386 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



plus capital in land. Mr. Astor became the richest proprietor of real estate 

 on Manhattan Island, and Mr. Smith the greatest landholder in the State 

 of New York. Tliere are many prominent names connected with the fur 

 trade in this country. The extent of the trade here cannot be accmately 

 stated, but some idea may be gained of its importance, in the Old World, 

 by tlie following statement of the fur skins imported into Great Britain in 

 the year 1851, which is given in detail to show variety of furs used and 

 their relative abundance: 



Sea otter, 100; otter, 17,500; seal, 15,000; lynx, 55,000; Kolinski, or 

 Tartar sable, 53,000; beaver, 60,000; Chinchilla, 85,000; stone and pine 

 martin, 120,000; minks, 245,000; rabbit, 120,000; red, cross, white, gray 

 and silver fox, 71,000; ermine, 181,000; Racoon, 525,000; musquash, or 

 muskrat, 1,000,000; squirrel, 3,000,000; fitch, or polecat, 66,200; wolf, 

 15,000; wolverine, 1,200. The whole number imported was about five 

 million, of which one million were exported. 



Mr. Emmet remarked that Leipsic was the European centre of the fur 

 trade; to this point furs are brought from all quarters to be disposed of at 

 the annual sale. ' 



The hour for adjournment having arrived, it was decided to continue the 

 discussion of this subject at the next meeting. Adjourned to Thursday 

 evening next. 



American Institute Polytechnic Association, ) 

 October 21th, 1864. j 



Chairman, Prof. S. D. Tillman; Secretary, Mr, B. Garvey. 

 The first subject discussed, during the hour devoted to miscellaneous 

 subjects, was 



Super-Heated Steam. 

 Mr. T. D Stetson wished to direct attention for a few moments to the use 

 of super-heated steam in engines. It was generally admitted by engineers 

 that there is no gain in heating steam beyond a certain point. The princi- 

 pal object in its use being to keep the proper temperature in the cylinder. 

 In the best engines jackets enclose the C3''linder and steam islet in between 

 to prevent the cooling of the cjdinder. Mr. Erastus W. Smith, a well 

 known engineer of this city, took out a patent for providing the steam for 

 heating the cylinder by means of a separate small boiler, such as is used 

 with donkey engines. A gentleman now proposes to super-heat the steam 

 to perhaps 150'^, and then to convey this steam first into the jacket and 

 then into the cylinder to be used upon the piston. His idea is, that the 

 steam in its passage between the cylinder and jacket will lose its surplus 

 • heat, and will enter the cylinder at about the temperature of the steam in 

 the boiler. 



. Dr. W. Rowell remarked, that Waterman tried this plan several years 

 agoi He found the steam was reduced in temperature about twenty-five 

 degrees below thai in the boiler. Ilis present plan was to make the cylin- 

 der of steel plate one-tenth of an inch thick; this is braced by another plate 

 of the same thickness. Between the two plates are thin stays, about an 



