CANALS AND RAIL-ROADS.
305
TABLE IX.
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Weight conveyed in cwls.
Distance in miles, being that which ahorse travels in a day.
Resistance upon a canal in lbs., takinga horse's power atll21bs.,and supposingthis force will drag a boat of 30 tons,at 2 miles an hour.
Resistance upon a rail-road in lbs., asper Table VIII.
Power which a horse can exert uponthe load, at the respective velocities,„ 224
front formula —
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Number of horses required to performthe work upon a canal.
Number of horses required to performthe work upon a rail-way.
! Ratio of the performance of horses,
with respect to work on canals andrail-roads.
2
800
20
150
418
112
1.3
4
4: 1.3
3
800
20
337
448
74§
4.5
6
6 : 4.5
4
800
20
600
448
56
10.7
8
18: 10.7
5
800
20
937
448
44j
21.2
10
10:21.2
6
800
20
1350
448
37i
36.
12
12: 36.
Prom this we find, that, when the rate ofspeed is about two miles an hour, the quantityof goods which a horse will convey upon acanal, is three times that which the same horsecan convey upon a Rail-road. And that,when the velocity on each is about 3 ^ miles anhour, the resistance of the canal increasing asthe square of the velocity while that on a Rail-road remaining the same, the two become equal;and a horse is then enabled to drag as muchweight upon a carriage on a Rail-road, as ina boat on a canal. When the velocity is fur-ther augmented, then the disproportion becomes
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