446 



SCIENCE. 



clam (Mya) from the shell heaps of Goose Island, Maine ; 

 Ipswich, Mass., and Marblehead, Mass., in comparison 

 with recent forms of the same species collected in the 

 immediate vicinity of these ancient deposits, showed that 

 the ancient specimens were higher in comparison with 

 their length than the recent specimens. 



A comparison of the common beach cockle (Lunatia) 

 from the shell heaps of Marblehead, Mass., showed that 

 the present form had a more depressed spire than the 

 recent forms living on the shore to-day, and this variation 

 was in accordance with observations he had made on 

 similar species in Japan. 



AMERICAN COAL FIELDS. 



The areas of the anthracite coal fields, confined to a 

 few counties of our State, are so well denned that we 

 need be in no doubt as to their extent ; and this limited 

 area admonishes us that we should carefully husband 

 our inheritance, and not waste it. The fact is well es- 

 tablished, that for every ton shipped to market, two are 

 wasted. The loss in the operations of mining, the pil- 

 lars left to support the roofs of the mines, the loss in 

 prepaiation, each contributes to this great aggregate. 

 How to prevent these losses, by use of improved ma- 

 chinery, and by more thorough methods of working the 

 mines, should be the study of our mining superintendents 

 and engineers. Several suggestions with a view to a 

 partial remedy, present themselves. 



First. — The owning of the land by the operators 

 would make them careful to mine all the coals. As 

 tenants for a limited term of years, their object is merely 

 to take out that coal, and in such a manner as will cost 

 them little, and bring them much. 



Second. — If the lands are to be leased, the term should 

 be long enough to enable them to mine all the coal beds 

 covered by the lease. 



Third. — The lease should contain clauses subjecting 

 the methods of mining, ventilation and drainage to the 

 supervision of the owner's mining engineers ; limiting the 

 lengths of " breasts " to seventy yards or less ; forbidding 

 the use of monkey rolls, or the rebreaking of the coal ; 

 providing for the dumping in separate heaps of the coal 

 dirt and the slate and rock. 



Fourth. — We need larger collieries, and fewer of them, 

 with perfected machinery, for hoisting, pumping and 

 breaking. 



Fifth. — More capital is required to open the mines for 

 extensive and exhaustive working, by driving the gang- 

 ways to the extreme ends of the territory, and then min- 

 ing towards the outlet, so as to obviate the necessity of 

 retracing our steps and robbing the pillars. 



In Schuylkill county we are specialists. We are de- 

 pendent upon one substance : coal is king. There is no 

 gold, silver, lead, copper, or other valuable metals. 

 Though we have good iron ores, they are so disseminated 

 as not to furnish us one workable bed. Yet we largely 

 help Pennsylvania to furnish nearly halt the iron manu- 

 factured in the United States. We have a large farming 

 area well cultivated by our industrious and frugal German 

 farmers. Our convenient location to the great markets 

 of the Atlantic seaboard, our canals and abundant rail- 

 road facilities, our great commodity, always give a 

 promise and an attitude among the great countries of our 

 grand old commonwealth, which we are ever proud to 

 realize. — Geology of Schuylkill County, by P. W.Scheafer. 

 Pottsville, Pa. 



The latest addition to microscope stands is the swing- 

 ing sub-stage. This American invention has been adopted 

 by most of the English manufacturers. In the last number 

 of the Journal of the R. M. S. we find the value of the 

 swinging sub-stages disputed by Mr. Crouch, and that Mr. 

 Stevenson concurred in this view, and described them as 

 useless incumbrances and unsuitable for use with certain 

 apparatus, which is essential to the display of some objects. 



ASTRONOMY. 



COMET C (SCHSBERLE), 1881. 



This comet has been observed here since the 16th of 

 July. When first seen it was large, round and bright, and 

 slightly condensed at the centre, being very plainly visible 

 in a i X-inch telescope. On the morning of the 19th it 

 had increased sensibly in brightness ; a faint tail could be 

 traced for a distance of fully 15', pointing in a northwest- 

 erly direction ; on the above date its position was obtainee 

 from 8 ( Thctd) Aurigas in the following manner : Thd 

 comet and star were separated too far to be both seen in 

 the field of the telescope together, the comet was also too 

 far north of the star for both objects to be seen at once 

 in the finder. One of the wires in the finder eye-piece 

 was made parallel with the meridian, and then the star, 

 which preceded the comet, was brought into the field and 

 its passage of the wire obtained ; the telescope was then 

 carefully moved northward in declination until the comet, 

 entered the field when its passage of the wire was ob- 

 served ; in this manner the difference of R. A. was ob- 

 tained ; the difference of declination was then estimated. 

 From a mean of several passages of the star and comet 

 its position on July 1 8th at 1 5I1. 40m., Nashville mean 

 time, was found to be R. A. 5h. 52m. 52sec, and Decl. 40° 

 15'. The R. A. will be very little out, but the declination 

 may be over a minute in error. 



Its position was obtained in the same manner on the 

 20th (A. M.), using the same star at 3h. 35m., R. A. 5h. 

 53m. 54sec, Decl. + 40 42', with probably several min- 

 utes of error in the declination. On July 24, at 15 hours, 

 the comet was visible to the naked eye, appearing about 

 as bright as a sixth magnitude star (Prof. Swift, of the 

 Warner Observatory, saw it with the unaided eye as early 

 as the morning of the 23d). 



On the 28th a small star-like nucleus was visible with 

 the telescope. 



Aug. 3 (A. M.), it was very easily visible with the naked 

 eye, traces of the tail being seen without a telescope. A 

 naked eye comparison with comet B showed C to be the 

 brighter. Comparing it with a six magnitude star it was 

 of the same brightness, but, covering a larger area, it was 

 more noticeable than the star. The tail, in the telescope, 

 was long and slender and straight as a shaft. 



Aug. 4 (A. M.), the comet was quite conspicuous with 

 the unaided eye, the tail stretching out for some distance. 

 In the telescope the nucleus was small, round and pale, 

 and star-like in form, Turning the telescope from comet 

 C to comet B, the two were identical in brightness, but B 

 was slightly broader about the head and tail, and the nu- 

 cleus was not so distinct ; but considering the low altitude 

 of C it must have been really much brighter than B. 



On August 14 it was visible in the evening after sun- 

 set, being quite plainly visible to the naked eye, with its 

 tail streaming upwards for several degrees. In the tele- 

 scope it was many times brighter than comet B. 



21 inst., in the evening, the comet was as bright to the 

 eye as a t> 1 A ma g- star - It appeared very graceful, 

 straight and slender in the telescope. On this occasion 

 I obtained its position with the aid of a ring micrometer, 

 referring the comet to Psi ursa minoris. 



l83i, August 21 ds., 14.1m. Washington, m. t. % a=nh. 08m. 08.5s. 

 This was the apparent position. \ J= + 45 13' 42" 



22 inst., evening, its tail could be traced with the tele- 

 scope tor a distance of about 6°, and was visible to the 

 naked eye for about the same distance. A faint lightish 

 stripe was visible on this date, extending from near the 

 head to a degree or so along the middle of the tail. The 

 following side of the comet's head and tail were distinctly 

 defined, the sky appearing quite dark up to the very body 

 of the comet, but the preceding side was ill-defined and 

 blended, the sky being whitish for some distance from 

 the comet ; there also appeared to be a diffused sort of 

 short tail running out some 10' or so from the n. p. side 



