THE TECHNICAL WORLD MAGAZINE

.

Automatic Signal Lead (Fig. 2), it is automatically detached

from its couplings; and, the strain on the MR.

(R. SJOSTRAND, a Swedish en-
gineer, has invented an ingenious is given by the clockwork included in the

wire being removed, an efficient signal
automatic signaling lead which affords a
means of protecting a vessel from get-

apparatus on deck. Being now free from ting aground when nearing the coast or

its couplings, the kite rises to the surface whilst in dangerous waters.

of the water, and, after having been This is

hauled in, is ready again to be thrown achieved by means of a "water-kite” fixed to a slender but substantial line in such a way as to remain always at a given depth with a given length of line, independently of the speed of the vessel. By. paying out a sufficient length of line, the kite may

be made to touch at any depth. As soon as the water shoals to the depth at which the kite is set, the latter, touching the bottom, causes a signal to be given in an apparatus installed on deck.

As seen from Fig. 1, the kite is designed like a roof with its planes aslant against the motion of the vessel, so as to cut down into the water when the latter is moving. It thus sinks to the bottom in the same way that an air-kite rises in the air. The wire to which the kite is fastened is kept strained, taking the shape

Fig. 2. WHEN THE LEAD STRIKES BOTTOM, A DEVICE IS

UNLOCKED, RELIEVING STRAIN ON CABLE, AND of a bow. The bend of the curve is quite independent of the speed of the vessel, as the resistance of the water increases or into the water, after a slight adjustment decreases in the same proportion on each has been made. part of the line and kite irrespective of In dangerous or unknown water, or in any alteration in speed. The actual ver

foggy or misty weather, when approaching a coast, or in other difficult cases, the signal-lead will afford a certain knowledge of the minimum depth of the water throughout the ship's course. In fact when giving out as much of the line as corresponds to a certain depth of water, the lead will give a signal immediately the vessel gets into shallower water. The depth may be ascertained at any time by slowly giving out the line until the lead strikes bottom. And, finally, the lead may be used in connection with observations to be used for pricking charts, and will prove useful in saving time and work, the signal being obtained as soon

as a certain depth is passed, without any tical depth at which the kite follows the slacking of speed. ship, accordingly, depends only on the The arrangement for signaling is a lengtır of line which is paid out, being mechanism placed in a kind of cupboard independent of the speed; this depth is on deck, which acts as soon as the strain read off the apparatus placed on deck. on the line is release 1 by the uncoupling

As soon as the kite touches bottom of the kite.

WORKING SIGNALING APPARATUS ON VESSEL.

Fig. 1. SIGNALING LEAD CARRIED AT END OF CABLE.

or

Flying Machine Model

CAUSE.

EFFECT. NOW

OW that the Wright brothers have 1. Weight too far for

made a successful flying machine it ward curvature of is natural that this new departure should wings too great with Darting attract the attention of a great many tail not slanted up downwards. unscientific people who are interested enough to counteract enough to try a few experiments of their these conditions. own. Not all, however, care to hurry life insurance along by testing mancarrying machines. Here is another line of endeavor for such.

Everybody has seen a bird soar and a few observers have spent a good deal of time and energy wondering how it is done. If they never tried to imitate they are probably still wondering, for mere watching the birds will never teach us to fly. A machine that will imitate the birds and give to a beginner his first lessons in flying is easily made out of inexpensive materials as shown in the sketch.

It is made of heavy drawing paper cut into the shape shown and braced with a thin piece of wood glued on top. The weight which is glued to the bottom of the model and which corresponds to the body of a bird may be made of any piece of wood or rubber shaped so as to present the least possible resisting surface to the action of the wind. The wings are curved as shown in the end view and the

a!? 3 4 6 8 102 tail should be bent slightly upwards. The

INCHES position of the tail, the curvature of the wings and the location of the weight will have to be altered in winds of different 2. The opposite of Darting speeds in order to make the model fly at the conditions in 1. upwards. its best. To test one of these gliders it is best to

3. Weight too much begin by casting the model from the

to one side or both sides Swerving to hand at a height of about six feet and

of wings and tail not ad- one side. by comparing the action of the glider in

justed evenly. each flight ascertain the correct adjustment of the wings, tail and weight. It

4. may then be launched into the wind from

Weight too far

Fore and aft any height with the assurance that the

back, or tail slanted up

ution. resulting flights will well repay you for

too much. the time spent in making and testing it.

