Two nozzles are used on a water wheel of small diameter where high speed is required. The power of the wheel is thus doubled, though twice the amount of water is required.
Red sealing wax is made of pure bleached lac, to which, when melted, are added Venice turpentine and vermilion. Inferior grades are made of common rosin and red lead. Black and other colors are obtained by adding proper pigments. Sealing wax was known in the seventeenth century.
The silver coinage of the United States contains 900 parts silver and 100 parts copper, while that of Great Britain contains 925 parts silver and 75 parts copper.
Rubber boots are, at best, hot things for Summer wear, yet the farmer must either wear waterproof shoes or go with wet feet much of the time. An exchange gives the following recipe for waterproofing to apply to shoe leather: One pint boiled linseed oil, one half-pound fresh mutton suet, six ounces clean yellow beeswax, four ounces yellow rosin. Melt the ingredients and mix well. Apply when warm, but not hot, and rub into the leather. This recipe is said to be used by New England fishermen with perfect satisfaction. They often stand for hours in water without damp feet.
The use of chemically treated carbons is increasing in many of the leading cities of Europe. In this case the carbons are either impregnated with a solution of certain salts, or they are cored and the salts in a solid form are placed in the inside of the carbon. The Bremer carbon is one of the most successful of these systems, and it gives a very brilliant and at the same time agreeable light which has a mellow hue and is not as trying to the eye as the ordinary arc light. In this case the earbon is treated with a fluoride of calcium solution. Besides the advantage as to the quality of the light, it is claimed that the Bremer carbon shows the highest efficiency has yet been obtained for an arc lamp, or 0.1 watt per candle-power. This form of lamp is generally used with a tight globe. It runs on ninety volts in some of the standard lamps. The light which it gives is of a yellowish color.
Steam is produced as follows: Water, although a continuous mass, is made up of a multitude of drops. Each drop of water is an elastic shell containing a certain amount of oxygen (air.) If one will take a clean kettle and place it on an ordinary fire he will notice that as soon as the water begins to get warm at the bottom little bubbles begin to form. This is caused by the expansion of the air in the water. The expansion continues until 212° Fahr. (boiling point) is reached, when the bubble bursts, the heated and expanded air passes through the water to the top, and in such passage picks up more or less of the water and becomes vaporous, when you get an expanded vapor caused by the passage of heated and expanded air through the water. In this state it has less friction than the air when expanded. In English we call it steam; the Frenchman says vapeur; the German says dampf, hot, moist air. We say a steam carriage, the German says ein dampf wagon.
New York City is about to try the experiment of making its own electric light. The high charges of private companies have had something to do with the new departure, and an interesting experiment in the use of city garbage as fuel has helped. It has been discovered that the street-cleaning department was payiag to have material carried out to sea and dumped when that same material, burned under proper conditions, would furnish power for a large part, if not all of the city's public lighting. If this can be done on a large scale, material which has been a source of ex-pense will become a means of considerable profit.