378 Feeding of Engine Boilers, &c. 
8. Feeding of Engine Boilers.—Thomas Hall, engine 
man to the Glasgow Water Company, having remarked the 
waste of fuel which occurred at those times when a steam 
engine stopped working, as at night, &c., was induced to 
alter his mode of feeding the boilers with water, with a view 
to prevent as much of this waste as possible. Instead of 
letting in a continual supply of water, equal to the portion 
converted into vapor, he took every opportunity, when the 
engine was stopped for a sufficient time, (30 or 40 minutes,) 
as at meal time, night, &c., of introducing water into the 
boiler to as much as 18 inches above its usual level, and it 
was continued to this higher level as long as the engine was 
rk bor was resumed, there was the 
an abundant supply of hot water in the boiler, the steam 
was ready, and no increase of fire to heat freshly introduced 
water, required. The saving which arose from this mode 
of management was 25 per cent. of the fuel. The appara- 
tus for feeding the boiler in this manner with accuracy, and - 
without trouble, is very ingenious, and is described in the 
Trans. Soc. Arts, xl. 127. 
9. Preservation of grain. &c., from mice.—Mr. Macdo- 
nald, of pa, in the Hebrides, having some years ag 
suffered considerably by mice ; put at the bottom, near the 
centre, and at the top, of each stack, or mow, as it was 
raised, three or four stalks of wild mint, with the leaves on, 
gathered near a brook, in a neighboring field, and never 4 
ter had any of his grain consumed. He then tried the same 
experiments with his cheese, and other articles kept 9 
store, and often injured* by mice; and with equal success, 
by laying a few leaves, green or dry, on the article to be 
preserved.—Phil, Mag. 
10. Yeast.—The following methods for making yeast for 
nd of good 
a pound of mashed potatoes, (mealy ones are best,) add two 
ounces of brown sugar, and two spoonfuls of common 
poo 
yeast, the potatoes first to be pulped through a cullender, 
