OCCASIONAL NOTES.

SAFETY IN RAILWAY TRAVELLING.

Mr Edward Harford, general secretary to the Amalgamated Society of Railway Servants, replying to a request forwarded by peers, members of the House of Commons, and others for information as to the causes of railway accidents, and the means which, in the opinion of the Society, ought to be adopted for the safety of the general public and of railway servants, has issued a list of twenty-three proposals which set forth the necessary requirements. The principal are the following:

‘All railways ought to be worked on the absolute block-system, strictly carried out, so that no two trains shall ever be in one section at the same time.

The blocks and interlocking systems should be electrically combined and controlled, so that the safety of a block-section shall be under the control of two signalmen.

Junction block-working should be adopted at all junctions, so that no two trains which can foul each other at the points and crossings shall ever be allowed to approach a junction at one and the same time. All sidings and goods-lines should be provided with properly interlocked safety-points.

One code of block-system regulations and one pattern of signals should be adopted throughout the kingdom. A red light should be the only danger-signal. The practice of using purple or other lights is highly dangerous.

Facing-points ought to be avoided as far as possible. All facing-points, and points leading to main-lines, ought to be provided with a locking-bar and bolts, and properly interlocked with the signals and with the electric apparatus.

All passenger-trains ought to be provided with an efficient automatic continuous brake, having brake-blocks upon the wheels of the engine, tender, and every vehicle throughout the train, and fulfilling the five conditions laid down by the Board of Trade, August 30, 1877, and highly approved by the Society. To avoid the present dangerous practice of brake-power being cut off and rendered useless by the introduction of an unfitted vehicle, it ought to be the law that the Company should not be allowed to send vehicles over the line of another Company unless each vehicle is provided with the same form of continuous brake as that used by such foreign Company.

All goods-engines should be fitted with brakes upon their wheels, and those required occasionally for passenger-traffic should have continuous brakes.

All passenger-trains should be fitted with efficient means of communication with the driver and guards. Passengers should be able to reach it without putting their hands outside the window. The present cord-system is unreliable, and the plan of having no communication on trains which stop every twenty miles is very risky to the public.

All passenger-platforms should be raised to the standard height, and all carriages fitted with a high continuous footboard, to prevent persons falling between platforms and trains.

The crank or driving-axles of locomotive engines should be taken out after they have run a certain mileage. What the mileage limit should be ought to be at once decided by the Companies and the Board of Trade.

Overwork on railways is highly dangerous, and ought to be abolished.’

HOW CHILDREN GROW.

During the International Medical Conference held in Copenhagen in the summer of 1884, a paper read by the Rev. Mailing Hansen, Principal of the Danish Institution for the Deaf and Dumb, was listened to with marked attention and interest. It gave the results of the daily weighing and measurements of height which he had carried on for nearly three years on the one hundred and thirty pupils—seventy-two boys and fifty-eight girls—of the Institution, and demonstrated facts as to the development of the human body during the period of childhood that perfectly startled and astonished the assembled medical authorities, opening an entirely new field for investigation and reflection. Since then, Mr Hansen has continued his observations; and though he has yet a tremendous amount of work before him, he believes himself able to state now the outlines of the results he has obtained.

The children are weighed four times daily in batches of twenty—in the morning, before dinner, after dinner, and at bedtime, and each child is measured once a day. The common impression is, no doubt, that increase in bulk and height of the human body during the years of growth progresses evenly all through the year. This is not so. Three distinct periods are marked out, and within them some thirty lesser waverings have been observed. As for bulk, the maximum period extends from August until December; the period of equipoise lasts from December until about the middle of April; and then follows the minimum period until August. The lasting increase of bulk or weight is all accumulated during the first stage; the period of equipoise adds to the body about a fourth of that increase, but this gain is almost entirely spent or lost again in the last period.

The increase in height of the children shows the same division into periods, only in a different order. The maximum period of growth in height corresponds to the minimum period of increase in bulk, and vice versâ. In September and October a child grows only a fifth of what it did in June and July. In other words, during a part of the year—autumn and beginning of winter—the child accumulates bulk, but the height is stationary. In the early summer the bulk remains nearly unchanged, but the vital force and the nourishment are expended to the benefit of height. While the body works for bulk there is rest for the growth, and when the period of growth comes, the working for bulk is suspended. The human body has, consequently, the same distinctly marked periods of development as plants.

A CHESS-CLOCK.

An ingenious clock has recently been patented by Messrs Frisch and Schierwater, 29 Church Street, Liverpool. It not only shows the ordinary time, but registers on separate dials—marked respectively ‘black’ and ‘white’—the period occupied by the players in a game of chess. It also indicates the number of moves in a game and whose turn it is to play. Another feature is the index upon the dial. This can be set for any time agreed upon—from one to fifteen minutes—during which a move must be made. The expiration of that time is shown by an indicator and by the ringing of a bell. By pressing a knob at the top of the clock, it is possible to temporarily check the progress of the mechanism. This would of course become necessary upon the players requiring a rest, or upon any other interruption taking place. The invention is, we believe, the first clock that has been constructed with a view to recording the movements in chess-playing. It may of course be utilised for other purposes. Being a travelling clock, it may be employed for indicating the times of different countries. The index and call-bell may be used, too, for public meetings, allowing so much time for each speaker; for a telephone Company, regulating an allowance of time; or for the testing of any machinery. The movement can be fitted to any existing clock. As a result of practical trial, the ‘Schierwater’s’ Patent Chess-Clock has been commended by many well-known chess-players.

NOVEL PHOTOGRAPHIC EXPERIMENTS.

The sinking of the caissons of the Forth Bridge has afforded opportunity for testing whether it was possible to obtain photographs below water in compressed air by the aid of electric light. To the novel conditions under which these attempts—the first, we believe, in this country—were made, their chief interest is due, rather than to any particular success hitherto achieved. We have recently described the method of founding by compressed air, and depicted the interior of a caisson, so that our readers are conversant with the surroundings under which the attempts were made.

A trial was made on shore by electric light at night to determine the length of exposure necessary for the plates; but subsequent experience proved the data thus obtained to be of little value in the air-chamber. Various trials were then made in the air-chamber with different classes of plates and gradually increasing lighting-power; eventually, five arc-lamps—each equivalent to twelve hundred candles—and plates of exceptional rapidity, were employed; and these, with an exposure of two minutes, gave the best results obtained.

The roof and sides of the air-chamber were whitewashed, to render them conspicuous and to diffuse the light. The formation of moisture on the lens threatened at first to give trouble; but after a little time the glass became warmed, and the difficulty ceased. The haze in the air-chamber, which any sudden expansion of the air—such as that due to its escape when the air-locks were opened—greatly intensified, proved a formidable obstacle, and must always render the highest results unattainable. The only course was to seize the most favourable moment when the haze was at its minimum. White objects and light clothing gave the best results; whilst the eyes of a group—presumably from their glistening properties—are remarkable for definition and sharpness.

So far as could be ascertained, no injury resulted to the dry plates either from air-pressure or moisture.