Prarie Wr verse rire Years Wh Ce eee ek A é ‘ ROA are ae ernie ir it eR acre SOC UY Re ee ee eon ce rr ee) a ee ae te Sees Brie oe ee ee Ce ee Rk Faerie ee er tee ee rea area Me Ye ee et we Re CV EPG FOF Fe aE Dated Tek Ow, VOTH tee Bg Nt ae Oe yD her eee’ pene MPN Shr CRON Ee CTO eC ee es ee Pr i ee cre Ly see Sor er were ee ee RC ee * Pe te ee ne Viv fed Oe Lm Hence Hae UD Ne Oe web gt UDR bets bin be Oe eat ee o9t VR aT ty Wire G'eekeged BDAY Wy bee ed brew ace seureeee Pe AEP ee me Fe FO tee Parmer aria i Weve ee Le a ee SC ee a reoey Ve FR ee ee ee em ee be OL ee em hy te ste Arn ern ee ee A en. Ons Cm ae Pe ae eee wien Koray we eT etc rt Se mur Pe ce paket Reet yea Pa ee a Pe on eee a SO ee re Ok oe E vee COA Am ee eet Se ee Pron mee PAC Oe Ts oe WER RD aor ae Oy bat 2th GAN te gd ee Oe Re me vears Aer ee See ee ke Ce OR Cea Veoe ee eO RR ee ee phe , . ‘ ve araree eee) fan) ue ie, . . ‘ . + . Streep tye SPM PL ET e Beet ower e oltre vree rt eee hee aes Cve dee eer eewy Ce ee pte eed Meee ' Cys gr eee eee ea’ ob Vig dees by hota aye ea gees ee ee yi ey Ve > et rete aa ene SiR gy yee beeestesur ey ae ee a pi ton tee bas Geka gw ' PT Se ee CL Teer Cre a Pores oe Paranoia 3. Sener Oc ae ve ROS OTe On ee SA ay] Pan ae ae oe ye Sb beige Pee See eck a Pe SAPO E PE eT TMNT TR el eee Cena Ute Ts akc ee We ee TTT pre ee eee ye rope Rabe ae PALES ERR ERAN Ey EM Sle eo BE vere haere tenes Parris Ta eM TOL eee a Oe Se ODL ti) Se et ee AUN ory fee VM Lah we (Vat ee oD ep yg te tiet ee a bee c +e yee Se eR Hs or ete Cee Sour a Wee Mere a Pe BAcireninar as err ei Ct er) eee (eae heer tings Wiberg ® ah ban Ve agen 8 Laces eke PPD aR Drees Pe Sr ee a. setae { ae tat hy \ we Pune Or EEE Pee t Mb Dur ad egw Sia diel og gd sk HE és r Lod Cod edad HW UP FB doetend os bee GP Td bee VTA S Diy Ride kedi ad bt pdt 2 bt ye Jap Oot Joiek BD td res OLY Beebobg de dL peds der ody tate nea ot eed Sebi She sere lee Ol Aes: De BD edie aig ad Fede teh ire eee ea. Jae 4th ba he ede neve @ he bik | Padi oe ed Dateded brome ed eta ih ay bible waa : ‘ doe . ; 4 Be ekiP ag Phy ’ ‘ E H E ‘ are ee a eg Md rete > Sobek Ld dtp bel thee’ Ob eed de bed ot BV aE ee beh etd rdoed pel eet BF basin th iter weddign ded ot Be Ah Eo At lte TAP Rots be fier ewe be derek pada gs va dda dhagy : Pi een © ae ee ae Ch 4 Md ons ibe bate Adeaig? ae dads ryte Fay b ad dina Fe i oe ee A GaP dae teed a Le ed 6G ay ere ce ee . Woe doed WS ope bereg pd ed ae eS ¢ emer eee ry Pe oe ‘ ‘ A ena teat bev eth Fw ke + Liebe bw fed the © hast 2 wie tld tes wiles cap hee beet ad PE CHAE Cee kee Bee se dite BG Aree Pree Were er eee en de heey . Abd daetepee Oh hee Ot Ww hd eee ea a4 Mit tok nd bd pe Bd itd dee Cf Parree Wie ete ee eer ee k ” padded ea hPa de Freer rar Prarie ara fe ie ee er eee re ee ee ihe ; Lite Bb a ah ba ae Po ES RRM Ed tees ow + (re aC ee ee ee ee ee OL ee eae ee PAS eke OE EE ee He greed lige hens ny oe Pore Ce te Ree eee 2 ed ee nd + Lue Joh Kbe7 * Berne ir) Arr me Me ae Bea ated bl wpe Gd Oa gas es Oe ee bd aed ee a Pedor boweidghieds te bene . bop bie db ee 6 eg ie ee Se po ded a eathh Fad tee am PP re ere ee ee , boat be ged aren te era or Sar er a i eee eae tee RE Te fede pte ds CC ee ee Fee ee aoe ee ee Vb A tai elk sos oe peda g bed aedg bb ey ad be igh ns bites b , La teed. ee ned fotmd, ae eee Dagrege Sle Gd i-bgr et $ Gab ebw ae ed i dE val pe bs Sho sega’ re ee) ee ee sh uee ia oe stead aoe Cr ee Serene are ne a Para) setus ity ta d vt +4 j ahaa ts Frere care a Wee a ee oe ba by ee ae Pe de ak eee ee ee aA deed ca Ce ae Oe Bek brea ea oD ED Ed Pd Got Cae Gof at bb he gs bhi kB 8 ee Qk e, be Pode yds cp debtor hig Pie ee ree ae Se Ty riper © ee Ce ee ee ee ee fosmid am de Vuadadé ean Pere de thaw ged”d ‘ ahabe Frere Wace ort at kN er bare oe Bah ? Fe perk hk Coen ge hay oie siege eye. nistaan: els face 6. Laks @& lee rkcll ~ i a lid j br 1 ‘ wy * 4 % OS, 7F s¢ THE AMERICAN JOURNAL OF SCIENCE AND ARTS. CONDUCTED BY PROFESSOR SILLIMAN AND BENJAMIN SILLIMAN, Jr. VOL. XLIX.—OCGTFOBER, 1845. NEW HAVEN: Sold by H. DAY.—Boston, LITTLE & BROWN and W. H.S. JORDAN.— New York, WILEY & PUTNAM, and C. 8S. FRANCIS & Co.—Philadelphia, CAREY & HART, and J. S. LITTELL.— Baltimore, Md., N. BICKMAN.— London, WILEY. & PUTNAM.—Paris, HECTOR BOSSANGE & Co.— Hamburgh, Messrs. NESTLER & MELLE. PRINTED BY B.L. ee ONAN INSTR sry. aks ee Art. I. II. Il. CONTENTS OF VOLUME XLIX. NUMBER I. On the Physical Geology of the United States east of the Rocky Mountains, and on some of the Causes affecting the Sedimentary Formations of the Earth; by Prof. Witiiam W.MarHeER, - - : - : 2 Account of some new Articles of Philosophical Appara- tus; by Prof. E. 8. SNELL, - - - : a Review of Dr. C. T. Jacxson’s Final Report on the Geol- ogy and Mineralogy of the State of New Hampshire ; by Tuomas T. Bovve, - : - - - - . Description of some Artificial Mounds on Prairie Jefferson, Louisiana; by Prof. C. G. Forsney, - - - . Caricography ; by Prof. C. Dewey,—(with a plate,) - . Origin of the constituent and adventitious Minerals of Trap and the Allied Rocks; by James D. Dana, - . Considerations respecting the Copper Mines of Lake Su- perior; by Lieut. D. Ruaetes, U.S. A., - - - . Singular case of Parhelion, with a statement of the Theory of ordinary Halos; by Prof. E. 8. Snexz, - - . Notice of a New Species of Batrachian Footmarks; by James Deane, M. D., : Bs 2 P . On the Copper and Silver of Kewenaw Point, re Supe- rior; by C. T. Jackson, - - E - . Practical Observations on the Generation of Statical Elec- tricity by the Electrical Machine ; by Lieut. GEorcz W. Rains, U.S. A., - : - Ec = A F . Ruins of Nineveh: Description of the Discoveries made in 1843 and 1844; by Rev. Azarian Suiru,M.D., - . On several New Plants; by Dr. M. C. LEavenwortn, . New Electro-Magnetic Engine; by Prof. Cuas. G. Page, 20 27 38 42 49 64 73 79 8] 93 113 126 131 LFLLO: iv CONTENTS. Page. XV. Axial Galvanometer, and Double Axial area Engine; by Prof. Cuarues G. Pace, - . 136 XVI. Report of Observations on the Transit of Mercury, May 8th, 1845; by Prof. OumsTeD, - - - - 142 XVII. Bibliographical Notices :—Narrative of the United States Exploring Expedition during the years 1888, 1839, 1840, 1841, 1842. By Cuartes Witxss, U. S. N., 149.— Prof. W. R. Jonson on the Heating Power of various Coals, 166.—Musée Botanique de M. Bensamin DE.zs- sErT; Notices sur les collections de Plantes et la Bibli- othéque qui le composent ; contenant en outre des docu- ments sur les principaux herbiers d’Europe; par A. La- SEGUE, 171.—De Candolle’s Prodromus, Vol. 9, 174.— De Candolle’s Theorie elementaire de la Botanique, 175.—Fifty Eighth Annual Report of the Regents of the University of the State of New York, 176.—Report of Experiments on Gunpowder, made at Washington Ar- senal, in 1843 and 1844; by Capt. Atrrep Morpscat, 180.—Rural Economy in its relations with Chemistry, Physics, and Meteorology : or Chemistry applied to Ag- riculture; by J. B. Bousstncautt, 182.—Proceedings of the Academy of Natural Sciences of Philadelphia, 183.—Mulder’s Chemistry of Vegetable and Animal Physiology, American Edition, 186.—Life of Godfrey William Von Leibnitz; by Jonn M. Macxis, 187.— Wiley & Putnam’s Catalogue of Scientific Books: Li- brary of Choice Reading: Handworterbuch der 'Topo- eraphischen Mineralogie von Gustav Leonuarp, 188.— The Botanical Text Book, for Colleges, Schools and Pri- vate Students; by Asa Gray, M. D., 189.—A Class Book of Botany, designed for Colleges, Academies and other Seminaries ; by AupHonso Woop, A. M.: Owen’s Illustrated Catalogue, 190.—Vestiges of the Natural His- tory of Creation: Dr. G. A. Manrett on the Geological Structure of the Country seen from Leith Hill in the county of Surrey, 191. MiscELLANIES.—Abstracts of the Researches of European Chem- y ists; prepared for this Journal by J. L. Smiru, M. D., 192.— New Instrument for the solidification of Carbonic Acid, 206.— CONTENTS. Remarks on the saltness of the Ocean, and the effects of light on turbid waters; by the Rev. Hector Humpureys, 208.— Kenawha Gas, 209.—Bromine and Iodine, 211.—Abstract of a Meteorological Register for the year 1844, kept at Steuben- ville, Ohio; by Roswett Marsn, 212.—Fossil Remains from Algoa Bay, near the Cape of Good Hope: Fossil Foot- marks and Rain-drops; by James Deane, M. D., 213.— Large Trilobite—lowa Coralline Marble: Dorudon: Foot- prints; by A. T. Kine, M. D., 216.—Large Skeleton of the Zeuglodon of Alabama, 218.—Bones of the extinct gigantic Bird of New Zealand, called Moa: Sixth Annual Meeting of the Association of American Geologists, 219.—Comets: Se- cond Comet of 1845: Third Comet of 1845,220.—The Earl of Rosse’s Leviathan Telescope, 221.—Notices drawn from a Letter of our London Correspondent, 227.—Columbite: Gray Antimony : Postage of Printed Sheets in England, 228. NUMBER II. Art. I. The Coast Survey of the United States, - - - I]. A Letter to Berzelius on Chemical Nomenclature; by Prof. Ropert Hare, M. D., - - - : III. Description of a Singular Case of the Dispersion of Blocks of Stone connected with Drift, in Berkshire County, Mass. ; by Enwarp Hircucocx, LL. D., - - IV. Meteorological Observations made at Hudson, Ohio, du- ring the years 1841, ’2, ’3, and °4, with a summary for seven years; by Prof. Ex1as Loomis, - - - V. On the Physical Geology of the United States east of the Rocky Mountains, and on some of the Causes affecting the Sedimentary Formations of the Earth; by Prof. Wititram W. Maruer, - - - - - VI. Description of the Solar Index, a new Magnetical Instru- . ment; by Marsuatnt Conant, - - : - VII. A Report to the Navy Department of the United States on American Coals, applicable to Steam Navigation and to other purposes ; by Prof. Waiter R. JouNnson, VIII. (1.) Description of a mass of Meteoric Iron, which fell near Charlotte, Dickson County, Tenn., in 1835 ; (2.) vi CONTENTS. Of a mass of Meteoric Iron discovered in De Kalb Coun- ty, Tenn.; (3.) Of a mass discovered in Green County, Tenn.; (4.) Of a mass discovered in Walker County, Alabama ; by Prof. G.'TRoost, - - - - IX. On the Allotropism of Chlorine as connected with the Theory of Substitutions; by Prof. Jonn Witi1am Drarer, M. D., - - - - - - - X. Bibliographical Notices :—Travels in North America in the years 1841-42, with Geological Observations on the United States, Canada, and Nova Scotia; by CHarLes Lyett, Esq., F. R.S., 368.—On the Liquefaction and Solidification of Bodies generally existing as Gases ; by MicuaEL Farapay, 373.—On the Geological Constitu- tion of the Altai; by M. P. de Tcuinatcuerr, 378.— Page. 336 346 Whitney’s Translation of Berzelius on the Blowpipe: ~ Fownes’ Chemistry for Students: Lieut. Wright’s Trea- tise on Mortars, 379.—Dissertation on a Natural System of Chemical Classification; by Otrver Wotcorr Gizss, 384.—New Books received, 386. MiscELLANIEs.—On the Hypothesis of Electric Currents in the Nerves; by M. Marteucci, 387.—New Researches on An- imal Electricity ; on the Muscular Current, and on the Proper Current; by M. Marrevcci, 388.—Structure of Electro-pre- cipitated Metals; by Warren De ta Rue: Electric Sound: An account of Compact Aluminum, 390.—Superoxyd of Silver: The blue color of Gold Leaf viewed by transmitted light: Xanthine: A curious change in the composition of Bones taken from Guano; by R. Warrineton: Detection of kinic acid; by Jonn Srennouse, 391.—On the decom- position of Salts of Ammonia at the ordinary temperature ; by H. Bence Jones, M. D.: Styrole: Salicine; by M. Praia, 392.—Composition of Fungi; by Dr. F. Scutosspercer and Dr. O. Dorrrine: Action of Animal Charcoal; by R. War- RINGTON: Thomaite ; a new mineral species, 393.—ScHEE- RER on Aventurine Feldspar: Spadaite, a new mineral; by von Kosett: Descriptions of Polycrase and Malacrone, two new minerals; by ScHEERER: R. Puixuips, Jr., on the state of Iron in Soils, 394.—Sillimanite: On the origin of Quartz and Metalliferous Veins; by Prof. Gustav BiscHor, i a ccpeet Rey CONTENTS. 396.—Mean Height of the Continents above the Surface of the Sea; by Baron von Humsotpr: Infusoria, 397.—On the Kunker, a Tufaceous Deposit in India; by Capt. Newzotp: On some of the Substances which reduce Oxide of Silver and precipitate it on Glass in the form of a Metallic Mirror ; by Joun Srennouse, 398.—New Self-registering Barometer ; by Rosert Bryson: On the Manufacture of Enamelled Cast Iron Vessels in Bohemia: The Tagua Nut or Vegetable Ivory ; by A. Connett, 400.—Lithographic Stones: On the Leaves of the Coffee Tree as a substitute for Tea: Upon Anastatic Printing, 401.—On a gigantic bird sculptured on the tomb of an officer of the household of Pharaoh; by Mr. Bonomt, 403.—On the Heat of the Solar Spots; by Prof. Henry: Notice in a letter from London to the Senior Editor, 405.—Supplement to Prof. Loomis’s Paper, at p. 266, of this Number: Burning Well, 406.—Particulars of the fall of Me- teorites in the Sandwich Islands, 407.—Remarkable Meteor at Fayetteville, N. C., 408. Vil ERRATA. Page 183, 1. 18 from bottom, for ‘“ Palagia,”’ read “Falagria;’’ 1. 16 fr. bot. for flavicernis,” read “‘ flavicornis.” P.185, 1.17 fr. bot. for “‘ ereola,”’ read “‘ ene- ola;” 1. 11 fr. bot. for “ Athoiis,’’ read ‘‘ Athous;”’ 1. 10 fr. bot. for ‘ zreolus,” read ‘‘eeneolus.” P. 291, 1. 21 fi. top, for “ contradiction,” read *‘ contraction.” THE AMERICAN JOURNAL OF SCIENCE, &c. Arr. —On the Physical Geology of the United States east of the Rocky Mountains, and on some of the Causes affecting the Sedimentary Formations of the Earth; by Wiuiiam W. Martuer, Professor of Natural Sciences in the Ohio University, Athens, Ohio.* Part I. On the Causes of the great Currents of the Ocean, and their Influence in the Transport and Deposition of the Sedimentary Rocks of the United States. Ir is well known to those who have attended to the geo- logical structure of our country, either by reading or observa- tion, that the whole territory of the United States south of the great lakes and the St. Lawrence river, and between the Rocky Mountains on the west, and the Blue Ridge, the Highlands of New Jersey and New York, and the Green Mountains on the east, * In discussing the subjects suggested in the title of our article, in this and some subsequent Nos, of this Journal, it will be found convenient to adopt the following divisions :— I. On the causes of the great currents of the ocean, and their influence in the transport and deposition of the sedimentary rocks of the United States. II. On the causes of elevation of the sedimentary rocks above the level of the sea, and of the plications and foldings of strata, particularly those of the United States. III. On the periods during which these elevations, plications, and foldings of the strata occurred. IV. On the metamorphic changes that the sedimentary and other rocks have un- dergone since their deposition and elevation. The first and second parts were read before the National Institute at Washing- ton, D. C. in April, and before the Association of American Geologists and Natu- ralists in May, 1844. Vol. xu1x, No. 1.—April-June, 1845. 1 2 On the Physical Geology of the United States, Sc. is composed of sedimentary rocks* which have been formed by the aid of water, and organic secretion. Attempts have been made to measure the thickness of these rocks in Pennsylvania, Virginia, New York, and Ohio. The measurements in Pennsylvania give a thickness that excites as- tonishment, (seven to nine miles.) 'Those of central New York and Ohio, where the rocks are nearly horizontal, and undisturb- ed since their deposition, indicate a less thickness; but eight thousand feet in New York, and four thousand to five thousand feet in Ohio, is about the average thickness of these sedimentary rocks, and they are spread over an area of at least one million of square miles in the United States, exclusive of their extent in ‘Texas, Mexico, and the British possessions. These rocks vary in texture from a coarse conglomerate to the finest clays and shales. Several rocks of the same kinds, as sandstones, limestones, slates, coal, &c. are repeated many times, yet each differs from the others of the same kind by some slight peculiarities, by which they may be recognized by careful study. Whatever may have been the causes of the formation and de- position of these rocks, it is evident that they have been so mod- ified in their action as to produce limestones at one time over nearly the whole of the vast area under consideration,—slates at another period, succeeded by sandstones,—again by limestones, slates, and sandstones,—and still again by conglomerates, slates, sandstones, coal, and iron ore, some of them alternating and re- peated many times. Similar causes have acted repeatedly over the same areas. The sand of the sandstones could be spread over such vast areas only by means of some cause tending to produce a broad current of moderate velocity ;+ the conglomerate would imply a * It is necessary here to make exceptions of limited tracts in Georgia, Missouri, and Arkansas, where primary and metamorphic rocks occur; also the mountain region of northeastern New York. These masses of primary and metamorphic strata stand as geological islands surrounded by sedimentary rocks. + Table showing the Transporting Power of Currents. VELOCITY OF CURRENTS. POWER OF TRANSPORT. Inches per| Miles per second. hour. Wears away fine, compact, tough clay, : : P 3 0:17 Removes fine sand, . ‘ ; : 6 0:34 os sand as coaike as fax: seed, ; F ¥ 8 0-45 fF fine gravel, : : . 12 0 68 ‘¢ pebbles an inch in diameter, 2 24 1:36 «¢ angular fragments 2 or 3 inches in diameter, 36 214 On the Physical Geology of the United States, Sc. 3 more rapid flow, while the slates and shales whose particles are very minute, and would remain long in suspension, required still and nearly tranquil waters. The limestone deposits have been formed in the thickest masses, where circumstances were favorable to the life of testaceous and radiated marine animals, of whose remains they are in part com- posed. Thick strata of limestone which are continuous and of the same geological age, abound with marine relics in one portion of the country, and are nearly destitute of them in another. It is therefore probable that although organic secretion azded in the formation of the limestone, it is not the sole cause. Testacea and Radiata are also found in some of the sandstones and slates, but they are comparatively rare. The sandstones and slates, however, are frequently found to contain abundance of the remains of the vegetable kingdom. All this great mass of rocks over an area of more than a mill- ion of square miles, and several thousands of feet in thickness, is composed of the wrecks of older rocks (except the parts of or- ganic origin) that have been disintegrated, ground up by attrition, washed away and deposited from suspension in water over the vast area where we now find them. Each layer of these rocks must once have been the bed of the ocean, over which at suc- cessive times and under modified circumstances, these various materials have been deposited in succession, to form the immense mass now exposed to the observation of man, many of the strata of which are some hundreds of feet above the level of the sea. It is evident that these rocks were formed in the ocean, for the following reasons. Ist. They are filled with the relics of animals such as are analogous to those living in the sea, and not to those of the fresh water. 2d. These relics are so perfect that many of them must have lived, died, and been entombed where we now find them. 3d. The materials of which the rocks are composed, are such as are commonly transported, and held in suspension and solution in water. Ath. The oblique lamination of the sandstones shows the di- rections of the currents that deposited them. 5th. At almost every point of the area mentioned, where deep borings have been made far below the flowing waters of the ad- 4 On the Physical Geology of the United States, Sc. joining valleys, salt water has been found, containing the same impurities as the waters of the ocean.* This salt water, on ac- count of its greater specific gravity than common water, might be expected to remain, filling the pores and vacuities of the rocks, the particles of which had been deposited in the bottom of the ocean. A minute examination of the sedimentary rocks, shows that they are composed of the fragments and comminuted grains of older and well known rocks, which have been washed away and deposited far from their original situations. Whence has this immense mass of fragments of older rocks been derived, that is found to have been deposited over this vast area in the United States? Are there any causes known, ade- quate to explain its origin? It may be said in answer, that there are data known from which we may reason with a probability of attaining an approxi- mation to truth. This subject is one that has scarcely been broached, and the causes that will be adduced as having proba- bly produced the transportation and deposition of a mass of such great thickness and extent, are such as may have been equally active on other parts of the earth’s surface. Before entering fully into this subject, it is necessary to con- sider some of the dynarnical causes that may have had an influ- ence in the production of the numerous and extensive sedimen- tary deposits upon the surface of the globe. Ist. It is generally admitted that the earth is a cooling body ; at least that its surface hasa much higher mean temperature than the regions of space in which it performs its revolutions around the sun; that the temperature increases rapidly from near its surface towards its centre ; and that it loses more caloric by ra- diation than it receives from the sun ;—in all which respects it is in the state of a cooling body. 2d. Cooling bodies diminish in volume. 3d. Bodies revolving on axes if diminished in volume, the quantity of matter remaining constant, revolve with increased angular velocities. * [have found bromine and iodine in several of the salt springs of Ohio. I have lately made some quantity of salts of bromine, and separated the pure bromine from the bittern of the salt springs near Athens, Ohio. The usual saline sub- stances of bittern are found in these springs except sulphates. On the Physical Geology of the United States, Sc. 5 If we apply these principles to the earth, which may be ad- mitted to be a cooling and revolving body, it must have dimin- ished in volume either secularly or paroxysmally. ‘This must necessarily have induced a greater velocity of rotation on its axis, also an increased centrifugal force, and the oblateness of the spheroidal form of the earth must have been increased in the same proportion.* The increased oblateness of the spheroidal form of the earth by the increase of the centrifugal force, would induce a flow of water from the polar to the tropical parts of the earth to restore the form of equilibrium of the revolving spheroid under these modified conditions; and as the earth revolves from W. to E. these currents from the polar regions would bend more and more to the westward as they advanced to lower and lower latitudes, and a current would set from E. to W. within the tropics, but strongest under the equator.t The polar and equatorial currents, branches of which are be- lieved to have been observed in every ocean, but variously modi- fied in direction by numerous causes, may have been thus estab- lished or heightened in the rapidity of their flow at particular epochs in the earth’s history. Another cause that may have been instrumental in the first instance in establishing, and subsequently in maintaining the flow of the polar and equatorial and other currents of the ocean, is the influence of the solar rays on the tropical regions of the earth. This influence is exerted both on the atmosphere and on the ocean, but both concur in aiding the flow of the currents under consideration. 'The water of the ocean being warmed more un- der the tropics than on other parts of the earth’s surface, expands, we ary Se r=" If ¢ represents the time of rotation, V== —>— and by substitution, I =e F:F!::75: gg These formule show that the centrifugal force va- ries directly as the square of the velocity of any point, and inversely as the dis- tance of that point from the axis of motion; and also that the centrifugal forces vary directly as the distance from the axis of rotation, and inversely as the squares of the times of rotation. t The reason of this deflection of currents will be explained farther on in this article. t It has been objected that the evaporation from the surface of the ocean under the tropics would compensate for this expansion; but it would be insufficient if the water becomes heated to 8U° to any considerable depth. The quantity of water that falls as rain, also in part compensates for the evaporation. 6 On the Physical Geology of the United States, &§c. and tends to flow off towards the polar regions, while an under- flow of colder and heavier water restores the equilibrium. The real effects of this cause may be deemed theoretically true without having any sensible influence; but the geological effects in the development of organic life, when considered in connection with the flow produced by other causes, are not unim- portant, and will be considered in another place. The effect of the solar rays upon the atmosphere, panbiGalaly under the tropics, is to produce a rarefaction of the air, and ascending currents that flow off toward the polar regions, and a counter flow from the polar towards the tropical regions, restores the equilibrium.* The northwardly compensating current of the atmosphere over the eastern part of the Atlantic Ocean, as it reaches successively lower latitudes, bends more and more to the westward until un- der the tropics it forms the trade wind.t 'This sweeps to the westward and by its constancy and moderate limits of variation in direction, gives great aid to the equatorial current of the ocean, and is perhaps more effective in producing and maintaining this current than any of the other causes. Another cause may be adduced for the westward flow of the equatorial current, viz. the current that flows southwardly along the eastern part of the north Atlantic, and that flowing north- wardly from the Lagullas banks along the coast of the southwest * This is the commonly received theory. Many facts are in opposition to this theory and seem irreconcilable with it; but of the great circular flow of the cur- rents of the atmosphere and smaller secondary gyrating currents, there is no doubt, and change of temperature and the rotation of the earth are the main causes. Vide Mr. Redfield’s papers, Am. Jour. Science, Vols. xxv and xuy. t Mr. Espy accounts for the trade winds on another principle, viz. that the up- ward ascending currents as they reach higher elevations and are more remote from the axis of rotation of the earth, have by their inertia a different linear velocity from that due to a point rotating at that distance from the axis with the same an- gular velocity, and as the earth rotates from W. to E., these uprising columns of rarefied air have a relative retrograde motion with regard to the surface of the earth, giving rise to a general westwardly motion of the air under the tropics, This cause however can have but little influence in the production of the trade winds, for, if we suppose uprising columns of air to exist and to ascend twenty miles in height, which is far more than we have any evidence of in the clouds, the increased velocity due to a point at this distance would be only 62-83 miles more in twenty four hours, than that of a point on the surface at the equator, or less than three miles per hour, which would produce a retrograde or westwardly wind scarcely perceptible there, and would influence the currents near the surface of the earth still less, in an almost infinitesimal degree. . On the Physical Geology of the United States, &§c. 7 part of Africa and towards St. Helena and Ascension, meet nearly in opposition to each other under the tropics; and although the velocity of the currents is small, the opposite momenta have a tendency to elevate the waters of the ocean higher than the true water level, the same as when a tide is obstructed by a coast, it rises higher than it would if unobstructed. The tendency of the water to restore the equilibrium would be to the westward and to the eastward. 'The flow to the eastward is partially obstructed by the African coast, but the eastward current by Cape Palmas and Cape Threepoints, and around the Gulf of Guinea, may be caused in part by this tendency.* ‘The flow to the westward in the direction of the equatorial current, is the one by which the equilibrium is mostly restored, for two reasons; Ist, the flow in that direction is unobstructed; and 2d, the waters coming from higher latitudes, where the linear rotative velocity of the earth’s surface is less than under the tropics, the tendency of the water is to flow to the westward. Another cause tending to aid in the production of the polar and equatorial currents may be adduced, although its real influence may be very minute. The evaporation from the tropical regions of the earth exceeds the amount condensed as rain, fog, and dew, and this excess is carried to the temperate and frigid zones by the great currents of the atmosphere, where it is condensed as rain, snow, fog, and dew. The excess of water deposited from the atmosphere in the extra-tropical regions, more than is evaporated, falls and flows into the ocean. The ocean level in those regions, particularly along coasts where large rivers debouche, may be said to be slightly raised above the level of the spheroidal form of equilibrium of the earth, and the water in consequence of its mobility, will tend to flow from the polar and temperate zones towards the tropics. All the various causes that have been mentioned as railadinelie the great currents of the ocean and atmosphere, (and which are the legitimate results of the action of gravitation, variations of temperature, and inertia, while the earth revolves on its axis, ) concur in their effects, and are believed to be the true causes of the Gulf Stream and the great currents of the ocean. The cur- * Currents have been observed between Cape Palmas and Cape of Good Hope, indicating with much probability a gyrating mass of waters in a great eddy be- tween Cape Palmas, Cape Formosa, Cape Negro, and St. Helena. 8 On the Physical Geology of the United States, Sc. rents both of the ocean and the atmosphere have a tendency to a circular flow; those flowing from the equatorial toward the polar regions bend more and more to the eastward as they ad- vance into higher latitudes, while those flowing from the poles towards the equator, bend to the westward as they approach the tropical regions. This may be seen in the southwest winds of the United States and the Gulf Stream, in one case—and in the prevailing currents of the atmosphere and of the Atlantic Ocean, that cause the trade winds and the equatorial current, in the other.