<J50 machine for sweeping chimnies. 



but the term blowing afTociates only with the accuftomed notion 

 of the adion of wind, and was the etTed to be produced by 

 the agency of fteam ; the terra blowing would more eafily be 

 difmiHed, and we might call the action driving it along. 

 The term fweep- When we aHociate this agency of the wind with its effe£l 

 ing IS in fomc ^^ ^ ^^j^ ^f ripening corn, we conceive of it fiveeping along 

 exprefs the or over the corn; and the fame efTedl would follow, were we 

 adtion of wind, jq conceive of a large brurti of long hair carried on the tops of 

 corn; fo that however popular expreflion, or the prejudice of 

 cuftom may operate to diftinguith the caufes producing the fame 

 ^ffefti it becomes us to waive fuch diftindions, and admit the 

 efficiency of the one as much as the other. 

 Inftances of the I haveobferved that when a door has been fuddenly opened 

 aftion of wind ©r fhut, it has brought down foot in a chimney which has a 

 iluggifh draft; or a piece of paper accidentally thrown on the 

 fire has had the like effed; and this by a momentary accelera- 

 tion of the current of air in the flue. What then will not fuch 

 a machine as this perform, with fuch a volume of air, with 

 fuch a velocity. 

 The air machine One circumftance prefents itfelf, by which the air machine 



fweeps chimnies ^^ ^^^^ ^ decided pi^ference over the bruthes; which is this, 



of all heightg, . 



and is durable, you muft know the heiglit of the chimney, and adapt the length 



of the rods to that height, or elfe you will not know when you 

 are in the flue or out of it. Whereas my machine knows no 

 neceflTity for fuch a pun6lilio; all that is necefl^ary being only to 

 give fo many ftiocks of the condenfer to a chimney of two 

 -ftories, and fo many to one of three, and fo on. And again, 

 thefe bruflies in the very outfet of trial made with them, are 

 fubjeft to accidents, and will moft aflfuredly wear out very faft. 

 What mufl: become of thofe whalebone rods when the fewing 

 is rubbed through in pafliing up and down againft the projec- 

 tions of unceremonious bricks and mortar? What repairs will 

 they not be fubje6l to in the courfe of one day's adlion? Whereas 

 the air machine wilt fweep a hundred chimnies, and be repaired 

 for two-pence; it wanting only a little oil in the condenfer. 

 It was tried at When this machine was carried to the Adelphi, it came to 

 the Adelphi be the third in courfe for the trial, and it was ordered down, 

 upon chimneys ^ j^ j^e foundation of thehoufe, for fear a chimney fliould 

 that coatameo no . , . , , . , - /• .. i -i i- 



foot. not be found high enough in any other part of the build mg.— 



But when it was brought, behold there had been two fweepers 



already, which obliged me to apologize for the machine, by 



^f ■ ' V obfervjng 



