50 



WATER BLOWING MACHINE. 



It is a thort ba- 

 rometer gage 

 inferted, the 

 fluid being 

 water. 



county of Foix, and is a particular kind of barometer, to 

 which the name of water anemometer has been given. See 

 Fig. 6. " 



It is compofed, lft. of a cylinder A; 2d. of a tube c, 

 bent twice, the lower extremity of which is flightly conical, 

 and terminates about two inches below the bottom of the 

 cylinder; 3d. of a graduated tube d inferted in a vertical 

 pofition into the cylinder, and reaching below the level n 

 of the water contained in it. 



The tube c being inferted into an auger hole made in the 

 fide of the blowing machine, and flopping that hole clofely, 

 the internal compreiled air communicates with the water con- 

 tained in the anemometer, prefles upon it, and in proportion 

 to its denlity raifes to a lefs or greater height in the graduated 

 tube. 



The cylinder A and the tube c are of tin. The lower part 

 of the tube d to the height of nine inches is of the fame ma- 

 terial, to which is fitted a glafs tube about 36 inches long. 



The cylinder A is four inches high and as many in diameter. 

 The greateft diameter of the curved tube is half an inch, the 

 fmalleft, at the extremity, a third of an inch. On obferving 

 however, that the fize of this opening contributed to increafe 

 the extent of the ofcillations in the graduated tube, we en- 

 deavoured to diminim it as much as poffible. For this purpofe 

 we clofed the lower part of the tube v with fealing wax, in 

 which we afterward made a very fmall aperture by paffing a 

 heated needle through it. 



The tube d was divided by a fcale of inches, beginning 

 from the furface of the water contained in the cylinder *. 



.Experiments X 

 with the blowing 



.machine. 



ACCOUNT OF THE EXPERIMENTS. 



Experiments relative to the Expenditure of Water, and the 



Quantity of Air difengaged. 



The blowing machine No. 1, fee the horizontal proje&ion, 

 Fig. 1 . to which for the fake of clearness we (hall refer our 

 different experiments, ferved for the trial. It was placed in 

 a T, oppofite the machine No. 2, deflined for the fame pur- 



* The great difference between the diameter of the tube d, and 

 that of the cylinder A allows the level n to be confidered as con- 

 stant. 



pofe. 