* The bending of these currents of the ocean and of the atmo- sphere to the eastward in the northwardly flow, and to the * In regard to the great currents of the ocean, the following are said to have been distinctly recognized as permanent, and with slight variations in velocity. Nu- merous local and variable currents have been noticed, which are caused by sub- divisions and deflections of the more general ones, and by those causes that pro- duce eddies. Theory would render others probable that have not been recognized. A. (1.) The equatorial current of the Atlantic is divided by the eastern coast of South America into two branches. The larger flows to the W. and N. W. into the Caribbean Sea and Gulf of Mexico, causing a higher level than that of equilibrium, and a flow through the Gulf of Florida called the Gulf Stream; the other flows along the coast of Brazil toward Sandwich Land. (2.) The equatorial current of the Pacific has a very moderate westward flow, which is nearly uniform and constant, like the trade winds in the central and western parts of that ocean. Branches of this current are said to set northward along the coasts of China and Japan, corresponding to the Gulf Stream; and southward by New Holland toward the Antarctic regions. (3.) The equatorial current of the Indian Ocean has a northwest flow, caused by a deflection of the same current from the Pacific among the reefs and islands between which a part of it passes, and by the southwardly polar current. The northwest current flows west from Cape Comorin to the African coast, thence along that coast through the Mozambique Channel to the Lagullas Banks near the Cape of Good Hope, where it meets the Lagullas current from the Antarctic seas. Numerous ccunter and variable currents are also found in the Indian Ocean. B. (1.) The polar current from the north issues from Davis’s Strait and floats icebergs even against the wind, and against the Gulf Stream in the vicinity of the Banks of Newfoundland. This current proceeds southwardly, and owing to the rotation of the earth, it presses to the westward along the coast of the United States, and gives that coldness to the water that modifies so materially the climate. (2.) Another polar current sets from the north in the Atlantic Ocean near its eastern shore, and these two polar currents by their action on the Gulf Stream, deflect a part of its waters across the Atlantic and along the western coasts of Eu- rope, to join again the equatorial current. (3.) Part of the Lagullas current flows along the southwest coast of Africa to- wards St. Helena and Ascension, to join the equatorial current. (4.) Another in the Pacific sets along the west coast of South America to join the westward flow from the Gallipagos. On the Physical Geology of the United States, &c. 9 westward in the southwardly flow in the northern hemisphere, is due to the same cause, viz. inertia, and the difference of linear velocity of points on the earth’s surface, as the particles of matter of the currents reach successively different latitudes. This may be illustrated by considering that a particle of matter at the equator moves with a linear velocity of about twenty five thousand miles in twenty four hours ; and supposing this particle ‘ (5.) Another from the southward sets into the Indian Ocean near the coast of New Holland. Very numerous currents depending on prevailing or periodical winds, like the monsoons, exercise much influence in particular parts of the oceans upon the cur- rents mentioned. The following references may aid those who wish to trace the state of present knowledge on the currents of the ocean and atmosphere. De La Becie’s Geological Manual, American edition, pp. 90—101. Purdy’s Atlantic Memoir. Kotzebue’s Voyages. Lyell’s Principles of Geology, Vol. 1. Lartigue, Description de la Cote du Pérou. Franklin’s observations, Am. Phil. Transactions, Vol. 1, p. 314. Blagden on heat of Gulf Stream, Phil. Trans. Royal Society, 1781, p. 334. Rennel on heat of Gulf Stream, Phil. Trans. Royal Society, 1793, Vol. txxxu1. Wollaston on heat of Gulf Stream, Phil. Trans. Royal Society, 1824. Poronall’s Hydraulic and Nautical Observations, quarto, London, 1787. Uumboldt’s Political Essay on New Spain, Vol. 1, p.53. Hum- boldt's Voyage to the Tropics, Vol. 11. Young’s Nat. Phil. Espy on Storms. Daniel’s Meteorological Essays. Redfield, American Journal of Science, Vols. xxv and xtv. Maury, (Lt.) American Journal of Science, Vol. xtvi1; Southern Literary Messenger, and Army and Navy Chronicle. Edinburgh Encyclopedia, Am, edition, Vol. x, pp. 158—159. Ed. Encyc., “‘ Navigation,” Vol. xiv, pp. 209—213. Ed. Encyc., “‘ Phys. Geography,” Vol. xv, p. 579. Ed. Encyc., “ Hy- drography of polar regions,’ Vol. xv1, p. 6. The modes of observation by which the set and flow of currents have been de- termined, are deflective, and liable to error; it is desirable therefore, that accurate observations should be multiplied in every ocean, in every latitude and longitude, with a view to elicit truth. A knowledge of the set and flow of ocean currents, local as well as general, and the laws that govern them, is readily perceived to be of the highest importance to the interests of navigation, and to the whole world. Such knowledge can only be obtained by amassing a multitude of facts, systemati- zing them, grouping them, and finally generalizing from them. Individual effort cannot accomplish this. ‘The aid, the influence, and the power of governments are necessary to cause the scattered rays of light to be brought to a focus. If an office be established under the direction of the Secretary of the Navy, where me- teorological registers accurately kept on board all our national ships; records of the set and flow of currents observed on the same ships; the temperature of the waters of the ocean at the surface and at considerable depths, (also made daily when practicable,) and similar records from our merchant marine could be re- corded, and occasionally published—and similar offices under the English, French, and other maritime governments, results may be obtained in a few years of great importance In navigation, and aid in deducing satisfactorily, the laws that regulate the currents of the atmosphere and of the ocean. Vol. xxix, No. 1.—April-June, 1845, 2 10 On the Physical Geology of the United States, Sc. to be moving northward in one of the currents of the ocean or atmosphere, without having lost any of its linear velocity due to the motion of rotation of the earth at the equator, it will, when it shall have arrived at 60° north latidude, still move eastward at the rate of twenty five thousand miles in twenty four hours, which would at that latitude, carry it twice* as rapidly to the eastward as is due to the velocity of a point on that part of the earth’s sur- face revolving around the axis of the earth. The resultant of ‘these two forces, one tending to carry the particle to the north with a moderate velocity, and the other to the east with a ve- locity of five hundred miles per hour more rapidly than the sur- face of the earth moves at that latitude, would give a course nearly east. What is true of one particle, is true of the aggre- gate of particles of the currents of the atmosphere and of the ocean. In the southern hemisphere the tendency of the currents from the tropics is towards the S. E., and those towards the tropics is to the N. W. The causes of the currents under consideration will be admit- ted to be permanent. ‘They must, from the operation of physical causes, have acted through all past time since the ocean has oc- cupied its bed, and the earth revolved on its axis and circled around the sun, and they may be expected to continue to act through all future time. We may therefore reason upon the effects that may be supposed to have been produced by the action of these currents through long periods of past duration. In the Final Geological Report of New York, I have shownt that the contour and relative relief of the country at, and imme- diately preceding the drift and quaternary epochs, while most of the present land of the United States was beneath the level of the sea, was in the main the same as now, and that the land was elevated in mass, with little relative change of position. The same may be shown to have been true at preceding epochs, with * Let y and 9’ represent the distances from the axis of rotation, R the radius of the sphere, and lJ the latitude. y:9!::R:cos.l.:. Ry!=ycos./, but cos. G0° — SR .-..9! = 69.00o)-4 asap Be cites of circles are proportional to their radii, the motion of a point ona sphere at 60° from the equator would be half the velocity of a point on the equator revolving around the axis of the equator. t Natural History of New York, Part IV, Geology of First District, by W. W. Mather, pp. 152-154, 629. On the Physical Geology of the United States, fc. 11 some comparatively local exceptions.* This is not mere hy- pothesis. 'The evidences will be adduced in the discussion of the causes and periods of elevation of the land and mountains. The primary ranges of rocks and mountains of the Atlantic states, those of northern New York and north of the great lakes, and those of the Rocky Mountains and Cordilleras of Mexico, existed in the same relative position as now before the deposition of the newer sedimentary rocks of the United States.t Similar primary ranges in South America give form also to its coasts. We will here withdraw our attention from the great equilibra- ting currents of the ocean, and consider only that part of the compensating system of circulation that constitutes the equatorial current, the Gulf Stream and the Labrador current in the Atlantic Ocean. From the operation of dynamical causes already ex- plained, the currents here alluded to, or others analogous to them in their directions and effects, may be supposed to have flowed during long periods, when the largest portion of the American continent was beneath the level of the sea. _ The equatorial current in its westward flow, may be supposed to have been deflected by the primary ranges of the coast of South America, (or at least by the Andes,) in part to the south- ward over the vast pampas, but mostly to the northward through the Caribbean Sea, the Gulf of Mexico, and over the broad val- leys of the Mississippi and St. Lawrence, which were then parts of the ocean. As the direction of the equatorial current before its obstruction was to the west, if deflected by the eastern coast of South Amer- ica, its course was then as now to the N. W., as above men- tioned ; but bending around more and more to the N., N. E. and K. as it progressed into higher and higher latitudes, in conse- quence of the dynamical law already explained. ‘This current flowing to the W., N. W., N. and N. E., would progress by the base of the Cordilleras to the N. and N. E. towards Hudson’s Bay ; another part deflected still more to the east by the primary range in Arkansas and Missouri, and by meeting the polar current from the north through the Mississippi valley,t seems to have flowed * The Green Mountains, Highlands, the Apalachian chain, &c., large in them- selves, but local when we consider the vast expanse of undisturbed rocks. t The evidence of this, is their unconformability. t The evidence of the transport by such currents in this direction, is found in the transported materials of various degrees of coarseness in Mississippi, Alabama, and Louisiana, &c. vies go? eee: 40", al 12 On the Physical Geology of the United States, &c. over the territory occupied by Missouri, Iowa, Illinois, Indiana, Michigan, Ohio, and Upper Canada, and thence eastward over Lower Canada and New York through the St. Lawrence and Mohawk valleys. The branch through the Mohawk valley would be deflected more to the E. and S. BK. by the polar cur- rent through the Champlain and Hudson valley,* and again to the S. and S. W. by the Green Mountains and Highland ranges. A circular flow would thus be induced, and nearly all the ma- terials transported by the equatorial current, from whatever sources they had been derived, may be supposed to have been deposited within this great eddy. 'These currents, as conse- quences of known dynamical laws, must have flowed in the way indicated from the period of the elevation of the primary ranges, until the continent was raised above the level of the ocean. We know also that marine currents are constantly transporting earthy and organic materials, depositing them at places more or less remote from their origin, and that they now circulate over vast areas of the ocean. It is believed therefore, that the ocean currents offer a satisfac- tory explanation of the transportation and deposition of the im- mense mass of the sedimentary rocks between the primary ranges north of the great lakes and the Gulf of Mexico, and between the Blue Ridge and the Rocky Mountains. Other areas of similar rocks and connected with that described, occupy a part of Vermont, the southern part of Lower Canada, parts of New Brunswick, Nova Scotia, Maine, Massachusetts and Rhode Island. They are believed to be due to the same causes acting more extensively than we have considered them, in which the mountain regions of northeastern New York and of New Eng- land were islands. Even"this is supposed to be but a limited view of the effects of these currents in the northern hemisphere, and the similar rocks of Europe may have been due to the same causes— the same currents. The uniformity of composition of the par- ticular masses, whether thick or thin, their similar mineralogical * The evidence of acold current from the north through the Champlain and Hudson valley, is treated of and believed to be established in the Geological Re- port of New York, by the author of this paper, in Part IV, Vol. 1, pp. 150-154, 225, 293, 299, 274-275, 277-278, in 4to. Albany, 1843. The subject of currents as aiding in the transport of materials, scoring of rocks, influence on organic life, and the evidences of their directions, are treated of under the quaternary, drift, and red sandstone formations in the same work. On the Physical Geology of the United States, §c. 13 characters over vast areas, the general similarity of organic con- tents not only on the American continent but even in Europe, indicate that the causes of these depositions and the conditions under which they were deposited from the ocean, acted with great uniformity over extensive portions of the earth’s surface. The polar and equatorial currents are believed to be adequate for the production of the effects observed. Without farther expla- nation, the foregoing conclusion might be deemed unsupported by other evidence than probability. In the final Report on the geology of the first district of New York, I have adduced the facts that first led to the observation of the directions of currents during the deposition of the sedimen- tary rocks. These facts when grouped, led from one generaliza- tion to another, until it was found that the cause was not con- fined to the United States or Europe, or even to the northern hemisphere, but in like manner affected the southern. The cause then was one affecting the earth. ‘The great and perma- nent currents of the ocean, modified in direction and velocity by known physical laws, by the trend of coasts, and the contour of the former bed of the sea, were found to harmonize with the phenomena of depositions in the United States. In the geological report above referred to, I have shown, (1st,) by means of the direction and distance of transport, that the distribution of bowlders and drift is such as would necessarily be the result, if such currents existed; and that the probabilities are that no other cause could have distributed them in a manner so peculiar.* 2. That the quaternary, composed of sands, clays, and loam, so extensive and uniform in composition and aspect, must have been owing to a cause as general as this.+ 3. That the sand and gravel beds of the quaternary, so exten- sive in some parts of New York, are situated where conflicting currents must necessarily have met and formed eddies, if the country was beneath the level of the ocean.} A, That the distribution of organic life, (being extremely abundant in some parts, and as rare in the same continuous rocks * Natural History of New York, Part1V, Geology of Ist District, by W. W. Mather, pp. 197, 210-213, 217, 218, 222-228. t Idem, pp. 129, 148-156. ¢ Idem, p. 148-150, ite as) 14 On the Physical Geology of the United States, &§c. in others,) corresponds with the supposed position of the warm equatorial current and the cold polar flow, favorable to the devel- opment of animal and vegetable life in the one case, while in the other, few traces of organization have been preserved.* 5. The amount of deposition has been greatest where currents must have been obstructed by conflict with each other and had their velocities lessened, and where islands and irregularities of the bottom of the former ocean produced the same effect.t 6. The coal formations of the United States are situated where, from the contour of coasts, islands, and the bottom of the ocean, the grand eddies would necessarily be formed, and in which plants brought from the tropics or other sources would float and circle around until they sunk.{ 7. That the cretaceous and tertiary formations, as characterized by abundant remains of organic existence, extend little farther to the north than Sandy Hook, caused it is believed by the polar flow through the Hudson valley, having mixed with the warm Gulf Stream and cooled the waters too much to favor the de- velopment of organic life.¢ 8. That the red sandstone formation which extends from Car- olina to Stony Point on the Hudson, and also believed to have been formed by the Gulf Stream, stops abruptly on the west shore of the Hudson River. The farther extension of the for- mation in that direction seems to have been cut off by the polar current flowing through the Champlain and Hudson valley, sweeping away the materials that were brought into it by the Gulf Stream. || 9. The fossil shells thus far found in the quaternary formation of the Champlain and Hudson valley are of an arctic character, corresponding to those of the Gulf of St. Lawrence, and those of Scotland, Denmark, Norway, and Sweden, indicating with * Natural History of New York, Part IV, Geology of Ist District, by W. W. Mather, pp. 274-275, 277-278, 295-296, 299. t Idem, pp. 129, 148-151, 223-225, 273-274, 289-293, 295-296, 299. { Idem, pp. 275, 295-296. § Idem, pp. 150-151, 274-275, 299, || Idem, p. 293. The evidences of a polar current in this valley during the qua- ternary and drift epochs had already been adduced; those of more ancient times, during the deposition of the Silurian rocks, are subsequently adduced when treat- ing of the rocks of the New York system. J Idem, p. 278; also Annual Geol. Report of N. Y. 1841, p. 47, by Mr, Conrad. On the Physical Geology of the United States, §c. 15 much probability a current from the north. Other evidences of such a current have been observed. 10. The great coal formations of the eastern and central por- tions of the United States are based upon a sandstone which, at its outcrop on the edges of the coal basins, is a conglomerate or coarse sandstone, and sometimes a very coarse puddingstone, while towards the centre of the basin itis much finer. This fact indicates a stronger flow on the exterior of the coal forma- tion than within its area. This is in strict conformity with the supposed origin of the coal formation—being formed in eddies, and that stronger currents immediately preceded the coal forma- tion. Periods of comparative repose, with gently varying cur- rents, preceded and succeeded the deposition of the conglome- rate, and strata of slate, shale, sandstones, limestones, &c. were extensively and abundantly deposited. 11. The tertiary and upper secondary formations of the east- ern and southern parts of the United States, and between the Mississippi River and the Rocky Mountains, may be attributed to the action of the Gulf Stream, and to a similar current on the western side of the Mississippi valley, before our continent was raised to its present level.* Examples might be multiplied indefinitely in illustration, and much space would be required for a full development of the sub- jects of this paper. I have treated of general principles and masses of facts as connected with the physical geology of the sedimentary rocks of the United States, without going into de- tails on local geology. All that is known in relation to the sedimentary rocks of the United States, from the oldest transition to the quaternary forma- tions, harmonizes, I believe, with the views here advocated of the causes of their transport, deposition, distribution, and organic contents; while on the other hand, I am not aware of any argu- ment that can be urged in opposition to its probable truth. We may therefore conclude, that the great masses of the sedi- mentary rocks of the United States have been deposited by marine currents before the continent fully emerged from the ocean. * Natural History of New York, Part IV, Geology of Ist District, by W. W. Mather, pp. 229, 274, 292. ei . Wee? ets 16 On the Physical Geology of the United States, §c. Thus far we have considered the causes of the great equili- brating currents of the ocean; the physical laws regulating their circulation, and the influences of these currents on organic life, and on the deposition of the sedimentary strata. It remains to consider whence the materials of the sedimentary rocks have been derived, that have been transported by currents, and depos- ited over so vast an area and of such great thickness in the Uni- ted States. If the great currents of the ocean have flowed in times past as we have shown from physical causes they must be supposed to have flowed, the greatest proportion of transported earthy matter in the northern and eastern parts of the United States (except between the mountains and coast) must have been brought from the northward and spread to the south and southwest,—the gen- eral trend of transport according to the physical law that has been explained, tending to the southwest by means of the polar current. Other large quantities, together with tropical plants and animals transported by the equatorial current in its north- wardly flow, would be spread over the areas occupied by the sedimentary rocks of the United States and British possessions, from the south to the north and northeast ; and by the blending of the currents, and the deflections caused by this and by obsta- cles in particular parts, would be spread in various directions as we now find them. Of the materials swept from the south and east by the equa- torial current, we can have little direct evidence. This current sweeps, and has in times past swept over vast areas of the bed of the ocean, and along coasts and reefs of rocks, from which large quantities of detrital matter might, in the course of un- numbered ages, be supposed to have been swept away and trans- ported to distant parts. Of the capacity of such a current to transport floating plants in ancient times to form our coal deposits, and the various traces of vegetation so common in all our sedi- mentary rocks below the coal formation, we have only to look at the effects of the present Gulf Stream, one branch of which carries large quantities of drift timber from the coasts of South America, the Gulf of Mexico, and the shores of the Atlantic, and lodges them on the shores of Labrador, Greenland, Iceland, Spitzbergen, Norway, and the Scottish islands ;* and the other * Lyell’s Geology, Lond. edition, 1833, p. 251; Malte Brun’s Geography, Part I, p.112; Edinburgh Encyclopedia. On the Physical Geology of the United States, §c. 17 carries the gulf-weed and other floating bodies, and finally col- lects them in the centre of the great eddy of the Atlantic be- tween the Cape de Verd, the Azores and Bahama Islands. This tract of the ocean has been known for more than three hundred and fifty years to be covered with such quantities of floating sea- weed, plants, wood, &c. as frequently to impede the passage of ships. These floating bodies are supposed to circle around in this grand eddy (which is said to occupy a million of square miles, called the grassy sea and Sargasso sea) until they become water logged, loaded with marine shells, or decayed, and sink.* The transport by the polar currents during the drift epoch is believed to be satisfactorily established ; and it has been shown to be highly probable, perhaps almost certain, that the phenome- na of the drift deposits are conformable to the action of the polar and equatorial currents. The phenomena of the transportation of the materials of the more ancient formations, have not been studied so attentively as to demonstrate the same sources and di- rections of transportation, but we may infer it as probable ina very high degree, that large quantities of earthy materials were transported by the flow of the polar currents over the barren and rocky regions in America, Europe, New Zealand, &c. where from the operation of physical causes the currents would flow from the poles towards the equator with a less depth and greater velocity than on other parts of the earth.t We may also infer it from the fact that the thicker masses of the coarser sediment- ary rocks that are not calcareous, have been deposited in those parts where the polar currents in the United States must neces- sarily have flowed, when most of the continent was buried be- neath the waters of the ocean. ‘Those parts of the earth over which the polar currents are supposed to have flowed in ancient times, and from which they are supposed to have washed away the materials of the sedimentary rocks, are represented by all travellers as barren, unproductive, rocky and inhospitable wastes. * Natural History of New York, Part IV, Geology of 1st District, by W. W. Mather, pp. 295-296. Vide Lt. Maury’s paper on ocean currents for a more full description; Army and Navy Chronicle, Lil, pp. 661-667 ; Southern Literary Mes- senger, Vol. X, No. 7, July, 1844; and American Journal of Science and Arts, Vol. xtvu1, p. 161. ‘t The reasons for this supposition willbe treated of in the discussion of the elevation of the continents above the ocean. Vol. xu1x, No. 1.—April-June, 1845. 3 18 On the Physical Geology of the United States, &§c. Heriot in his travels through the Canadas says of the vicinity of the river Moisa, north of the St. Lawrence—‘ No country can exhibit a more wild aspect than that which here extends on either side of the river. Stunted trees, rocks and sand, compose these inhospitable and desolate territories, which cannot boast of an acre capable of yielding any useful production.”* The same traveller, speaking of the vicinity of Camarousca, says—‘‘ The sulphureous springs found here, and the immense masses of bro- ken rocks, which appear to have been thrown together by some violent and uncommon effort of nature, afford grounds for sup- posing that this part of the country has undergone material changes.’”’* Speaking of Newfoundland, near the harbor of St. Johns, he says—‘‘It is bordered by dark and gloomy rocks, which exhibit a barren, inhospitable appearance ; the country on a nearer view of its soil belies not the character of its rude unin- teresting features, which amid their nakedness, display neither grandeur nor sublimity.”’} Hearne, describing his journey to the Arctic sea, speaks of Marble Island, on which Messrs. Knight and Barlow were wreck- ed, and they and all their ship’s crew perished, says—‘‘ Neither stick nor stump was to be seen’’—“ the main land is little better, being a jumble of barren hills and rocks, destitute of every kind of herbage except moss’’—‘“‘ and the woods are several hundred miles from the sea-side.’”’¢ Again he says—‘ With regard to that part of my instructions which directs me to observe the nature of the soil, it may be ob- served that during the whole time of my absence from the fort, IT was invariably confined to stony hills and barren plains all the summer.” In latitude 68° N. and longitude 119° W. of Greenwich, Hearne came to the Stony mountains, and he says—‘‘No part of the world better deserves the name. On our first approaching these mountains, they appeared to be a confused heap of stones, utterly inaccessible to the foot of man.” Again—“ The face of the whole country from the 59th to the 68th deg. of north latitude—be- tween Hudson’s Bay on the east, and the Athapusean Indian * Heriot’s Travels, p. 70; also Hayden’s Geological Essays, pp, 70-71. t 6c “6 p- 38 ; (73 (79 66 ce 66 (74 t Hearne’s Introduction, p. 29. § 6c 6c p: 18. On the Physical Geology of the United States, §c. 19 country on the west, is scarcely any thing but one solid mass of rocks and stones, and in most parts is hilly.’* McKenzie says—‘ There is hardly one foot of soil to be seen from one end of French river to the other, its banks consisting of hills of entire rock.” ‘The coast of Turtle lake is the same, but lower.” ‘The country has the appearance of having been overrun by fire, and consists in general of huge rocky hills.”’+ Speaking of the country north of Lake Superior, he says— “The face of the country offers a wild scene of huge hills and rocks separated by stony valleys, lakes and ponds.’”’{ -After giv- ing a general view of the country northeast of the lakes, he says—‘ Of this great tract more than half is represented as barren and broken, displaying a surface of rock, and fresh-water lakes, with a very scanty proportion of soil. Such is the whole coast of Labrador, and the land called East Main, to the west of the heights which divide the waters running into the river and the Gulf of St. Lawrence, from those flowing into Hudson’s Bay.’’$ Captain Cook, seeking a northwest passage, says—‘‘' The ap- pearance of the country (North America) in latitude 57° 3’ N., discovered little else than naked rocks.”|| Also—‘ The barren isles in latitude 59° N., are composed of naked rocks.’ ¥ The various travellers over the country within the United States between Lake Superior and the sources of the Mississippi, over a great breadth of country, give the same general characters of a rocky, barren, hilly region, with numerous small lakes.** The same general characters hold true of Norway, Sweden, Finland, Lapland and Iceland in the northern hemisphere ; and of New Zealand, Patagonia, Sandwich Land, Graham’s Land, &c., in the southern hemisphere. We perceive from these and other descriptions of travellers and voyagers, that in those parts of the earth where the polar currents would have the greatest velocity and least depth,ty the * Hearne’s Travels, p. 227. + McKenzie’s Travels, pp. 36, 37. Vide also Hayden, Geol. Essays, pp. 72, 73. ¢ McKenzie’s Travels, p. 49. § McKenzie’s Travels, p. 426. || Cook’s Voyoges, II, p. 186. 1 Cook’s Voyages, II, p. 193. ** Schooleraft’s Travels. Lieut. Allen's Report to Sec. of War, 1834, &c. tt Vide p. 17 of this article. 20 Prof. Snell on new articles of Philosophical Apparatus. surface of the earth is destitute of soil, and is formed of bare and almost naked rocks that show few traces of vegetation. Although the quotations from travellers lack that accurate ex- amination that is necessary to a determination whether the sur- faces thus described have been exposed to the action of violent and long continued currents, yet they have their weight, when considered in connection with the effects of known physical causes, and render it more than probable that the currents under consideration have flowed from the polar regions towards the equator, and from the tropics towards the poles, when this con- tinent was beneath the ocean, and that the matter’of the vast deposit of the sedimentary rocks of the United States was washed away by these great equilibrating currents from the bed of the ocean, from reefs, islands and coasts, and finally deposited from suspension over the great area where we now find it exposed to observation. (To be continued.) Arr. Il.—Account of some new Articles of Philosophical Appa- ratus ; by Prof. E. S. Snexx, of Amherst College. 1. Instruments for illustrating sea waves, and waves of sound. Tue idea of constructing apparatus for such purposes was first suggested to me by seeing acut of Prof. Powell’s machine for exhibiting plain, circular and elliptical polarization of light. ‘The thought struck me that every species of wave motion might be produced mechanically, and that such visible representations might be advantageouly used in giving instruction. I formed the design, therefore, of providing myself with a series of instru-— ments to illustrate the oscillatory* waves of the sea, the acoustic waves of the air, and the undulations of the luminiferous ether, both ordinary and polarized. For the two first, which presented the least difficulties, I soon devised and executed a simple and convenient mechanism; and the instruments have more than answered my expectations in their operation and in their value as means of instruction. * See Russell’s classification of waves, Reports of British Association, 1837, p. 425, and Vol, xxxvuii, p. 100, of this Journal. Prof. Snell on new articles of Philosophical Apparatus. 21 Figures 1 and 2 present a view of the two instruments as they stand connected in the philosophical cabinet. They are, how- ever, entirely distinct, and the upper one may be removed from the lower, and either of them taken into the lecture room by itself. Fig. 2 exhibits the movements of sea waves. The box containing the mechanism is about two feet long, one foot wide and seven inches high. The lower half of the front projects beyond the upper half, so as to leave a space one fourth of an inch wide, in which the iron pieces (a a) rise and fall. ‘There are thirty pieces of sheet iron, marked (a a), three fourths of an inch wide and four inches high, standing as closely as possible without danger of contact. They are painted black, to appear in strong contrast with the white front, which forms the ground behind them. These represent columns of water, and by turning the crank are made to rise and fall in such order that the waves which they form advance regularly in one direction and pass off, while other waves form and succeed them perpetually. If an observer fixes his attention upon the form of the waves, he sees them roll along horizontally, like billows of the ocean; but the moment his attention is directed to a single column, he as plainly 22 Prof. Snell on new articles of Philosophical Apparatus. sees it simply rising and falling in its place. He is thus enabled to conceive of the co-existence of these two facts with a distinct- ness not easily acquired in any other way. The motion is produced in the following manner. Hach piece of iron is fastened at its lower extremity toa stiff iron wire, which is bent upward three inches just within the front, and thence proceeds horizontally to the back side of the box, where it is se- cured by a pivot, allowing only of vertical motion. Each wire with its strip of sheet iron forms a lever of the third order, which should rise and fall with the greatest freedom, while lateral mo- tion is prevented by perpendicular guides. The axis, turned by the crank (6), is placed as near the front as possible, and extends the whole length of the box. It is furnished with thirty excen- tric cams, each of which gives vertical motion to one of the wire levers just mentioned. Fig. 3 shows a section of the box, per- pendicular to its length, with a lever and its supporting cam; (a) represents a vibrating column; (0) the lever; (¢) its pivot; (d) the cam; (f) the axis; (g) the guide, which prevents lateral motion. 