PROCEEDINGS OF THE POLYTECHNIC ASSOCiItION. 557 



is required for old engines, to which it may be applied, beyond 

 the introduction of a slightly better description of packing 

 for the glands. The Peninsular and Oriental Steam Navigation 

 Co. have, in many of their engines, realized an economy of up- 

 wards of 30 per cent, by the introduction of superheated steam ;" 

 and a steamer lately built of 2,600 tons burthen, with engines of 

 400 horse power, in which steam jackets, surface condensers, and 

 superheated steam are applied, has realized, we are told, a sav- 

 ing of fifty per cent, in fuel, compared with a steamer of like 

 tonnage and power without such appliances. These statements 

 claim the attention of all steam engineers and steamship com- 

 panies. It has been found most advantageous to superheat the 

 steam to about 100*^ above that in the boiler, when no difficulty 

 is experienced in lubricating valves, pistons and glands. Every 

 new economical application of steam deserves to be generally 

 known and carried into practice. 



The regular subject was then taken up. 



SALTING STREETS. 



Prof. Seely. — There was one point made by Dr. Gardiner at the 

 last meeting, which, perhaps, ought to have been considered at 

 our first discussion of this subject — that is, whether we want 

 snow in New York city. In regard to that, I would say that for 

 those who have the means to purchase fine horses and sleighs, 

 and the leisure to indulge in the recreation, sleigh-riding is a 

 very agreeable luxury. I like it very well myself. But I cannot 

 afford to indulge in it, and I have no doubt that in this city there 

 are a thousand persons like myself in this respect to one who can 

 enjoy sleigh-riding ; and I think that the few should be willing to 

 give way to the many. Even for those who have sleighs tlie 

 streets are not very good places to ride in, and most of those who 

 indulge in the recreation go into the suburbs or out of town. 

 This subject has recently been thoroughly investigated in Phila- 

 delphia. It being proposed to prohibit the use of salt on the 

 railroads, a committee was appointed by the city government to 

 take testimony, and fully investigate the matter. The College 

 of Physicians and the Board of Health were both called upon for 

 their opinions, and all citizens interested were invited by public 

 notice to present their views. The testimony was very contradic- 

 tory, but it seems to me that the preponderance is decidedly in 

 favor of the practice. The strongest opinions are in opposition 



