HEAT BY A BLAST FROM BELLOWSi '^[^ 



To thofe who confult an Encyclopaedia for fcientific matter, 

 Ihefe publications are of indifpenfable utility, by continually 

 pointing out the numerous improvements as they become pub-- 

 lie, and by that means the general fyftem of philofopliical 

 knowledge is kept to the level of the exifting fta'e of dif- 

 eovery. 



To the mechanic a repofilory of this kind muft be highly 

 ufeful, as the receptacle in which he may record his labours 

 and improvements, and fecure to himfelf the well-earned fame 

 of nis difcoveries, at the fame time that he derives advantage 

 from others following his example in their contributions to the 

 general fund of fcience. 



In fiiort, there is no clafs of individuals but may profit 

 from this method of extending ufeful knowledge. The fmall 

 fum of feven-pence or eight-pence a week to any economical 

 perfon is trifling, and there is no doubt but every enquirer 

 will find fomething of which he may abridge himfelf, in order 

 to become poflefled of fuch an afiemblage of fafts and opinions. 

 He is as it were making himfelf intimate with a clafs of men 

 whofe names will be read with admiration by a grateful polte- 

 rity. It is only by familiarizing the mind with the fublime 

 objefis of fcience, and diffufing them over the face of the 

 earth, that we can expelS^ to eftablith that fpirit of philan» 

 thropy and focial order, which is fo neceflary to the happinefs 

 of the human race. 



I will leave it to your judgment to abridge, or cancel the 

 whole of this paper, as it would perhaps exclude more va^ 

 luable fubjeds. 



I am. Sir, 



With the greateft refpeft. 



Your very humble fervant, 



RICHARD WINTER. 



21, Bolfover Sireei, 

 DecU, 1805. 



The following experiments were made in order to afcertaln The thermonje- 

 whether a current of air proje6ted upon a thermometer would ^,'^l^f^^ ^l ? 

 increafe or diminifli the temperature. I made ufe of a pair lows, 

 of common bellows, the contents of which, when opened, 

 were 95 cubip inches j the di^ipeter of the end of the pipe 



was 



