Illustrated articles on topics of timely interest are solicited for publication. Those that are short and accompanied with good photographs will receive special attention. Accepted articles will be paid for at regular space rates.

Don't loaf.

Look for good, not evil.

Keep your eyes open and your mouth shut.

Do just as much as you can do well, no

more.

A man who never makes mistakes never makes anything else.

You will never find time for anythingif you want time, you must make it.

Take pride in the hard, consistent, straightforward, and uncompromising effort which has been stamped as "the strenuous life."

You cannot prevent the birds of the air from flying over your head, but you can prevent them from building their nests in your hair.

Electrification of a Steam Railroad

FLSEWHERE in this issue will be found an interesting description of the remodeling of the Grand Central terminal in New York City, which, when completed according to the plans outlined, will undoubtedly be one of the most important and best equipped of railroad terminals ever built. It is also of interest to note that in connection with this great engineering work electricity is to be one of the most important factors. Electric locomotives will be used exclusively for the operation of all suburban trains, and for a distance of 34 miles on the main line of the New York Central & Hudson River Railroad and 24 miles on the Harlem division of this road.

The fact that trains have hitherto entered New York City through a long tunnel, is one of the strongest arguments for the use of electrical propulsion, as there is to-day a growing feeling among engineers that electric power is the only safe power to use in tunnels or subways. Where ventilation is not very

thorough, the fumes from steam locomotives endanger the lives of passengers, while escaping steam has caused serious accidents by obscuring signals.

The first of the new electric locomotives built for this service was given an official trial a few weeks ago. It has four driving axles, each of which carries the armature of an electric motor mounted directly upon it; and the motors have a normal rating of 550 horse-power. This makes the total rated capacity of the locomotive 2,200 horse-power, although for short periods it is capable of developing considerably greater power than this. It is of interest to note that this is more powerful than the largest steam locomotive in existence.

The heaviest trains which are to be handled by electric locomotives weigh 875 tons, and are drawn at a maximum speed of from 60 to 65 miles per hour. For hauling these heaviest trains, two locomotives are coupled together; and, when so coupled, the method of electrical control is such that they can be operated by a single crew from either locomotive, only one controller being used to actuate all the motors on both locomotives.

On the trial trip a maximum speed of 63 miles per hour was attained with an eight-car train; and with a four-car train, 72 miles per hour was reached. Both of the trains were still accelerating at these speeds, but the length of the track electrically equipped did not permit of reaching higher speeds.

The electrical system which is being adopted by the New York Central is, however, applicable only for terminal purposes or over limited distances, as the low voltage of the current used entails a cost for electrical conductors and sub-stations along the line of the road which would be prohibitive if extended over great distances. But the fact of electricity being used in such heavy and severe service is no small triumph of electrical engineering; and it is not improbable that the experience of steam railroad men with this flexible, powerful, and cleanly motive power may pave the way for the adoption of high-tension alternating current systems which will be able to operate economically over very long distances.

Growing Use of Steam Turbines

TWO years ago the steam turbine was

hardly considered in connection with large power plants, although this was one of the earliest suggested forms of steam engines. Turbines of the Parsons type, having an extremely high velocity of rotation, and using gearing to reduce this to practicable speeds, have been in use for some time to a limited extent, for special applications; but, within a comparatively few months, turbines having several stages and operating at comparatively low speeds have been perfected and introduced to such an extent that they have already brought about considerable modification in the design and arrangement of steam plants.

One of the most noticeable features in a turbine plant is the relative size of the turbines and reciprocating engines of the same capacity. The floor space occupied by a large crosscompound engine would be sufficient for three or four times its capacity in turbines, and this saving in space means considerable in the case of plants located at cities where real estate is very valuable.

Another modification due to turbines is the very noticeable increase in the pressure and temperature of the steam. From 150 to 200 pounds' pressure, and from 100 to 200 degrees of superheat, are frequently used in connection with steam turbines; and much higher vacua are also generally employed, as the economy of high vacua is more marked in the case of the turbine than in that of the reciprocating engine. The efficiency of the steam turbine is somewhat higher than the average efficiency of steam engines, although a multiple-expansion reciprocating engine oí European make has been tested under high vacuum and extremely high superheat, which showed a higher efficiency than the turbine has yet reached. Where average working conditions are found, however, the turbine undoubtedly has some advantage in the matter of efficiency.

Aside from high efficiency, the turbine has many points to recommend it, among which may be mentioned the absence of reciprocating parts, the absolute uni

formity of turning moment throughout an entire revolution, the ease and simplicity of repair, the absence of all bearing surfaces, except the two main journals, and immunity from accident by reason of water being carried over with the steam. Its overload capacity is also very large, and its economy under varying loads very marked. These points of advantage have been sufficient within a very short time to make the steam turbine a formidable rival of the highest grades of reciprocating engines on the market.

THE

Compressed Air

HE vast number of applications of compressed air to modern engineering problems have proved it to be one of the most flexible and efficient agents for the transmission of power over comparatively short distances; and when its advantages come to be more generally appreciated, its use will be extended to many of the operations of everyday life. In view of its rapidly growing field of usefulness, the description of various forms of air-compressors, which will be found elsewhere in these pages, is of timely interest. Owing to the wide variations of air pressure required for different services-which range from a few ounces' to several hundred pounds' pressure per square inch-a number of different types of compressors have been developed. With the fan and blower types, whose limits of economical operation are within one pound pressure, few difficulties are found in the construction of the compressing machinery, which is extremely simple.