'To produce the wave motion already described, the cams must obviously be arranged according to a uniform law, the summit of the second being turned a given number of degrees farther round on the axis than that of the first, the third than the second, and so on through the whole. The axis with its entire series of cams will thus have the form of a helix. The exhibi- tion of the instrument is most satisfactorily made, by presenting it first in a room partially darkened, so that the intervals between the columns are invisible. On turning the crank the illusion is complete—a liquid, or at least something flexible, is seen to roll in dark horizontal waves, and no other motion is dreamed of. But on admitting the light it is immediately apparent that every moving particle oscillates in a perpendicular direction, and has no other motion whatever. Fig. 1 represents the instrument designed to illustrate acoustic waves. 'These are waves of condensation and rarefaction; and the molecular vibrations are made in the line of wave motion, and not perpendicular to it, as in sea waves, which may be termed waves of elevation and depression. The box is of the same length as the other ; its breadth and height are a little less. The front is constructed in the manner already described. ‘Thirty slips of japanned sheet iron (ee), one and a half inch long and Prof. Snell on new articles of Philosophical Apparatus. 23 three eighths of an inch wide, project upward nearly their whole length between the two front boards. ‘These slips are taken to represent a series of atmospheric particles. It may be supposed that a line of balls, supported on slender white wires, would be a more appropriate representation. This was tried, but found not to make a sufficiently distinct impression of waves. A broad band rather than a delicate line needs to be seen in motion. The points of greatest’ condensation are at (d,d,d); and those of greatest rarefaction at (7,7). As the crank is turned, the waves of condensation and rarefaction advance regularly in one direction, constantly succeeded by similar waves, that are every moment forming themselves anew. It is more difficult in this case than in the former to render the molecular vibrations invisible, and to fasten the observer’s attention wholly upon the waves. This effect is best accomplished by employing oblique vision. Let the observer look directly at some object about two feet above or below, while his attention is still directed to the instrument, and he will, without much distraction from the motions of the indi- vidual parts, receive an impression of dark waves travelling over the length of the box in regular and constant succession. Then, on turning the eyes upon the machine, each molecule is readily seen vibrating back and forth in the line in which the waves are running. A similar formation of condensed waves occurs in the legs of the centipede when walking. The operation of this instrument is less interesting to the casual observer than the other; but in the hands of the lecturer it is far more valuable to the pupil, because the subject to be illus- trated is not so easily understood. But here, as in the other case, a glance of a few moments will give one a clearer conception of the manner in which a minute vibration of every particle of a substance in regular order, I will not say occasions, but zs the same as a succession of waves advancing through it, than can be obtained in many hours by means of verbal description. Indeed, I believe many individuals, by witnessing this experiment, soon comprehend the circumstances of a phenomenon, of which they would never have formed a distinct conception without such aid. The several pieces of iron (ee) receive their motions from a cylinder three inches in diameter, running lengthwise through the box near its front, and turned by the crank (g). The surface of the cylinder is cut by thirty grooves, three sixteenths of an inch 24 Prof. Snell on new articles of Philosophical Apparatus. wide and of about the same depth. Each groove lies in a plane cutting the cylinder obliquely, and is of course an ellipse. But the several planes are not parallel. The second groove is revolved on the cylinder a certain number of degrees from parallelism with the first, the third holds the same relation to the second, and so of all the rest. The slips of iron (ee) at their lower extremities are firmly attached to as many horizontal levers, which extend to the back side of the box, where they are confined by vertical pivots allowing free motion horizontally, but in no other direction. Hach lever, passing just beneath the cylinder, is furnished with a short smooth iron pin projecting upward, which runs freely in one of the oblique grooves, and thus receives a horizontal oscil- Jatory motion. The ends of the levers near the front are sup- ported on a soft smooth edge, made by stretching morocco leather over a thin metallic plate, which extends through the length of the box. By this means the levers move silently and with little friction. Fig. 4 presents a cross section of the box; (e) is one of the vibrating pieces; (2) the lever to which it is attached ; (p) the pivot; (s) the leather edged support; (¢) the grooved cylinder. ‘ The fore-mentioned arrangement of the grooves causes the vibrating pieces to arrive at a given phase of their oscillations in regular succession. 'The same remark might be made of the cams and iron columns in the other machine. Indeed, this reg- ular gradation of all possible phases, both in successive particles at the same time, and in the same particle in successive times, is the essential condition imposed on the vibrations of every con- ceivable kind of wave. It is a consequence of this condition that a wave always travels just its length during one vibration of any particle. This and all other relations that exist among the particles of an undulating medium, may be very satisfactorily presented to the eye by means of the instruments I have at- tempted to describe, or others of analogous construction. 2. Instrument to exhibit caustics by reflection. The lecturer on optics, in illustrating the focal aberration oc- casioned by spherical mirrors, wishes to show the caustic curves as produced by reflection. He can indeed easily refer to exam- ples; since these curves are sometimes distinctly formed by a horizontal light on a white cloth beneath an inverted tumbler, Prof. Snell on new articles of Philosophical Apparatus. 25 and on the surface of milk or other white opake substance in a circular vessel. These, however, are inconvenient modes of ex- perimenting for the lecture room. A watch-spring, bent into a circular form and laid on white paper, serves a better purpose. But I have recently furnished myself with an instrument which pre- sents the phenomenon in its greatest beauty; and not only so, but by successive reflections produces caustics of several orders in the most perfect manner. I regard this little instrument as an important addition to our optical apparatus, and think it may not be unworthy of description in a public journal. I procured a steel ring, whose internal diameter was three and a half inches, made by bending and thoroughly welding a square half inch bar. Of course its external diameter was four and a half inches. A much less thickness between the inner and outer circumferences would, however, be sufficient. The interior was then turned in a lathe to as perfect a cylindric surface as possible, and highly polished. This is the essential part of the instrument ; but for convenient use it is mounted in the following manner. The steel ring (7,7), fig. 5, is enclosed in a ring of sheet-brass (aa), and by it secured to a disk of wood (6), from the back of which projects a brass stem; and this stem is united by a tight hinge-joint to the top of the brass pillar (c). ‘The whole stands firm on a heavy base of suitable size, as represented in the figure. The space within the ring is covered with smooth white paper, pasted down on the wood, so as to be perfectly plane. By turn- ing the base horizontally, and the hinge vertically, the face of the ring may be brought into any desired inclination with a sun-beam admitted into a dark room. At a certain inclination, the light reflected from one half of the cylindric mirror will be thrown down strongly upon the paper, forming the ordinary caustic curves, but far more delicate and true than I have ever seen them in any other mode of experimenting. These are marked (1, 1) in fig. 6. If the plane of the ring be less inclined to the beam, the rays will pass across to the opposite half, and after a second re- flection fall upon the paper in caustics of the second order, marked (2, 2). A still further diminution of inclination will reveal the third order (3,3); and in favorable circumstances I have seen the fourth (4, 4), very faintly and delicately traced. The general form of these figures is the same, but the size diminishes from the first order through all the higher ones; the position Vol. x11x, No. 1.—April-June, 1845. 4 26 Prof. Snell on new articles of Philosophical Apparatus. also is every time reversed, since the cusp is necessarily turned away from the surface which produces the last reflection. It should be remarked, that all the orders are never in full view at once, as represented in the figure. When the first is most dis- tinctly formed, no others are to be seen; and generally, when the caustic of either order is brightest, the higher orders are not formed at all, and the lower ones only in part. The caustics of the first order extend only half round the mirror, and are termin- ated by it in opposite points ; but in all the others the two branches intersect, and may be traced round much more than the entire circumference. In proper positions of the instrument, the branches of many successive figures are seen, crowding closely upon the mirror, and upon each other, nearly parallel, and of exquisite del- icacy. A pleasing and instructive experiment is performed by placing a pin perpendicularly upon the paper, and moving it back and forth. Its several shadows run along the curves as tangents, and reveal at once, for each point, the direction of the rays em- ployed in forming it. 3. Apparatus for experiments on inflection and interference of light. There is one class of experiments on inflection and interfer- ence, which, if the instructor in optics attempts to show them to his pupils, must necessarily consume much time. I refer to those in which are employed a metallic screen with minute apertures, and a magnifier, through which the light, having suffered inflec- tion by passing the apertures, falls into the eye of the observer beyond. If any considerable variety of combinations is inter- posed for acting on the light, much trouble is experienced and much time wasted in exchanging one pattern for another. ‘The article [ am about to describe is merely a simple contrivance for reducing the time and labor of exhibiting this beautiful class of optical phenomena. In fig. 7, (a, a) represents a wooden ring one foot in diameter, one inch anda half wide and one fourth of an inch thick, strength- ened by two pieces of the same width and thickness, crossing each other perpendicularly in the centre. (6) is an upright flat pillar fastened to the heavy base (c), and having a height a little greater than the diameter of the ring. A short axis (d) is firmly attached to the middle of this pillar, on which the ring is con- Review of Dr. Jackson’s Final Report, Sc. 27 fined by a nut, and turns with some friction. Thirty six holes, half an inch in diameter, are bored through the ring, having their centres carefully arranged in a circumference concentric with the axis. Another hole of the same size is made near the top of the pillar, with which each one.in the ring comes in range, as it is turned. The plates of punctured lead, and other inflecting ob- jects, are placed upon the apertures in the ring, being let into the surface of the wood by shallow dove-tailed recesses, or fastened in any other convenient way. A light spring (e) falls into a notch in the edge of the ring, whenever the aperture of the pillar coincides with one of those in the ring, as the latter is turned on its axis. The hole in the pillar being once adjusted in the line with the magnifier and the focus of light, the ring may be turned as fast as the experimenter chooses; and the inflecting patterns will all come in succession to the proper place to be seen by the observer. ‘The spring offers a slight check to the motion, as often as an aperture of the ring attains the right position. The instrument here described is already furnished with about thirty varieties of inflecting objects. A large proportion of them are made of sheet lead, with punctures and slits variously com- bined. Other holes are occupied respectively with a net of fine wire, a piece of fine comb, screws of delicate thread, placed almost in contact, &c. A very fine effect is produced by two pieces of fine ivory comb, one fastened in the aperture and the other fixed in a revolving cap; the latter, as it is tarned round, makes, in conjunction with the former, a net-work of all possible angles, while the picture seen through the magnifier every mo- ment changes its pattern and its color in the most pleasing and wonderful manner. Art. IIl.—Review of Dr. C. T. Jacxson’s Final Report on the Geology and Mineralogy of the State of New Hampshire. (Read before the Boston Society of Natural History, by Tuomas T. Bouvs, March 5th, 1845.) THE survey of the State of New Hampshire was made under an.act passed by its legislature during the session of 1839. In September of that year, Dr. Jackson received his commis- sion as State geologist, and he commenced his duties under it on 28) Review of Dr. Jackson’s Final Report the first of the following June, 1840. By the terms of his en- gagement he was expected to complete the survey in three years ; and it was understvod of each year, four months should be devoted to field operations and four to the analysis of minerals. ‘This would of course leave four months for the less active, though not less important duties appertaining to the survey—in reviewing the proceedings in the field, and in preparing maps, with such other documents as might be necessary in a final report—a suf- ficiently short time for the purpose. So extensive and laborious, however, were the operations of the laboratory, that these alone, we are informed, instead of taking only four months of the year, required nearly all the eight not allotted to the field ; a fact which, in view of what was accomplished in this way, will hardly sur- prise any one at all aware of the time necessary for the accurate analysis of minerals. Notwithstanding this, Dr. Jackson seems by no means to have limited himself to the specified duties of his commission, arduous as they were; on the contrary, he has contributed largely of his observations upon the agriculture of the State, and has furnished numerous analyses of the soils, neither of which were required of him by the authority under which he acted. In the introduction, so called, to the work, after some observa- tions upon the utility of such surveys as the one authorized by the State, our author proceeds to give a general view of the va- rious rock formations that compose the strata of the earth’s crust and of the fossils that characterize a portion of them. In remark- ing upon the Silurian and Cambrian rocks of Murchison and Prof. Sedgwick, (the New York system of the New York geol- ogists, ) he takes occasion to object, and most justly, to the course adopted by some of introducing local names to define classes of rocks found in every quarter of the earth. It is much to be hoped that his views in this particular may generally prevail; whilst at the same time, it may be remarked that a numerical arrangement, for which he expresses a preference, might not be found wholly free from objection. In the brief but comprehensive view given of the various formations of the earth’s surface, those which are developed in the strata of New Hampshire have of course received particular attention. In this connection, we are informed that a great anti~ clinal axis of primary rocks exists in New Hampshire, the trans- on the Geology of New Hampshire. 29 ition Cambrian series being found to rest upon them, both in Maine on the east and in Vermont on the west, dipping in oppo- site directions. Upon these last are found, at more distant points from the centre of the anticlinal axis, the Silurian fossiliferous rocks, containing similar organic remains. Thus says the report— “We find trilobites occur near Lubec in Maine, on the 'Tobique river in New Brunswick, and at Clements, Nova Scotia. And in New York, the same fossils abound not far from Albany, at Lock- port and Trenton falls. Besides the trilobites, we observe also the same shells in the rocks of Maine, Nova Scotia and New York. This fact seems to indicate that the strata on the north- east and southwest sides of this axis belong to the same forma- tion, and were deposited under similar circumstances, while the primary rocks may be regarded as an immense wedge which was driven up from below, separating or disrupting the formerly continuous mass of strata.” Of the later formations, limited deposits of the tertiary are mentioned as occurring near Portsmouth. The introductory chapters close with some interesting obser- vations upon the diluvium or drift epoch, in which the theory of Agassiz is dwelt upon at some length, and facts are stated to show that however applicable it may be to some of the phenomena presented in the Alps, it is by no means so to those of New Eng- land. ‘The grooves or scratches on the rocks, so common every where in New England, are stated by the author to be “ better marked in Maine than in any other section of the United States,” and that they there as elsewhere “cross the mountains with but little deflection, and run over extensive table lands where there could have been no slope for a glacier to move upon.” ‘The course of the general current, according to the observations of Dr. Jackson, in Maine, New Hampshire and Rhode Island, was from north 15° west to south 15° east, as shown not only by the scratches, but by the rock masses which have been borne from their original locations and deposited in a southeast direction upon other rocks. In view of all that is known of the move- ment of diluvium in this country, we cannot but regard the gla- cial theory as wholly inadequate to produce the results met with, and we think with Dr. Jackson, “that the grooves on the rocks, if produced by glaciers, should radiate from our principal moun- tain ranges and should be more abundant in their immediate vi- 30 Review of Dr. Jackson’s Final Report cinity, while they would be wanting in the level country and on our extended table lands.” Thus much for the general introduction. As preliminary to the first annual report we have an account of the plan pursued in the survey, of which one may get an idea in a few words from the author. iat “In order to effect a systematic examination of the geological structure of the State, it was necessary to lay down some regular plan of operations, and knowing from previous explorations of the neighboring States, that the stratiform rocks pursue a general northeast and southwest direction, I was enabled to lay down on the map of the State certain lines, along which our first surveys should extend ; intending to prepare sectional views or profiles of the strata, and determine their axis of elevation and the limits of the unstratified rocks. “Tf the course or trend of the strata was northeast and south- west, then a line running northwest and southeast would cut all the stratified rocks at'right angles and exhibit the order of strata and their anticlinal axis, while a northeast and southwest line would exhibit their extent in a linear direction. By laying out our work in this manner, the strata would be divided into a series of triangles, which might be again subdivided, according to the minuteness of the’ surveys required. In some districts which were complicated and interesting these subdivisions were made ; while in others they were not required, or the limited time al- lowed for the exploration of the State, would not admit of their completion.”’ While upon these preliminary remarks we will quote a para- graph more, which we should think would satisfy one pretty fully that geological surveying can hardly with justness be ranked among sedentary occupations. “The general outline of our work will give some idea of the various duties which have been attended to in the survey, and no one will venture to regard them as unimportant. ‘Travelling in a wagon and making frequent excursions on foot, we have al- ways found our time fully occupied in explorations, and the actual number of miles we have journeyed in New Hampshire in three years, nearly equals the diameter of the globe. Most of the lines of our explorations have been measured barometrically, and certain points have been determined by astronomical observations on the Geology of New Hampshire. 31 and bearings from other places. The direction of every vein of metalliferous ore, or bed of limestone and soapstone, and the course of all the drift striae on the rocks, have been taken by means. of the compass, while the inclination or dip of all the stratified rocks was measured by the clinometer,’’ &c. To this succeeds a theory and description of the primary un- stratified rocks, and some notice of the minerals contained in them. . We now come to the detailed account of the operations in the field during the three years of service. In these, as also the labors of the laboratory, Dr. Jackson was assisted by gentlemen who had been his pupils, and who appear to have faithfully and acceptably performed the duties assigned them. In this connection it is pleasant to be able to remark that the author in the work before us, as well as in others published by him, has exhibited a strong desire to accord to those from whom he has in any manner received aid, all that strict justice could require. From Messrs. Whitney and Williams, two of the assistants, we have reports upon a number of sections which Dr. Jackson gave to their charge, and among others one upon the northern corner of the State, of which they give the geology and topography. The account by them of their journey into this distant and compara- tively little known portion of the State, and of their operations there, though far too brief, will not be read without interest. To it the lovers of the romantic and beautiful in nature will feel in- debted for the notice given of the Dixville Notch, which they speak of as perhaps surpassing the famous Notch of the White Mountains, in picturesque grandeur. Camel’s Rump mountain, situated in the line of boundary that divides New Hampshire from Canada, and one of the highest elevations in the State next to those of the White Mountain range, was ascended by Messrs. Whitney and Williams, who from not being able to find any marks of former visitations, judged it the first ascent ever made by white men. Of the view presented from the summit they thus speak :— _ “ But although the ascent was difficult, we were amply repaid by the magnificent extent of the view which was displayed be- fore us, as the veil of clouds gradually rolled away before the wind. Inthe north a series of high hills stretching beyond each 32 Review of Dr. Jackson’s Final Report other for five or ten miles, divide the waters flowing into the St. Lawrence from those of the Magalloway and Connecticut, be- yond which as far as the eye could reach, lay the extended table lands of Canada, unbroken by any abrupt elevation ; to the east, the lofty granite ranges of Maine, Mt. Bigelow and Mt. Abraham ; farther south, the numerous large lakes near Umbagog and the Diamond Hills; while in the farthest distance were seen the lofty peaks of the White Mountains; and to the west lay the lakes and tributary streams of the Connecticut, and the rolling ranges of the Green Mountains.” We have thus particularly noticed the report by Messrs. Whit- ney and Williams upon the northern section of the State, because so little is generally known of the region it relates to. We are, however, not quite contented with the knowledge we obtain of it from their remarks. These are, so far as they go, interesting and instructive, but they do not embrace all that we would like to learn, and which only a more thorough survey can impart. That as much was accomplished by these gentlemen as was possible under the circumstances of the case is manifest, but we cannot but. think time would have been well spent in giving this section of the State a more accurate examination than it received. The interest in the part of the work under consideration is much enhanced to the reader by the character of some of the country described in it. In the section from Haverhill to the White Mountains, surveyed by Dr. Jackson in person with his assistants, we have an account of that portion of the State, which embraces the most wild and romantic scenery of our country,— the mountains themselves towering to the heavens, presenting a thousand views of surpassing grandeur and beauty,—the well known Notch of the White Mountains, so called, and that of Franconia,—the “flume” and the “ basin’ of the latter place,— the profile view of “the old man of the mountain,” &c. &c., these are all embraced in this region, and have received proper notice from the ready pen of our author. In the narrative of field operations, we have of course an ac- count of the development of the various rocks in every portion of the State, and of the minerals imbedded in them, some of which latter were not before known to exist in New Hampshire, as for instance tin (which indeed has not been found in any on the Geology of New Hampshire. 33 _ quantity elsewhere in the United States) and chlorophyllite, a new species, first discovered in this country by Dr. Jackson at Unity, whilst engaged in the survey. Of the localities of minerals we have a great number described in the reports upon the several towns visited. We will mention a few of the most interesting and important. Acworth.—Here are found the immense beryls which have given the place celebrity wherever mineralogy has avotary. ‘The largest of the crystals are upwards of a foot in diameter and eighteen inches in length; the smaller, however, as is generally the case, are the most perfect. The color of them is a light blue green, and they are of the variety generally known as the aqua- marine. Black tourmalines and soda feldspar also occur here. Unity.—In this town isa spring strongly chalybeate, possessing tonic properties. Granular quartz, and copper and iron pyrites, both in sufficient quantity for exploration, are met with. In this place was discovered the mineral chlorophyllite before referred to. It occurs in the syenite rocks, not far from the copper mine. _ Orford.—Here are quarried granite, limestone and talcose slate. In the latter rock, clove brown tourmalines are found in large crystals, some of which are more than two inches in diameter and six in length. Haverhill.—Mica slate, satan extensive beds of excellent limestone, granite of Beal quality, and hornblende slate, abound here. There have also been found veins of copper and iron pyrites, sulphurets of lead and zinc, native arsenic, arsenical py- rites, and large crystals of garnet in chlorite. Lisbon.—Within the present limits of this town is found the well known magnetic iron ore which is worked in the Franconia furnaces near. It occurs in granite, and composes a vein from three and a half to four feet in width. It is now taken up from a depth of one hundred and forty four feet. Accompanying the ore are numerous minerals which may be easily procured, among others, deep red magnesian garnet, crystallized and granular epi- dote, hornblende, &c. In the mica slates of this town, beauti- fully crystallized staurotides and garnets are found in abundance. Barilett.—In this place inexhaustible quantities of iron ore occur, of a character suitable for the manufacture of the best iron or of steel, chiefly composed of the peroxide, combined with a small quantity of the protoxide and a little manganese. This Vol. xu1x, No. 1.—April-June, 1845. 5 ie 34 Review of Dr. Jackson’s Final Report ore is found upon Baldface Mountain, in granite, at an elevation of fourteen hundred feet above the waters of the Saco. A num- ber of veins have been opened, one of which has a width in some parts of fifty-five feet. Jackson.—This is the locality of the tin ore before noticed as having been discovered by Dr. Jackson. It is found on East- man’s hill, and occurs in veins (of which five have been discov- ered) accompanied by copper and arsenical pyrites, arseniate of iron, native copper, phosphate of iron, fluor spar and other min- erals. Some of the crystals are hemitropic, similar to those which are frequently found in the ores of Europe. The largest vein measures in its widest part eight inches. The richest specimens of the ore in the narrow veins yield about seventy three per cent. by assay. It occurs both compact and crystallized, but there cannot probably be enough obtained from the veins yet discovered to make it profitable to work it. Haton.—There is a very valuable vein of ed sieeaeee of lead and zine in this town, which has been wrought to some ex- tent for lead. The vein is however mostly made up of the sul- phuret of zinc, and is about six feet in width. Dr. Jackson ex- presses the opinion that it might be profitably worked, provided the zinc ore should be reduced with that of the lead. The former contains about sixty three per cent. of metallic zinc, the latter about eighty four per cent. of lead. Frrancestown.—Soapstone of the richest quality exists here, and is extensively wrought for the markets of Boston and other places. Amherst.—In this town is a bed of limestone in mica slate, associated with which are found some interesting minerals. Ege- ran in large crystals, some measuring four inches in length and two and a half in diameter, of a deep red brown color. They occur in right square prisms, with lateral and terminal edges and solid angles replaced. Large dodecahedral crystals of the cinna- mon stone garnet are also abundant, both in the limestone and in quartz connected with it. There are likewise found in granite, in this town, crystals of magnetic oxide of iron, from one to two inches in diameter, and from the soil fine crystals of amethystine quartz (some of which are four inches in diameter and eight inches in length) have been ploughed up. on the Geology of New Hampshire. 35 - Warren.—Valuable ores of copper and zinc exist in this town, the former of which have been wrought to some extent. The copper ore is mostly pyrites, the zinc ore is the black blende, and associated with them in some veins are tremolite, iron pyrites and rutile. Before passing from the account of field operations, we may remark that several lithographic prints of some of the most inter- esting views in thé State adorn its pages. These are “ Dixville Notch,” “‘ Lake Winnipisseogee,” “ Flume at Franconia,” “ Slide at the Willey house” and ‘Monadnock Mountain.” 