SCIENCE. 



[Vol. XI. No. 280 



chronographic register. The magnetic azimuth of the meter can 

 be measured within a degree or two, and it is thought that current 

 speeds as low as two-tenths of a foot per second can be accurately 

 registered. This meter was used by the Coast and Geodetic Sur- 

 vey parties in their observations of currents in New York harbor 

 last summer, and proved highly effective. 



Cabinets of Typical American Rocks. 



About four years ago Major Powell concluded to make a collec- 

 tion of all the typical rocks of the United States, systematically and 

 scientifically arranged, so that a student of mineralogy, by compar- 

 ing any piece of rock he might find with a corresponding specimen 

 in the test collection, and studying the descriptions which would 

 accompany the latter, might determine the name, composition, and 

 proper classification of the unknown piece of rock he had in his 

 hand. When this collection of typical rocks was complete. Direc- 

 tor Powell proposed to have a number of duplicates of it made for 

 gratuitous distribution to the leading colleges and universities of 

 the country, for use in the classrooms as aids to the teaching and 

 study of mineralogy. 



Instructions were therefore issued to all the field-parties of the 

 Geological Survey to collect and bring in specimens of the typical 

 rocks of the regions they visited, and at first the work went on 

 bravely. But what was everybody's business soon became no- 

 body's business, the work of collecting was neglected, and finally 

 little or nothing was done about it. 



But Major Powell was unwilling to give the matter up, and about 

 a year ago he assigned Prof. J. S. Diller especially to the work, and 

 during the past few months it has been pushed forward with great 

 vigor. A complete set of specimens of the typical rocks of the 

 United States will be sent to the Cincinnati exhibition, and the 

 work of preparing the duplicates is progressing very rapidly. Each 

 set will consist of from one hundred and thirty to one hundred and 

 forty specimens, each four inches long, three inches wide, and one 

 inch thick ; and there will be a pamphlet to accompany the collec- 

 tion, giving a description of each specimen. Two hundred of these 

 sets are being prepared, and will be ready for distribution in about 

 a year to those colleges and universities which file with Director 

 Powell official application for them, and agree to make the use of 

 them for which they are designed. 



It will be impossible, of course, in a brief notice like the present, 

 to give any thing like an adequate description of one of these col- 

 lections ; but a few outlines may convey to the reader some idea of 

 their scope and the plan upon which they are arranged. Each col- 

 lection will be divided into two departments. The first will be a 

 sort of alphabetic collection, intended to show the general condi- 

 tions of rocks, their structure, means of alterations, etc. For in- 

 stance : one specimen will show a stratified rock, and another an 

 unstratified one ; a veined rock will be exhibited, also specimens of 

 rocks jointed in various ways, those containing ripple-marks, lime- 

 stone weathered by rain, spheroidal weathering in eruptive rocks 

 and shale, rocks changed by the crumpling of strata, etc. In the 

 second division the separate classes of rocks will be represented in 

 their varying forms. For instance : in showing the stratified rocks 

 not metamorphosed, the first specimen will be loose pebbles, or 

 simple masses not cemented together ; the second will show these 

 simple masses partially cemented ; and the third will show them 

 entirely cemented, like the mill-stone grit and Roxbury pudding- 

 stone. In the same way a specimen of loose sand will be shown, 

 such as is found upon the seashore ; then sandstone like many of 

 those of the East, where the grains are cemented by oxide of iron ; 

 then sandstone like the Potsdam, cemented by siliceous matter; and 

 finally sandstone where the cement is carbonate of lime. Many 

 different kinds and colors of sandstones will be shown, so as to en- 

 able the student to recognize by comparison any specimen of com- 

 mon sandstone he may have. In the same way the varieties 

 of the other classes of rocks will be illustrated, — the volcanic ; 

 the limestones of every texture, variety of color, and degree of 

 purity ; infusorial earth and deposits of hot springs ; gyp- ■ 

 sum ; specimens showing all these rocks metamorphosed ; sedi- 

 mentary rocks ; eruptive rocks ; lavas of the same composition as 

 granite, that came to the surface ; and specimens ranging from the 

 most acid granitic rock to the most basic. 



