650 Transactions of the American Institute. 



and there is as much motion in one as in another. That of the sensi- 

 tive plant is more apparent, but they are all equally wonderful when 

 we observe them. 



VI. On the Descent of Glaciers. 

 Henry Moseley, Canon of Bristol, continues in the Philosophical 

 Magazine for August, the discussion on the cause of the descent of 

 glaciers. He opposes the generally received theory, the object of his 

 various memoirs being to show : 1. The mechanical impossibility of 

 the descent of glaciers by their weight alone : 2. The actual cause of 

 their descent to be their dilatation and contraction by alterations of 

 temperature, in addition to their weight. 



Adjourned to Friday next, at half-past 7 o'clock, p. m. 



November 24, 1871. 



Prof. S. D. Tillman, in the chair ; Mr. Robert Weir, Secretary. 

 Dr. Firman Coar read the following paper : 



Sewerage Systems at present in use. 



Mr. President and Gentlemen. — It is perhaps proper that I 

 should make some apology for appearing before you, an entire stran- 

 ger as I am. Although born and raised in the old Keystone State, 

 my profession called me to Europe about seventeen years ago, where, 

 with the exception of a few months that I spent here last year, I 

 have been residing ever since. The calls of a profession alone do 

 not, in Europe, suffice to satisfy the desire of many active profes- 

 sional men, and you will find such persons devoting their leisure 

 hours to some particular hobby, which in Germany they call a " hobby 

 horse." These hobbies range from the grandest theories in science, 

 down to that of drinking twenty-five mugs of beer in one evening. 



Falling in with the custom, I also mounted my hobby, and that is 

 the subject of sewers, and feeling that I did not like to relinquish 

 it entirely upon my return to my native country, and having occasion 

 to lay the subject before your worthy professor here, he was so 

 kind as to ask me to present it in the form of a lecture before the. 

 Polytechnic Society. This, gentlemen, is my excuse. 



I therefore propose this evening to call your attention for a short 

 time to the history and working of sewers ; to point out some of the 



