One famous model engineer constructed a 1 1/4 inch gauge steam loco, " Sir Morris de Cowley," which pulled three people along at quite a fast pace. Another engineer made a steam engine, fitted with dummy slide valve cylinders and valve gear, real displacement lubricating, and worked by an oscillating cylinder inside the cab, only 3 inches in length and about H inches high!
The chief drawback to the clockwork engine is the speed, most of them going much too fast. It does not look very realistic to see a shunting engine in a goods yard travelling at a scale speed of 80 m.p.h., but this has been overcome at last by a sort of governor. Everyone knows the governor in a gramophone, two collars on a shaft, one fast and the other loose, connected by two lengths of clock spring, and in the middle of the springs, weights are secured, so that when the shaft rotates, the weights fly out and cause the loose collar to approach the other, and the faster the shaft turns, the nearer the collars get. At the side there is a fibre block which stops the collars getting too near, and thereby governs the speed. It is nearly the same in the clockwork mechanism, the block being adjustable by means of a threaded rod.
In the late Sir Henry Segrave's model railway, which is of 1} inch gauge, he imagined a Channel Tunnel, and ran the line from London, through the Tunnel, through France and into Germany.
On this model railway, there are about forty engines, far too many for the rolling stock.
The chief charm about a model railway is that it is the real thing in miniature, and the real thing has a sort of lure, there are not many people who can resist looking at an express thundering along the track.
P. HINTON.
HOW COAL GAS IS MADE.
The "Gas Light and Coke Co.'s" works at Beckton, are the largest in the world. Nearly 5,000 tons of coal are used daily to make over 75,000,000 cubic feet of that wonderful gas which lights and heats so many homes every day of our lives!
When the coal arrives at the works, the trucks are placed in revolving frames which turn them over bodily, pouring the coal on to an endless chain conveyor which carries it into-the works.
The coal is then placed in air-tight retorts or ovens and heated in a temperature of 1,325 degrees Centigrade. The gas is then driven off to be purified.
The coal is placed in the retorts by an electrically operated machine called a "charger"; as it moves along, the retort doors are automatically opened and the coal is shot in. There are many types of charges. Nowadays coal gas is mixed with another gas - carbon monoxide -a poisonous gas, with no taste, no smell, and impossible to be seen. Steam is passed over red-hot coke, with the result that hydrogen and carbon monoxide are formed, these two gases when mixed are called water gas. To draw the gas from one part of the works, a very powerful exhaust is needed. When the gas is ready it is pumped through London at 3,000,000 cubic feet an hour. V
When the gas has been extracted from the coal, coke is left, and as this is emptied from the retorts, it is cooled and carried away by an endless chain conveyor, which empties it into a heap, or on railway trucks or carts as required.
E. SHAW.
"CROOKS CAUGHT BY FINGERPRINTS."
Hundreds of criminals have been brought to justice as a result of the wonderful system used at the Scotland Yard Fingerprint Bureau.
It is uncanny ! For instance, one day a detective yvas on the trail of a suspected criminal, and followed him into a restaurant where the criminal left his fingerprints on a knife and fork.
They were rather peculiar prints, and on investigation were recognised. The man was taken to Scotland Yard.
In a private room his fingerprints were taken. The great files of the Yard were run through and within a quarter of an hour it was proved that this man was the " wanted " man.
Directly a prisoner is convicted his fingerprints are taken. An ordinary-looking ink paid is used, the prisoner