From this brief outline it may be seen of what great practical value 

 each of these collections may be made, if used as Major Powell 

 designs that they should be. About forty institutions have already- 

 made application for sets. 



Fine Specimens of Serpentine. 



Among the mineralogical specimens which the National Museum 

 will send with its collection to the Cincinnati exhibition will be 

 some pieces of serpentine which are more beautiful, probably, than 

 any previously exhibited in the United States. They were found in 

 the Gordon limestone-quarry, near Montville, Morris County, N.J.^ 

 and were collected by Prof. W. S. Yates, who was sent to Mont- 

 ville by the National Museum last summer for the purpose. The 

 specimens are of a light yellowish-green color, differing entirely 

 from the pure green serpentine metamorphosed from olivine rocks, 

 which occurs in mountain-masses near both the Atlantic and 

 Pacific coasts. 



Prof. G. P. Merrill, curator of rocks, etc., at the National Museum, 

 who has studied these specimens, has determined that the serpen- 

 tine has been derived from the alteration of pyroxene ; in fact, in 

 nearly all the specimens the process of alteration is incomplete, the 

 serpentine surrounding the pyroxene, which remains unaltered in 

 the centre. A number of the specimens, ranging from a few inches to- 

 a foot and a half in diameter, have been cut open, and the exposed 

 surface polished in the laboratory of the Geological Survey, and 

 these show the structure and bring out the colors very beautifully. 



These specimens are found in comparatively small masses, — 

 from a few inches to a few feet in diameter, — irregularly distrib- 

 uted through the limestone, and the pyroxene from which it is 

 derived occurs only in such limestone as has been metamorphosed 

 by the mountain-building forces. The only other locality in which 

 similar serpentine has been found in the United States and de- 

 scribed is in the Leadville region, Colorado, where it was discovered 

 by Professor Emmons, and treated of in his recent report. A 

 peculiarity both of the commoner serpentine derived from erup- 

 tive rocks, and also of that metamorphosed from pyroxene, is the 

 frequent occurrence of slickenside, showing that the rocks have 

 been subjected to great pressure and movement. , 



Some of the New Jersey serpentine has already been utilized ia 

 ornamentation. 



Ojibwa Pictographs in the West. 



" In the neighborhood of Odanah, on the Bad River," says Capt^ 

 Garrick Mallory of the Bureau of Ethnology, in a paper from which 

 extracts have already been made in Science, " is a large, vertical, 

 soft rock on which pictographs are still to be observed, although 

 nearly obliterated. The objects figured are chiefly birds and quad- 

 rupeds, many of them being repeated, and are all probably totemic. 

 Indeed, that is the direct evidence of an old Indian who saw some 

 of them made in his boyhood. He says that when Indian visitors 

 came by there, that being on a well-known trail, they would each 

 cut his totem on the rock to show to what clan he belonged, either 

 to establish his identity to the resident Indians who might happen 

 to be present, or as a record of his passage. This is interesting in 

 comparison with a similar proceeding in New Mexico and Arizona. 



" In my examinations at three reservations in Wisconsin, I dis- 

 covered some variants of the Mede ceremonies. The full cere- 

 monies of the Mede lodges, which they call ' grand medicine,' were 

 performed twice a year, — in the fall and in the spring. Those ia 

 the spring were of a rejoicing character, to welcome the return of 

 the good spirits ; those in the fall were in lamentation for the de- 

 parture of the beneficent spirits. The drums were beaten four 

 days and nights before the dance, which lasted for a whole day. 

 After the dance twelve selected persons built a lodge, about the 

 centre of which were stones, which were heated, and dancing 

 went on around it until the stones were moistened by the sweat 

 of the performers. Singing, of course, was an accompaniment of 

 the dances. These ceremonies were performed by the body of the 

 people, and were independent of the initiations of the secret order. 

 With regard to the candidates who passed initiations, it was ob- 

 served that they always became stronger and better men ; perhaps- 

 because those were the ones who had the requisite strength of 

 mind and body to endure the various ordeals, and to understand 

 the mysteries. 



