me to the action of the oxy-hydrogen blowpipe, or the lime may be placed in the flame of a spirit-lamp fed by a jet of pure oxygen gas.
Drummond's apparatus was so constructed that the lamp fed itself automatically with spirit and with oxygen, supplying itself with balls of lime as they were gradually consumed, and was provided with a parabolic silvered copper mirror.
With this apparatus the light produced by a ball of lime not larger than a boy's marble, at Londonderry, was visible at Belfast, a distance of nearly seventy miles, in a direct line.
Subsequently, Colonel Colby made a lime-light signal visible from Antrim, in Ireland, to Ben Lomnd, in Scotland, a distance of ninetyfive miles in a straight line.
It is stated that, intensified by a parabolic reflector, it has been observed at a distance of 112 miles.
It is understood that the first application in practice was when it was required to see Leith Hill, in Surry, from Berkhampstead Tower, in Hertfordshire.
6. Diamond weight and pearl weight, including the carat.
7. Avoirdupois weight.
8. Weights for hay and straw.
9. Wool-weights; using as factors 2, 3, 7, 13, and their multiples.
10. Coal-weights, decimal numbers 1, .5, .2, .1, .05, .025.
Besides these the gramme, etc., of French metric system, are used by many scientists.
There are also ten different stones.
A stone of wool at Darlington is 18 pounds.
A stone of flax at Downpatrick is 24 pounds.
A stone of flax at Belfast is 16 1/4 pounds, and also 24 1/2 pounds.
The hundred weight may mean 100, 112, or 120 pounds.
A pound weight varies in the avoirdupois and the troy.
Weights for small scales are nest, cup, ring, or disk.
One in which the rest is held down firmly on the shears by a suspended weight.
（Founding.) When the flasks in which a mold has been made cannot be held together by cotters, glands, or clamps alone, the top part has to be held down by weig<