NOVEMBEH 11, 1898 ] 



SCIENCE, 



673 



Prominent as the object is thus lilcely to become, 

 it deserves a good name. I would suggest that 

 of Pluto, and desire to urge the claims of this 

 gentleman to the distinction. He is the only 

 one, of the six children of Saturn whom that 

 unnatural father was unsuccessful in eating or 

 otherwise destroying, who has not yet stood as 

 godfather or godmother to some member of our 

 planetary system. The other five, Jupiter, 

 Neptune, Ceres, Vesta and Juno, have been 

 worthily assigned, either to major planets or to 

 the earlier discovered members of the Mars- 

 Jupiter belt of asteroids. For the use of the 

 later discoveries in this numerous group the 

 list of available female goddesses has long since 

 been exhausted, and now sweethearts, wives, 

 girl-babies, and even provinces, cities and towns, 

 are jumbled together in our lists of these objects 

 in a ludicrous way. Will it not assist to a slight 

 return to dignity and sanity of nomenclature to 

 give some of the neglected male gods a chance, 

 and destroy the unfair monopoly of the heau 

 sexe in such matters ? This seems a good time 

 to begin. The body in question stands apart 

 from the Mars-Jupiter belt, practically a stunted 

 twin of Mars himself. Moreover, there is a 

 certain fitness in the appellation arising from 

 its faintness or invisibility on ordinary occasions. 

 Pluto, under hjs older name, Hades, was the 

 ' invisible ' or ' unknown,' the God of Darkness. 

 This invisibility he removes, with the helmet 

 forged for his concealment by Vulcan, when he 

 comes to perihelion opposition, shining then as 

 a comparatively bright star, perhaps visible to 

 the naked eye. This helmet, by the way, could 

 serve as his conventional planetary symbol, if 

 one is desired. 



The addition of new asteroids to our lists has 

 become such a nuisance that ordinarily the at- 

 tachment of ridiculous names may be regarded 

 as one of the helpful influences in discouraging 

 further useless multiplication of these trouble- 

 some wards of astronomy. But when one is 

 born into the solar system which gives promise 

 of paying for its keep, some attention should be 

 devoted to a proper christening. In the solu- 

 tion of the problems I have indicated, Pluto may 

 be counted on to pay handsomely for his board 

 and clothes. 



It is hoped that the discoverer will take these 



considerations, and others which could be urged, 

 into account in his selection of a suitable name 

 for this interesting and important little object. 

 S. C. Chandler. 

 Cambridge, October 31, 1898. 



THE MINOR PLANET DQ. 



The notice in Nature, September 29th, quoted 

 in Science, October 14th, seems to indicate a 

 misunderstanding in reference to the orbit of 

 the new minor planet DQ, by implying that it 

 lies wholly within that of Mars. This is not 

 the case ; while the perihelion distance of the 

 new planet is about 23,000,000 miles less than 

 that of Mars, or only 12, .500, 000 miles greater 

 than the mean distance of the earth, the eccen- 

 tricity of its orbit is such that its aphelion dis- 

 tance is 37,300,000 miles greater than the peri- 

 helion distance of Mars, or nearly 10,800,000 

 miles greater than the aphelion distance of 

 Mars. The periodic time of the new planet is 

 only 643.7 days, or 1.76 years. The periods of 

 all the other asteroids lie between 3.0 and 8.4 

 years. 



The above numbers are derived from the ele- 

 ments of the orbit of DQ which I have com- 

 puted from observations embracing an interval 

 of 43 days. These elements confirm the results 

 of Dr. Berberich. 



"W. J. HUSSEY. 



Lick Observatory, October 27, 1898. 



THE STRESS-STRAIN RELATIONS OF RUBBER. 



In the issue of Science of November 19, 1897, 

 is a very interesting article by Professor Thurs- 

 ton upon the singular stress-strain relations of 

 rubber, accompanied by the strain diagram for 

 the same. This curve shows very clearly the 

 peculiar and sudden increase in the value of 

 the ratio of the stress to the strain as the point 

 of rupture is approached. 



It seems to the writer that this form of curve 

 is to be expected as the result of the peculiar 

 microscopic and physical constitution of rubber. 

 It is well established that rubber consists of a 

 mixture of two modifications of the same sub- 

 stance, one hard and fibrous and the other soft 

 and viscous. These are identical in composi- 

 tion and similar in general properties and re- 

 actions. In other words, rubber consists of a 



