Some classes of engines have a single bar guide, with a crosshead of the enclosed type, three sides of which are babbitt lined. The crosshead is put in place on piston rod and guide and the babbitt poured in. I find it an advantage to coat the guide heavily with white lead before pouring the babbitt. This allows the crosshead to be removed with little trouble and requires but little scraping to get a good running fit. J. V. N. Cheney.
South Portland, Me.
The following is an excellent method of washing oily waste. The chief objection to most of the common methods employed is that the waste, after being dried, is found to be matted and of a hard, gritty texture. The common method of washing the waste, using sal-soda in solution, is a good one, as far as the cleaning qualities are concerned, but it leaves the waste hard and matted, so that it is difficult to handle. A simple remedy for this is to rinse the waste (after being cleaned in the sal-soda solution), in very hot water, to which has been added a quantity of liquid ammonia. This will render the waste soft and light when dry. T. E. O'Donnell.
The following mixture is one which can be used for making molds for rubber stamps, special shapes of rubber, or for complicated, odd, or queer-shaped patterns of small size, as the working must be done inside of ten minutes; the surface takes a finish as smooth as glass if well rubbed. If an impression is to be made, the surface of the type or article to be impressed should be rubbed with a solution of kerosene, and graphite. Plaster of paris, 5 pounds; French chalk, 2 pounds; china clay, 2 pounds; dextrine, ½ pound. Mix with dextrine water, which is made by dissolving 1 pound of dextrine in one gallon of water. Frank G. Sterling.
A valuable oilstone can usually be saved when broken, even if there should be several pieces. The pieces must first be thoroughly cleaned and all oil driven from the fractured surfaces by heating on a hot iron plate. After the surfaces to be joined are properly prepared, they are well dusted with powdered shellac and again heated until the shellac is melted and flows well into the joints. The heating should be done on a smooth metal plate and the stone kept from the flame; otherwise it is likely to crack in other places. Neither must it be overheated, for the same reason. When the shellac has melted, the parts are pressed together and clamped until they have cooled. A joint so made often lasts as long as the stone, and if carefully made leaves no mar in the cutting surface.
Chicago, Ill. O. M. Becker.
To remove the scale from cast iron use a solution of 1 part vitriol and 2 parts water; after mixing, apply to the scale with a cloth rolled in the form of a brush, using enough to wet the surface well. After 8 or 10 hours wash off with water, when the hard scaly surface will be completely removed.
Schenectady, N. Y. It. B. Casey.