JOHN MONTGOMERY BATCHELDER. 307 



proper places in the structure. Half-bricks weighing two pounds 

 were thus transferred, and many of the stones were of much greater 

 weight." A friend of Mr. Batchelder, a distinguished engineer, to 

 whom these observations on eels were communicated, said in reply : 

 " I have been recently studying cosmic and synthetic philosophy, and 

 looking back, not to final causes exactly where we run plump against 

 the wall, but at any rate some way back, for previous causes and 

 modes of action. Now, I want to know who began, who laid out the 

 work, and acted as boss in the case you describe. From an ex-dam 

 builder." 



We repeat this bit of humor to show a peculiar and taking quality 

 of Mr. Batchelder's mind. No matter how dry or technical the busi- 

 ness was in which he engaged, he never failed to evoke a sense of hu- 

 mor in those about him. Ilis kindly manner and gentle raillery gave 

 every one an opportunity to effervesce ; and no one enjoyed a good 

 laugh more than he who had made the occasion for it. The play of 

 humor in the letters of Professor Benjamin Peirce to Mr. Batchelder, 

 and in the replies of the lattc, show this genial receptivity in a 

 marked degree. Professor Peirce's correspondence with Mr. Batch- 

 elder extended over many years ; and we find the mathematician 

 presenting his theories of tidal action and of cosmical phenomena 

 to the inventor, and the inventor in turn writing of the mechanical 

 appliances which interested his mind so greatly. Thus Professor 

 Peirce, in a letter written in 1855, says : " I highly approve of your 

 dynamometer log, and think it will be of undoubted value. Let me 

 suggest to you to lay it before Bache as soon as possible, for he will 

 find it of the greatest use in the determination of the velocity of 

 currents, and has been seeking this very thing in a totally different 

 way." 



In a letter to Professor Joseph Henry, Mr. Batchelder says : " I do 

 not remember any published records of the increase of the tempera- 

 ture of the earth caused by falls of snow and the consequent decrease 

 of radiation. Can you inform me whether such observations have been 

 made ? Enclosed is a sheet showing results of observations in my 

 well (at Cambridge, near the Agassiz Museum) during the years 1868, 



1869, 1870, and part of 1871 ; also a rough sketch of the position of 

 the well. Please notice the sudden fall of one degree during: the first 

 week in September, 1868, and the sudden rise in the same week in 



1870. The observations would have been continued had not the well 

 become dry in consequence of the construction of a deep sewer in the 

 street. If you think that notes of this kind will be of value, I should 



