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architect may improve his principles by studying the pillars 
and supports of the human skeleton, and the skeletons of the 
lower animals. The most perfect arch is contrived in the 
human foot, and no artificial system of fortification can equal 
in perfection that of the spine and skull appertaining to 
animal life. The pullies, joints, and hinges of living struc- 
tures, are inimitable in their construction. The hydraulic 
and pneumatic principles of animal life are destined yet, I 
trust, to teach us much which may be of the utmost im- 
portance to the interests of mankind. 
It was from reflecting somewhat on these subjects that 
I took up the idea that ventilation generally might be 
rendered more perfect and effective, and that large cities 
and towns might be better, and with more facility, sup- 
plied with pure fresh water. I have got this very rough 
and imperfect instrument made by a common mechanic,* 
which combines, as it were, a pneumatic and hydraulic 
principle in conjunction, and which I intended for the 
purpose of showing how fluids may be easily lifted into 
any position, independently of their tendency to find their 
level under ordinary circumstances. Thus, by working 
this small exhausting syringe, and withdrawing the air 
from the first compartment of this zinc tube or pump, the 
water in which it stands in the basin immediately rises, to 
occupy the spaces vacated. And thus, by successively 
exhausting all the air of the several compartments into 
which this tube is divided by three or four valves, the 
water at length rises to the top, and by turning this stop- 
cock, flows out. 
Now if this tube was a mile long, or a hundred miles, or 
even encircled the globe, the whole of its contents, to the 
furthest extremity, would be moved forward by simply con- 
tinuing a process of exhaustion at its commencement ; and 
* Dr. Bodington exhibited the instrument alluded to, to the meeting. 