'There are also several wood engravings of other scenery and of appearances presented by the strata in many places. ‘The lithographic views are from sketches made by Mr. J. D. Whitney, Jr., and were drawn on stone by Mr. Charles Cook of Boston. A considerable portion of the work is devoted to ‘‘ economical geology,” so called, and to “‘agricultural geology and chemistry.” In these departments, perhaps it may be said without disparage- ment to others, that among those of our countrymen who have treated upon them, our author is of the highest authority. His thorough knowledge of analytical chemistry, and his acquaint- ance with the application of this knowledge to the arts, must make his observations of great service to such of those interested in the working of metals and other minerals, as also of those en- gaged in agriculture, who choose to take advantage of them. Economical Geology. Under this heading a description is given of the various min- eral substances found in New Hampshire, that are or may be ser- viceable in the arts. We state them as follows :— Granite, Syenite, Gneiss, Mica Slate, Talcose rock or Soap- stone, Granular Quartz, Milk Quartz and Limestone, the uses of which are well known. Novaculite, of which oil stones and hones are made. Mica, used for lanterns, windows, &c. Infusorial silica, serviceable as polishing powder, &c. Moulding sand, for moulding purposes and making Bristol brick. Clay, used for brick-making and pottery. Calcareous Marl, for agricultural purposes. Black Lead or Graphite, for pencils and founder’s pots. Of precious stones, such as are used in jewelry, there are found— 36 Review of Dr. Jackson’s Final Report Beryls, Iolite, Garnets, Amethysts, Quartz crystals, (some of which latter contain acicular crystals of the red oxide of Tita- nium.) . Of those serviceable in making paints may be mentioned— Red, Yellow and Brown Ochres, Manganese, sibicbei Ochre, Yellow Blende. Of metals, we have an account of seventeen, without Fncleudieng the bases of earthy and saline minerals. They are: Jron found in great abundance, Zinc, of which some mines can be wrought, Copper in considerable quantities, Lead, Tin, Antimony, Silver in the antimony and lead ores, Gold in minute quantities, Mo- lydenum, Manganese, Chrome, Titanium, Cadmium, Cobalt, Arsenic, Tungsten and Uranium. Of all these various sub- stances full accounts are given of their localities, means of obtain- ing, and uses to which they can be applied. Respecting limestone and its conversion into lime we have a detailed statement, which embraces an account of some of the most important beds, the manner and cost of working, description of kiln used, &c. &c. We have, too, the full analyses of ten varieties of the stone. Metallurgy.—The pages on this branch of economical geology we would particularly notice, as being in our estimation the most important, in a practical point of view, that the report contains. They are filled with the most valuable information upon almost every point connected with the mining and working of the va- rious metals that are made subservient to the use of man, and would be the means, could they be placed in the hands of those most interested, of saving to them thousands upon thousands of dollars yearly, that are sacrificed for the want of a little knowl- edge of the chemical principles that have so great an influence in their operations. _ We know something of the ignorance often displayed in the working of the metals in this country, particularly in that of iron, and we know too that unfortunate results frequently happen therefrom, which a little knowledge of science might prevent. In the present state of the art of reducing metal from the ore, in some sections of the country, a single suggestion will sometimes accomplish wonders. We have known instances where a few words from one scientifically acquainted with the action of the earths upon the ore in a furnace, have led to a greatly increased a ae ‘on the Geology of New Hampshire. 37 yield, and this without additional expense. We therefore feel the importance of diffusing just such information as this article on Metallurgy gives. We have in it an account of the various ores in the State, the methods of reducing them to a metallic state, their analysis, their yield, the best fluxes for their reduction, the prob- able cost in particular cases, together with full descriptions of the best kinds of furnaces in use, and plates explanatory. We have likewise the expenses of transportation from the ore beds to the markets, and the value of the product in such markets. Impor- tant information too is furnished in relation to the working of mines abroad, and valuable hints thrown out upon the subject of working some ores in this country that have hitherto been neg- lected. Agricultural Geology and Chemistry. Our proposed limits will not permit of more than a very brief notice of this portion of the work under consideration. It con- tains an account of the origin and distribution of soils; of the origin of organic matters in soils; of peat and swamp muck ; of the analysis of peat and the action of alkaline salts upon it; of the origin of saline matters in soils and plants, and of the relative proportion of starch, of oil and of gluten in grains. Remarks are made on the improvement of soils, and the uses in agriculture of salt, nitre, the phosphates and sulphates. Agricultural observations upon some of the best farms in the State are added, and much more matter in relation to the subject, which is well worth the attentive perusal of those interested. In the appendix we have barometrical and thermometrical ob- servations made in different parts of the State for the measure- ment of heights; also barometrical registers, with other matter more particularly interesting to the scientific, and annexed we have some sectional profile views of the rocks from point to point, with a geological map of the State. In conclusion, we will express the hope that Dr. Jackson will at some not very future period, present us with a connected ac- count of his observations, not only upon the geology of the States surveyed by him, but also upon that of the provinces north, as we are sure he might do this to much advantage, with but little additional labor in the field. 38 Description of Artificial Mounds in Louisiana. ArT. IV.—Description of some Artificial Mounds on Prairie Jefferson, Louisiana; in a letter to the Editors, dated Trinity, La., January 19th, 1845, from Prof. C. G. Forsuey. In a letter I addressed you some months since,* I made some mention of many systems of large mounds found throughout this region of country, promising from time to time to give such descriptions as may prove interesting to the antiquarian, of any of these unrecorded monuments of departed races. Jn executing this promise, it will not be in my power to proceed with them in the order of their importance, but in such order as they may fallin my way, when I have leisure to make accurate surveys. Such accounts only are to be relied upon. Many are found in the fastnesses of forests rarely penetrated by those who write of these things, and are vaguely described from hearsay, or second- hand evidence. Though we frequently find isolated mounds, they are com- monly found in groups, and occasionally constructed with such reference to each other as to indicate design. Not that the spe- cific object is ever very manifest; but that their conformation indicates arrangement in a particular order. Probably no ques- tion has more successfully baffled inquiry among antiquarians, than the specific object of these extensive works, and I have no solution to offer, deeming it, as Ido, much more important to give a faithful detail of their present appearance. In this immediate vicinity there are extensive works, which I have frequently visited, but having made no accurate survey I forbear giving them more than a passing notice, until I shall have given them a careful survey, such as has enabled me to present you with the map and detailed account of the mounds in Prairie Jefferson. 'The Ouachita river and its western tributaries abound in similar monuments, all of inferior magnitude, however, to those in this vicinity. These have been described, yet imper- * An abstract of this letter may be seen in the close of this number.— Eds. t The distinction of mounds into classes should not be forgotten. The tens of thousands of small, hemi-spheroidal tumuli noticed in my first letter, are rarely disposed with any reference to each other; whereas the angular, larger mounds, evidently of more recent construction, are much rarer, and generally arranged in groups, and sometimes with much system. Description of Artificial Mounds in Louisiana. 39 fectly, by Sir William Dunbar, in a published account of his ex- plorations of the Ouachita in 1804, under the instructions of Mr. Jefferson, as also by myself in the Concordia Intelligencer of June, 1842. Both are from observations without measurements. The levelling hand of American industry is fast obliterating these dumb, yet eloquent records of the past; and hence the necessity of early attention and accurate description. Prairie Jefferson is a tract of very fertile diluvial land, situated ‘in the southeast part of Moorhouse parish, Louisiana, near to the Boeuff river, an eastern tributary of the Ouachita, some twenty five miles northeast from Monroe. It lies within the grant of and made by the Spanish government to the Baron de Bastrop; the same to which Aaron Burr is supposed to have been making his way, in his southern expedition. Near the southwestern ex- tremity of the prairie, and partly in what is woodland at present, we find the works delineated in the topographic sketch below. It is probable that the whole area of the works was then prairie, as there are no forests that bear the mark of great antiquity ; and as the whole diluvial surface must have been, at no very remote date, (geologically speaking,) destitute of forests. There are no streams of water nearer to this prairie than about five miles, and hence the necessity, with a dense population, of resorting to the making of artificial ponds. Accordingly the excavations, usually made without apparent design in constructing the mounds, are at this place so economized as to produce the ponds in the imme- diate neighborhood. Then the conformation of the surrounding lands, which are very gently undulating, rendered it easy to con- struct large ponds or lakes, to contain a perennial supply of water. This has plainly been the object of the extensive leveés, or em- bankments traced in the map. The general inclination of the land is southward, and the drains or wakes in the land, were with some skill called into aid. Generally, however, we find little to admire in the way of design or economy of labor. The mound at A, termed ‘the Temple,” from the supposi- tion that it was the place of worship and sacrificial fires, is about fifty feet in height, with steep faces on every side, and accessible only by the causeway, which is a winding road on the southeast face, at ‘‘a.” Its base covers a square of about fifty yards, and its summit, one of fifteen yards. All its angles are very much rounded, still it has the four faces very plainly marked. Since x » ey 40 Description of Artificial Mounds in Louisiana. ww N —— ee niin _—lommons ~ \\| ss My B= WX Mo ne? Wit. H Ws AWS a —N == \ A RS Mca GST AG A AUSWSS WZ Gun sli = t E aoe E Smug nnn if sda LOVES go= = — DIMENSIONS OF THE MOUNDS. -, ae & JAMO VRID A MULALLY TOO ANNOY | SULT pre length width height length width height T Je (A) ea in yds. in on af Ree in ess in emple = 2 ‘ in front, Temple on summit, ; 17 15 —_|No. 4, (surmmit,) ; in rear, 20 No. 1, (summit,) . 3 20 14 10 No. 5 a inrear, 9 . Causeway from 1 to 2, 45 4base 3 2 in front, be 15 M4 : inrear, 20 14 12|No. 6, sf ‘ : 0 25 No. 2, (summit,) ; in front, 26 No. 7, (base,) . j 44 44 4 No.3 i in rear, 13 17 12|No. 8, (summit,) . : 40 40 4 ue in front, 20 Causeway bed,. . 350 2tod 1to3 Ditch bcd, ¢ . | B50 tas manors C, C. Causeway four feet high and forty feet base.—P. Ponds.—S, 8. Natural swale.—S/, S!. Swale of regular channel, embanked inside in low grounds. Description of Artificial Mounds in Louisiana. Al the clearing of the trees from it, several slides have marred its symmetry. From the summit a good view may be had of all the circumjacent works and country. The slides as well as ex- cavations made in it, have developed its internal structure; viz. a series of strata or tables at about three feet distance, one above another, each surmounted by a pavement of rude bricks. No bones have been found in it; but the examination is avoided, from a desire to preserve the original symmetry of the 'Temple. All these principal mounds are so well known to have been used for places of burial by the builders,* that the fact ceases to be curious. Much credit is due to Dr. Harrison and H. Duval, Esq. for the care and taste they manifest in protecting and restoring the forms of the mounds. The five mounds which face the Temple from the eastward, have great uniformity of figure and dimensions, being highest in the rear, excepting No. 1 and No. 5, which are nearly level on the top. Nos. 1, 2, 4and 5 have terraces in front, and all incline gently to the hii, which has been somewhat Rec aratad. In the rear, however, and chiefly on the sides, they are very abrupt. The pond in the rear is evidently artificial, and constructed by removing the earth for building purposes. Around them area breastwork and ditch, (6, c,d), the latter produced by throwing up the earth for the former, probably to serve as a leveé around the pond to the high land at band d. See the table for the di- mensions of the several mounds. Those which we have numbered 7 and 8, have great similarity in their magnitude, form and relative position to the Temple. But lying as.they do in the midst of a cultivated field, their def- inite outlines are fast disappearing. No. 6, however, differs essen- tially from all the other mounds of the system. It is perfectly level on the surface, of gentle declivity and moderate height, (about five feet,) and has been fitly chosen as the site for a dwell- ing house and yard. The house fronts the area surrounded by the mounds, and the tasteful proprietors are about to improve the whole as ornamental grounds, with walks, shrubbery, flowers and grass, and thus protect them from deterioration. * Peruvian, Natchez and Choctaw crania are usually found, and with them are buried a variety of potter’s ware, curious pipes, and beautifully finished stone hatchets, of various shapes and sizes. Vol. xuix, No. 1.—April-June, 1845. 6 42 Caricography. The several ponds, it will be seen, have outlets for the water at particular points, which probably were controlled as the mound builders desired. The large embankment, (e,f,@), is abruptly cut off at s, and continued again towards h, diminishing in mag- nitude as the land grows higher, till it almost disappears at 7. The swale continues up to very near the pond at J, but has no actual connection with it. It does not appear that the lake in the woods, within this leveé, has been produced by excavation. The smaller ones adjacent, however, are manifestly produced by throwing up the earth about them, as at e,f. The whole work, although exhibiting very little ingenuity, bears evidence of the vastness of the population, their industry, and not less certainly their ignorance and folly. Arr. IX.—Caricography ; by Prof. C. Dewey. (Appendix, continued from Vol. xtyvi11, p. 144.) No. 184. Carex Hoodit, Boott. Tab. Ee, fig. 106. Spica composita; spiculis 6-10, distigmaticis dense aggregatis ovatis superne staminiferis; fructibus ovatis lanceolatis plano- convexis ore obliquo bidentatis apicem subserratis, squamam lato- ovatam acutam subequantibus. Culm near two feet high, glabrous, acutely triquetrous, sca- brous above, erect, leafy towards the base; leaves linear, narrow, scabrous on the edge, sheathing and long as the culm, with short leaves at the root; spikelets ovate, densely compacted into a head of half an inch or more long, close-fruited, staminate above, with a squarrose mucronate bract; stigmas two; fruit ovate, lanceo- late, slightly serrate at the apex, bifid or two-toothed, with an ovate and acute tawny scale about equalling the fruit; light green. Found by Douglas and Sconler on Columbia River, and named by Dr. F. Boott, secretary of the Linnean Society, England, in honor of one of the intrepid men engaged in the Arctic exploring expeditions, and described in Hooker’s Fl. Bor. Am. Vol. IL. No. 185. C. Lyoni, Boott. 'Tab. Ee, fig. 107. Spica solitaria ¢ristigmatica oblongo-lineari pauciflora superne staminifera; fructibus Janceolatis ore obliquis paucis sublaxifloris, squama ovato-oblonga subacuta paulo longioribus. Caricography. 43 Culm 2-4 inches high, erect, slender, stiff and small, 3-sided, cespitose, leafy; leaves flat, narrow, nerved or striate, subseta- ceous, rising towards the root, scabrous, sheathing, and much longer than the culm; spike single, short, linear, staminate above; stigmas three; fruit lanceolate, subscabrous ; scale broad, ovate-lanceolate, submembranaceous on the edge and rather longer than the fruit ; plant is light green, and hasastinted appearance. Rocky Mountains, Drummond, and named and described by Dr. Boott like the preceding. No. 186. C. marcida, Boott. 'Tab. Ee, fig. 108. Spica composita oblonga densa basi bracteata; spiculis ovatis distigmalicis superne staminiferis stricte aggregatis; fructibus late ovatis lanceolatis supra convexis ore diviso cilio-serratis, squamam ovatam acutam subzequantibus. Culm about two feet high, erect, stiff, triquetrous, rough on the upper part and leafy below ; leaves lanceolate, flat, often involute on the edges, nerved, shorter than the culm; spike oblong, com- pounded of many small and ovate spikelets closely aggregated, and chiefly staminate towards the summit; stigmas two; fruit roundish-ovate, lanceolate, chiefly at the lower part of the spike- lets; scale ovate acute, hyaline on the edges, about equal to the fruit; pale green. Columbia River, Scouler, and named and described by Dr. Boott in Hooker’s work with the two preceding. No. 187. C. Torreyi, Tuckermani Enum. Tab. Ee, fig. 109. Spicis distinctis ; spica staminifera unica oblonga brevi-pedun- culata; pistilliferis subbiuis ¢ristigmaticis brevi-oblongis sub- sessilibus pedunculatis erectis; fructibus obovatis glabris sub- triquetris ore integro subrostratis perobtusis densifloris nervosis, squama acuta vix duplo longioribus. Culm 12-18 inches high, erect, triquetrous, and with the sub- radical leaves pubescent ; one oblong linear staminate spike with an oblong submucronate scale; pistillate spikes 2-3, oblong, nearly sessile, with leafy bracts; stigmas two; fruit oblong, ob- ovate, tapering towards the base, dense; pistillate scale ovate, acute or submucronate, about half as long as the fruit; plant light green, and, the fruit excepted, pubescent. Found near Carlton House, Richardson. Resembles C. palles- cens, L.. very much, but seems to be sufficiently removed from it. Mr. Tuckerman refers its locality also to the state of New York. 44 Caricography. No. 188. C. spherostachya, Dew. C. canescens, L. var. spherostachya, Tuck. Enum. Tab. Ee, fig. 110. Spiculis 3-5, ovatis subglobosis remotis sessilibus inferne sta- miniferis paucifloris (2-6) bracteatis ; fructibus distigmaticis ova- tis oblongis lanceolatis vel tereto-rostratis glabris, squamam ova- tam hyalinam longioribus; culmis prostratis glabris. Culm 1-2 feet high, slender, flaccid, subprostrate, leafy to- wards the root; leaves narrow and long; spikelets ovate, round or subglobose, remote, sessile, 2 to 6-flowered, staminate above, bracteate ; stigmas two; fruit ovate, oblong, lanceolate or taper- ing-rostrate, longer than the white hyaline ovate scale; light green. Wet plains—common. _ This plant agrees with C. gracilis, Schk., which he afterwards united with C. loliacea, L. It is certain that the species here de- scribed, as well as C. gracilis, Schk., is far removed from C. loli- acea, Li. It is so different from C. canescens, that it deserves the name above given, as Schkuhr cancelled the other. No. 189. C. Sullivantit, Boott. Tab. Ee, fig. 111. Spicis distinctis; staminifera unica oblonga erecta pedunculata fructiferam vix superante ; spicis pistilliferis ternis oblongis eylin- draceis sublaxifloris bracteatis, inferiore longo-pedunculata et in- ferne distanti-flora; fructibus ¢tristigmaticis ovatis acutis vel sub- rostratis bidentatis subtriquetris, squamam ovatam oblongam mucronatam subequantibus. * Culm 16-24 inches high, erect, rather slender, triquetrous, sca- brous above; leaves flat, linear-lanceolate, shorter than the culm, and shorter towards the base; staminate spike single, erect, cylin- dric, oblong, with oblong and obtuse scales; stigmas three; pis- tillate spikes three, oblong cylindric, not close-flowered, subdis- tant, bracteate, upper one subsessile, the lower long pedunculate and quite sparse-flowered below; fruit ovate, acute or subrostrate, bifid, subtriquetrous, about equalling the ovate obtuse or oblong obtuse and mucronate scale; light green. Ohio, Sullivant. No. 190. C. chordorrhiza, L. Schk. Tab. G, and Ii, fig. 31. _ Spiculis 3-5, androgynis distigmaticis superne staminiferis in capitulo aggregatis ovatis sessilibus; fructibus ovatis acuminatis eee Caricography. 45 subrostratis superne convexis, squamam late-ovatam acutam zequantibus; culmis basi vel radici ramosis. Culm a foot high, with rather short leaves, branching or send- ing up stems from the roots; spikelets 3-5, ovate, sessile, short, closely aggregated, with stamens at the apex; stigmas two; fruit ovate, acuminate, glabrous, convex above, equalling the broad-ovate acute scale; pale green. Marshes, New York, Gray and Sartwell; Michigan, Cooley. No. 191. C. Liddonz, Boott. Tab. Ff, fig. 112. Spiculis 5-7, oblongo-ovatis arcte aggregatis ebracteatis inferne staminiferis; fructibus distigmaticis ovatis lanceolatis acuminatis ore obliquis glabris margine serrulatis, squama ovato-lanceolata acuta margine hyalina vix longioribus. Culm 16-30 inches high, striate, scabrous above, leafy towards the base, and much longer than the flat linear lanceolate leaves, rough on the edges; stigmas two; spikelets staminate below, 5-7, closely aggregated ; fruit ovate, lanceolate, acuminate, sca- brous on the upper edges, scarcely longer than the ovate lanceo- late scale, acute and hyaline on the border; scales and fruit rather chesnut brown; yellowish green. Columbia River, Scouder ; Michigan, Cooley. Named and de- scribed like No. 186. No. 192. C. rigida, Good. Schk. Tab. U, fig. 71. Spicis distinctis; staminifera unica, raro binis, oblongo-cylin- dracea, squama oblonga obtusa; pistilliferis binis vel ternis distig- maticis oblongis cylindraceis densifloris crassis approximatis bre- vibus latisque bracteatis, inferna brevi-pedunculata; fructibus ovatis subobtusis partim recurvis ore integris, squama oblonga obtusissima vix duplo longioribus; culmo brevi basin foliaceo. Culm 3-8 inches high, erect, triquetrous, stiff, sometimes in- curved, with short and stiff leaves at the base; stigmas two; pistillate spikes 2-3, sessile, oblong, short and thick, often with some staminate flowers at the apex, lowest subpedunculate with a bract longer than the culm; fruit ovate, obtusish, sometimes recurved, entire at the orifice, at first a little longer than the scale, and in maturity nearly twice the length of the oblong and very obtuse scale; glaucous green. Ipswich, Essex Co., Mass., Oakes; long confounded with C. cespitosa, L. 46 Caricography. No. 193. C. Steudelii, Kth. Tab. Ff, fig. 113, Spicis androgynis superne staminiferis paucifloris; fructibus 1-4 subglobosis vel ellipsoideis tristigmaticis teretibus unico ros- tratis binervosis ore obliquis, cum squama ovata acuta et inferiore foliacea margine scabra; culmis vel pedunculis subradicalibus nunc brevibus nunc perlongis. Culm or subradical peduncles an inch to 6 or 8 inches long, tri- quetrous, scabrous on the edges, much shorter than the flat linear and radical leaves; staminate flowers several, with short and small ovate scale; stigmas three; fruit 1-4, globe-like or ellip- soidal, glabrous, tapering at both ends, and with a rostrum articu- lated to the body of the fruit; pistillate scales of very different lengths, ovate and acute, or long lanceolate and foliaceous; light green. Near maturity the articulated beak drops off, leaving the fruit obovate and very obtuse. Differs from C. Willdenovii, Schk. in its fruit; that being oblong, and this spheroidal. Found in New York; Ohio, Sullivant; Kentucky, Short; also in Indiana. No. 194,..C., Backii, Boott.. Tab. Ff, fig: 114. Spicis androgynis superne staminiferis paucifloris; fructibus 2-A, tristigmaticis ovatis globosis conico-rostratis ore integris gla- bris binervosis maturo subpyriformibus ; squama inferiore longo- foliacea lanceolata, superiore fructum subeequante et acuta. Culm short, sometimes a few inches long, triquetrous, scabrous on edges, much shorter than the flat and subradical leaves; spikes staminate above, with few and small staminate flowers; stigmas three; fruit ovate and globose, with a conic beak articulated to the fruit, glabrous; pistillate scales of various length, the lower leaf-like and lanceolate, upper shorter, and highest about equal to the fruit and inclosing it; light green. Arctic America, Drummond and Richardson. In the speci- mens from the Cumberland House, the plant was little cespitose. Named by Dr. Boott in honor of Capt. Back, so distinguished in the Arctic expeditions. Differs from the last two in its fruit and spike. No. 195. C. Hoppneri, Boott. ‘Tab. Ff, fig. 115. Spicis distinctis ; spica staminifera unica oblonga lineari, squa- mis oblongis obtusis instructa; pistilliferis binis déstigmaticis brevi-ovatis sessilibus subdensifloris erectis; fructibus ellipsoideis TaN er Caricography. AT subconvexis ore integris subapiculatis, squama ovata obtusissima submucronata longioribus. . Culm 3-6 inches high, slender, obtuse-triquetrous, shorter than the narrow and subinvolute leaves; pistillate spikes two, short- ovate and rather compact-fruited; stigmas two; fruit flat sphe- roidal, obtuse, and often with a slightly protruded apex, and longer than the ovate, and very obtuse scale; plant light green, but the iron or dark colored spikes and scales give it a sombre aspect. Arctic America, Drummond. 'The specimens from Cumber- land House have a stiff or rigid and stinted appearance. Named and described by Dr. Boott with the preceding, as before noticed. No. 196. C. riparia, Gooden. Schk. Tab. Qq, and Rr, fig. 105. Spicis staminiferis 2-4, oblong, cylindraceis nigricantibus, squama lanceolata instructis; pistilliferis 2-4, tristigmaticis, cylin- draceis oblongis brevi-pedunculatis densifloris, fructibus rotundo- ovatis perbrevi rostro bifurcato contractis, squamam _ ovato-cuspi- datam vel lanceolatam subeequantibus. Culm two feet high, large, and with long leaves and bracts ; staminate spikes many, large, oblong, thick, dark colored, sessile, with lanceolate scales; pistillate spikes 2-3, cylindric, long, sometimes with long and subrecurved peduncles and lax-flow- ered below, leafy-bracteate ; stigmas three; fruit broad-ovate, oblong, contracted into a very short bifurcate beak, glabrous and dark colored ; pistillate scale ovate cuspidate, scarcely equalling the fruit, or lanceolate equalling it; dark green. Marshes; New England, New York, and Michigan; has been confounded with ©. lacustris, Willd., with which it is often associated, from which it is easily distinguished by its fruit and scales. No. 197. C. monzle, Tuck. Enum. C. vesicaria, var. cylindracea, Dew. Tab. Ff, fig. 116. Spicis staminiferis 2—4, longis, gracilibus, cylindraceis, squama longa lanceolata dotatis ; pistilliferis binis cylindraceis longis sub- laxifloris brevi-pedunculatis ; fructibus ovatis longo-conicis sub- triquetris inflatis rostro bifureato glabris, squama oblongo-lan- ceolata plus duplo longioribus ; culmo bipedali margine levi, folia lineari-lanceolata superante. ; 48 Caricograp hy. Marshes—not common; fruit much longer than that of C. ve- sicaria, and its scale shorter. No. 198. ©. Tuckermani, Dew. Tab. Ff, fig. 117. Spicis staminiferis binis vel ternis, cylindraceis sessilibus, infe- riore brevi, squama oblonga subacuta instructis ; pistilliferis binis vel ternis oblougis cylindraceis crassis pedunculatis subdensifloris ; | fructibus inflato-ovatis turgidis conico-rostratis bifureatis glabris nervosis, squama ovato-lanceolata sub-duplo longioribus; culmo bipedali glabro erecto ; bracteis foliisque planis longisque. Wet meadows—common; confounded with C. bullata, Schk. ; difference obvious; and the fruit and spikes separate it far from C. monile. Var. cylindracea, Dew. C. cylindrica, Schk. Spicis et fructibus minoribus brevioribus ; squamam ovatam acutam fructibus duplo superantibus. Nore.—The following species was described under the name of C. aristata, R. Br. As this name designates another plant, it becomes necessary to give to this a different name, and the fol- lowing is adopted. C. mirata, Dew. For description and figure, refer to Vol. xxv, p. 240, of this Journal; Tab. V, fig. 67. Along the shores of Lake Ontario, Sartwedl, and in the state of Georgia, and in Arctic Arnerica. Figures of the following species accompany this paper. No. 184. C. Hoodz, Boott, Tab. Ee, fig. 106. No. 185. C. Lyoni, Boott, ju ed OF: No. 186. C. marcida, Boott, fe ane 108: No. 187. C. Qorreyi, Tuckerman, “ “ TOS No. 188. C. spherostachya, Dew. “= “ eas No. 189. C. Sullivantiz, Boott, dal at sa) We No. 191. C. Liddoni, Boott, Tab. Ff, ae No. 193. C. Steudeliz, Kunth, sat lees « 1 No. 194. C. Backii, Boott, slits Chay ai | No. 195. C. Hoppneri, Boott, Ae Be es No. 197. ©. monile, Tuckerman, “ “ alliak No. 198. C. Tuckermanit, Dew. “ “ sae eo az | Fe : : = : § : é Ne S = ke e \ rat y ’ CO LTuekermuanz Lew. e Vinx ls, VOL XLIX WE7. PLATE 1 \ | | CHloppner\ WBeot. |l) \I | |, } \ / f J in OC Tuchermantr, lew, ae CLiddeniBoott. C. Steulttt Kunth. CBuckw, Beott. DEWEY'S | CART CKS, TAB .Ee. 4 J Comemtle, Tuckerman. | Re iz > saad On the Minerals of Trap and the allied Rocks. 49 i * Art. VIL.—Origin of the constituent and adventitious Minerals of Trap and the allied Rocks; by James D. Dana. (Read before the Association of American Geologists and Naturalists, May, 1845.) In the remarks which I have the honor to submit to the Asso- ciation at this time, it will be perceived that I pass over in part the same ground, and appeal in some instances to similar facts with those considered by Prof. Beck in his valuable memoir read two years agoat Albany. Without making myself his opponent, which position I would entirely disclaim, I have simply en- deavored to hold up the subject in another point of view, hoping that the truth, with whomsoever it be, will the sooner claim its place among the facts of geological science. It will be remarked also, that the views presented bear closely upon those proposed by me at the session of this Association at Albany. 4 The minerals of trap and the allied rocks may be arranged in two groups. 1. Those essential to the constitution of the rock, or intimately disseminated through its texture. 2. Those which constitute nodules or occupy seams or cavities in these rocks. Of the first group, are the several feldspars, with augite, horn- blende, epidote, chrysolite, leucite, specular, magnetic and titanic iron; and occasionally Hauyne, sodalite, sphene, mica, quartz, garnet and pyrites. Of the second group are quartz, either crys- tallized or chalcedonic, the zeolites or hydrous silicates, Heuland- ite, Laumonite, stilbite, epistilbite, natrolite, scolecite, mesole, Thomsonite, Phillipsite, Brewsterite, harmotome, analcime, cha- bazite, dysclasite, pectolite, apophyllite, Prehnite, datholite, to- gether with spathic iron, calc spar and chlorite. Native copper and native silver might be added to both groups, yet they belong more properly to the latter. To the same also might be added sulphur, and the various salts that are known to proceed from decompositions about active volcanoes, including the crystalliza- tions of alum, gypsum, strontian, &c.; but these more properly form still a ¢hzrd group, and being well understood, will not come under consideration in the remarks which follow. We observe with regard to the minerals of the first group, that they are all anhydrous—that is, contain no water. In this re- Vol. xt1x, No. 1.—April—June, 1845. 7 50 On the Minerals of Trap maied the allied Rocks. spect, the essential constituents of _ and basalt are like those of granite and syenite. But in the second group, consisting of the minerals occurring in cavities or seams, all contain water except pectolite, quartz, cale spar and spathic iron ; and the last three are known to be always deposited in an anhydrous state from aqueous solutions. We proceed to give a few brief hints with regard to the first group, intending only to glance at this branch of the subject, and then take up more at length the group of adventitious minerals. E'ssential constituents of modern Plutonic rocks.