T

HE span of wireless telegraphy is rapidly widening. It was but a short while ago that Mare Island, California, and League Island, Philadelphia, a distance of 3,150 miles, were in aerial communication; and one of our naval vessels bound for the Philippines was "picked up" by the wireless station at Los Angeles when the ship was quite 3,000 miles away. All of this is astonishing, and yet it is but one direction in which ether waves can be put to service.

The science of telautomatics is that branch of "wireless" in which ether waves are used for the purpose of directing some mechanical movement at a distance without employing connecting wires.

Within the past few months England, Germany and France have taken up the problem anew to give it a practical value, and in the United States the same question has been approached in another way with encouraging results.

The experiments in Europe have been principally confined to that of guiding either submarines or torpedoes by means of Hertzian waves-ether disturbances

of electrical origin. The three nations in question have quite carefully guarded the results of their experiments and particularly the apparatus employed, but it is known that in England the submarine so equipped was able to go through many of the maneuvers which it ordinarily performs under the guidance of its crew. The directive impulses were sent from a cruiser fitted with a wireless outfit.

The mere idea of giving a submarine this power of action without having a crew on board opens up startling possibilities. The first thought is, No one need be exposed aboard to the hazards which now exist even in time of peace. But that phase of the matter is of secondary importance to the military mind. When the human factor is eliminated from the submarine, the vessel becomes radically different so far as her internal requirements are concerned. It becomes truly a machine in every particular, and space and weight which had to be utilized for the safety and the convenience of the living crew can be put to other uses, and means of propulsion can be employed which could not be used with equal facility or security if men were aboard.

In addition to this, an under-water craft guided and managed by ether waves could be conveniently equipped with a fairly large number of torpedo tubes or torpedo-launching frames, and, with this extra armament made possible by weights saved otherwise, a submarine of this sort would be far more formidable as a dirigible base from which to discharge torpedoes. Of course, the essential part of the whole scheme is that the guiding station should have the submarine always responsive to the director's command, and this involves some difficulties which are being met in different ways by the present experimenters. How ever, the mind of the man of peace is sufficiently alert to picture some of the possibilities of a military instrument of this sort; and there are other directions in which this means of wireless control can be used to advantage.

The general public knows enough about wireless telegraphy to understand that waves are created in the ether by an electrical discharge at the sending station, and these waves travel through the air to a receiving station where they induce action in a delicate coherer which makes and breaks a local electrical circuit. But Hertzian waves of this character are not the only waves which may accomplish the same result.

Sound waves passing through either air, water or the earth can be employed in a kindred manner; and light waves-acting principally at night-can also serve as

65

a means by which to set in motion or arrest some mechanical action at a distance. But in every case electricity serves as an agent to transmit the message or impulse of those waves directly to the mechanism to be set going. The waves that span space are, in themselves, too weak to provide energy for a display of power, but they answer, like a little child, to bear their message to another source which is capable of putting some vigorous action in motion. The receiving station, in each case, brings into play a local reserve or "relay," as the electrician expresses it, and this relay is strong enough to do the work required, that is, to open a valve, swing a lever, or operate the electrical switches that may be needful to start, stop, or reverse some form of motor. This, in brief, is the foundation of the science of telautomatics.

In France, the Gabet wireless submarine or torpedo boat has been directed from a distance. It was found that the little vessel responded to the guiding Hertzian waves within one-sixth of a second from the time they were dispatched from the sending station. In the Gabet system, a hand, something akin to that of a clock, passes over a number

of contacts, each of which is for a separate use. Ordinarily, the touching of any one of these would close a circuit and set things going then and there. But this would

never do for proper distance control. Gabet makes this

hand sweep completely back and forth across all of these connections in a very short period, and the hand must stop at the right contact for a longer while before the circuit is properly closed, in order to start the particular

movement for which that contact is designed. It is this interval of lag which furnishes the margin of security and allows the connecting hand to settle upon the chosen contact-mere passing rapidly over the others does not produce any result. With the present methods of "tuning," the receiver on the submarine or torpedo can be made responsive only to waves of a certain arbitrary length. This minimizes the effects of interference by other waves generated at an enemy's station. The experiments in England and in Germany have been along kindred lines so far as the employment of Hertzian waves has been concerned, but the

governments of neither of these countries have given out details. There are, of course, several ways of accomplishing the same end, and the Gabet system is only one of them.

The aeroplane is now being fitted with apparatus for receiving and transmitting wireless messages over space from a height of quite five thousand feet. In a way, the task is somewhat more difficult than that of guiding a torpedo or any form of naval craft, but there is nothing impossible in the problem, and the dirigible balloon and the aeroplane in the near future will probably be directed by some form of wireless for certain kinds of military service where the presence of a human director or observer may not be needed. All of this may seem astounding now, but actual achievements have blazed the way to their attainment. We are living in an age of rapid and tremendous strides.

-WALT WHITMAN.

FIRST STEPLESS STREET CAR

STREET car travelers of New York

and other cities of the United States will soon be using a new type of car. The aged and women and children will undoubtedly welcome the advent of the new "stepless" car which will add to their comfort and conveniences and also reduce danger. The accompanying illustration shows the first of these cars to be operated in New York. It is now making its daily run on the Broadway Line from 59th Street and 7th Avenue, the terminus to South Ferry. Passengers climbing in and out of the street cars are in almost constant danger, resulting in many injuries. In the new car the floor is placed only ten inches above the street. In the old style of cars, the floor is from thirty to forty inches above the street. Passengers enter

and leave the car at the middle, so that they travel the shortest possible distance from the street to and from the seats in the car. The principal advantages of the stepless car are the prevention of accidents and the saving of time in loading and unloading passengers. No grab handles are needed and passengers mount and

alight without effort or hesitation. The street car company is as well pleased with the new type of car as are the passengers.

MOTOR DRIVE CLOCK
WINDING MECHANISM

A NOVELTY in the field of electric

motor application may be noted in the accompanying photograph. This is an attachment of a miniature motor to the complicated mechanism of large hall clocks. Clock makers have in the past followed a general rule for winding which necessitated the use of three brass weights, one driving the time train of gears, weighing approximately fifteen pounds and a third attached to the quar

ter hour stroke weighing from thirty-five to fortyfive pounds.

These weights were wound up by hand, three different insertions of a key being required to perform the operation. The idea of winding the clock by electricity simplifies its construction and renders the whole selfsustaining.

The motor used is a universal 110