Mica

The best comes from the Eastern States. New-York mica is good. Canada mica is of several different shades, from light brown to intensely black.

Extraction Of Odoriferous Oils From Plants

This can be done by glycerine. The flowers are introduced into the liquid and left for 3 weeks. The glycerine is then drained off, and may be dissolved in all proportions in alcohol or water to make perfumed liquids or washes.

Testing For Acids In Lubricating Oils

Dissolve a crystallized piece of carbonate of soda about as large as a walnut in an equal bulk of water, and place the solution in a Mask with some of the oil. If, on settling after thorough agitation, a large quantity of precipitate forms, the oil should be rejected as impure. As oils are often clarified and bleached with acids, which injure the metals on which they are used, this is an important point to know.

How To Dissolve Raw Hide

This can be done completely in water heated under pressure.

Fastening Beams In Walls

The usual custom of building the ends of floor-timbers into brick and stone walls is apt, in case of fire, to throw over the walls; and resting the timbers on corbels interferes with the cornice-line below. By cutting the ends of the timbers on a bevel and laying in the wall, as in the annex ed diagram, the cornice-line will not be broken; and, in case of fire, the timbers will fall with little injury to the wall.

Setting Beams In Walls

Blasting

In small blasts, 1 lb. of powder will loosen about 4-1/2 tons of rock. In large blasts, 1 lb. of powder will loosen 2-1/2 tons. 50 or GO lbs. of powder inclosed in a bag and hung against a barrier will demolish any ordinary structure. One man can bore with a bit 1 in. in diameter, from 50 to 60 in. per day of 10 hours in granite, or 300 to 400 in. per day in limestone. Two strikers and a holder can bore with a bit 2 in. in diameter 10 ft. per day in rock of medium hardness.

Bricks From Gas-Coal Ashes

These are of remarkable lightness, porosity, and dryness. The ashes, after being taken from the retorts, are spread on the surface of a clean floor; they are then finely pulverized, and 10 per cent of slaked lime, together with a small proportion of water, is intimately stirred and incorporated with them. After a rest of 24 hours, the mixture is made into bricks by the ordinary process. The bricks are immediately transferred to the drying sheds, where a few days' exposure renders them fit for use.

Preventing Effects Of Smoky Chimneys

A screen or blower of wire gauze, from 36 to 40 wires to the inch, placed in front of range or stove fires, will prevent, it is said, smoke coming into the room when the chimney fails to draw well.