How To Mark Tools

Coat over the tools with a thin layer of wax or hard tallow, by first warming the steel and rubbing on the wax; warm until it flows and let it cool. When hard, mark the name through the wax with a graver and apply some aquafortis (nitric acid); after a few moments wash oft" the acid thoroughly with water, warm the metal enough to melt the wax, and wipe it off with a soft rag. The letters will be found etched into the steel.

Varnish For Tools

lake 2 oz. tallow, 1 oz. resin; melt together and strain, while hot, to remove the specks which are in the resin. Apply a slight coat on the tools with a brush, and it will keep off the rust for any length of time.

Boiler Incrustation

The following remedies have been used, with varying success, to prevent the incrustation of boilers.

1. Potatoes, in weight one-fiftieth part that of the water, prevents the adherence of scale.

2. 12 parts of salt, 2 1/2 parts of caustic soda, 1/8 part of extract of bark, 1/2 part of potash.

3. Pieces of oak-wood suspended in the boiler and renewed 'monthly.

4. 2 ounces of muriate of ammonia in the boiler twice a week.

5. A coating, consisting of 3 parts of black-lead and 18 parts of tallow, applied hot to the inside of the boiler every few weeks.

6. 12 1/2 lbs. of molasses, fed into an 8-horse boiler at intervals, prevented incrustation for six months.

7. Mahogany or oak saw-dust in small quantities. Use this with caution, as the tannic acid attracts iron.

8. Carbonate of soda.

Non-Conducting Covering for Steam Pipes

Sawdust mixed with flour and water into a thick paste is a nonconducting covering for steam pipes, cylinders, etc. The flour should be made into a very thin paste, and then the sawdust is stirred in. The adhesion of this composition is very great when applied on clean surfaces of wrought or cast iron; but on copper pipes it is necessary to wash them first with a clay-wash, made with potter's clay, until it forms a thin coating, after which the sawdust and paste will adhere firmly. It is very simple to apply; a small trowel is all that is necessary. Lay on five successive coats one-fifth of an inch thick. Let the pipes or other objects to be covered be kept warm by the aid of a little steam, and let one coat be perfectly dry before applying a second. Should the pipes be outside, exposed to the open air, give them three or four coats of coal tar to make them waterproof, but if inside a building it is not necessary. It is well to pass the sawdust through a riddle to cleanse it from the coarse fragments of wood which are always to be found amongst sawdust. Steam pipes so covered lose less heat than when covered by any other known or patented process sold for that purpose.

It is much less expensive and much more efficient.

How To Harden Wood. Pulleys

Soft maple is often used in the construction of friction pulleys. If it is boiled in olive-oil it will prove beneficial in a number of ways. It will harden the timber and render it less liable to split, but at the same time the gear will slip more after such treatment.