—lIt is ob- vious that modern igneous rocks, although in some cases derived from the original material of the globe, have proceeded to a great extent from a simple fusion of rocks previously existing, and especially of the older igneous rocks. In accordance with this view, we may with reason infer that the trachytes and porphy- ries, which consist essentially of feldspar, have proceeded in many instances at least, from feldspathic granites; the basalts and trap from syenites, hornblende or augitic rocks. A theory proposed by Von Buch supposes that the feldspathic rocks, as they are of less specific gravity, are from the earliest eruptions, or the more superficial fusings, while the heavier ba- salt has come from greater depths. Darwin thus accounts for the granites of the surface being intersected by basaltic dykes ; the latter having originated from a deeper source, where their constituents took their place at some former period from their superior gravity. It virtually places hornblende rocks below feldspathic granites in the interior structure of our globe. ‘The hypothesis is ingenious and demands consideration ; but it may not be time to give it our full confidence. But supposing these more modern rocks to have been derived from the more ancient granitic—what has become of the quartz and mica which occur so abundantly in the latter, while they are so uncommon in the former? By what changes have they disappeared ? In the fusion produced by internal fires, the elements are free to move and enter into any combinations that may be favored by their affinities. If silica, alumina, magnesia, lime, iron, the alkalies, potash and soda, were fused together—and these are the actual constituents of basalt—what result might we expect? From known facts, we should conclude that the silica would * On the Minerals of Trap and the allied Rocks. 5il combine with the different bases, and these simple. silicates would unite into more complex compounds. The silicates of alumina and the alkalies or lime, form thus one set of compounds, the feldspars; the silicates of magnesia and the isomorphous bases, iron and lime, another set, to which belong augite, horn- blende and chrysolite; and if much iron is present, we might have with the lime and alumina, the mineral epidote. The ex- periments of Berthier, Mitscherlich, and Rose, and the facts ob- served among furnace slags, confirm what is here stated. But not to go back to a resolution of the fused minerals into their elements, we may consider for a moment what changes the minerals themselves might more directly undergo in the pro- cess of fusion. Much of the mica in granite, differs from feldspar in contain- ing half the amount of silica in proportion to the bases—the bases in each being alumina and potash or soda. The change then in the conversion of the mica into feldspar, would require an addition of silica, which might be derived from the free quartz of granite. Other varieties of mica contain magnesia, which would go towards the formation of some mineral of the mag- nesian series. It is possible that trachytes and porphyry have thus been made from granite; but trap rocks could not have been so derived, as they contain from 10 to 25 per cent. less of silica. Again, hornblende and augite are so nearly related, that they have been considered by Rose the same mineral, the differ- ent circumstances attending the cooling giving rise to the few peculiarities presented. There can be no difficulty therefore in deriving augite by fusion from hornblende rocks. ‘This moreover has been actually confirmed by experiment. Augite by giving up half of its silica, and receiving additional magnesia in place of its lime, is reduced to chrysolite.* The Gehlenite, nepheline, anorthite and meionite of Vesuvius, contain like scapolite, only 40 to 45 per cent. of silica and a large. pro- portion of lime, and it is no improbable supposition, judging from the small amount of silica, and from the lime present, that. scapo- lite rock, or rather limestones containing scapolite, may have con- tributed in part towards the lavas of that region. The ejections * The formula of augite is R3 Siz ; that of chrysolite, R3 Si. 52 On the Minerals of Trap and the allied Rocks. of unaltered granular limestones, and many mineral species per- taining to such beds, strongly support this view ; and it is no: less sustained by the fact, that in the Vesuvian basalts, Labra- dorite, which includes lime instead of the alkalies, replaces com- mon feldspar. The nbs“ feldspar seems to ‘ean given way to leucite and Labradorite.* An important source of new combinations is found in the sea- water which gains access to the fires of voleanoes. ‘The decom- position which takes-place eliminates muriatic acid, so often de- tected among volcanic vapors; but the soda and other fixed con- stituents remain, to enter into combination with some of the ingredients in fusion. Is not this one source of the soda forming the soda feldspar, or albite, and of the muriatic acid and soda in sodalite? Phosphates have been long known to occur occasionally in volcanic rocks, and lately phosphoric acid has been proved to be generally common in small quantities. Sea-water is also.a very probable source of this ingredient, as has been shown by late analyses of the same by Dr. Jackson. These few hints are barely sufficient to indicate something of the interest that attaches to this field of investigation, which the future developments of science will probably open fully to view. We do not attempt to explain why in these modern fusings, mica should not have remained mica, and the quartz still free uncom- bined quartz. The facts prove some peculiarity of condition at- tending the formation of the granitic rocks. Of this condition we know nothing certain, and can only suggest the common supposition of a higher heat and slower cooling, attending a greater pressure and different electrical conditions, and the same circumstances may have existed during the granites of different ages. With these brief suggestions, I pass to the second division of the subject before us. 2. Minerals occupying cavities evil seams in amygdaloidal trap or basalt.—These minerals have been attributed to a variety of sources, and even at the present time there are various opinions re= * Using R for the bases and Si for silica, the formula of leucite is Rsid; that of common feldspar, R Si2; that of Labradorite, R Si. From this, it appears that feldspar may be reduced to leucite by giving up one third of its silica, the bases being the same in the two; and with this excess and other silica combining with the lime at hand, Labradorite might be formed. wa On the Minerals of Trap and the allied Rocks. 53 specting their origin. According to some writers, they result from the process of segregation ;—that is, a separation of part of the material of the containing rock during its cooling by the segre- gating powers of crystallization; and in illustration of the pro- cess: we are pointed to the many segregations of feldspar, quartz, and mica, in granite and other rocks, the siliceous nodules in many sandstones, the pearlstones in trachytes and obsidian. Others have thought them foreign pebbles, enclosed at the time the rock was formed. Again, they are described as proceeding from the vapors which permeated the rock while still liquid, and which condensed as the rock cooled, in cavities produced by the vapors. By a few it is urged, admitting that the cavities are inflations by vapors like those of common lava, that they may have been filled either at the time the rock cooled or at some subsequent time, either by crystallization from vapors, or from infiltrating fluids, | but more generally the latter. Of these views we believe the last to accord best with the facts. Macculloch in his system of Geology—a work which anti- cipated many of the geological principles that have since become popular—dwells at length on this subject, and supports the opin- ion here adopted with various facts and arguments. Lyell also admits the same principles. A review of the facts will enable us to judge of its correctness. 1. In the first place, the cavities occupied by the nodules are in every respect similar to the common inflations or air bubbles in lava. These cavities are open and unoccupied in common lava, and may be no less frequently so in the ejections under water ; and should they not be expected to fill in some instances by in- filtration? They are the very places where an infiltrating fluid would deposit its sediment, or collect and crystallize if capable of crystallization; and such infiltrating fluids are known to per- meate all rocks, even the most solid, and especially if beneath a body of water. It is evident, therefore, that we are supporting no strange or improbable hypothesis. On some volcanic shores one variety of the process may be seen in action. ‘The cavities of a lava may be detected in the process of being filled with lime from the sea-water washing over dead shells or coral sand, and at times a perfect amygdaloid is formed. But the positions and characters of the minerals themselves establish clearly the view we support. 54 On the Minerals of Trap and the allied Rocks. 2. The mineral in these cavities sometimes only fills their lower half, as if deposited from a solution; and again, it incrusts the upper half or roof, as if solidified on infiltrating through. In the large geodes of chalcedony, stalactites depend from above like those of lime from the roof of caverns, and, as Macculloch states, the stalactite is often found tocorrespond to an inferior stalagmite, the fluid silica having dripped to the bottom and there become solid ; moreover the superior pendent stalactite is sometimes found united with the stalagmite below. The same results are here observed as with lime stalactites in caverns, and often a similar laminated or banded structure, the result of deposition in succes- sive layers. Such results can proceed only from a slow and quiet process,—a gradual infiltration of a solution from above into aready formed cavity; they cannot be supposed to arise from ascending vapors, or gaseous emanations from below, no more than the stalactite in the limestone cavern. Another fact is often observed. A geode of quartz consti sometimes amethystine,—in which every crystal is neatly and regularly formed, is found with the surface coated over with an incrustation of chalcedony, the part above hanging in small sta- lactites; and this chalcedonic coat sometimes scarcely adheres to the crystals it covers,—or is even loose and may be easily sepa- rated. There can scarcely be a doubt of a subsequent infiltration ina case of this nature. We might rest our argument here, since the fact being ascer- tained with regard to quartz, it is necessarily established as a general principle with reference to the zeolites and other amyg- daloidal minerals: for quartz or chalcedony, when present in these cavities, is, with rare exceptions, the lower or outer mineral. We find zeolites implanted on quartz, but very seldom quartz on zeo- lites. I have met with no instance of the latter, while the former is the usual mode of occurrence. Any deduction, therefore, re- specting quartz, holds equally for the associated minerals. How a cavity coated with a deposit of chalcedony can still be afterwards filled up with other minerals, has been deemed a mys- tery in science, but the possibility of itis now not doubted. . Kven flint and agate, as Macculloch states, are known to give passage to oil and sulphuric acid; and much more will this take place in the moist rocks before the agate has been hardened by exposure to the air. Silica remains in a gelatinous state for a long period On the Minerals of Trap and the allied Rocks. 55 after deposition, and in this condition is readily permeable by solutions. It is not necessary that the fluid which has acted the part of a solvent and filled the cavity, should yield place to an- other portion of fluid; for the process of crystallization having commenced, a new portion of the material is constantly drawn in to the same fluid, and the necessary chemical changes are also promoted by the inductive influence of the changes in progress —the catalytic action as it is called—one of the most efficient, and at the same time one of the most universal agencies in nature. Other evidence with reference to amygdaloidal minerals is pre- sented by the zeolites themselves. 3. The zeolites occupy veins or seams as well as cavities. Often the seams were opened by the contraction of the cooling rock, and at other times they were of more recent origin. In either case the minerals filling these seams must be subsequent in formation to the origin of the rock itself, and could not have proceeded from vapors attending the eruption. ‘These seams sometimes open up- _ ward and can be seen to have no connection with the parts below, the rock in this portion being solid. Origin from above or from either side, is the only supposition in such cases. Messrs. Jackson and Alger, in their valuable memoir on the geology of Nova Scotia, mention the occurrence of crystals of analcime attached to the extremity of a filament of copper, the copper having been the nucleus about which the solution crystal- lized, and state that their formation must have been subsequent to the formation of the rock. 4. Zeolites, moreover, have been found forming stalactites in basaltic caverns, as was observed by the writer in some of the Pa- cific islands; and Dr. Thomson has described and analyzed one (Antrimolite) from Antrim in Ireland near the Giant’s Causeway. These facts favor throughout the view we urge, that the amyg- daloidal minerals have in general resulted from infiltration, and were not necessarily formed simultaneously with the erupted rock. 5. We remark farther, that no lavas have ever been shown to contain at the time of ejection, any of the zeolitic minerals. The zeolites of Vesuvius are known to occur only in the older lavas, and afford no evidence against our position. The cavities in lavas, as far as observed, are empty as they come from the vol- canic fires, with the exception of those containing sparingly some metallic ores which are condensed within them. Considering 56 On the Minerals of Trap and the allied Rocks. the fusibility of the zeolites and their easy destruction by heat and by volcanic gases, sulphureous and muriatic, we should @ priort say that they could not be formed under such circumstances. 6. Besides, as we have stated, none of the proper constituents of trap or basalt—or the minerals disseminated through these rocks, —contain water. They are all anhydrous.. The minerals form- ed accidentally in furnaces are anhydrous. The constituents of granite, syenite and porphyry are all anhydrous. It is only those minerals which are found in geodes or seams that contain water. Of equal importance is the fact, that none of the essential con- stituents of these rocks have ever been found in these geodes or cavities along with the zeolites, as might have been the case had they been formed together, by segregation or otherwise. Neither feldspar, although so abundant, nor augite, nor chrysolite, have been found filling, like zeolites, or with them, the cavities of amygdaloid. There is then a wide distinction between the an- hydrous constituents of these rocks, and the hydrous zeolitic minerals. A few zeolites have been found in granite or gneiss, but they are so disseminated that they can be shown to be of more modern origin than the rock, and to have resulted from some decomposi- tions of true granitic minerals. They differ entirely in their mode of distribution from the feldspar, garnet, &c. of granite. Along with a decomposing feldspar, it is not unusual to find stilbite in the cavities formed by the decomposition. Zeolites also have been found disseminated through the tex- ture of basalt, clinkstone, &c., like the feldspar, augite, &c. But the proportion varies widely, and in some parts of the same bed they are found to be wanting; so that we have sufficient reason for classing these disseminated zeolites with those in the cavities, as formed or introduced by infiltration. 7. Bearing upon this subject, it should be observed, that the constituents of amygdaloidal minerals are, in general, those of the containing rock. Silica, potash, soda, alumina, are found in the feldspars; lime, magnesia and iron in augite or hornblende; iron and magnesia in chrysolite. These are all the constituents needed, except a little baryta for one species. The feldspardecom- poses readily and gives up its ingredients, its potash or soda, silica and alumina; the same is true of augite and chrysolite, which af- ford magnesia, lime, silica and iron. With water to infiltrate, we On the Minerals of Trap and the allied Rocks. 57 should therefore have all the necessary ingredients at hand for the required compounds. ‘The fact already stated, that zeolites have been found as stalactites in caverns, seems to prove that they do actually result from decompositions and recompositions, such as have been supposed. Thus we have all the conditions at hand necessary for producing, by infiltration, the zeolites and the chlo- rite nodules of these rocks; the alumina, alkalies and lime, con- tribute, along with a portion of the silica, to the zeolites, and the magnesia, iron, and another portion of the silica, to the chlorite,* often as abundant as the former. The amygdaloidal nodules frequentiy have a green coating, which farther indicates the pro- bable truth of these views ; for it appears evidently to be a precip- itate from the solution before a crystallization of the zeolites took place—a settling, perhaps, of the insoluble impurities taken up by the filtrating fluid in its passage through the rock, or of the formed chlorite, less soluble than the zeolites. Occasionally, when the rock contains copper, these nodules have an earthy coating of green carbonate of copper—the carbonate having pro- ceeded, apparently, from the native copper of the rock, by the same process as explained. The hypothesis of filtration seems, then, to be at least the prin- cipal source of these minerals. In some instances the filtrating fluid may have derived its ingredients from distant sources. ‘The salts of sea-water may act an important part in these changes. Silica is dissolved on a grand scale during submarine eruptions, as we have elsewhere urged, and is thence distributed to the rocks around. Lime, also, is taken up in a similar manner. But the rock itself has often afforded the ingredients for the forming minerals, during the passage of the filtrating fluid through it. By the same means, the adjoining walls of a seam or dyke— which receive the drainings from the rock of the dyke—are often penetrated by zeolitic minerals. It may be thought that I am giving undue influence to a favor- ite theory, and in the minds of some, these conclusions may be set down among mere speculations in science. But the cireum- stances attending submarine igneous action, I am persuaded, is not generally apprehended. What is the condition of the deep * Chlorite consists of the same elements as augile or hornblende, except that the lime is excluded and water added. They are silica, alumina, magnesia, oxyd of iron, with 12 per cent. of water. . Vol, xurx, No. 1.—April-June, 1845, 8 58 On the Minerals of Trap and the allied Rocks. bed of an ocean? Even at a depth of three miles, the waters press upon the bottom with a force equivalent to a million of pounds to the square foot ; and with such a forcing power above, can we set limits to the depth to which these sea waters—mag- nesia and soda solutions—will penetrate? Will not every cav- ern, every pore, far down, be filled under such an enormous pressure? Leta fissure open by an earthquake effort, and can we conceive of the tremendous violence with which the ocean will rush into the opened fissure? Let lava ascend, can we have an adequate idea of the effect of this conflict of fire and water? The rock rises, blown up with cavities like amygdaloid, and will a long interval elapse before every air cell will be oceupied from the incumbent water? Suppose an Hawaii to be situated beneath the waves, pouring forth its torrents of liquid rock ;—this island contains about five thousand square miles, which is less than the probable extent of many a region of submarive eruption ; —suppose, I say, the fires were opened and active over an area of some thousands of square miles—are there no effects to be dis- covered of this action? ‘There is no geologist that pretends to deny the premises—the fact of such submarine eruptions, the ocean’s pressure, the effect of fire in heating water, and in giving it increased solvent power; and why should they not reason upon the admitted facts, and study out the necessary consequences ? Surely, if there have been effects, we might expect to see some of them manifested in the cavities of the ejected rocks, which were opened at the time to receive the waters and any depositions they might be fitted under the circumstances to make. We are led by these considerations to another point in connec- tion with this subject: the probable condition under which the different amygdaloidal minerals have been formed. Have they all proceeded from heated solutions, or all from cold solutions? or can we distinguish some which are indubitably of one or the other mode of formation? Bearing on these questions, we notice such facts as are afforded by the condition and relative positions of the minerals in geodes. And I would here acknowledge my obligations to the valuable memoir, before alluded to, by Messrs. Jackson and Alger. The paucity of information on this subject, to be found in the various accounts of similar rocks by other writers, is surprising. Even where special pains have been taken to describe the mineral spe- cies, the relative positions of the minerals is very seldom noted. On the Minerals of Trap and the allied Rocks. 59 It has been altogether too common among geologists to treat min- eral information with a degree of neglect almost amounting to contempt, although, as facts will probably hereafter show, they lie at the basis of an important branch of geological science. But to proceed with the subject before us. We find that Quartz or chalcedony, and datholite, very seldom overlie other mineral species in geodes or amygdaloidal cavities, while the lat- ter often overlie them.* Prehnite is usually lowermost with reference to all the species except the two just mentioned. Occasionally it is found upon analcime, as at the Kilpatrick hills. Analcime is commonly situated below all, except quartz, datho- lite and Prehnite. Of the remaining species, chabazite, stilbite, harmotome, Heu- landite, scolecite, mesole, Laumonite and apophyllite, it is more difficult to distinguish an order of arrangement. My investiga- tions only enable me to state that chabazite is usually covered by the rest, (when associated with them, ) yet it is sometimes super- imposed on stilbite; and apophyllite is almost uniformly above all with which it may be associated ; cale spar is at different times above and below. We thus arrive at the following as the usual order of superposition. 1. Quartz. 2. Datholite. 3. Prehnite. A, Analcime. 5. Chabazite, harmotome. 6. Stilbite, Heulandite, scolecite, natrolite, mesole, Laumo- nite, apophyllite. It is a reasonable inference that the species which covers the bottom of a cavity was first deposited, and, as a general rule, that the others above were formed, either simultaneously, or in succes- sion upon the lowermost, as their order,may indicate. Each is usually perfect in its most delicate crystallizations, so that we can not suppose that the miuerals first deposited often underwent change after their deposition, though instances of this may no doubt be detected. It is also evident that if there were any species formed previous to the complete cooling of the rock, or if any require for their for- * The writer has observed stilbite, apophyllite, cale spar and Prehnite overlying datholite, and various species over Prehniie. 60 On the Minerals of Trap and the allied Rocks. mation an elevated temperature, they are those first deposited— the first in the above series. A few considerations will place this if possible in a clearer light. Quartz, as we have stated in a preceding page, and fully re- marked upon elsewhere, enters largely into solution during sub- marine eruptions. ‘This solution has been shown, by actual ex- periment, to be a necessary consequence of such action. ‘This fact corresponds most completely with the above deductions. Quartz usually forms the first lining of the geode or amygdaloidal cavity, when it is found at all, and, moreover, it is the most abundant of all amygdaloidal minerals. Quartz may also proceed from decompositions of the rock in the cold, and incrustations of this kind are known to occur; but such an explanation does not account for its generally preceding all other species in filling cavities and seams in trap rocks, and is insufficient to produce the large deposits of silica, sometimes amounting to many tons in a single geode. It should not be understood that the quartz is supposed to be derived always from the same heated waters that attended the formation of the containing rock ; for later eruptions in the same region might, at a subsequent period, produce a like result: yet, as its place in the series proves it to be the earliest in formation, it has probably been generally deposited from the water heated du- ring the eruption of the rock. Leaving quartz, we pass to the other minerals. It is a striking fact that the minerals next to quartz in the ta- ble given—datholite, Prehnite and analcime—contain less water than either of the following species. While the others include from 10 to 20 per cent., the first, datholite, has but 5 per cent., Prehnite about 44 per cent., and analcime 8 per cent.* ‘This fact certainly leans towards the view of their having origi- * The following table shows the percentage of water, and gives at the same time a general view of the composition of the zeolites. Silica, boracic acid, lime.—Datholite (5 Aq.) Silica, alumina, lime.—Prehnite (44 Aq.) Heulandite (14 Aq.) Scolecite (134 Aq.) Epistilbite (14 Aq.) Stilbite (17 Aq.) Laumonite (17 Aq.) Silica, alumina, lime and potash or soda.—Mesole (12 Aq.) Thomsonite (13 Aq) Phillipsite (17 Aq.) Chabazite (21 Aq.) Silica, alumina, and either soda, baryta or strontia.—Analcime (8 Aq.) WNatrolite (98 Aq.) Harmotome (15 Aq.) Brewsterite (13 Aq.) Silica, lime and potash.—Apophy lite (16 Aq.) Silica, lime.—Dysclasite (16$ Aq.) On the Minerals of Trap and tie allied Rocks. 61 nated at a somewhat more elevated temperature than the other species—the same conclusion that is drawn from their lower po- sition in geodes. The fact, also, that Prehnite has been found forming pseudo- morphs, bears the same way ; for heat would be necessary, in all probability, to aid in removing the original mineral. 'The vast extent of some Prehnite veins—occasionally, as Dr. Jackson has observed, three or four feet wide—refers to an origin like that of the quartz in similar rocks. Indeed, there seems little doubt that Prehnite is often derived from that portion of the silica in solution which entered into combinations at the time with the alumina and lime which the siliceous waters contained ; and probably the lime as well as silica was derived in part from an external source. The pseudomorphs prove that Prehnite may have been the result also of subsequent eruptions, at the same time that they show the probable necessity of heat for its formation. Datholite is a compound of silica, lime and boracic acid, with - about 5 per cent. of water. Besides the small percentage of wa- ter, and its being, next to quartz, the lowermost mineral in geodes, we find an additional fact, alone almost decisive with regard to its origin, in its containing boracic acid. Boracic acid is often evolv- ed about volcanoes or in volcanic regions. The hot lagoons of Tuscany, and the volcano of Lipari are the most noted examples. Although boracic acid has never been detected in sea water, there can be little doubt of its occurring in it. The usual modes of analysis by evaporation would dissipate it, and of course it could not thus be detected except with special care and by operating on a large quantity of water. Borate of soda (boracite) is found only in beds of salt and gypsum,—both sea-water pro- ducts. Moreover, borate of lime has been lately found on the dry plains in the northern part of Chili, along with common salt, iodic salts, gypsum and other marine salts, and all are so distri- buted over the arid country, that the region has been lately de- scribed as having been beyond doubt once the bed of the sea. These facts render it altogether probable that sea water which gains access to volcanic fires is the source of the boracic acid in volcanic regions.* * The only other known source is the mineral tourmaline, quite an improbable one in the case before us. It is possible that tourmaline may have received its boracic acid from the sea during granitic eruptions, and the occurrence of this mineral in the vicinity of trap dykes is explained in the same manner. 62 On the Minerals of Trap and the allied Rocks. If this be its origin, the necessity of heat and pressure must be admitted, in order to produce the chemical combinations in datho- lite. Its elements are not those of the feldspar or other trap minerals, like the zeolites superimposed on it; but they have come from an extraneous source, and none is more probable than the sea waters, which were heated at the submarine eruption, and permeated the bed of molten rock shortly after ejection. ‘Thus placed in circumstances of pressure and confinement, along with silica in solution, the volatile boracic acid might enter into the combination presented in datholite. An interesting fact bearing upon the history of datholite was observed by Dr. Jackson at Keweena Point, Lake Superior. The datholite is often formed there in veins with native copper, and is associated in some places with a curious slag of boro-silicate of iron and copper. Sometimes the crystals of datholite, as well as the Prehnite and calc spar, contain scales or filaments of native copper. ‘These very important observations seem to establish the same origin for the three minerals—for Dr. Jackson states that they appear to be cotemporaneous—and if calc spar has been de- posited from a solution, the same holds true of the others. They have all been formed subsequent to the copper filaments of the cavities, for they were deposited around them; yet may have been the next to form during the cooling of the rock. ‘The boro- silicate of iron and copper has resulted from the same causes. Analcime approaches the zeolites in composition, but like the Prehnite and datholite it contains less water, and is very dif ferent in its crystallization. We have less evidence as to the heat necessary for its formation; yet it was probably formed at a somewhat elevated temperature. . With regard to the other amygdaloidal minerals we are in still greater doubt as to, the necessity of heat. We cannot at present fully appreciate the efficiency of chemical agents in a nascent state acting slowly without heat through long periods. - Many of them may require heat, and some may be the last depositions from the filtrating waters after they have nearly or quite attained their reduced temperature. But the formation of zeolitic stalactites in caverns favors the view that some at least may form at the ordi- nary temperature by the slow decomposition of the containing rock after it had emerged from the waves.* Kersten has lately * Annales des Mines, ii, (4th Ser.) 465, 1842. On the Minerals of Trap and the allied Rocks. 63 described a modern stellated zeolite forming incrustations on the pump-wells of the Himmelsfurth mine near Freyberg. It consisted of silica, oxyds of iron and manganese and water. Further examin- ation will probably bring more of these modern products to light.* The formation of particular minerals in certain regions, depends of ‘course upon the supply of the necessary ingredients. Where the supply of lime has been large, we should expect to find some of the minerals, Prehnite, Heulandite, Laumonite, stilbite, scolecite, dysclasite, chabazite, for carbonate of lime decomposes the silicates of potash or soda. Instances of this association of the lime zeolites with a large supply of lime in the vicinity are common. When there is little or no lime, or only the results proceeding from the decomposing rock, the other zeolites are formed—the hydrous silicates of alumina and potash or soda, occasionally with some lime. But if a salt of baryta or strontia is present, the decom- position of the silicates of the alkalies takes place as by the lime, and the mineral harmotome or Brewsterite is produced. In the above explanations we have scarcely appealed to one source of amygdaloidal minerals admitted in the outset—their pro- ceeding from vapors rising with the erupted rock ; for it seems to be of but limited influence. Besides the arguments already brought forward, we state that the vapors which rise at the mo- ment of eruption are insufficient. They inflate the rock, or blow up the cavities; but the little vapor required to open the cavities most assuredly could not afford by condensation the mineral matter necessary to fill them,—to produce stalactites, stalagmite and successive layers of minerals. 