Recipe for Making Instantaneous Ink and Stain Extractor.—­Take of chloride of lime 1 pound, thoroughly pulverized, and 4 quarts soft water.  The foregoing must be thoroughly shaken when first put together.  It is required to stand twenty-four hours to dissolve the chloride of lime; then strain through a cotton cloth, after which add a teaspoonful of acetic acid to every ounce of the chloride of lime water.

Wood, which is a more unyielding material, acts with tremendous force when wetted, and advantage has been taken of this fact in splitting blocks of granite.  This process is largely adopted in Dartmoor.  After a mass of granite has been rent from the mountain by blasting, it is measured in every direction to see how best to divide it into smaller blocks.  These are traced out by straight lines on the surface, and a series of holes are drilled at short intervals along this line.  Wedges of dry wood are then tightly driven into the holes and wetted, and the combined action of the swelling wood splits the block in the direction required, and without any destructive violence.  The same process is then carried out upon the other faces, and the roughly-shapen block finished with the hammer and chisel.

The Weight and Value of a Cubic Foot of Solid Gold or Silver.—­A cubic foot of gold weighs about 19,300 ounces, and gold is worth $20.67 per ounce.  Silver is worth $1.29 per ounce, and a cubic foot weighs 10,500 ounces.  Consequently the cubic foot of gold would be worth $398,931, and the silver $13,545.

To Remove Spots on Brass.—­Sulphuric acid will remove spots from brass that will not yield to oxalic acid.  It may be applied with a brush, but great care must be taken that no drop of the acid shall come in contact with the clothes or skin, as it is ruinous to garments and cuticle.  Bath brick or rottenstone may be used for polishing.

A Formula to Make a Good Shoe Dressing.—­Gum shellac, 1/2 pound; alcohol, 3 quarts; dissolve, and add camphor, 1-1/2 ounces; lampblack, 2 ounces.  The foregoing will be found to give an excellent gloss, and is especially adapted to any leather, the surface of which is roughened by wear.

Receipts for Dyeing Cotton Fabric Red, Blue and Ecru.—­Red:  Muriate of tin, two-thirds cupful, add water to cover goods; raise to boiling heat; put in goods one hour; stir often; take out, empty kettle, put in clean water with Nicaragua wood one pound; steep one-half hour at hand heat, then put in goods and increase heat one hour, not boiling.  Air goods, and dip one hour as before.  Wash without soap.  Blue:  For three pounds goods, blue vitriol 4 ounces; boil few minutes, then dip goods three hours; then pass them through strong lime water.  Ecru:  Continue the foregoing operation for blue by passing the goods through a solution of prussiate of potash.

MOTION OF WAVES.—­The progressive motion of a wave on the water exactly corresponds in speed with that of a pendulum whose length is equal to the breadth of the wave; the same law, gravity, governs both.