Every railroad wreck that has as one of its horrors the burniug to death of imprisoned passengers, calls attention afresh to the steel car and the larger place it must take in the construction of passenger as well as freight cars. The resistance of steel to the terrific impact of the train recently derailed at Mentor, Ohio, might have saved a number of lives. Certainly with steel cars there would have been no kindling pile and no charred bodies. The purchase of steel cars for the New York Subway was prompted chiefly by the desire to make the best provision against fire, derailment and collision. The latest of the tube railways in London is equipped with steel cars for the same reason. It would seem that the large death list from fires on steamers, in public halls, hotel buildings and in railroad wrecks in the United States in the past eighteen months have given sufficiently terrible emphasis to the need of a larger use of non combustible materials for buildings, cars and vessels.

By resistance, eleetrically speaking, is meant something placed in a circuit for the purpose of opposing or resisting the passage or flow of the current in the circuit or branches of the circuit in which it is placed.

Intense cold, as is well known, burns - if we may use the term - like heat. If a "drop " of air at a temperature of 180° below zero were placed upon the hand it would have the same effect as the same quantity of molten steel or lead. Every one who has the care of horses ought to know the pain inflicted by placing a frosted bit in a horse's mouth. It burns like hot iron.

Heating the feed water of a boiler will save from 25 to 30 per cent of the fuel. A good heater will utilize the exhaust of the engine, which will raise the feed water almost to the boiling point.

At sea level the rending force of black powder is deemed better for coal mining than dynamite, the former breaking it into convenient shape, the latter tending to waste by shattering it into dust.

The Atehison, Topeka & Santa Fe Ry. is making a series of experiments with an oil burning locomotive on its lines in Kansas. A very heavy crude oil which, it is claimed, cannot be refined, is being used. Particular interest is attached to these tests because of the fact that this company has mines of coal from which it gets very cheap fuel for its lines in Kansas, and if the oil proves to be cheaper and safer in this case, it will have a large influence in extending its use for locomotives in other parts of the country.

What must surely be the oldest steam-engine in the world is described by a correspondent of the American Machinist. It was still working, when the writer came across it in 1899 or 1900, at the Douglas Bleach-field, Forfarshire, and was considered by experts to be one of the best examples of Watt's earlier work. It was originally built for a Newcastle firm, and after many years' work was sold into Scotland in 1797, where it saw a hundred years of active service. The fittings of the machine include a good deal of leather and buckles, and a quaint story was told of a machinist who was once called in to do sonic repairing on it, in the absence of the usual man. This man thought he would be all right if he took a hammer, a monkey wrench and a chisel with him. When he saw all the straps, harness, buckles, etc., he called up the superintendent and said to him, " Hi, mister, it's a saddler you want, and no an engineer, for this job!" The machine is now enjoying a well-earned retirement at Dundee.

According to documents found in the archives of Genoa, the discovery of America by Columbus cost a little over $7000. The fleet of Columbus was worth about $3000. His salary was $200 a year.

When a column of liquid is heated at the bottom,, ascending and descending currents are produced. It is by these that heat is mainly distributed through the liquid and not by its conductivity. These currents arise from the expansion of the inferior layer, which, becoming less dense, rise in the liquid, and are replaced by colder and denser layers. The mode in which heat is thus propagated in liquids and gases is said to be by convection.

Red lead, the most important of the oxides, is made by heating litharge in a reverberating furnace, the metal's color being changed thereby from yellow to red.

The Bessemer process of steel making was invented in 1856, but it was not until 1876 that open hearth steel has been introduced.

The operation of producing liquid air is, air compressed to 1200 to 2000 pounds to the square inch; passed into receptacles where it is purified by separating the moisture, oil, etc., and passed thence into expansion chambers and through coils of pipe of considerable length. During the process it becomes intensely cold, reaching finally 312 below zero, at which point it becomes liquid. It is drawn off into insulated vessels, where it is kept for days, gradually lessening in quantity until it is entirely evaporated.

Kerosene is the main product of the distillation of petroleum, the crude domestic oil yielding up to 75 per cent of its weight in kerosene.

A good mixture for use as a slush to prevent the rusting of machinery is made by dissolving one ounce of camphor in one pound of melted lard; skim off the impurities and add enough black lead to give the machinery carefully, smear on the mixture. It can be left indefinitely, or if wiped off after twenty-four hours will prevent rust for some time. When removed tho metal should be polished with a soft cloth.

Carborundum is the result of the fusing of coke and pure silica (quartz) in the electric furnace, and is at present only done in the United States at Niagara Falls.

Concentrate ! A one inch stream at close range is more disastrous than a three inch torrent at one hundred yards.

Henry S. Pritchett, president of the Massachusetts Institute of Technology, says: "To the great essential qualities of character, which good men must have - energy, sincerity, devotion, moral courage, unselfish purpose - must be added that rarest of all human endowments which we call common sense; that is, the ability to think straight, the power to see both sides of a question."

If the devious and important processes of painting putty plays an indispensable part. It comprises the material and process of making good the existing defects of wood and metal, and without it the painter would find himself in a sorry plight. It may be said, in good truth, that there is positively no limit to the putty mixing formulas in use, but for ordinary purposes of an average grade of work, the formula next following is probably best adapted: Dry white lead, three parts; bolted whiting, one part, mixed to the proper working consistincy in equal parts of quick rubbing varnish and coach japan. Some thoroughly good painters prefer to vary this formula to the extent of omitting the whiting. In either case the putty may be accepted as reliable, if kneaded completely and worked out in mass fine and smooth. Such a putty under proper drying conditions should sandpaper clean and without tearing up in texture at the expiration of 48 hours. A slower but more elastic putty is made of three parts of oil ground lead and two parts of dry white lead, mixed in elastic rubbing varnish and gold size japan.

Meerschaum is a mineral of white or grayish color and is a hydrous silicate of magnesia. It is of soft, earthy texture, has the appearance of chalk, has a hardness of 2.5 and a variable specific gravity, very

, as when dry it will float on the water. can be made in it by the finger nail and smooth feel. The principal source of the min-eral is Asia Minor, where it occurs in vein form and mined at places from pits and horizontal galleries in a much similar way to coal. When first brought to the surface it is white with a yellowish tint, and is covered with red clayey soil. It is sold as brought from the mine. Its only treatment is in cleaning and drying, which takes place in the open air in summer time, requiring five or six days of heat to perfectly dry. Meerschaum has been found at a few places in the United States, but sparingly in each instance. It has been found in serpentine quarries in Chester County, Pennsylvania, in Delaware County, Pennsylvania, and at Richmond, Massachusetts, and in Utah and New Mexico. Its main use is in the manufacture of pipes and holders for tobacco smokers. The heavier mineral is the most valuable. Meerschaum of very light weight is too porous for producing the best pipes. Meerschaum is a most valuable commodity, and a deposit located anywhere in the United States would be of much value.