'The vapors then, if the source, must have continued to rise for some time afterward. But is it possible that vapors should rise up through the solid rock ? Such does not happen about recent volcanoes ; for fissures are first open- ed and then the vapors escape. And could it happen with the water above pressing down into the rock with the force of an ocean even a mile deep? ; There may be instances of this mode of formation ; but that it should be the usual mode is irreconcilable with the many facts sta- ted. The form and condition of quartz or chalcedony in geodes, as well as the vast amountof this mineral in some cases,—the rela- * Carbonate of iron seems never to form from water at the surface, its solutions depositing a hydrated peroxyd of iron instead of the carbonate: it may therefore require a submerged condition of the rock, although not necessarily a raised tem- perature. ae 64 Lieut. Ruggles on the Copper Mines of Lake Superior. tive positions of the zeolites, and their occurrence as incrustations on rocks, or as fillings of cavities or seams, and never in dissemi- nated crystals through the texture of the rock,—the green coating of the nodules, which is sometimes a carbonate of copper when there is native copper in the rock to undergo alteration,—the cor- respondence between the elements of the minerals and the com- position of the including rock, and at the same time their con- trast in being hydrous while the constituents of the latter are anhydrous,—and the known formation of zeolites in caverns,— these various facts appear to establish infiltration as the principal means by which amygdaloidal minerals have been produced. Art. VII.—Considerations respecting the Copper Mines of Lake Superior ; by D. Rueexezs, Ist Lieut. 5th Regt. U. 8. Infantry. Recentty I had the honor to communicate some particulars in relation to the copper mining region, as well as the discovery of a vein of black oxide of copper, tinged with the carbonates, near Copper Harbor. Now, I propose extending those views, accom- panied by observations touching collateral points, and deem it proper to recapitulate some of the circumstances connected with this discovery, as a basis for more extended observation.* It has already been stated, that the troops, while engaged about the middle of November last, in making some slight excavations, connected with the establishment of this post, found some bowl- ders of black oxide of copper of great density, richness and beau- ty, inducing an examination of a circuit of some fifty or sixty feet in diameter, from which some tons of bowlders, of uniform composition, were taken. (See fig. 1.) Description of Fig. 1.—A. Copper Harbor.—B. Lake Fanny Hooe.—C. Lake Martha Stevenson.—D. Lake Clara Geisse.—E. Fort Wilkins.—F. U.S. Mineral Agency.—G. Pittsburgh company’s cabins.—H. Main channel.—l. Centre reefi— K. Lake Superior—Q. Lake Anna Stannard.—L. Silicate of Copper.—m. Bowl- ders of black oxide.—n. Trap dykes protruding.—n!'. Mother trap range.—Scale of diagram, nearly two inches to the mile. * The present communication appears in a great measure to supersede the pre- vious one received Feb. 12, 1845. That paper, agreeably to the author’s wishes, has been forwarded to another destination. The historical fact, cited by him anterior to 1821, may be found in Mr. Schoolcraft’s memoir in Vol. II of this Journal, p. 202, with a figure of the large mass of native copper, now at Washington.—Eds, % ~~ E. Za 2 LG a = ZA = | | A\\\ lu Ss} ! } | a aS \ LTT SS i? WIHMULLAL Ab “lth im = Mi ia LLL = Was AS N aii x r ay 8 SN S is (-% ‘Sy ‘uondes 909) ‘soqIey ay} Jo yey} BAOe 399] U99zINOT qnoqe st a0vjIns sjiT ‘siaqea sy Jo AjypMbueny oy. Jo souepiaa AlojoKJses Suipjioye oyno st 3e VIqISIA TJS Wep JaAveq e& Jo sa0eI} oy} Aq poyUeIIeA\ UOIsNjOUOD B { UOTyepUNUT 0} pajoefqns JoAe JL Wopyes st pue ‘AjIUIOIA S}VIPSWUI oY} UL Saye] ]TewWs Ul Suisit ‘sjayNAl saTNUIUTIp Aq poy St Oye] SIU, ‘ejqeiejedun pue ‘1ajeA\ pue Apueig Surjquiasar ‘ystyovrq ore sioyem st‘ yydap ut yooj ApxIs Jnoge saseiaav pure ‘peosg oil ve Jpey ‘Suoy sari ao1y} Ajrwou ‘axel 9]131] Ayoid e st ‘eooxy Auue,y oye'T “oyeIoUO[Suoo ‘ye1oues Ul ‘sI WUNyeI)s [eloy.edns 9, J, 66 Lieut. Ruggles on the Copper M Lieut. Ruggles on the Copper Mines of Lake Superior. 67 The point ois distant about forty yards from g, and at o the vein of black oxide rises within two feet of the surface, through well- defined walls of conglomerate rock, near the crest of an elevation of eight feet above the crop of the new red sandstone. The latter rock dips some degrees towards the harbor, and rests upon, at its outcrop, most probably, a trap dyke, running parallel with the small lake. The metallic bowlders were found at m, in a stratum of drift, consisting of coarse gravel intermixed with a va- riety of pebbles and bowlders, presenting the characteristics of a well-worn shingle beach. During the progress of discovery, the first question was, whether these metallic bowlders were genuine drift, in their present distinct masses, or an accidental deposit from an iceberg,* subsequently broken into fragments ; or, indeed, of local and isolated formation. Their number, density, and uni- form composition, together with evident marks of attrition and abrasion in the characteristic stratum in which they were found, left no doubt in my mind that they were genuine drift; and accordingly, keeping in view their clustered position and density, that they were, at a remote period, driven from a vein of identical composition. This naturally led to the examination of a faint undulation, near the crest of the elevation close at hand; which proved to be a crevice in which the vein was subsequently found, and in which a space of some twenty feet, filled with detritus containing occasional bowlders of ore, confirmed my previous con- victions, that it was from this crevice the whole mass of metallic bowlders had once been driven. Another enquiry necessarily follows, viz. to what agency must the translation of these bowlders be attributed, and did the united agency of present causes produce these results? It has been already remarked, that the bowlders were found about ten feet above the present surface waters of the lake, and that the vein lies in the slight elevation some eight or ten feet above the bowl- ders. It is to be observed, that the vein ranges, under a small angle with a perpendicular, to the longitudinal axis of the lake and the direction of the subterranean dyke; consequently, some of the heaviest bowlders must have been transported fifty or sixty feet, and almost all nearly that distance, over the crop of the new red sandstone. These masses have a density approximating * This, also, would be comprehended under the general scope of drift.—Eps. 68 Lieut. Ruggles on the Copper Mines of Lake Superior. closely to that of cast iron. 'The conclusion is therefore evident, that present causes* combined cannot, by any possibility, have produced such aresult ; and that it is attributable to the agencies of the great diluvial or drift period, or those of subsequent action, and which have long since reposed in equilibrium. If we sur- vey the geological aspect of the surrounding district, the indica- tions of causes sufficiently powerful meet us on every side. A species of well characterized trap-conglomerate extends west- wardly along the southern coast to the head of Lake Superior, also several miles inland, embracing an area, probably, unparal- leled in the history of this formation. This stratum is composed of pebbles and small bowlders of every variety and description, cemented by calcareo-siliceous matter firmly solidified, disclosing clearly defined traces of ancient igneousaction. On the elevated range south of the small lake, where: the mother trap appears, the conglomerate has been ruptured along its longitudinal axis, and pitched outwards, and even now displays the ragged faces of large masses once violently fractured. But in the vicinity of the lower trap dykes, the disruption of the conglomerate has in a great measure disappeared under the ancient abrasion of incumbent waters, while the rock was still comparatively soft—from the elements of which a partial re-arrangement resulted. ‘Thus re- markable inequalities in the thickness of this stratum have arisen. The numerous trap dykes and traversing fissures, as well as the peculiar tinge of the new red sandstone, disclose unerring indica- tions of a remote period of volcanic or igneous action. There is, also, in this vicinity, a remarkably well characterized straiwm or bed of black oxide of manganese. It crops out in the precipitous bank of the creek leading from Lake Martha Stevenson to Lake Fanny Hooe, at g. (See fig. 1.) An extent of some sixty feet is developed, and is about two feet in thickness; it is compact, in- termixed with and disseminated through a pearly, semi-crystalline calcareous spar. The stratum runs in a lateral direction, and the crop ranges at an angle of at least 45° with the horizon, parallel with the course of the creek and perpendicularly to the axis of the mother trap range, over which it doubtless lies. The undu- lating appearance of the crop, the high angle under which it is * The author doubtless intends by “ present causes,”’ those that are now operating under existing circumstances, in that region; he doubtless admits that the causes, whatever they have been, are still existing, and elsewhere in action. —Eps. ag | = Lieut. Ruggles on the Copper Mines of Lake Superior. 69 presented, together with the lateral direction or bearing westward, and the associated semi-crystallized limerock, seem to prove incon- testably that this once constituted a bed or horizontal stratum at- tributable to aqueous origin, subsequently solidified—perhaps pu- rified—and elevated into its present position by volcanic or igne- ous action. It is also worthy of remark, that an extensive vein of calcareous spar, of a well characterized crystalline structure, is situated at 1, on the shore of Lake Superior, and is some eight feet in breadth ; and east of this about two miles} a similar vein of four feet in width is found. Now, if we assume that these veins, as well as the great number of a similar character holding the same general bearing, namely, S. 15° W., are attributable to igneous action, - under great pressure, analogous experiments prove that it is a ra- tional deduction. (See Hitchcock’s Geology, p. 244.) The con- clusion would therefore seem irresistible, that the Copper Harbor vein of black oxide was formed either under the pressure of wa- ter, or submerged during a long period after formation, when the metallic bowlders in question were driven from their original po- sition. In connection with this conclusion, I observe, that there is evidence of gradual elevation at remote periods, without corres- ponding subsequent depression. ‘The south shore of Lake Fanny Hooe appears to have been, upon its narrow margin, at one period, a regular beach, judging from its inclination and the composition of the detritus, which weuld have made the narrow isthmus where the fort now stands a sunken reef, as well as the arms of the present harbor, while the small lake must have been at one period a safe and commodious harbor amid the dreary waste of waters surrounding. In the present instance, the elements have placed a record within our reach, by which we can determine approximately that this region has found uninterrupted repose during along period past, and that the forces from which the present aspect and order of things resulted, are now held in equi- librium. We observe that a trap-dyke ranges and sinks in front of the landing at this post. (See fig. 1.) 2 ¢, is about 200 yards long, and a perpendicular from its centre strikes the shore at the distance of 100 yards. The east bank of Fort Wilkins creek has been swept away at least eighty yards inland from ¢, whilst the western bank of the same composition still remains entire—pro- tected by the dyke in front from the violence of the open road- Bs ea i ie Ay it | ") ae 70 Lieut. Ruggles on the Copper Mines of Lake Superior. stead waves. The superficial portion of the isthmus, close at hand, is composed principally of the detritus of conglomerate, and as we descend, this rock is disclosed in its characteristic solid- ified form. The space thus presented near the landing sinks from the beach outward to twenty-five feet water, and lies before the eastern channel of the open roadstead—leaving the mind to comprehend, involuntarily, that it has been gradually cleared of an immense mass of conglomerate and its detritus by the abrading waves. Nearly opposite the western roadstead channel, at d/,a similar impression has been made upon the isthmus. The evi- dence of cause and effect is here strikingly exemplified by the result, and the conclusion is therefore rational, that a long period of repose has elapsed since disturbing forces have left records of their power. Nevertheless, I regard the Kewaiwenon peninsula as the result of progressive elevating periods, and accordingly that most if not all of the mineral veins throughout this region have been formed by volcanic or igneous action, under the pres- sure of incumbent waters. That the trap was first projected through the conglomerate, and that then the mineral veins were formed, there can be little doubt. I have entered into these details because I regard this region as presenting many striking peculiarities, a knowledge of which will become of great importance as the mines are progressively developed, and which will be found to extend, by practical analo- gy, to the whole mining region of the northwest; and I know of no method by which to arrive at important and practical gen- eralizations in the geology of mining, except by a just apprecia- tion of elementary indications and principles. I am not aware that any more remarkable instance is found on record where me- tallic bowlders, of great richness, density and beauty, have been traced, in a manner so satisfactory, to the parent vein. ‘The question is thus presented, hypothetically, whether the true veins, containing copper and its combinations, were formed by subter- ranean igneous agency, under the pressure of incumbent water, - or subjected only to the pressure of the atmosphere ; and the same views extend, by analogy, tothe lead mines. The question is very important as regards the origin of mines, and especially since this rich vein appears to have been formed and preserved under the pressure of a great body of water,—while disseminated me- tallic copper, found in many veins, may possibly indicate that Lieut. Ruggles on the Copper Mines of Lake Superior. 71 portions of the valuable combinations of this metal have been de- stroyed and dispersed by subterranean heat in consequence of the absence of pressure. I will now endeavor to indicate, briefly, the vast region to which this question has direct application. 'The general dissemination of copper, and indications of its combinations, extending from near Grand Island along the southern shore of Lake Superior to its head, and several miles inland, as well as abundant indi- cations on Isle Royale, near the N. W. coast, is now well estab- lished. 'The native copper bowlder, so long known to have lain in the Ontonagon, has been very justly regarded as an anomaly in the mineral kingdom. ‘There is also an inland trap range running some two hundred and thirty miles south of the Kewai- wenon bay, and extending inland past ‘“‘ Lac Vieu Desert” towards the sources of the Chippewa and Wisconsin rivers. Indications of copper and its combinations are said to have been found through- out the whole extent. The Indians describe a massive bowlder of native copper, surrounded by calcareous spar bowlders, a little to the west of ‘‘ Lac Vieu Desert,” so vast that actual examination alone would overcome incredulity. I have received authentic ac- counts of small fragments of native copper found in sand-rock by troops, in 1819, ’20, while quarrying near the junction of the Mississippi and St. Peter’s rivers, for building Fort Snelling, and where the hand of man could never have placed them. Recently ores of copper have been discovered, in the vicinity of Prairie du Chien, estimated to yield twenty per centum. Some eight or ten years since, a mine, bearing nearly N. and S., con- taining earthy oxides associated with the ferruginous sulphuret, yielding about fifteen per cent., was opened near Mineral Point, and since then other localities have been discovered in its vicinity. A large portion of this region, especially that comprised within the Mississippi valley, which has come under my personal obser- vation, presents clear and abundant traces of submergence during a remote period—this, indeed, independent of the incontestable evidence indicated every where by organic remains; of these waters, the Mississippi appears to have been the final outlet. A similar subsidence, though less clearly indicated, probably took place contemporaneously in the region of the great lakes, through the valley of the St. Lawrence. Now it is to be observed, that galena is found geologically associated with copper, in strata flanking the trap ranges, and at 72 Lieut. Ruggles on the Copper Mines of Lake Superior. distances from their axes, subjecting them but partially to the in- fluence of the great disturbing cause. It is also to be observed that in the immense mining district embracing portions of Illi- nois, Wisconsin and Iowa, galena is generally found in the older secondary limerock, in fissures ranging north and south, east and west. The former is usually crystallized in cubes, and the latter frequently laminated. At Dubuque these fissures lead through extensive caverns, in which immense masses of galena are found. The geological position of this ore is precisely that which we might reasonably anticipate, as resulting from the projection of metallic lead, enveloped in a dense atmosphere of sulphur from the fountain of igneous action, through fissures in the rock strata, resulting from concurrent disturbing causes, under the pressure of an immense mass of water—otherwise the sulphur would have escaped by sublimation, and the lead sunk or entered partially into other combinations. This opinion is in a measure confirmed by the fact, that blende, sulphuret of zinc, is very gen- erally associated with, and indeed usually overlying, galena in the mining region; which accords with reason, as indicated by their relative specific gravity—being 4 to 7.5—taken in con- nection with the sublimation of zinc unconfined after fusion. ‘Thus, experience seems to prove that atmospheric pressure is en- tirely insufficient to produce condensation, and hold this metal in combination. Galena is also found in beds of alluvium, where: it may have been projected in its nascent state, or subsided under the abrasion of the subsequently receding waters, which destroyed extensive portions of the metalliferous limestone stratum. Ex- perience shows, moreover, that galena is very generally imbedded in, or associated with, a species of plastic mineral clay, with indi- cations of oxidation. The combinations of copper at Mineral Point and Prairie du Chien, are probably accidental projections from the seat of igneous action, and consequently of rare occur- rence in that district, where the limerock is supposed to average one thousand feet in thickness. This corresponds, I conceive, with observations made in the copper-mining region, connected with the disappearance of mineral veins in very thick, overlying conglomerate. In most cases, boring should precede mining, as this simple and comparatively cheap operation will decide the question of the existence of ores in profitable quantity. Fort Wilkins, February 26, 1845. ¢ _ Prof. Snell on a singular case of Parhelion, &c. 73 Arr. VIIL—Singular case of Parhelion, with a statement of the Theory of ordinary Halos; by Prof. E. 8. Sneri, of Am- herst College. On the 23d of last March I witnessed an optical phenomenon in nature, which was to me entirely new. ‘The sun had ascend- ed eight or ten degrees from the horizon, and I was stepping from my door, which opens to the east, when I was surprised to no- tice a luminous curvilinear band, three or four feet wide, thickly studded with shining points of every prismatic hue, stretching over the dead grass of the wide street before me. Its form seemed to be that of a parabola or hyperbola ; its nearest point, which was the vertex of the curve, was not more than twelve or fifteen feet distant, and its two branches extended several rods, one to the _ right and the other to the left of the sun,—the axis being the in- tersection of the ground plane with a vertical through the sun and the eye. Though the band could be thus distinctly traced, yet the illumination was not continuous, as in the rainbow, but pencils of intense light were seen to come from innumerable but. separate points; and these exhibited, without much order of ar- rangement, the countless shades of the prismatic spectrum. As I moved, the luminous arch moved also in the same direction, so as to retain its relations to my eye and the sun, while the in- dividual points changed from hue to hue and were extinguished, and others started into sight, to twinkle fora moment in their turn, and then disappear. My first thought was, that it was the lower limb of a rainbow, such as I have often traced in dew-drops, as they rest on vege- table leaves and are strung upon spider lines that are stretched along the grass. Its form appeared the same as the rainbow must assume when seen in such circumstances. But it was in the wrong direction ; 1 stood facing the sun, and the colors plain- ly came from points not more than thirty degrees from it. I per- ceived in a moment, however, that there were no dew-drops, but that the spires of dead grass were feathered over with frost crys- tals of unusual size. The true nature of the phenomenon in- stantly flashed upon my mind; and I was delighted to witness a most interesting confirmation of the truth of the generally re- ceived theory respecting the large solar and lunar halos. In the Vol. xxix, No. 1.—April-June, 1845. 10 74 Prof. Snell on a singular case of Parhelion, first place, though the colors were scattered promiscuously, yet there was evidently a prevalence of the red on the most distant, that is, the concave edge of the band. And in the next place, I ascertained, by a rude measurement, that the distance of the curve from the sun was about twenty twodegrees. These two particu- lars characterize that species of halo, most frequently seen encir- cling the sun and moon, respectively called the parhelion and the paraselene.* The only hypothesis offered for the explanation of the halo of AA or 45 degrees in diameter, which is at all satisfactory, is that of M. Mariotte and Dr. Young, who considered it the effect of the transmission of light through snow crystals, whose refracting angle is 60°. This is known to be one of the most frequent angles in such crystals. The index of refraction for ice is about bt. Now suppose a pencil of light to traverse a prism of ice, whose refracting angle is 60°, in such direction as to cut perpendicularly the bisecting line of the refracting angle ; this pencil will be found, by asimple calculation, to deviate 21° 50’ from its original direc- tion. If the prism be revolved either way from the position just named, the angle of deviation will increase; yet so slowly at first, that a change of 10° in the prism will not occasion a disturbance of more than one fourth of a degree in the emergent ray. But if the prism be revolved through large angles, the deviation increases more rapidly ; and the greatest deviation occurs, when the prism is revolved in one direction, till the angle of incidence equals 90°, or in the opposite, till the angle of emergence is 90°. In either case, the deviation I find to be 43° 27’; this is the maximum. Let there be a stratum of these crystals floating in the air, of such depth as to produce only haziness, through which, of course, the sun can be plainly seen. ‘The refracting edges must be supposed to lie in all possible positions. We are at present concerned only with those whose edges are perpendicular both to the line of vision and the solar ray, and whose refracting angles are turned away from the axis, or line joining the eye and the sun. And of all such, it is plain that no crystal, lying nearer the sun’s * These terms are often used to designate those bright images of the sun or moon, sometimes seen at the intersection or contact of two halos, also called mock-suns and mock-moons. ButI find good authority for applying the words to the halos themselves. S75 Se mes and the Theory of Halos. 75 direction than 21° 50’, can transmit a ray to the eye of the ob- server; otherwise the deviation would be less than 21° 50’, which, according to the above calculation, is the minimum. But those crystals, which are about 22 or 23 degrees from the sun, may, as already stated, be revolved on their own axes, so as to change the angle of incidence 10 or 15 degrees, and yet send their transmitted ray to the eye. Some of these positions are represented at B, in the figure. That I might render my own ideas of the case as definite as possible, I constructed the following table, for every five degrees of incidence. Angle of incidence. Angle of emergence. Angle of deviation. 13° 27’ 90° 43° 27’—maximum. 15° Poeey 34° 19’ 20° 66° 40’ 26° 40’ 25° 59° 37" 24° 37’ 30° 53° 23° 35° aa a Ze Oot 40° Ao ae 21°51" 40° 55’ AQ° 55’ 21° 50’—minimum. A5? 36° 59/ 21°59’ 50° 32° 30’ 22° 30’ 55° 28° 22/ 23° 22’ 60° 24° AZ! 24° 43’ 65° 21° 287 ere? mor 70° 18° 42/ 28° 42' 15° 16° 287 31° 28’ 80° 14° 487 34° 48’ 85° te 49' 38° 49’ 90° 13° 27’ 43° 27’—maximum. This table shows that no crystal can transmit light, unless so situated that the angles of incidence are between 13° 27’ and 90°, on that side of the perpendicular most remote from the refracting angle. This range equals 76° 33’. It shows, also, that if the angles of incidence are between about 29° and 55°, (a range of 26°, or one third of the whole,) the emergent ray will vary but about one degree and a half from the minimum deviation. Hence, of all the light which can come from the sun by trans- mission through crystals of 60°, one third is refracted by those 76 Prof. Snell on a singular case of Parhelion, which lie within the narrow limits between 21° 50/ and 23° 22/. Therefore, although the entire width of the halo is 21° 37’, (=43° 27/—21° 50’,) only one or two degrees of the inner bor- der will be noticeable. But the inner edge of what seems to be the entire halo will be tolerably well defined, and the outer edge will shade off gradually to the light of the sky. Every careful observer must have noticed, that the area lying within the halo is darker than that without. The reason is made obvious by what has just been stated; the space- which is regarded as out- side, is in fact a part of the halo itself. Every crystal decomposes as well as refracts the light, and no one can send more than a single color to the eye. But other crystals, closely contiguous, by slight differences of position, may transmit other colors ; and the effect will, in general, be that of white undecomposed light. On the inner edge, however, the red may almost always be seen, uncombined with any other col- or, because no other can deviate so little from the original direc- tion,—red being the least refrangible, and the crystals being, by supposition, at the minimum limit. Outside of the red, the other colors are sometimes seen in the prismatic order, growing more and more faint, from the mixture already spoken of. For in- stance, suppose a crystal B, at such a distance from the axis, ES, that when lying in the position for minimum deviation, it throws the green ray to the eye; then other crystals in the same visual direction, on which the light falls at angles of incidence a little larger and a little smaller, will also refract the same color to the eye, on account of the slight changes in deviation which occur there ; but there are others, still farther revolved, which will bring the less refrangible colors, yellow, orange and red. And thus the green, though predominant, is rendered impure. 'The violet at C is partially neutralized by add the other colors, and can rarely be seen. Beyond the colored ring, whose width is represented by A BF, the light, though just as much decomposed, is reduced to whiteness again by the union of all the colors from crystals in different positions. In the rainbow, the several colors are equally pure and distinct. The reason of this difference isobvious. If the distance of a rain-drop from the axis of the bow be given, the color thrown to a certain point is given also, because a revolution of the drop in its place does not change the relations of its surface to the sun, or to the observer’s eye. Not so with a crystal; both dis- - and the Theory of Halos. 7 tance and position must be given, or the color transmitted to a particular point is indeterminate. In the accompanying figure, the eye is supposed to be at E;; the sun in the direction of ES, AS, &c. Arepresents acrystal at the inner edge. D and D‘ show the different positions at the outer edge. he other parts of the figure will be understood from the preceding description. s 4 s ig | | iN / / Al }Y} Ds D The halo of 91 degrees in diameter is much more rare than the kind just described. It is believed to be formed in the same manner by crystals of 90°; and this angle occurs in the crystallization of water with much less frequency than the angle of 60°. Halos occur in summer as well as in winter; for vapor often floats higher than the limit of perpetual congelation. The halo of 44° in diameter is a phenomenon of very fre- quent occurrence. Ihave reason to believe that it might be seen, 78 Prof. Snell on the Theory of Halos, Sc. more or less perfectly formed, on an average one day in a week the year through. In the year 1839, in which I watched for this phenomenon with more than usual diligence, I recorded forty nine halos; of which forty four were formed about the sun, and five about the moon. And I cannot question that several, during the year, entirely escaped my notice. I have mentioned my reasons for believing that the colored band on the grass was nothing more or less than the lower limb of the common parhelion; and its peculiarities are explained, as soon as we attend to the circumstances of the case. ‘The va- rious prismatic colors were seen, not in regular succession, nor blended into white light, as in the halo of the sky, because the number of crystals was not sufficient,—there being only a single layer spread on the ground, instead of a stratum many feet or rods in depth, and filled with myriads of floating crystals. A cleam of yellow light, for instance, might come from a crystal in any part of the band, (except near the concave edge,) while no crystals were lying in exactly the same direction, and so turned in position, as to throw the other colors of the spectrum, to ob- literate or modify the yellow. The hyperbolic form of the halo is too plain a matter to need explanation. Yet itis not long since I saw an article in a scien- tific periodical, (I cannot now tell when or where, ) in which the writer seemed perplexed by a similar peculiarity of the bow form- ed in the mists of Niagara. From each end of the usual arch, he saw a band containing the same colors, extending horizontally in a straight line toward himself; and this appearance, if I mistake not, was regarded as something inexplicable. But had the mist been near enough, he might have traced these apparently straight lines to their place of meeting ina single curve, perhaps withina few feet of his station, and then he would have seen the entire bow. Ionce saw a bow formed in a dense morning fog, which filled the Connecticut valley, and could follow the curve from the for into the dew on the grass; and the nearest point was not more than four feet from the place where I stood; so that, witha wallking-staff, I could have extinguished the most beautiful part of the phenomenon. The higher and remoter part of the bow was circular, the lower and nearer part was hyperbolical. It is obvious, that in every such phenomenon, the light forms the sur- face of a cone, whose vertex is at the eye; and if the bow is Notice of a New Species of Batrachian Footmarks. 79 seen projected on a surface perpendicular to the axis, it appears circular ; if on an oblique surface, it will assume the form of an ellipse, parabola, or hyperbola, according to the degree of obliquity. The form in the particular case I have described was that of a hyperbola; because the axis ascended from the eye toward the sun, while the surface on which the halo was projected was horizontal, or slighly descending. It surprises me much that I have never seen any thing of the kind before ; and more still, that I have never seen it referred to, as an argument in favor of the hypothesis which I have at- tempted to state somewhat in detail in this paper. Yo my mind it is a demonstration of its truth. My engagements at college were such as to prevent my watching for the recurrence of the phenomenon while cold weather continued, but Dr. Hitchcock, whose attention was called to it on the 23d, saw it again a few mornings after, formed in the same circumstances ; and I think it might be often witnessed during the season of frost, as one of the glories of a sunny morning. Amherst, Mass., April, 1845. Art. 1X.