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V. The Syphon applied to the JVorm Tub as a Refrigerator; 

 or, A Plan for conveying Water in any Quantity to a 

 IVorm Tub of the largest Dimensions, if perfectly Air 

 tight. By Alexander Joiinstosj, Engineer*. 



A. -C iG. !2. Plate II. The feed pipe of cold water, 



B. The hot water, or waste pipe, the end of which must 

 be about two feet lower than the teed pipe, to make it act 

 with full effect. 



When VGU commence work, you must shut the cocks, 

 and fill the tub through a hole at top, and, of course, both 

 pipes, and, when full, stop the hole at top, and open the 

 cocks together; the water will then commence running, and 

 continue as long as the supply holds good, as it acts in every 

 respect on the principle of a syphon. 



By this means pumps, horse mills, and other machinery, 

 are rendered unnecessary for that purpose. 



The application of this improvement is simple, and exe- 

 cuted at a very little expense. The saving, I think, may be 

 calculated at upwards of one hundred horses per annum, for 

 the city of Dublin alone. 



I have executed one for Nicholas Roe, esq. Marybone- 

 lane. 



Alexander Johnston. 



Dublin, July fi, 1803. 



\l. Description of a Cometarium invented by 

 Ez. Walker, Esq. 



To Mr. Tilloch. 



sin Lynn, Jan. 21, IHOG. 



1 HAVE lately constructed a cometarium, which produces a 

 more beautiful effect than anv instrument of the kind that I 

 am acquainted with. It is founded on a property of the 

 convex lens, that I do not remember to have seen taken 

 liolice of by any writer on optics ; and thinking that it may 



• Fropi Traiisa(.lu/is af ihe Diiilin Suiiety, vol. iii. 



C: 3 afford 