As the pressures increase, however, the machines become more and more complicated, owing not only to the greater power required, but also to the heating of the air during compression. The dissipation of heat, is in fact, one of the most difficult problems with which the designer of air-compressors has to contend. The use of water-jackets for cooling the air in the compression cylinders is general, but this does not effect thorough cooling, as only a small portion of the air in the cylinder comes in contact with the jacketed parts. This difficulty has led to the use of compound ma

chines, in which case inter-coolers are generally used between the different stages of compression, which cause the air to shrink in volume between the stages. A properly designed inter-cooler should reduce the air in the cylinders to the temperature of the outside air. The economy of compressing in several stages-or, in other words, compound compressors-is shown from the fact that in compressing air up to 100 lbs. the heat loss reaches about 30 per cent. By compressing in two stages, this loss is cut down to less than half; and in four stages, it is reduced to four or five per cent. It is evident, therefore, that the higher the pressure required the more essential is the use of compound machines. It is probable that much of the delay in the adoption of compressed air for numerous purposes has been caused by the complicated and ponderous machinery formerly used; but this objection is rapidly disappearing with the introduction of simple, durable machinery which can be readily operated by entirely unskilled attendants.

Training Sailors

Technically

THE old-time able seaman had to know

how to "hand, reef, and steer." Such, nominally, is the requirement of the able seaman of the navy of to-day, though in practice he has neither to hand nor reef. and the ship steers by a mechanical gear which responds to the touch of a finger even in the heaviest seas. The sailor who would rise above the ordinary to-day, must have technical training. Seamen for our increasing Navy are none too plentiful, and those who come to it with technical training are few indeed; so the Government is taking the matter in hand and giving it to them after they arrive. The United States Navy is establishing the most thorough system of wireless communication in the world, and to operate this it must have many wireless operators. At present a corps of twentyfive sailors is being trained in these mysteries at the Brooklyn Navy Yard. It takes three months to make a wireless operator out of the average sailor from the warships; and as soon as he is made,

he is turned over to one of the various stations far or near, to begin active service at a salary increasing as he shows efficiency and is promoted. The ordinary seamen recruits receive but $16 per month, but the wireless man when graduated is rated as a third-class electrician at $30 per month. From that, advancement brings rapid increase up to the position of Chief Electrician at $70 per month. The Bureau of Equipment is preparing to establish a network of wireless stations covering the entire coast of the United States from Key West in Florida to Alaska and the Aleutian Islands in the north, and extending to Honolulu, The Philippines and the Panama Canal strip. When you add to this the fact that every warship in our great and growing Navy is equipped with similar apparatus and must hence carry two or more operators, it will be seen that the chance for electrically trained young men in the Navy is a good one. The modern battleship is no longer a fine sailing ship equipped with guns, but a huge and complicated floating mechanism requiring scores of highly trained men to make her efficient. In this fact lies the hope of advancement for the man who enters the service already equipped with a good mechanical training.

ΝΑ

济

Natural Gas Again ATURAL gas, not such as bubbles from political orators, but the kind which flows from the depths of the earth, is again coming into constant and increasing use, because the supply is once more to be depended on. When this great source of light, heat, and power from the chasms of the earth was first discovered, it was used with reckless extravagance. The cities and towns near the wells received it at merely nominal rates, and acted as if they knew the supply was exhaustless. Dooryards were lighted by it at night, and it was burnt in countless ways for the fun of the thing. Great industries were built up dependent on its use; and when the supply, as might have been expected, began to decline, suffered from the lack of it. The supply ran low and lower, and gas was regarded as a declining product, likely to pass away almost entirely. But

a lesson was learned from this prodigality, and the safeguarding of the much reduced supply began. During the last few years new wells have been struck, and, the lesson having been learned, the industry seems to be once more on a prosperous basis. The supply is virtually confined to four States-Pennsylvania, West Virginia, Indiana, and Ohio. Last year's output from these States was the most valuable since the first wells were sunk. In round figures it represented nearly $36,000,000. The volume at atmospheric pressure was 238,769,067,000 cubic feet, and its heating value was estimated as equal to that of 11,938,453 tons of bituminous coal.

Valuable Invention

Lost?

THE fact that "dead men tell no tales" has lately caused much uneasiness in the scientific world, for two men who recently died are feared to have taken with them a secret of great importance. In certain classes of spectroscopic work, a concave mirror is used on which are engraved parallel lines, sometimes 100,000 to the inch. Professor Rowland of Johns Hopkins University, a scientist of splendid mechanical ability, invented a machine for making these lines. Its principal mechanism. was a screw with an exceedingly fine thread that had to be cut and ground under water by a method hitherto unknown, which the professor taught only to his head mechanic. These two men alone held this priceless secret for years, and ground out the machines regularly for the whole world, but did not grind out the secret with them. Then one day Schneider, the head machinist, died. Professor Rowland at once set to work teaching the secret to another foreman; but before it was accomplished, Rowland himself died.

Is the secret lost? It remains to be seen. Attempts have lately been made to cut a new screw like those cut by Schneider and Professor Rowland, and the scientific world is waiting the result with great interest. If it fails, the three machines already in working order will be priceless.