—WNotice of a New Species of Batrachian Footmarks ; by James Deane, M. D. Wuie recently engaged in searching the sandstone beds of Connecticut River, for its peculiar fossils, my attention has been frequently arrested by a pair of singular footsteps, which were ac- companied by other impressions of obscure character. ‘T’he pe- dal impressions consist of five massive toes radiating from a tarsal centre, like the spokes of a wheel, and a line intersecting them from centre to centre, leaves three of the toes pointing forward and outward, and two outward and backward, the whole com- pleting a semicircle. (See the diagram, A. A.) _ Regarding these anomalous imprints to be due to quadrupeds specifically different from any thing hitherto observed, I sought diligently for the corresponding set of members, but without suc- cess. From the position of the feet, it was apparent that the pro- gressive movement of the animal was by leaping, and this opin- ion was corroborated by the many instances that came under my observation, the position of the feet being in all cases identical. The lobate forms of the joints, with the claws, were accurately TS = é. Ra) XAG a 80 Notice of a New Species of Batrachian Footmarks. impressed, and hence the inference, that if the other set of feet touched the ground, their forms would necessarily have been re- tained. But on the contrary, there is situated, invariably, be- hind each footprint, a deep elliptiform impression, pointing for- ward and somewhat outward, the pair being more widely sepa- rated than the footprints. (See the diagram, B. B.) From a patient investigation of these curious forms, aided at length by an exquisite specimen, the inevitable conclusion is, that the compound impressions were produced by the animal when advancing by leaps, and that from its peculiar organization, one set of feet did not touch the earth.* It is difficult to explain * To render these views more intelligible, the accompanying diagram is given, taken from a beautiful specimen in the possession of T. Lronanrp, Esq., reduced one half in linear measure. A, A. The footprints. Each foot is comprised of five toes, the central one having four \ articulations, while each lat- eral one from it, diminishes in 4 Cl ey number by one, in their order. The impress is exquisitely A fine. Thespread of each foot, Se eee or rather its diameter, meas- ures two and one half inches. hee: B, B. The posterior oblong impressions, five inches in length by one and one half in breadth. The outline is not only irregular, but the ¢ impression varies much in depth. It is a deep concav- ity at a, and becomes superfi- cial at b. Itis deep and con- cave atc. At d, d, d, it is superficial, but the outline is clear. The appearance of this impression suggests the 6b probability that it was produ- ced by the flexed limbs while in a sitting posture, a, b, c, be- ing the first or lower joint, and d, d, d, the succeeding one, folded upon and overlap- ping it. The impression of the integuments, is absolutely life-like. Ate, on the opposite impression, it is ob- literated by a splendid ornithichnite. The impressions in question are associated with several species of bird tracks and with rain-drops in wonderful preservation. ts a ie eM eee Copper and Silver of Kewenaw Point, Lake Superior. 81 this phenomenon, although the presumption is, that the animal was some Batrachian reptile. It is not improbable however, but the entire aggregate of impressions were made by the posterior feet and limbs, the fore feet not reaching the ground, after the fashion of the kangaroo. ‘This method of locomotion would cer- tainly be adapted to the turbulent era in which the animal lived. But I will not indulge in speculations, contenting myself with reciting facts, and leaving it to the learned reader to draw the in- ference. i I have also drawn from this prolific rock, other marvellous signs of once living creatures, to the interpretation of which, I know of no analogies to apply. The study of the sandstone fos- sils, grows intensely absorbing. It incessantly reveals to our ad- miring eyes, new modifications of ancient life, which, although they seem incomprehensible, are nevertheless authentic evi- dences of harmonious creation. Greenfield, Mass., May 21, 1845. Art. X.—On the Copper and Silver of Kewenaw Point, Lake Superior ; by C. T. Jackson, of Boston. A BRIEF description of the geology and mineral resources of Lake Superior, may not prove unacceptable, at a time when pub- lic attention is called to that region, and mining enterprises are about to be entered into by many individuals and companies, some of whom have already gained valuable information concern- ing the most important mines, while others may be acting under erroneous impressions and hopes which may not be fully realized. The earliest accounts of the metals found on the coast of this lake, are those of Alexander Henry, who travelled around its shores in the years 1760 and 1776, and published his researches in 1809 in an octavo volume—printed in New York; and of Capt. Jonathan Carver, who visited the lake in 1766, and published his travels in a similar volume in Philadelphia in 1796. Both Henry and Carver describe numerous loose pieces of metallic copper, found on the lake shore, and express a favorable opinion of the probable value of the country for mining purposes, Mr. Norberg, ‘‘a Russian gentleman acquainted with metals,” who accompanied Mr. Henry, discovered, among the pebbles and Vol. xtix, No. 1.—April-June, 1845. sf ae 82 Copper and Silver of Kewenaw Point, Lake Superior. loose stones on Point Aux Iroquois, a blue, semi-transparent stone, weighing eight pounds, which he carried to England and deposited in the British Museum. This stone, he says, yielded sixty per cent. of silver. Quere. Was not this a mass of chloride of silver? If it is still in the British Museum, I hope some one will give an account of it. It is somewhat remarkable that neither of these travellers discovered copper or silver, or their ores, in the rocks in place. cr Since those ancient explorations, many individuals have trav- elled on the lake shores, and have described generally the loose masses of metallic copper seen in the soil or in the possession of the Indians. Henry R. Schoolcraft has given us a very particu- lar description of those which were seen by him during his ex- cursions with General Lewis Cass. He visited the great copper bowlder on the Ontanagon River, and has published a very accu- rate account of it in his travels, and in this Journal, Vol. III, with a plate. So far as I have been able to learn, no full description of the rocks and ores found in place has been published, excepting those of Dr. Douglass Houghton, who has given a general account of the geological structure of the country, and of the metalliferous con- tents of the rocks, in his interesting annual reports on the geo- logical survey of Michigan. A full and detailed description of the minerals and mines of that country, will be published in his final report, which will appear on the completion of his extensive and arduous surveys. My object in thiscommunication, is to give an account, for the information of miners and miveralogists, of the region which I have specially explored ; and in order to a more full understand- ing of the subject, I shall have to explain the geological structure of the country in which the mines are situated. I trust that some of my observations will prove interesting to the scientific community, as well as to those interested in mining. In July, 1844, I was employed by the trustees of the Lake Superior Copper Mining Company, to visit and examine certain tracts of land on Kewenaw Point, of which they had procured leases from the United States government. In the performance of this duty, I was assisted by Messrs. C. C. Douglass, Joseph S. Kendall, and Frederick W. Davis, and was accompanied by Hon. David Henshaw, one of the board of trustees. r Se Ager La iy Copper and Silver of Kewenaw Point, Lake Superior. 83 _ After a pleasant journey and voyage from Boston to Mackinaw, we took a boat for the Sault St. Marie, and made a trip of about ninety miles from Mackinaw to the Sault, encamping two nights on the islands on our route, and reaching Lake Superior on the evening of the third day. Most of the islands which we passed were composed of compact white limestone, containing a few fos- sils, and apparently of the same age as the Niagara limestone of New York, and like it containing occasionally a little gypsum. On reaching the Sault, the character of the rocks is altogether changed, and red and grey sandstone, which, according to Dr. Houghton, is of the old red series and destitute of fossils, is ob- served, and forms the falls or rapids by discharging the waters of Lake Superior over the outcropping edges of their strata. The sandstone: dips towards the lake, and the waters, passing up their gently inclined surface, fall in foaming rapids from the up- per edges of the strata; while along the whole upper side of this slope, myriads of large rounded blocks of primary and trappean rocks have been deposited by the sheets of ice, which must have transported them from a great distance—no such rocks being found in place near the outlet of the lake. These bowlders were probably brought by the ice, or streams coming from the moun- tains, to the lake shore, and from thence ice-rafts have transported them to their present resting places. They abound not only in the rapids, but also on the more elevated land around the falls, and indicate the ancient level of the waters of the lake to have been much higher than it has been during the historical epoch. The geologist will observe among these rounded blocks of stone, representatives of all the different rocks of the lake coast and of the country traversed by its tributary streams. Those which are most remarkable are syenite—often mixed with epidote, a mineral not unfrequently mistaken for copper ore—red porphyry, quartz rock, greenstone trap, conglomerate and red sandstone. The rock in place beneath this covering of bowlders, as before observed, consists of strata of mixed red and gray sandstone, which is covered with only a few feet of sandy soil, and is fully exposed along the line of alittle canal made for a now abandoned saw mill. This canal extends from the lake to below the falls, and is nearly amile in length. The fall from the level of the lake to the river St. Mary below the falls, is from eighteen to twenty feet, according to the measurements which I made at the termi-: ke Uy 84 Copper and Silver of Kewenaw Point, Lake Superior. nation of this canal. The feasibility of constructing a ship canal from Lake Superior to the St. Mary’s river is perfectly obvious, only three locks of six feet each being required for the purpose. The only difficult part of the work will be in preparing a good entrance into the canal from the lake, where a breakwater will have to be made to protect the boats and the mouth of the canal. This work the United States government contemplates, and it is to be hoped will soon execute. There can be no better ground for a canal, for it will be cut wholly through soft sandstone, easily © wrought, but solid enough for substantial embankments, while the numerous erratic rocks near by, will furnish all the stone re- quired for building substantial locks. The sandstone on the lake shore at the head of this canal, dips to the S. W. 48° and runs N. W. and 8. E. Dr. Houghton has observed that the strata of this rock, wherever it comes on the lake coast, dip towards the lake, and so far as my observations have extended, I was able to confirm this remark. If it should prove to be the case around the entire lake, which has not yet been fully explored, it would lead to some interesting geological conclusions respecting the formation of this great basin ; for al- though there are many places where the elevation of trappean rocks has thrown up the sandstone strata at a bold angle, yet we should not be able to account for the elevation of so extensive a brim by local elevating forces; and since they act in directions deviating but little from a right line, or in gentle curves to the northwest, they would be inadequate to account for the phenom- ena, and we should have to regard the lake basin as a valley of depression. At Eagle Harbor the sandstones have evidently been disturbed by the intrusion of trap rocks, and dip N. N. W. 25°, but still towards the lake shore. The same dip was observed two or three miles in- land at Cat Harbor, and in every place where the sandstone was ob- served on the north side of Kewenaw Point. This would be ac- counted for by the direction of the great trappean ranges, which run in a general N. E. and 8. W. course, in the peninsula, with a gentle curve to the northwest. ‘The opposite or southeastern side of this point has not yet been examined, so far as I know, by any geologist, and it will be quite interesting to know the dip of the strata on that side of the trap rocks. If the dip should be to the northwest, then the trap dykes will be found to overlay the Copper and Silver of Kewenaw Point, Lake Superior. 85 strata, after passing between them, just as they do at Nova Scotia, and on the Connecticut River, and at New Haven. Having given some account of the sandstone strata, I would observe that the conglomerate rocks belong to the same system, and are evidently formed from the coarser pebbles and gravel, de- rived from primary and intrusive porphyritic and trappean rocks. The pebbles are all rounded and smooth, indicating the long con- tinued action of water, and abrasion of the fragments of rock by attrition, in a manner similar to that we now observe on the sea coast, where the surges of the ocean are continually at work, grinding the loose stones against each other. _ No remains of animals or of plants, unless indeed some obscure traces of Fucoides, have yet been found in the Lake Superior sandstones or conglomerates, and I understand that Dr. Houghton thinks he has satisfactorily traced this deposit below the coal bear- ing strata. If this should be fully established, the formation would be ranked as belonging to the old red sandstone series, al- though it so strongly resembles the sandstones of Nova Scotia and of the Connecticut River, that I have been disposed to regard it as higher in the series, and suspect it to belong either to the Permian or new red sandstone series; perhaps we have not yet sufficient data to fix the relative ages of any of our sandstone rocks, and it might be a useful work for some geologist to devote some years to their special study. 'The absence of characteristic fossils, pre- vents the ready determination of their age, and it will be re- quired to trace the strata continuously until their relation to other rocks is known. The conglomerate on Kewenaw Point is composed, as before observed, of pebbles of the older rocks cemented together by the more finely comminuted materials or clays, originating from their decomposition and disintegration. That the rock since its depo- sition has been acted upon by heat, is evident, not only from the induration of the cement and adherence of the pebbles, but also from the latter being cracked through the midst and separated from each other. Deep chasms are thus not unfrequently pro- duced by the contraction of the sundered rock, and veins of cal- careous spar often occupy the spaces. The calc spar often con- tains filaments of native copper, with a little of the carbonate, the latter being produced only when the vein is exposed to the atmosphere. When these veins occur near the trap dykes, anal- bf 86 Copper and Silver of Kewenaw Point, Lake Superior. cime and Prehnite also abound, and were formed, without doubt, through the igneous agency of the trap on the contents of the vein and the ingredients of the wall rock. ‘T'he spar veins are sometimes six feet wide, but their ordinary width is from a few inches to three feet. They generally traverse the strata at right angles to the line of strike, and resemble veins of igneous injec- tion. The calc spar is highly crystalline in its structure, and the veins are too wide to have been formed by infiltration. If they were formed by the washing in of limestone, we would ask where the carbonate of lime came from, no limestone being found in this region. If the carbonate of lime was deposited as a tufa from mineral springs, then it has been since fused into calcareous spar by heat under pressure. If injected, then the walls of the veins should be silicate of lime, and should bear strong marks of fusion, which does not obviously appear. Iam, therefore, still in doubt as to the origin of these veins. Among the accidental ingredients in the conglomerate, the most remarkable is the green hydrous silicate of copper, which has long been known to the voyageurs on the lake as the green rock. This occurs at Hayes’ Point, at Copper Harbor, and has recently been wrought by miners, who have extracted a considerable quan- tity of it.** The brown and black siliceous oxides also occur there, and are evidently the results of igneous action on the chrysocolla.t Black oxide of copper has lately been discovered in the conglo- . merate at Copper Harbor, at the military post called Fort Wilkins. The ore is a vein in the conglomerate, and is fourteen inches wide, and has been traced to the distance of fifty feet in length by the miners under the direction of Lieut. Ruggles.t Dr. Houghton has, I believe, found other veins of this ore ina similar rock, but has not yet given an account of the localities. * The chrysocolla when free from rock yields from 25 to 30 per cent. of copper, but the average of the ore extracted from the mine, when picked as well as it can be for the furnace, gives but 9 or J0 per cent. t This brown siliceous oxide contains,— Copper, : : : : ; 51:08 per cent. Silica, , : : : ‘ 20; 00... af Oxide of iron, : A ‘ : 0:80 ze Oxygen and Water, - ie : Pe GIIE! pan oct . 100-00 ¢ This black oxide of copper yields from 68 to 70 per cent. of copper, and is a very valuable ore. Copper and Silver of Kewenaw Point, Lake Superior. 87 _ The most interesting rock on Kewenaw Point is the greenstone trap, which is there observed in immense dykes or ranges of hills, running in an HK. N. E. and W.S. W. direction, or nearly parallel with the northwestern shore of the peninsula, with a slight cur- vature or convexity ‘to the northwest. ‘These trap dykes are equalled in extent only by those of Nova Scotia and the eastern part of Maine. ‘They pursue the same course as those in Nova Scotia and are probably of the same age, and agree with them in most of their characters and in many of the included minerals, as also in their geological position. The trap rocks of Lake Superior pass through the red sandstone and conglomerate rocks, and are interfused with them, producing at and near their junction avery porous amygdaloid, which is always found at the lower side of the dyke where it is next to the sandstone, as is the case also in Nova Scotia. On Kewenaw Point there are found in this rock very handsome agates, which at a place called Agate Harbor, form the pebbly beach. Stilbite, Laumonite, analcime, datholite, Prehnite and cal- careous spar, are among the minerals frequently found in the geodes in the amygdaloid. Prehnite and datholite also form veins in the trap, which are sometimes three or four feet in width, and of considerable extent. ‘These veins also include native copper, and not unfrequently the individual crystals contain within them delicate leaves of the bright metal, not thicker than gold foil, while the whole mass of the vein is strung together by filaments of pure copper. ‘The principal vein of datholite is situated in the rocks on the westerly point of Eagle Harbor, where it has been opened by the miners in search for copper. The finest specimens of Prehnite are obtained at the company’s vein No. 5, three miles south of Cat Harbor. Analcime crystals are found in most of these veins, associated with calcareous spar. Stilbite and Laumonite occur in the small geodes in the amyg- daloid, and although generally disseminated are rarely obtained in handsome specimens. Heulandite, which is so abundant in Nova Scotia, was not observed in this region. Calcareous spar occurs in the form of the dog-tooth variety, and has a great number of planes on the angles and edges of the scalene dodecahedron, the crystals being the most complicated of any I have seen of the same species. Associated with this mineral, crystals of analcime 88 Copper and Silver of Kewenaw Point, Lake Superior. as large as pistol and musket balls occur in trapezohedral forms. Some of them are very perfectly crystallized. The best specimen I have, was given me by Mr. Jacobs, one of the explorers of mines on Kewenaw Point. " Native copper is disseminated in the trap rocks and in most of the veins of other minerals found near it, but it is far more abun- dant in the amygdaloid, and not unfrequently fills the cavities in that rock. Isolated masses of many pounds weight are occasion- ally found, when the rock has undergone decay ; and all the loose bowlders of metallic copper which are found at the mouths of the rivers and on the lake shore on Kewenaw Point, were derived from the amygdaloidal trap. The great copper rock found on the On- tanagon river, is an erratic bowlder, which was transported to that spot during the drift epoch, and originally was included in ser- pentine, arock very different from any found in the Ontanagon district. Since the only known deposit of copper in serpentine is on Isle Royale,* and that island is nearly north from Ontana- gon river, or in a direction from which the drift current came, it is supposed that it originated on that island and was transported in ancient times to the southward by an ice raft, which deposited it as a drift bowlder on the spot where it was found. I have not visited that locality, but form this opinion from the best informa- tion I could obtain. This great copper rock is now deposited at Washington, D.C. and is in possession of the Government. This enormous mass of metal, weighing between two and three thousand pounds, is well calculated to inspire too strong ex- pectations of obtaining valuable mines on the coast of Lake Su- perior, and those who have such: hopes should be warned that masses of metallic copper of that magnitude are great rarities, if indeed there is another like it in the whole country. Native cop- per is rarely a favorable sign in mines, and it is looked upon favor- ably only when it is so abundant as to constitute a considerable part of a large vein, or when it is pretty uniformly mixed with the rock. There are a few such loealitieson Kewenaw Point, and those I have examined with great attention. There are nine veins of native copper already discovered on the locations leased to the Lake Superior Copper Mining Company. Ofthat number only two * Dr. Locke is of opinion that the mineral supposed to be serpentine is epidote. I have not examined it. Abege Copper and Silver of Kewenaw Point, Lake Superior. 89 or three have been selected, by my advice, as undoubtedly val- uable, and of sufficient magnitude and richness for profitable min- ing. 'The others are problematical, and may perhaps ultimately be explored, by sinking shafts into them to some depth, when the value of the ore may be estimated. The most valuable locality is on the west side of Eagle River,* eight miles from Eagle Harbor, and a mile and a half from the lake shore, on rocky land, elevated above the lakes about 200 feet. Fragments of the rock and lumps of native copper found at the mouth of the river, first attracted the attention of explorers to ex- amine the bed and banks of the stream, when metallic copper mixed with silver was discovered in place. This locality was then examined by me, and by the aid of the company of miners the value of the mine was sufficiently proved to warrant the out- lay required in exploring it thoroughly. An exploration shaft was then directed to be made, and the result has proved very satisfactory to the company. The ore, if it may be so called, consists of an intimate mixture of copper and silver, and an alloy of those metals in an amygda- loidal trap rock, the cavities in it being filled with metallic glob- ules, and fine particles being thickly mixed with the rock, so as to constitute from 10 to 30 per cent. of its weight. The crevices and veins in the rock are also filled with thin sheets of an alloy of copper and silver, and occasional lumps of the metals are found of considerable magnitude. The most singular and interesting chemical and geological phenomenon observed at this place, is the occurrence of pieces of copper and silver, united together side by side by fusion, without any alloying of the silver, although the copper contains ,°, per cent. of silver, united with it chemically. The silver, however, is always absolutely pure. There are also specimens in which the copper alloy is absolutely porphyritic, with patches of fine silver. I have apiece, about the size of a dime, in which one half of it is pure silver, and the other an alloy of copper with 75 per cent. of silver, containing patches of pure silver mixed with it but not alloyed. The two metals are completely soldered. * Dr. Houghton says that this is not the stream known to voyageurs as Eagle River. I have therefore proposed to name it Silver River, a name evidently quite appropriate. ‘ Vol. xxix, No. 1.—April-June, 1845. 12 veh Baie? 90 Copper and Silver of Kewenaw Point, Lake Superior. together at their points of contact. Other specimens exhibit square and triangular pieces of silver in the midst of the copper, or contain veins of it traversing the latter and firmly united at the edges. Crystals of silver, in the form of a regular octahedron, also occur, but are not common. Fine particles and strings of silver are more frequently observed. Glistening scales or fine crystals of an- timonial silver ore are found ina part of the lode where the rock is most decomposed. Veins of quartz and of calcareous spar traverse some parts of the metalliferous rock, and the copper is most highly crystallized in the quartz; while the silver is more apt to be found in the calcareous spar or in the amygdaloid containing it. The first exploration which I made at this place, was at the base of the cliff about three feet above the level of the river, and the rock was blasted away until the influx of water: prevented further operations. 'The cliff is fifteen feet high, and presents a mural precipice, in which the metallic copper and silver could be readily discovered ; and it was seen that the rock became richer as we descended, even though our researches were only to the extent of twenty feet from the top of the cliff to the place where we blasted for the last time. I felt confident, therefore, that the quantity of metals would increase in the rock to some depth ; and in order to have this point settled, the miners were directed to sink a shaft, beginning on the top of the ledge and going down at least forty feet beneath the bed of the river. The shaft was then sunk, under the able direction of Mr. Charles H. Gratiot, the skillful superintendent of the mines, and its present depth from the surface is seventy four feet. By this exploration shaft, the value of the mine has been proved, and the proportions of metal were found to augment considerably as the work proceeded. Several hundred tons of rich ore have been raised, and among the fine specimens obtained, is a mass of copper with an ounce of pure silver attached to it. The ore raised is probably somewhat richer than that extracted by me, and will richly repay the cost of exploration. F Another exploration shaft has been sunk a few hundred feet farther from the river, and the ore has been found equally rich. These two shafts are now to be connected by a drift or level made along the course of the vein; one of the shafts will be used for ventilation and the other for the machinery used in hoist- ing the ore and pumping the water from the mine. Copper and Silver of Kewenaw Point, Lake Superior. 91 - The vein has no regular walls, but on the upper side of the lode there is a line of division between it and the trap, where no metal is found. On the lower side, the copper extends to the distance of ninety feet, but the limits in which I calculate the ore to be rich enough to work, give but eleven feet as the width. Its extent in length is yet unknown, but it has been seen interrupt- edly for the distance of about half a mile—there being only a few places where it was uncovered. Farther up Eagle River, at the distance of half a mile, a reg- ular vein of copper was discovered in a rock composed of crys- tallized feldspar and chlorite—the vein stone consisting of a mix- ture of green earth, quartz and calcareous spar. It is from two to three feet wide, is fully exposed on the river’s side for the distance of one hundred and ninety eight feet, and was seen in- terruptedly for a quarter of a mile. It runs N. by W., 8S. by E., and dips tothe E. 83°. This vein contains lumps of pure metal- lic copper, some of which weigh from a few ounces to halfa pound, and others are of an irregular form and as large as a man’s finger. Smaller pieces are thickly interspersed in the vein stone. On analysis this metal was found to be perfectly pure copper, without any trace of silver—a curious circumstance, considering its proximity to the silver vein above described. It will be wrought for copper in conjunction with the other mine. Analysis and Assay of the Eagle River Copper and Silver Ore.—In order to discover the real working value of an ore of this kind, it became necessary to make a selection of a fair aver- age lot of the ore, of a quality such as could be depended upon asa regular product of mining operations. I therefore blasted off specimens from the whole width of the vein, and rejecting the sheets and loose lumps of metal found in the crevices, took fifty pounds of the rock, containing a pretty uniform and fair mix- ture of the metals, for analysis. This was crushed at Henshaw, Ward & Co.’s mills, and sifted in coarse and fine sieves to sepa- rate the flattened plates of metal, which weighed 11 lbs. 4 ounces, and consisted of plates of copper and silver mixed with a little rock. On being carefully washed, the weight of metal was re- duced to 8 lbs. 13 ounces. This dissolved in pure nitric acid, and parted by chlorohydric (muriatic) acid and reduced, yielded 662:8 grs. of metallic silver—equal to 252, lbs. per ton. The copper amounted to 5 lbs. 8$ ounces, or 1257 lbs. of copper per ton of coarse metal, as it comes from the washing table. 92 Copper and Silver of Kewenaw Point, Lake Superior. The fine sifted ore being washed, yielded 8 lbs. 12 ounces more of metal, mixed with heavy ferruginous particles of rock. This being dissolved gave 1 1b. 1 ounce of copper and silver, which when separated yielded 101 grs. of silver, and 1 lb. 2 oz. of copper. The silver then in the fine washings is equal to 345 Ibs. to the ton, and the copper from the same is equal to 250 ve Then 50 lbs. me: the rock yield— Coarse plates of metal, . , " 8 lbs. 13 oz. Fine washed ore, . ‘ ‘ : 8 lbs. 12 oz. Amount of washed metal in 50 lbs. rock, 17 lbs. 9 oz. or 35 lbs. 2 oz. per 100 Ibs. of rock, or 700 lbs. per ton. The value of the coarse sifted metal after washing is per ton as follows— For silver, 25 lbs. in a ton at $20 per lb. $500 00 For copper, 1257 lbs. per ton at 16 cts. per lb. 201 12 See EEEEEEEEEEEEeeeeneemeeame Value of the coarse metal, . : : $701 12 ’ A ton of the fine sifted ore, washed and reduced as above de- scribed, yields— Silver, 3,4; lbs. at $20 per lb. . ; : $68 Copper, 250 lbs. at 16 cts. per lb. : AO Value of one ton of fine washings, s - $108 The value of the rock per ton is as follows. Jt yields in 50 Ibs., silver 763°8 ors. = 1744, 0z.; equal to 4 lbs. 5 oz. 3644 grs. per ton; value, $87 25. Copper in 50 Ibs. of rock, 6 Ibs. 94 oz. = per ton 263 lbs.; value, $42 10. Value of one ton of the rock, $129 35. Resumé.—In the rock the value is $129 35 per ton. In the coarse ore, —_ silver = $500 copper, = $201 In the fine washings, “ = 68 pn | rs ee Silver, $568 Copper, $241 Total value of one ton of clean metal, $809. It is to be observed that the large sheets of copper which oc- casionally occur in the crevices, are not considered in this ac- count; and since they probably will be found not unfrequently in the mine, they will go to augment the value of its produce. The best flux for the fusion of the fine washings, which will be smelted at the mines, is carbonate of lime or calcareous spar, , m On the Generation of Statical Electricity. 