348 Mr Carmichael on Water as a Moving Power , §c. 
dated 13th September 1824, as the most eligible under present 
circumstances. 
The area of the loch is about seven miles, and suppose the 
mills require a supply of 3000 cubic feet per minute, and that 
the rivulets and springs which empty themselves into the loch 
be one- third of the supply, then a steam-engine going night 
and day, Sundays excepted, would be upwards of 120 days, or 
nearly five months in reducing the loch 2 feet in perpendicular 
height. I have supposed the engine to go night and day ; per- 
haps experience would admit of a little less, without injury to 
the mills. 
A steam-engine of fourteen horses’ power would lift upwards 
of 3200 cubic feet in a minute to a height of 3 feet * * ; but as the 
loch is upwards of 300 feet above the level of the sea, it fol- 
lows, that, after the water is raised 3 feet, it must fall 300, and 
by this means gain more than 900 horses’ power. 
If we take the data as given in the last Number of the Jour- 
nal, the above quantity of water falling 800 feet, would be up- 
wards of 2000 horses’ power, which is a temptation sufficient to 
induce the most parsimonious mill-masters on the Leven to go 
into the measure of supplying themselves by such simple means. 
But to make the matter appear in a still more clear point of 
view, it may be stated, That the employing of a fourteen horse 
steam-engine to lift water out of the loch, will make every foot 
of fall on the river equal to three horses’ power *J-. 
* More exactly 26 inches. — E d. 
*f* The term Horse-power , used in designating the force of steam-engines, ia 
merely conventional, the action of one horse being considered as equivalent to the 
raising of 32,000 pounds of water to the height of a foot in the space of a minute. 
