354 
ANNALS NEW YORK ACADEMY OF SCIENCES 
journeys for the enjoyment of travel, his native city was his continued home 
and with its institutions and its scientific and philanthropic work he was 
identified during his sixty-three years of useful life. 
On completing his preparation in the schools, Mr. Caswell entered 
Columbia College in 1861 and graduated in 1865. During his college course 
he came under the influence of Professor Charles A. Joy, then occupying the 
chair of chemistry, a man of enthusiastic devotion to science and of especial 
interest in mineralogy. Professor Joy had earlier received European train¬ 
ing; he was an old student of Bunsen’s and was one who turned eagerly to 
the renewal of his pleasant relations with his old professors in Germany. 
On Mr. Caswell’s graduation he accompanied Professor Jov to Europe, and 
in the autumn was enrolled in the famous old Mining Academy at Frieberg. 
Three very happy years of study ensued, varied during the vacations by trips 
to the mining districts of Norway and Sweden and of the Hartz Mountains. 
During his residence at Freiberg, Mr. Caswell had as fellow-students Arnold 
Hague now of the United States Geological Survey, Professor H. B. Corn¬ 
wall of Princeton and A. D. Hodges, Jr., later to be an engineer of exceptional 
influence in the mining development of this country. All three remained his 
lifelong friends. Mr. Caswell, who had from boyhood loved natural science 
like many another Freiberger, became still more strongly enamoured of 
mineralogy and found in its pursuit one of the great enjoyments of his life. 
In 1864, the School of Mines of Columbia College was established so 
that on his return to New York in 1868 Mr. Caswell became assistant in 
mineralogy to Professor Thomas Egleston. For three years he held this 
position, but the death of his father in 1871 compelled him for the time 
being to resign his scientific work and devote himself to the business of the 
estate. While connected with the Columbia School of Mines the “Wander¬ 
lust” did not fail to seize him, and it was so strong that his summer months 
were spent with his friend Air. Hodges in the mines of what is now Colorado 
and in Nevada and California. 
Mr. Caswell continued his interest in mineralogy despite his immersion 
in business cares. In 1874 he resumed his position in the School of Mines 
and held it for three years. During this period Henry Newton and Walter 
P. Jenney were engaged in the geological survey of the Black Hills of Dakota. 
Their collections embraced great numbers of igneous rocks which were 
obviously of unusual scientific interest. When they came to New York to 
work up their results in Professor Newberry’s laboratory, they persuaded 
Mr. Caswell, then in the department of mineralogy, to undertake the micro¬ 
scopic investigation of this material. Petrography was in its infancy. A 
few Americans returning from European study had learned something of it 
abroad, and one or two Americans had busied themselves in its pursuit 
