PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 559 



M., and Nos. 2 and 3 at four o'clock P. M. When I left at 

 BIX o'clock a considerable portion of tte snow in No. 4 re- 

 mained unmelted. The temperature was in this case reduced 

 much more than it would be if the salt was sprinkled upon the 

 surface of snow lying upon the ground. Here the salt was all 

 through the mass, and could obtain heat only at the outside, 

 while if it was sprinkled upon the surface it would form a thin 

 sheet which could readily obtain heat from the air above and 

 from the ground below. This would also cause the snow to melt 

 more slowly in my experiment than it does upon the ground. I 

 have no doubt that one per cent, of salt, if judiciously used, will 

 carry off the snow in one-fourth of the time in which it would 

 usually be removed by our winter weather. I am still of the 

 opinion, Mr. President, that the use of salt, under intelligent 

 direction, for the removal of snow, will tend to promote the com- 

 fort and health of our citizens. 



Capt. Bartlett. — Mr. President,, this is simply a question of 

 dryness. If you wet your boots with salt water they will remain 

 moist a long time, but if you wet them with fresh water they will 

 soon dry. He also cited many facts drawn from his experience 

 in the navy to show that the wearing of wet clothes is exceed- 

 ingly injurious to health. 



Prof. Seely. — It is true that clothes wet with sea water will 

 remain moist longer than if wet with fresh water ; but this is 

 not the case with salt and water. There are salts in the sea 

 which absorb and retain moisture, but chloride of sodium is not 

 hygrometric. 



Mr. J. K. Fisher. — During the discussion, on the second even- 

 ing of the subject of salting the streets, certain positions which I 

 had assumed were admitted, but turned against the general view 

 I advocated. It was admitted that the people desire comforts 

 and even luxuries, and are willing to pay for them ; and on this 

 ground it was claimed that snow ought to remain for the sake of 

 sleighing. If this luxury could not be enjoyed without allowing 

 snow to remain, we should have to choose beetween the comfort, 

 or luxury, if it be so, of dry and clean streets, and the luxury 

 of sleighing ; and, in my judgment, we should estimate the former 

 luxury the greatest, and not consent to sacrifice it for the latter. 

 But the disposition claimed by me, and conceded by those who 

 dissent on certain points, the disposition of the people to pay 

 liberally for luxuries, private and public, has already brought 



