698 THE POPULAR SCIENCE MONTHLY. 



all numbers that give the same remainder when they are divided 

 by the same number. In his " General Disquisitions on Curved 

 Surfaces/' he established the famous theorem that in whatever 

 way a flexible and inextensible surface may be deformed, the sum 

 of the principal curvatures at each point will always be the same. 

 The calculations of the elements of the asteroids Pallas, Ceres, 

 Juno, and Vesta, were made by Gauss, and attracted all the more 

 attention because they furnished the first occasions on which all 

 the elements of a planet had to be determined in a short time and 

 by a small number of observations. The methods were not yet 

 even fixed, because no one had taken up the subject. The process 

 adopted by Gauss was simple and confessedly worthy of the 

 attention of astronomers. Gauss has been called the godfather of 

 the planet Vesta, from his having selected the name for it. In 

 two papers on the comets of 1811, he gave a new and much more 

 simple method than had been practiced before to determine the 

 elements of a comet with the smallest number of observations. 

 While actively engaged in the measurement of the degree in 

 Hanover, Gauss devised the instrument known as the helio- 

 trope, which has since come into general use in all geodesic 

 observations. 



Gauss engaged also in researches on magnetism, concerning 

 which he published a paper in 1833 on the intensity of terrestrial 

 magnetism. He and Prof. Wilhelm "Weber invented new mag- 

 netic apparatus, including the declination instrument and the 

 bifilar magnetometer. They erected at Gottingen an observatory, 

 free from iron, where he made magnetic observations, and — antici- 

 pating the electro-magnetic telegraph — sent telegraphic signals to 

 a neighboring town. 



His collected works, edited by E. J. Schering, have been recently 

 published by the Poyal Society of Gottingen in seven volumes. 

 With them are included notices by him of many of the memoirs, 

 and of works of other authors in the "Gottingen gelehrte An- 

 zeigen," and a considerable amount of previously unpublished 

 matter. Gauss was a member of all the important learned so- 

 cieties. 



One of Gauss's last acts was, a little while before his death, to 

 have engraved at the foot of his portrait, as giving the best sum- 

 mary of his views and labors, the lines from Shakespeare's " King 

 Lear " : 



" Thou, Nature, art my goddess; to thy laws 

 My services are bound." 



