512 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



was Stirling's. Mr. Cowper has one in England which heats the 

 blast to 1,300 deg. It had occurred to him that one of Cowper's 

 regenerators might be used advantageously on the caloric engine. 



Mr. Koch stated that one pound of coal would give about ten 

 per cent as applied to the best of coal engines. (?) 



Mr. Babcock said that after making all his deductions for fr-ic- 

 tion and loss by expansion, etc., he had found that there was a 

 saving in favor of the air engine of 25 per cent. One properly 

 constructed using air at high pressure of not less than 10 atmos- 

 pheres, ought to give this result. He proposed to use compressed 

 air, and not to be obliged to compress the air at each stroke. 



Mr. Koch said they had no mechanical means of getting so 

 great a degree of compression. 



Mr. Babcock stated that in all his calculations he had allowed 

 50 per cent for loss in the furnace, and 50 by friction. (?) 



Mr. Bruce read a paper, stating that he had seen in the World 

 of November 5, a cut representing Hoe's ten cylinder press, and 

 read a portion of a very elaborate article upon the history of 

 printing. He (Mr. Bruce,) claimed that Mr. Hoe's press was but 

 an improvement of a cracker machine which he had invented as 

 early as 1826. 



Mr. Babcock said Mr. Hoe was not the first man to use a press 

 with type on the cylinder. 



Mr. Barnes said that one with the type on the rolling cylinder 

 was invented before the close of the last century. 



PRESERVATION OF WOOD. 



Mr. Bruce said it was stated at the Farmer's Club that immers- 

 ing wood in sulphuric acid would preserve it. It was also stated 

 at those meetings that wood so immersed had been preserved for 

 12 years. 



Mr. Dibben said he occupied premises where they were manu- 

 facturing soda water. Small quantities of the acid used to fall 

 on the floor and his benches, and wherever they were touched by 

 it they were completely destroyed, and the ceiling fell out alto- 

 gether. One of his tool handles also got saturated with it, and 

 it shared the same fate as the ceiling. From these facts it was 

 clear to his mind that it was deleterious. 



Mr. Veeder wished gentlemen to state how far creosote could 

 be used for the preservation of wood. In Ohio, on the railroad, 

 midway between Pittsburg and Cleveland, there is a coal yard 

 where they can produce 500 gallons per day of crude coal oil. 



