300 JOHN MONTGOMERY BATCH ELDER. 



Batchelder made many experimental inquiries, among which were 

 the following : — On the compressibility of rubber. Expansion and 

 contraction of highly calendered paper. On the compressibility of 

 sea wafer and some other liquids by pressure, and on the effects of 

 temperature in compression in relation to Saxton's sounding instru- 

 ments. On the use of vulcanized india-rubber in a compression 

 sounding apparatus. On Leonard's dynamometric log for determin- 

 ing the speed of vessels and of currents of water. On the manufac- 

 ture of braided sounding-line of hemp, saturated with india-rubber. 

 On Saxton's pressure apparatus, and the effect of temperature and 

 rate of cooling when encased in wood. Ou the effect of inclination 

 on the compensating base apparatus. 



In the Coast Survey Report of 1858 it is stated that he prepared 

 ice charts, showing the boundaries of ice during certain years in the 

 harbors of Gloucester, Salem, Marblehead, and New Haven. Pro- 

 fessor Bache, in his correspondence with Mr. Batchelder, often ex- 

 presses very high appreciation of his work and of his abilities. 



In 1858 Mr. Batchelder was detailed from the Coast Survey to 

 assist Dr. B. A. Gould in the Dudley Observatory at Albany. His 

 work there, we learn from a letter of Dr. Gould, was " to bring the 

 calculating machine into shape, and also to aid in arranging the tele- 

 graphic connections and apparatus." The calculating machine was 

 Scheutz's tabulating engine, and Mr. Batchelder mastered its intri- 

 cacies and put it in successful operation. The writer of this notice, 

 while a student, well remembers that Mr. Batchelder was pointed out 

 to him as the only man in the country who could work a wonderful 

 calculating machine at Albany. 



Mr. Batchelder's mind was essentially scientific ; and no one can 

 examine the note-books of observations which he has left without 

 being impressed by his keen interest in the phenomena of nature. 

 Nothing seemed to escape his attention, from the fluctuations of tem- 

 perature in a well to the quivering of the aurora borealis. In a long 

 series of observations on the temperature of the Saco River, made in 

 1838, he notes : "I have observed that in extreme cold weather the 

 vapor from the falls has a very sensible effect upon the temperature 

 of the atmosphere, — the mercury commonly standing four or five de- 

 grees higher within a few rods of the river than it does at the distance 

 of one fourth of a mile." While at Saco he watched lamprey eels 

 building a dam in the stream, and in an article, carefully descriptive, 

 says : " I noticed in many instances that the heavier stones were lifted 

 by two eels, working alongside of each other, and carried to their 