93 / which makes, with the ferruginous trap rock, a perfectly liquid glass or slag, through which the metallic alloy of copper and silver quickly settles. The proportion of silver in the metal, re- duced in the furnace, varies from 5 to 16 per cent. according to the nature of the ore. The average yield of the rock when as- sayed in the crucible with limestone and charcoal, is 7,4; per cent. of metal; and the metal analyzed yielded 94-864 per cent. of copper, and 5:136’per cent. of silver. The silver being worth ’ $102 50, and the copper $15 17 = $117 67 for 100 lbs. of metal. In the furnace operations there may be a loss of copper by mis- management of the blast, or for want of skill in the workmen; but the silver, being incapable of oxidation in the fire, cannot be lost. By numerous experiments, we have ascertained that the best proportion of lime is about one third the weight of the ore, or if calc spar is used, about half the weight may answer. Even less than this would render the molten mass sufficiently liquid in a blast furnace, where the weight of the metal and the intensity of the heat render the assay much more easy than it is in cruci- bles. The cale spar of some of the localities on the Company’s lands, contains a considerable quantity of native copper, with a little of the carbonate. This should be preferred as a flux, for the copper it contains will be saved. The vein of datholite at Eagle Harbor will also make an ad- mirable flux, and the copper it contains will add to the yield of the furnace; while the borosilicate of iron and copper mixed with it, being saturated with oxide of copper, will not take up the metal in fluxing the ore. Ihave used it with advantage in some of my experiments, and find it to work perfectly well. Art. XI.—Practical Observations on the Generation of Stat- ical Electricity by the E'lectrical Machine; by Lieut. GeorcE W. Rains, U.S. A., Acting Assistant Prof. of Chem., Min. and Geol., U. S. Military Academy. Havine experienced, at different times, some difficulty in caus- ing an abundant and uniform supply of electricity to be generated, by the apparatus employed, when the state of the air and other circumstances appeared entirely favorable, sufficient inducement was offered to devote a few leisure moments to the study of the causes of failure. bg eh he 94 On the Generation of Statical Electricity. In completing a course of experiments with this object in view, results have been obtained in the excitation of statical electricity, deemed of sufficient value to merit attention. 'The invention of electrical machines being of such long standing, and the subject having received the attention of so many eminent persons, the wri- ter, with some hesitation, ventures to suggest ideas derived from his own observations. The improvements proposed, however, being few in number and of simple application, he has thought proper to state them, allowing each one who may feel interested, an opportunity of satisfying himself of their utility. Russers.—Commencing with the rubber of the machine, as the supposed principal source of failure, it was proposed to ascer- tain, first, its mode of action ; second, that substance which would be most efficient in its action. In regard to its mode of action, the questions which presented themselves, were—does it produce electricity by friction, by chemical action, or by friction and chemical action ? Assuming at first that the effect is produced by friction, its mode of action appears to be as follows. ‘The rubber touches the glass at any given moment with a certain number of its parts or points, and does not, therefore, come into contact with the re- mainder; the friction of these points generates the two electrici- ties,* of which the positive remains with the glass, and the nega- tive with the rubber. At the succeeding moment, the excited parts of the glass have passed opposite to those points of the rubber which do not touch; an inductive action then takes place—the positive electricity of the rubber is repelled, and the negative at- tracted, by the excited portions of the glass. If the negative elec- tricity produced by the first action, has remained with the rubber, it will then be in such excess at the points in question, as to force itself throngh the thin intervening stratum of air, and neutralize the corresponding positively excited points of glass. Hence to remove the negative electricity is of the first impor- tance; and the necessity of being freed from it was perceived in the earliest experiments. Should this be accomplished, however, as perfectly as possible, it is evident that a diminished similar ef- fect would necessarily take place, rendering neutral a quantity of electricity already excited. What has been observed of the situa- *It isnot intended to assume that electricity is one or more fluids, but the ordina- ry language is used fur convenience. ba, "44 On the Generation of Statical Electricity. 95 tion of the points of the glass and rubber, at the first and second consecutive. moments of action, evidently continues during the entire period of operation. From what has preceded, two primary objects are to be attain- ed: first, to determine the best method of disposing of the nega- tive electricity of the rubber ; second, to obviate the injurious ef- fects of those of its parts not in contact with the glass. To attain the first object, it naturally suggests itself to conduct it off by forming a communication with a conductor between the rubber and earth; and consequently, the directions given, and carried out in the construction of the best electrical machines, have been, to form a metallic connection with the back of the rubber, and the surrounding conducting objects. The idea ap- pears not to have occurred, that such communication should be made with the metallic face, in place of the back of the rubber. The cushions being made of non-conducting materials, as sill or leather, stuffed with similar substances, the faces of the rubbers are insulated, and the negative electricity is prevented from es- caping freely. ‘This insulation is so complete in some rubbers, that with a twelve-inch plate machine scarcely the smallest quan- tity of electricity could be obtained, until the amalgam faces of the cushions were connected by a wire with the floor, when its amount was suddenly and greatly increased. It has been inter- esting to observe the numerous near approximations to this result, which, however simple, appears not to have been exactly hitherto attained ;—the nearest approach, probably, being the suggestions to stuff the rubbers with elastic fragments of metal,* and the prop- Osition to moisten their interior substance.} Electrical excitation, in all descriptions of apparatus made use of for that purpose, will be increased by adopting the preceding suggestion. Should the amalgam faces of the rubbers be con- nected with the exterior coating of a Leyden jar, in the act of being charged, the effect would be much more satisfactory—the positive electricity of the coating neutralizing the negative of the rubbers. The first object having been thus obtained, it remains to pass to the second, viz. to obviate the injurious action of those parts of the rubber not in contact with the glass. For this purpose, it is plain that if a non-conducting substance be interposed between * Am. Jour. Sci. and Arts, Vol. xxiv, p. 256. t Franklin’s Letters. 96 On the Generation of Statical Electricity. them and the excited glass, the desired result will be obtained ; and the question resolves itself into the proper manner of applying the best substance. If an oxidizable metal or amalgam be em- ployed, the oxide which is formed will answer this purpose itself, to a certain extent, as the oxides of the metals are imperfect con- ductors. For this purpose the oxygen of the air is of service. The prominent points in such cases will be kept bright by the rubbing of the glass. The oxides thus formed, continue to in- crease in most cases, particularly with the amalgams, and ulti- mately fill up the intervals; then sustaining the pressure of the glass, all farther action of the exciting points of the amalgam ceases : in such cases, the surfaces of the amalgam require renew- al. The oxides, as will be seen hereafter, are but feeble genera- tors. ‘Tallow, lard, and substances of a similar nature, answer the purpose much better, and hence they were soon discovered to be of service in the earlier researches of electricians. The tallow or lard being spread over the surface, or mixed up with the amal- gam, surrounded each exciting point of the rubber with a non- conducting medium, and hence fulfilled the required conditions. As, however, these substances readily combine, mechanically, with the metallic oxides, forming a black, adhesive mass, which collects on the glass, soiling its surface, and is troublesome to re- move, bees-wax and shellac were substituted, both of which sub- stances, when properly applied, answer the purpose remarkably well. Neither of them soils the glass, and what is of much im- portance, they give rubbers permanent in their action. The question now arises, whether there be not other parts of the rubber, besides those surrounding the exciting points, which may have an injurious effect? "That portion which precedes the first exciting points at the entrance of the glass, obviously can do no harm, as the glass is supposed not to be excited when passing in their vicinity ; but the case is materially different with the op- posite termination of the rubber, which, not being pressed against the glass, is highly injurious—abstracting largely from the elec- tricity previously generated. This has also been observed by electricians, who do not, however, appear to have proposed any substantial remedy ; the best hitherto given, apparently, depends for its success on the regularity of the pressure ;* and still another plan which is liable to the same difficulty.| The silk flap, whose * Parlington’s Nat. Phil., p. 151. t Nicholson, Phil. Trans., 1789. On the Generation of Statical Electricity. 97 utility appears to have been discovered by accident, and whose real object seems to have escaped attention, has succeeded or failed, as chance regulated its proper or improper application. A certain quantity of electricity is doubtless produced by the silk, in what- ever manner it may be applied, and the amount is considerably in- creased by particles of amalgam which adhere to its surface ; but the total quantity thus produced is small compared with that given by the rubber, and a larger amount will be obtained by removing the flap and increasing the pressure, so as to bring as many new points in contact as will equal by their friction that of the silk. Hence the above cannot be its true value, neither ded its utility ap- pear to depend, principally, on its being an interposed non-conduct- ing obstacle between the excited glass and the molecules of air ; but rather, having been fastened to the loose edge of the amal- samated leather, this edge was pressed against the glass by the adhesion of the silk, and thus prevented from diminishing the amount of electricity already evolved. It possesses, also, to some extent, the power of preventing the electricity of the surface of the glass from being drawn off or neutralized by surrounding ob- jects. In modern machines, the rubbers are hair-stuffed cushions without the loose leather, and the flap is of varnished silk, which is so arranged, in some plate machines, as not to touch the glass. The first and principal advantage of the silk is thus lost, but the second more certainly obtained. From what has been stated, it appears to be important to cause that edge of the rubber which the glass last leaves in its revolu- tions, and which is covered with amalgam, to press constantly and firmly against its surface. This is best secured by making use of a leather strip, covered with the amalgam, whose edge in question shall be firmly pressed between the glass and cushion, and which is consequently narrower than the latter. The idea now suggests itself, that in thus contracting the rubbing surface, its action may be lessened ; hence, the proper dimensions for the rubber are next to be determined. ‘To solve this proposition, re- quires a further investigation into the phenomena of excitation. Statical electricity has been assumed to be produced by friction, and hence the result of molecular disturbance. ‘Taking one of the exciting points of the rubber, resting on a corresponding por- tion of the glass surface ; suppose such portion of the glass to move through an indefinitely small space ; molecular disturbance Vol. xx1x, No. 1.—April—-June, 1845. 13 98 On the Generation of Statical Electricity. will then be produced, both in the exciting point of the rubber and in the corresponding portion of glass surface ; by hypothesis, the molecular vibration of the rubber producing negative, and that of the glass, positive electricity, each within itself. If it be sup- posed that the portion of the surface of the glass, in this indefi- nitely small movement, has continued in contact with the exciting point of the rubber, then the two electricities, respectively gene- rated in each, will combine or interfere, and a neutral state will be the result whilst such contact continues. But should this por- tion of glass in its further movement pass beyond the exciting point, its molecular vibration continuing for a certain period, will evolve an additional quantity of positive electricity, which will remain after the molecular vibration has ceased ; and this portion of glass will be electrically excited. Should the movement be still further continued, and this excited part brought into contact with the consecutive exciting point of the rubber, its electricity will, by the influence of this point, be nearly if not entirely neu- tralized. For otherwise it is difficult, if not impossible, to con- ceive of the evolution and absolute contact of the two electrici- ties, at such point, without combining or interfering. This view of the subject being taken, it follows, that only the ‘ last exciting points of the rubber produce the effective result. This, on first appearance, isa startling conclusion, as it apparently reduces the rubber to a mathematical line; on examination, how- ever, this is found not to be the case; there must be a certain number of these last exciting points, in each of several consecu- tive parallel lines, as the points necessarily have spaces between themselves; hence a portion of electricity excited on the glass may pass between several, before it emerges entirely from the rubber. It follows, therefore, that a certain breadth of rubber is necessary, although it must be comparatively small. With rub- bers, properly constructed, as will be described hereafter, the max- imum effect for the larger machines, was produced by rubbers one fourth of an inch in breadth; and for the smaller, one eghth of an inch; the smaller rubbers having generally a greater pres- sure. To determine the above, as well as to ascertain and confirm all other results given in this paper, a numerous set of experi- ments was instituted, by means, principally, of three machines. One was a glass plate of 12 inches, previously alluded to; one a On the Generation of Statical Electricity. 99 cylinder of 10 inches diameter and 15 inches long; and lastly a large and beautiful instrument of 38 inches plate, manufactured in Paris. 'To measure accurately the quantity of electricity in each case, one of those admirable galvanometers of 3000 turns of wire, constructed by M. Goujon of the Polytechnic School, Paris, was employed ; the amalgam of the rubbers being connect- ed, by means of a copper wire, with one extremity of the coil, the other extremity communicating with the prime conductor, by means of a glass tube containing water, having a wire inserted in each end. The maximum permanent deflection of the needle by the 12 inch plate was 16°. Having thus attained, satisfactorily, the two objects proposed, the discussion will be taken up on the questions first suggested, viz. is statical electricity produced by friction, by chemical action, or by friction and chemical action? The solution of the first two solves the third. ‘To this branch of the subject, it was not considered necessary to devote much attention; for the results obtained by others, superior to the writer in abilities, have decided quite conclusively, that chemical action does not produce the ex- citement of the electrical machine. Indeed it is difficult to con- ceive, how ordinary chemical action in the amalgam of the rub- bers, can influence the generation of electricity, except in the single case previously mentioned. For if it be supposed, that the sur- face of the amalgam is made up of numerous small galvanic cir- cles, as is doubtless the case, the air acting, possibly in conjunc- tion with its watery vapor, as the exciting medium ; no action could be produced, unless such circles, either singly or collective- ly, were closed. Under the improbable supposition, that parts of the glass acted as conductors to complete such circles, it would be contrary to all analogy to suppose, that in their movement, they carry off a portion of such current. Neither can it be sup- posed, that it acts by inductive influence; as in such case, the induced electricity would be of a tension, so extremely low, as not to be apppreciable. In order, nevertheless, to satisfy any existing doubt, a tube electrical machine was constructed,* whose piston performed the part of a rubber; and the apparatus arranged, so as to admit of being filled with different gases. It was thus found that air, oxy- * American Journal of Science and Arts, Vol. xxv1, page I11. 3 : 3 100 On the Generation of Statical Electricity. gen, nitrogen, and carbonic acid gases, when thoroughly dry (and a vacuum) produced nearly the same amount of electrical action, when the same oxidizable or non-oxidizable rubbers were em- ployed ; hence this result coincides with that obtained by others.* The conclusion is therefore adopted, that the electrical machine produces its effect entirely by friction. The second branch of the subject will now be examined, viz. to ascertain what substance is most effective, in generating elec- tricity by friction. In the endeavor to attain this point, numer- ous experiments were made with various substances: a list of some of them is given, arranged according to their effective ac- tions. 1. Bisulphuret of Tin and amal-20. Bismuth. gam. ' 21. Galena. 2. Common Amalgam. 22. ‘Talc. 3. Pure Mercury. 23. Chromate of Iron. A, Bisulphuret of Tin. 24, Protoxide of Copper. 5. 'Tin foil. 25. Protosulphuret of Mercury. 6. Zinc filings, (fine.) 26. Chromate of Lead. 7. Copper filings, (fine. ) 27. Protoxide of Bismuth. 8. Silver. 28. Peroxide of Manganese. 9. Gold. 29. Peroxide of Mercury. 10. Platina. 30. Protoxide of Zinc. 11. Lead. 3L. Protoxide of Mercury. 12. Caoutchouc. 32. Protoxide of Tin. 13. Silk. 393. Shellac. 14. Paper. 34. Wax, (no action.) 15. Leather, (soft.) 35. Tallow, ‘ 3 16, Woolen. 36. Lard, zs 17. Plumbago. 37. Bisulphuret of Mercury with 18. Iron filings. lime, gives negative elec- 19. Antimony. tricity. From the preceding, it appears that bisulphuret of tin rubbed over a surface of amalgam, containing but little mercury, is the most efficient of all substances employed ; it is, however, inferior _in value to the common amalgam, on account of its transient ac- * Dans la production de ]’éléctricité par frottement, l’action de l’air sur les en- duits, plus ou moins oxidables des frottoirs, ne parait exercer aucune influence sur les effets électriques qui en resultent.—Peclet’s Memoirs. > Pate aay or a hs ME Leb i i Ane Y ™ On the Generation of Statical Electricity. 101 tion, requiring frequent renewal ; and the quantity of electricity evolved, soon being but little more than that capable of being produced by the amalgam itself. 'The amalgam, in case the sul- phuret is employed, acts principally, by serving as a metallic com- munication to convey off the negative electricity, as rapidly as generated. Tin or copper filings answer the same purpose, nearly as well as the amalgam. Hence the common amalgam has been selected, as the most suitable material, on account of the quantity of electricity pro- _ duced, as well as its ease of application ; and, when properly ap- plied, the valuable steadiness of its action. Its composition is but of little importance, equal parts, by weight, of zinc, tin, and mer- cury, answering every purpose. ‘The zinc and tin are to be melt- ed together, the mercury then added, and the melted mass pour- ed into a wooden box, and agitated violently until cool; then it is to be still further reduced to a fine powder, by being rubbed in amortar. The various results obtained by different electricians, each recommending a new proportion of ingredients, appear to have been caused by the different conducting powers of the cush- ions of the rubbers employed; they having failed, probably, in each case to connect the metallic faces with the earth. It will be observed that the oxides of zinc, tin and mercury, yield but a small comparative quantity of electricity ; hence the necessity of frequently renewing the amalgam of the rubbers, constructed after the ordinary method. 'The combination of mer- cury with the common metals, being rapidly oxidized by reason of the galvanic action, shows the reason why “amalgams con- taining much mercury are of transient and variable action.”* It is probable that pure mercury, if it were possible to apply it, sO as to cause as much friction between its particles and the sur- face of glass as takes place with other metals, would surpass all other substances in its effective capabilities. 'This, however, is impossible as long as it continues fluid, on account of the mobility of its particles; and this mobility constitutes its chief value, by allowing a more perfect contact with the glass; hence its maxi- mum effect can be approximated to, only by rendering it semi- fluid, in forming an amalgam. The number of rubbers to be employed demands some atten- tion, and at the same time the action of the double rubbers, of * Singer’s Treatise on Electricity, page 52. 102 On the Generation of Statical Electricity. the plate machines, will be examined. Theoretically, the num- ber of rubbers is unlimited ; for if one produces a certain effect, six would produce six times that effect, if the electricity be re- moved as rapidly as evolved ; but in practice, the number is neces- sarily limited, and this limit depends, collaterally, on the size of the plate or cylinder, and the convenience of construction. COryl- inder machines have but one rubber, which arrangement may have had its origin, in the larger machines, merely from the slightly increased difficulty of construction. This arrangement necessarily lessens their power one half. Plate machines have generally two pairs of rubbers, or four in all; in large plates, this number might be increased to three or four pairs, with corresponding increase of power; but the labor of working the machine would increase in the same ratio ; which, in this kind of machines, is a material circumstance. However, with rubbers constructed after a manner to be described, the labor caused by two rubbers, is but little greater than that caused by one, of the common construction. The action of double rubbers will now be discussed. A single rubber evolves a certain quantity of electricity; one surface of the plate being thus excited, the inductive influence causes a cer- tain amount of positive electricity to become free on the opposite face; which acts also by its induction on that of the opposite surface, and increases its amount; and this action and reaction between the surfaces, continue until an equilibrium is established ; the result being, that with the ordinary glass plates the original electricity generated is nearly doubled in its amount. If in this condition, the positive induced electricity of the second surface be removed, it will leave the corresponding quantity of negative elec- tricity on this surface of the glass, which will neutralize the oppo- site positive surface; and nearly all signs of excitation, on such surface, will consequently cease. By continuing this process, the second surface of the glass gradually ceases to give off electricity ; and the quantity generated on the first surface, not being increas- ed by induction, becomes comparatively feeble in itsaction. The plate has now become charged, in a manner similar to that ina Leyden jar; and if removed and placed on a ring of metal, a cor- responding ring being then placed upon it, and opposite to the first, by forming a connection between the two, a strong dis- charge will take place, and the plate resumes its first condition. On the Generation of Statical Electricity. 103 From the preceding, the following conclusions are drawn: Ist, the quantity of electricity generated by the rubber with the com- mon glass plates, has its amount nearly doubled by inductive ac- tion ; 2d, to maintain this increased effect, it is necessary that the induced electricity of the second surface be allowed to remain on that surface. The inductive action being a decreasing function of the distance, it follows, that the thinner the glass, the greater will be the effect; which indicates the value of the first conclu- sion. From the second, it appears, that if a cylinder have a damp interior surface, its effective action will be much diminished ; all eylinders should, therefore, have their interior surface perfectly dried, and then be sealed up air tight. If varnished with shellac, which has not been colored by the addition of any other sub- stance, the cylinder, after having been once dried, may remain open without material injury to its generating powers. The machine being in action with one rubber, it will be supposed that a similar one may be arranged to the second sur- face of the glass, and diametrically opposite to the first rubber. A certain quantity of positive electricity being generated by the second rubber, it will find itself in contact, and will unite with, the similar electricity induced on that surface of the glass, by the action of the first rubber. Hence the amount on this sur- face will be much increased ; and this additional quantity, acting inductively on the first surface, will likewise increase its excita- tion ; the final result being, that the electricity produced by the rubbers, on each surface of glass, is nearly doubled by inductive influence. It may at first appear, that by arranging points to each surface of the glass, nearly four times the quantity evolved by one rub- ber might be collected; on a closer examination, however, it will appear that but little more than one half of this amount can be rendered available ; for as soon as the free electricity of one sur- face is removed, that of the other, to a great extent, becomes ne- cessarily neutralized. ‘The plate acquiring a charge, similar to that produced in the experiment of the single rubber, although to a much less extent; andas the plate revolves, passing between the connected metallic faces of the rubbers, this small charge is neutralized. It has been so far assumed, that the rubbers were placed dia- metrically opposite ; allowing one to retain its situation, the oth- 104 On the Generation of Statical Electricity. er will be supposed to change its position. A certain quantity of induced positive electricity being evolved on the second surface of the glass, by the action of the first rubber as already discuss- ed; this passes with the glass surface in its revolution, to the me- tallic face of the second rubber, where it necessarily becomes ab- sorbed by the negative electricity of that rubber, and the free positive electricity, generated by the first rubber on the first sur- face, is thus, to a great extent, rendered neutral. If the metallic faces of the two rubbers be in connection, as is the supposition, the glass surfaces will thus be brought back nearly to their primi- tive state, and the product of the action of the first rubber ceases almost entirely to exist. It follows from this, that it is important that the rubbers be placed opposite to each other ; a slight variation is not, however, very perceptible, by reason of the vibrating molecules of the glass, continuing to produce positive electricity, after passing to a certain distance the exciting points of the rubber. ‘That this is a correct hypothesis may be shown by the following experi- ment: let the back of the hand be held near the second surface of the glass plate of the machine; on rubbing the opposite sur- face with a piece of silk, every motion of the rubber, will be distinctly and instantly perceived; hence, if the electricity of the surfaces ceases to be generated, when the portions of glass pass beyond the exciting points of the rubbers, it follows, that if one of the rubbers be somewhat in advance of the other, the electricity induced by the remaining rubber, will be mostly ab- sorbed, and the practical action of this rubber destroyed, which for a slight variation is not the case. The length of the rubbers will now be determined. In cyl- inder machines, the rubbers should extend so as to rub the en- tire exposed surface of glass; the ordinary practice of limiting their length to a portion of the surface, appears to be deficient in principle. For, let it be supposed that such is the case; then those parts of the exposed glass surface, not subjected to the rub- bing action, hence not yielding electricity, must conduct off a small quantity of that produced elsewhere. But should the rub- bers extend to the axis, an additional quantity will be evolved, and if the axis abstract a portion, on account of its proximity, it will be but a small part of this additional quantity. It cannot be supposed, that in exciting those portions of the glass near the axis, the glass itself becomes a better conductor. On the Generation of Statical Electricity. 105 It is important that the elements of the glass, subjected to the action of the rubbers, be as long as possible ; for the glass surface may be considered as composed of an indefinite number of con- secutive portions, and as each one of these portions, when excited, acts inductively on those around it, it follows, that the greater the number excited at the same time, the greater must be the re- ciprocal inductive influence. Hence large machines, when un- der the same circumstances, must give electricity of a higher tension, than that produced by smaller machines. Having thus discussed the principles of action, of the various parts of the rubber, it remains to apply them practically. To obtain the narrow strip of rubber, requires the following process : being provided with a strip of common amalgamated leather, subject it to strong pressure, in order to render the surface flat and smooth; it is then to be rubbed with a clean cloth, to remove any excess of lard or tallow, if such substances be employed ;* which must still further be removed from the exciting points, by rubbing the amalgam with a piece of smooth leather dipped into mercury, to which a few particles will adhere ; this not only cleans the exciting points, but enlarges their extent. If the amalgam be now applied to the glass with pressure, those portions of the surface still covered with the lard or tallow, might come into contact at some points with the surface, and produce a detrimental effect ; to avoid this, reduce some plum- bago (black lead) to a fine powder, which is to be rubbed over the surface of the amalgam, and by adhering to such portions will render them excitable points. It also permits greater press- ure for the same amount of friction; and thus the surface is brought more intimately into contact with the glass. From the leather prepared as above described, a strip one fourth of an inch broad, and somewhat longer than the rubber, is to be cut; carefully avoiding to break up the amalgam at the edges, which may be accomplished by covering it with pasteboard and cutting through both substances. : ‘The rubber proper being prepared as above directed, it remains to apply it to the cushion, which, to avoid unnecessary resistance, should be three quarters of an inch or one inch in breadth, and this last dimension should not be exceeded in the largest machines. * Wax and shellac, as previously stated, may be used with advantage, but they require more care in the manipulation. Vol. xix, No. 1.—April—June, 1845. ae 106 On the Generation of Statical Electricity. The cushions should be made quite firm, and not stuffed with hair, as that does not allow them to offer sufficient resistance ; they should be as perfect non-conductors as possible; the backs of the cushions should be of glass or well-baked wood, in order to prevent the cushion from abstracting a portion of the electricity generated by the rubber.