52 WATER BLOWING MACHINE. 



Confumptlon of Now the breadth of the channel employed is 3 feet, 6 

 water. inches, and we obferved, that the current, the velocity of 



which we have given, is J 8 inches 9 lines deep. Hence we 

 may conclude, that the confumption of water by the ma- 

 chine, under the circumftances above mentioned, is 173 

 cubic feet in a minute, the height of the column of water in 

 the inftrument being 26 inches. 

 Quantity of air From the method defcribed in the Hydrodynamics of Boflut, 

 emitted. we ca I cu l a ted the quantity of air which this mafs of water 



caufes to ifTue from the machine in a given time. This 

 quantity of air was found to be 7.35 cubic feet in a fecond, 

 or 441 in minute *. 



II. Experiments on the Effect of the Air-Holes. 



Effe& of the 1. On (lopping the four air-holes, the water in the tube of 



air-holes afcer- tne j n ft rum ent defcended to nine inches, and ofcillatcd very 

 tamed by ex- . 



periment. little. The effiux of the water from the machine acquired a 



velocity fufficient to diminifh the depth of the water in the little 



channel C, Fig. 1 and 2, near the T, fix inches. 



2. One of the air-holes being opened, the water in the 

 tube ofcillated between 22 and 24? inches. The mean = 23 

 inches. 



3. A fecond air-hole being opened, the mean height of the 

 water in the tube was 25 inches. 



4. A third air-hole being opened, the columns of water in 

 the tube rofe to its former height of 26 inches. 



5. The fourth hole being opened, no perceptible altera- 

 tion in the inftrument took place, which proves, that this hole 

 has no effect on the machine. 



III. Experiments on the life of Cmffes placed at the fuperior 

 Orifice of the Machine, 



ther crofs Some iron-matters are accuftomed to place two round bars 

 bars in the top * n the form of a crofs at the upper orifice of the funnel of the 

 ofthetubete machine. Xhefe they imagine increafe the effeft of the 

 machine by dividing the water at the moment of its fall. 



Cylindrical bel- * If tnefe ^^^ be compared with thofe of the cylindrical bel- 

 lows of Namur lows of the country of Namur, defcribed by Cit. Bailbet, in No. 16*, 

 give more air f t h e Journal des Mines, it will appear, that, to give out an equal 

 with lefs water. quant j tv f a ; r> the quantity of water expended by the blowing 

 machines, with a fall more than twice its height, is nearly double 

 that employed to move the cylindrical bellows. 



To 



