POPULAR MISCELLANY. 



859 



The collection of clocks comprises nearly 

 every conceivable variety of time-pieces, 

 from sand-clocks to the Dresden Universal 

 Clock which gave the time at three hundred 

 and sixty places, and automatons driven by 

 clock-work. The collection of telescopes 

 covers nearly the whole history of the in- 

 strument, beginning with a Galileo's tele- 

 scope and including a Kepler's, a Rheita's, 

 the Huygens's, Dolland's, and Frauenho- 

 fer's refractors, and several kinds of re- 

 flectors. One of the most precious articles 

 in the collection is a very elaborate globe, 

 with all the principal constellations and as- 

 tronomical lines, and the magnitudes of the 

 stars carefully indicated, which bears an 

 inscription stating that it was made by 

 Mohammed Ben Muwajed-el-Ardhi, without 

 date or place of making. Beigel, of Dres- 

 den, calculated in 1808, from the positions 

 of some of the stars on the globe, that it 

 must have been made in the ninth century. 

 Dr. Adolph Drechsler believes that the 

 maker was a son of the famous astronomer 

 Muwajcd, who was called by Hulagu, the 

 third emperor of the Mogul dynasty, from 

 Damascus to superintend the observatory at 

 Maragha, and that the date of the instru- 

 ment was about a. d. 1279. The chief val- 

 ue of the collection is in the opportunities 

 it affords for the study of the development 

 of instruments in the several branches of 

 science. 



Evolution of Deer-Horns. Mr. W. 



Boyd Daw-kins has called attention to the 

 confirmation of the doctrine of evolution 

 afforded by the development of the an- 

 tlers of animals of the deer-kind. In the 

 middle stage of the Miocene, the cervine 

 antler consists merely of a forked crown. 

 This increases in size in the Upper Miocene, 

 though it still remains small and erect, being 

 not quite eleven and a half inches long, 

 with four small tines in Ccrvus Matheri. 

 The antlers of the succeeding (Pliocene) 

 deer, in the Auvergne, were longer and 

 larger and more branching than those of 

 any earlier deer, and had three or more 

 well-developed tines. The Ccrvus dicranios 

 of the Upper Pliocene of the Val d'Arno 

 had antlers so complicated as almost to 

 defy description, though they were still 

 smaller than those of the Irish elk. That 



animal survived into the succeeding age, 

 and has been described in England as Sedg- 

 wick's deer. The Irish elk, moose, stag, 

 reindeer, and fallow deer, appeared in Eu- 

 rope in the Pleistocene age, all with highly 

 complicated antlers in the adult, the first 

 having the largest antlers as yet known. 

 " From this survey," says Mr. Dawkins, " it 

 is obvious that the cervine antlers have in- 

 creased in size and complexity from the 

 mid-Miocene to the Pleistocene age, and 

 that their successive changes have been 

 analogous to those that are observed in the 

 antlers of the living deer, which begin with 

 a simple point and increase in number of 

 tines till their limit of growth is reached. 

 In other words, the development of antlers 

 indicated at successive and widely separated 

 pages of the geological record is the same 

 as that observed in the history of a single 

 living species." 



Tests for Color-Blindness. Dr. William 

 Thomson, of Jefferson Medical College, has 

 devised a test for color-blindness, for use 

 ! on the Pennsylvania Railroad, which is in a 

 measure self-working, and may be applied 

 with precision by any agent at any station on 

 the line. It is based on Holmgren's system 

 of many-colored yarns, but the number of 

 skeins is reduced from the one hundred and 

 fifty used by Ilolmgren to forty. The forty 

 skeins, each bearing its serial number, are 

 hung by buttons, that can be easily un- 

 hooked, upon a stick about two feet long, 

 in such a way that the numbers are hid. 

 The first half of the series of yarns, num- 

 bered from one to twenty, are devoted to 

 the green test. The odd-numbered skeins 

 are of shades of green, and the even-num- 

 bered ones of "confusion colors" grays, 

 tans, light browns, etc. The other half is 

 similarly occupied with skeins of red, and 

 the " confusion colors " for red-browns, 

 sages, and dark olive, arranged alternately. 

 A man placed before the instrument is told 

 to select ten skeins to match the green test- 

 skein, which is shown him. If his eyes are 

 normal, he will readily select the ten green 

 skeins, and the clerk simply finds the num- 

 bers of the skeins thus selected and puts 

 them down. If the man's eyes are defect- 

 ive, he will hesitate in selecting the skeins ; 

 if color-blind, he will throw out skeins at 