Much can be learned by watching the 5. Weight too far flights of this and similar models, and it back or wings slanted at is not long before the experimenter a dihedral angle when learns just what changes in the machine the type of machine Lateral are necessary to produce certain results. used goes better with oscillation. To the beginner, however, the accom- them horizontal or with panying table of cause and effect may the tips slightly decome in handy in clearing up some of his pressed.• principal difficulties.

-LAURENCE LESH.

SMALL FLYING MODEL.

Cycles for Police and Soldiers

By Fritz Morris

D

EVELOPMENT of the bi- volvers, which they are not supposed to cycle-police idea has been use except in extreme emergency, yet steadily growing in many their service is competent and effective. of the big cities of the They ride the boulevards and greater world and American cities thoroughfares always in pairs, and traffic

have not been behindhand of all kinds is absolutely under their conin making use of the wheel as a help to trol. Motorists and cyclists have a their police departments. But the city of wholesome respect for them, for they Brussels has an organization, perfected carry speed indicators in their wheels within the past five years, which, in some and when an offender against speed-limit features at least, leads other municipali- regulations appears, they have only to ties along this line, and which in some follow him a short distance to secure respects is unique.

certain proof of his offense. Arrest, imThe bicycle police of Brussels ride mediate or subsequent, is sure to follow chainless wheels, carry neither swords and fitting penalty is exacted. The men nor clubs and are armed only with re- are carefully selected for their task upon

the streets, are experts in handling blockades and other street troubles and are under a system of telephone reports and calls which makes them quickly available at any point. The statement is made by observers of their work that two mounted men are worth ten foot-men. They are also used as messengers in all sorts of police duty.

During the last ten

cycle, also, for mounting a force of riflemen. They use a folding wheel and are armed with the regulation service rifle. Being picked men, and crack shots, they give excellent service as scouts, for they can cross all sorts of country, riding when possible and carrying their folded wheels when not. In their sober, dark green uniforms, with yellow trimming and cloth caps they are neat but not gaudy and are a very useful body to the service.

Sham battles are very popular with the Belgians. When one occurs the people turn out en masse to witness the spectacle. Shops are closed and the citizens arrayed in their best garments, the ladies in gaily colored finery, add interest to the maneuvers. Belgium is one of the minor military powers of Europe that dread the aggressions of their more powerful neighbors, notably Germany. Hence she

TYPES OF Belgian Cycle RiflEMEN. represents the latest innovations in all things pertaining to military science and back means a very serious thing if a tactics.

march of some distance has to be made. The bicycles used as a regular part of The lay of the land in Belgium is, on the their equipment by the sharp-shooters whole, however, well-adapted to bicycle hitherto referred to are necessarily of riding, and it is not for very long the very lightest build and weight, com- periods' that these strangely mounted patible with strength and service; for a scouts and sharp-shooters have to carry few pounds extra weight on a soldier's their vehicles.

D

Seeing Through a Brick

By Livingston Wright
ANA DUDLEY of Wake

ening paper or magazine to a comfortable field, a suburban town of parental peep at your dear little tots in Boston, has devised the ap- the nursery above. Indeed, if you should plication of the "seeing- feel disposed to peer over into the next through-a-brick” principle county or the next state you can look at

to a machine which will en- your business friend the while you talk able you while seated in your luxurious with him over the 'phone. Dudley's office chair or your comfortable, lazy brain has hatched the basic contrivance library chair, to turn to a sort of “re- that will enable you to do these very ceiver” and take a squint at what your things and many others as wonderful. employees are doing 'way up at the south- It may be that Dudley will never reeast corner of the 'steenth floor above alize his deserved fortune from his presyou, or turn from the pages of your ev- ent “seeing-through-a-brick” device, but

there is little question that his invention will be added to and perfected by others, so that vast manufactories will find it as indispensable as the telephone, houses will have it as much a matter of equipment as open plumbing, great office buildings will be using it to communicate with other great office buildings hundreds of

miles away.

For, there are times and callings when for a man to gaze upon the distant face of another may be just as consequential as to hear that person's voice.

Think of what it would mean for a manufacturer to have the power of quietly and unsuspectedly watching his employees while they are at work. Think of what it would mean for the bank official to be able at any moment he might choose, to peer into the bank vault just before he