426 Different “ Rates” of Pennington’s Astronomical Clock, 
As there is not a shadow-of doubt but that an able-bodied 
man can in this way exert the power of a horse, I should not 
despair of seeing, were I to live but a few years longer, carriages 
of every description travelling the public road without the aid of 
horses. For mill-work of every kind this mode of working will 
have a decided advantage over animal power. In the first place, 
it will not require a twentieth part of the space; in the second 
place, not a tenth part of the expense of machinery; and lastly, 
it will save all the original cost of the horses and their daily 
decrease in value :—the space required for four men to work in, 
need not be more than four feet square, and the expense of the 
machinery will not exceed five pounds: _ But the most extensive 
application of this principle 1 look for in navigating vessels. 
When we take into consideration the immense expense of a large 
steam-engine, the space “it occupies, together with the fuel to 
work it, and the combined danger of fire and its blowing up, no 
prudent man would hesitate which he would adopt. In the 
fisheries it would be particularly useful. The fishing-vessels could ” 
go out and return at pleasure, so as always to bring their fish 
fresh to market, to say nothing of the facilities it would afford of 
dragging their nets. 
I am, dear sir, very faithfully yours, 
65, Halford Place, May 29, 1819. EDMUND CARTWRIGHT. 
LXXI. On the different “ Rates’ of PENNINGTON’s Astrono- 
mical Clock, at the Island of Balta, in Zetland, and at Wool- 
wich Common, Kent; with comparative Tables, and Remarks 
upon the Results of various other Pendulum Experiments. 
By Ottyruus Grecory, LL.D. of the Royal Military Aca- 
demy ; Honorary Member of the Literary and Philosophical, 
and the Antiquarian, Societies of New-York; of the Literary 
and Philosophicat, and the Antiquarian, Societies of New= 
castle-upon-Tyne ; Corresponding Associate of the Academy 
of Arts, Sciences, and Belles Lettres, at Dijon, &c. 
I; was my original intention to postpone the publication of. any 
account of the experiment with Pennington’s' astronomical clock 
in the Zetland Isles, till after 1 had ascertained its “‘ rate’’ at 
Dunnose, and some other stations to which it was proposed to 
take it ; but, as circumstances which I need not now explain, pre- 
vented me from taking the clock to Dunnose last summer, and - 
continue still to operate in the same way, I do not conceive it 
would be right to wait till the series of proposed operations with 
the clock is completed, before I put the public in a capacity to 
judge 
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