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Description of a Patent Blowing Machine. 373 
-frain from sending you a short account of it, with a request that 
you will allow it, if possible, a place in your Magazine. 
I am, sir, most respectfully yours, 
Clifton, May 1, 1816. W. H. Gitpy, M.D. 
————— 
The engine itself is made of wood or metal ; and to have an 
accurate conception of its form, we have only to imagine a drum 
turned sideways, and in this situation to be supported a few 
inches from the ground by being connected at each end witha 
supporter, through the means of a pivot proceeding from the 
centre of the parchment ends, so as to fit into a corresponding 
hole in the supporter. In this situation by the help of a single 
lever it is made to turn to and fro in the segment of a circle. 
From the top of the vessel placed in this lateral position there 
descends about two-thirds the depth of the machine a partition 
board, cc, which being firmly attached to each of the ends as. 
well as to the top, and in this way made air-tight, serves to di- 
vide the interior into two compartments. At each end near the 
top there are two valves, one on each side of the partition board. 
At one end they open outwards, and at the other inwards, con- 
sequently the use of each set of valves is different. The lower 
part of the vessel is occupied by water, which is made to rise a 
little ubove the bottom of the partition board. 
Having given this explanation of the construction of the vessel, 
we have now to enter into the description of its operation.— 
Having said that the machine, when in action, moves to and fro 
in the segment of a circle, it is quite evident, whichever way it 
turns, that the water will always remain at whatever part comes 
to bethe bottom. The vessel in fact will move round the water. 
Such being the case, to whichever side the vessel moves, or in 
other words, whichever of the two compartments comes to be 
lowest ; it is manifest, that the air included in that compart- 
ment will be powerfully compressed by the partition hoard de- 
scending towards the fixed body of water, and will be’forced with 
a blast proportionate to the weight of water through the valve 
_ into a pipe. Upon the re-ascent of this compartment the same 
operation will take place in the other, while at the same time 
the air will again rush into the former by the valve opening in- 
wards, In this way, by the rotation of the engine to and fro, 
the air will be alternately discharged from each compartment, 
and a vigorous and almost constant blast will be maintained. 
I say almost constant, for while the vessel is in the act of turning 
after the expulsion of the air from the compartment, it is ob- 
vious that there will be a momentary suspension of the blast. 
This inconvenience is obviated, and at the same time a great 
accession of blast is obtained, by using two engines, which by 
Aas machinery 
