144 



POPULAR SCIENCE MONTHLY. 



very dear at the time, the thought occurred 

 to him to try its properties as a combustible. 

 This black earth was coal. The man's name 

 was HuUioz; whence the French word for 

 coal — hoaille. Authentic documents show 

 that coal mines were fully worked in Belgium 

 in 1228 and 1229. The use of coal was in- 

 troduced into England in 1340, but did not 

 become common till the beginning of the six- 

 teenth century. It was first mined in France 

 in the fourteenth century ; in Austria and 

 Bohemia in the last century ; while it was 

 mined in North Germany about the year 

 1200. 



Some seeds of common plants — such as 

 bloodroot, the large-flowered uvularia, and 

 trillium — are furnished with whitish fleshy 

 appendages, forming a slight ridge on one side. 

 These crests are not conspicuous to be noticed 

 by birds, but Mr. Charles Robinson, of Carlin- 

 \ille. 111., has found them attractive to ants. 

 He has often exposed seeds of bloodroot in 

 situations frequented by ants, and has ob- 

 served that the insects invariably seize them 

 and carry them away, the crest serving as a 

 convenient handle by which to take hold of 

 them. He has also experimented with seeds 

 of the other plants named with like results. 

 These seeds seem to have no other means of 

 dissemination, being such as simply drop 

 from the capsules and lie where they fall, till 

 the ants carry them away. They thus add 

 one other to the variety of means by which 

 seeds are scattered. 



The possibility of electrifying air entirely 

 free from dust particles is still an open ques- 

 tion. Late investigations by Lord Kelvin 

 and S. Arrhenius tend to prove that dust is 

 not essential to electriti cation. 



The Proceedings of the Meeting of the 

 American Railway Association held in Octo- 

 ber, 1897, contains a carefully compiled re- 

 port of the committee on the metric system, 

 in which is embodied a brief, convenient, and 

 useful history of the English and French 

 standards, enlivened witli interesting inci- 

 dents. We learn from this report that " the 

 tendency in railway operations has been 

 toward the use of a decimal system. Rates 

 are made on the basis of one hundred pounds. 

 Civil engineers have abandoned the Gunter's 

 chain of sixty-six feet for that of one hun- 

 dred feet, and divide the foot decimally. 

 The ton of two thousand pounds and the 

 hundredweight of one hundred pounds are 

 now generally used, instead of twenty-two 

 hundred and forty and one hundred and 

 twelve pounds. These changes, both Amer- 

 ican in their origin, have commended them- 

 selves because they permit calculations in 

 decimals." 



During the year covered by his last re- 

 port, the director. Dr. Elkin, of Yale Ob- 

 servatory, studied the photographic trails of 

 five Perseid meteors which were secured in 



August, 1896. So far the results are not 

 very conclusive as to the character of the 

 radiant, but each year is expected to add to 

 the data, and it is hoped that most valuable 

 deductions may be ultimately possible. A 

 portion of the work on the parallaxes of 

 the ten first-magnitude stars in the northern 

 hemisphere has been passed through the 

 press ; and values have been calculated 

 which the director believes can hardly be 

 modified appreciably by further discussion. 

 Dr. F. L. Chase, assistant astronomer, has 

 taken up the heliometer work on the paral- 

 laxes of large proper motion stars. 



Eight new asteroids — a smaller number 

 than the average of previous years — were 

 discovered in 1897, bi-inging the whole num- 

 ber up to four hundred and thirty-three. In- 

 stead of names the later discoveries are 

 designated by combinations of letters of the 

 alphabet— as DH, DI, DJ, DK, DL, DM, DN, 

 and DO for those of 1897. 



An exhibition of culinary art recently 

 held in Vienna met with a prodigious suc- 

 cess. It included everything appertaining 

 to cooking, from a richly served table to the 

 emperor's bivouac kitchen. Under a system 

 of reducing the prices of tickets each day, 

 the attendance on the second day was double 

 that on the first, and on the third the ticket 

 office had to be closed against the crowds. 

 It is observed that such throngs came as are 

 never seen at industrial expositions or dis- 

 plays of pictures. 



We have to announce the deaths of Dr. 

 Waldemar von Schroeder, professor of 

 pharmacology in the University of Heidel- 

 berg and author of a number of treatises on 

 physiological chemistry ; William A. Rogers, 

 professor of astronomy in Colby LTniversity, 

 and formerly assistant in the observatory of 

 Harvard College, at Waterville, Me., March 

 1st, aged forty-six years. He was the author 

 of some important contributions to astrono- 

 my and physics, and especially to the tech- 

 nique of measurement. Leon Jambert, di- 

 rector of the Popular Institute of Science at 

 the Trocadero, Paris ; M. Charles Cornevin, 

 professor of hygiene and zooteehny at the 

 Veterinary School of Lyons, France ; ex-Di- 

 rector Winneke, of the Strasburg Observa- 

 tory ; Charles Scofer, a distinguished Ori- 

 entalist, at Paris, aged seventy-eight years ; 

 Sir Henry Bessemer, by whose invention the 

 manufacture of steel was revolutionized, at 

 London, March loth, aged eighty-five years; 

 Sir Richard Quain, the eminent English physi- 

 cian, March 13th, aged eighty-three years ; 

 Admiral Popoff, Russian inventor of a curi- 

 ous form of circular ironclad war ships ; Pro- 

 fessor Kirk, of the Department of Forests of 

 New Zealand and author of valuable works 

 on the timber and timber trees of that col- 

 ony ; and Dr. Ferdinand Huster, near Liver- 

 pool, a chemist of considerable local reputa- 

 tion. 



