404 PIONEERS OF SCIENCE IN AMERICA. 



omission. In the fall of that year he entered the second class, 

 thus coming to the studies of chemistry and mineralogy in the 

 curriculum of the academy, Webster's book being used. Ca- 

 det Mather at once took the head of the class in these sub- 

 jects, and easily kept his place to the end of the course. 

 When off duty he explored the hills of the vicinity to collect 

 minerals for his private cabinet and that of the lyceum. The 

 chemical laboratory of the institution was also a place of re- 

 sort for his leisure hours. During the last year of the course 

 he was an assistant in the laboratory. He seemed to have a 

 special aptitude for science and took great delight in experi- 

 menting. Mr. Austin illustrates this tendency by the follow- 

 ing account : 



" The winter of 1826-27 was very cold. The ice, floating 

 down to the narrow gorge between the precipitous shores of 

 West Point and the opposite bank, became wedged there and 

 was exceedingly thick. It occurred to Mather that a favour- 

 able opportunity was thus offered to ascertain the temperature 

 of the water at the bottom of the river while the surface was 

 covered with ice. After several attempts he succeeded in 

 making a self-registering thermometer, and an apparatus for 

 bringing up a specimen of the water of the lowest depth. A 

 hole was cut through the ice about the middle of the river, 

 and the apparatus, attached to a strong cord was let down 

 into the water, but the current was so strong that it failed to 

 reach the bottom. With a heavier weight it sank far enough, 

 but the pressure forced the cork into the bottle. The next 

 attempt was successful ; water was drawn from below, and its 

 temperature ascertained from the self-registering, compared 

 with that indicated by a detached, thermometer. The result 

 of this experiment, in which the writer assisted him, is not 

 remembered, but Mather declared that he was satisfied with it. 

 Such was his occupation, on one of the coldest days in winter, 

 during the whole of the Saturday afternoon allowed to the 

 corps for recreation." 



On graduating he was assigned to the Seventh Infantry with 

 the customary rank of second lieutenant. He remained at 

 West Point as acting assistant instructor of artillery during the 

 summer encampment of 1828, and was then ordered to the 

 School of Practice at Jefferson barracks, where he remained 

 until April, 1829. From April to the end of June he was on 



