Smokeless Psowder

Since the advent of the speedy torpedo boat iind since rapid flring guns have been placed on battleships and cruisers an explosivo that would allow to the offlcers and gunners an unobstrncted view of an enemy under all conditions has beeu songht, and thonsands of dollars have been expended in the effort to obtain a satisfactory substituto f or black gunpowder. Cordite, the latest explosive, is said to be the most satisfactory propellant of modern times for naval warfare, and the expert opinión seems to be that in a few years gunpowder as now understood will have vanished. The earliest records of established powder milis show that there was only one in operation in 1590, this one being ín Kngland. During the year 1787 the Waltham Abbey Powder milis were purchased by the English government. They are still conducted by it. The Faversham milis, which up to that date were the largest in the world, passed into the hands of a private Corporation in 1815. The manufacture of powder was continued without much improvement, except in the efficiency of the grinding and mixing machinery, until about 35 years ago, the formula for black powder being saltpeter 75 parts, charcoal 15 parts and sulphur 10 parts, the whole forming a mechanical mixture and not a chemical compound. Smokeless powder, however, became absolutely a necessity, for the reason that smoke producing powders maskec the object aimed at, and the torped boat, which was becoming a recognizec feature of naval warfare, could dash u and discharge one or more deadly mis siles under cover of the smoke. Smokeless powders were first pro iuced in France, and for some time th secret of the manufacture was guardec jealously. As soon as the necessity fo this kind of powder became apparent bowever, a number of manufacturer ievoted attention to it, and as a resui rarious brands of smokeless explosive svere placed on the market. The most satisfactory results eventuilly made their appearance in cordite, ivhich was produced through experinents made by Professor Dewar and Sir Frederick AbeL Cordite is composed of ïitroglycerin 58 per cent, gun cotton 37 per cent and vaseline 5 per cent Nitrojlycerin is an oily, colorless liquid and in active poison. It is produced by mixng a quantity of sulphuric acid with dmost doublé the amount of nitric acid ind allowing it to cool. About oneilghth of the total weight of glycerin is then added gradually, the mixture be ing kept below a temperatura of 70 de grees F. by passing air and cold wate through it. Af ter the mixture has stooc a sufflcient time the acids are drawn off and the residuo (nitroglycerin) is wash ed and filtered. Nitroglycerin cannot be ignited easily by a fíame, and a lighted match or ta per plunged into it would be extinguish ed. It is sensitive to friction or percus sion, either of which will detonate it Another peculiarity is that the highe the temperature the more sensitive i becomes. It will solidify at a temper ature of 40 degrees, and its explosivo forcé is estimated to be about trwelve times that of gunpowder. One of the most approved method used in the manufacture of gun cotton Is this: The raw cotton is torn into shreds, dried and dipped in a mixture of sulphuric and nitric acids. It is then placed in a stream of running water and washed thoroughly. The cotton is then wrang out, usually in a centrifuga! chine. It is afterward boiled, dried, cut into pulp and pressed into disks. When the gun cotton is finished, there should be no trace of the acids remaining. Vaseline, the other component part of cordite, is the well known extract from petroleum, and its usefulness is chiefly to lubrícate the bore of the gun and thus lessen the friction between it and the projectile. It also has a tendency to impart a waterproof nature to cordita A color less liquid pre pared from acétate of lime, called acetone, is used as a solvent in the manufacture of cordite. The method of preparing the explosive is: The required proportion of nitroglycerin is poured over the gun cotton, and the two, with the addition of acetone, are kneaded together into a stiff paste. Vaseline is then added, and the whole compound, after being thoroughly mixed, is put into a machine and the cordite pressed out and cut into lengths, after which it is dried. To the artillerist the nature of cordite is represented by a fraction whose nnmerator gives in hundredths of an inch the diameter of the die through which the cordite has been pressed, its denominator being the length of the stick in inches. The cordite known as 80-12, which is the size used for the 6 inch quick firing guns, signifles that its diameter is three-tenths of an inch, and it is 12 inches long. It is necessary to use a fine grain powder to ignite a charge of cordite, it being secnred in such a marmer that a flash from the tube firing the gun will cause the explosión of the charge. A full charge of powder for a 12 inch gun is 295 pounds, while the cordite charge, having the same efficiency, is only 167} pounds. Cordite is one of the safest explosiyes known, and is not dangerous uniese it is confined. It can be held in the hand and lighted without danger. It burns slowly and with a bright flame. Although comparatively a new discovery, it is used extensively in every navy throughout the world. It was manafactured first in Great Britain and was in Reneral use on her battleshiüs before