-planes, auto-gyros, in fact, almost every type of aeroplane that exists. But undoubtedly the most popular is the light single or double-seater landplane.
In the King's Cup air race, most of the machines entered are of this type. Many famous flights have been made in them. Mollinson's recent flight, in the little single-seater comper " Swift " ; Amy Johnson's and Mr. Scott's flights in their two-seater De Haviland " Moths "; Bert Hinkler in his Avro " Avian." These last three have engines of 100 h.p., and the " Swift " has an engine of 40 h.p. ! What a difference between these and the " Hannibal," with its four engines, each of 550 h.p. !
It is very interesting to wonder in what direction the aeroplane of to-morrow will develop. Will it be on the same plan as to-day, or will it develop on the lines of an auto-gyro, dirigible, or rocket 'plane?
P. HlNTON.
IF COAL GAVE OUT.
Have you ever thought what would happen if the world's coal supply failed?
A casual thinker would reply, "Oil or petrol," but prohibitive prices would soon eliminate these.
Imagine London, the North with its industries, both would soon be at a standstill. On the Thames, picturesque barges would tack up the river in place of the puffing tugs, the streets would be like a city of the dead.
Imagine Mr. Business Man ! He arises for his morning dip. No gas, hence no hot water. Decidedly inconvenient and uncomfortable, especially in winter. It is useless to switch on the electric stove. No coal to generate the power, and petrol engines cost £1,000 an hour to run ! Mr. Business Man turns on the cold water and philosophically braves the terrors of that refined element.
This meagre toilet completed, the maid offers a breakfast of slices of bread, fruit, and a glass of cold water. Gone are the eggs and bacon of yesteryear.
He picks up The Daily Misery-now a single sheet-and learns that the coal supply will only allow the printing-presses to run for another week. But habit is a strong characteristic, and, snatching up his hat and attaché case, he sprints for the 8.15. The station is deserted. He realizes -no coal-no train.
Wheeling round, he espies an old hansom cab and a decrepit horse attached. He engages it and calls "City, please," with an air of offended dignity.
At the office all is quiet and peaceful, the staff, from chief to office boy, are morbid and depressed. The arrival of luncheon" hour gives him an opportunity to contemplate the crisis.
He comes home thoroughly dejected, but no cheerful fire -all available wood has long since been consumed. Silently he eats his cold collation.
But presently, a bright idea! The pleasure of smoking still remain. He pulls out his favourite briar and proceeds to drown his sorrows in smoke, leaving the rest of the world to wonder how much longer they will have to be without that important factor-coal.
D. POTTS.
F. TOLPUTT.
THE GRAMOPHONE.
The first actual machine to be used for the recording of articulate speech was the phonautograph, invented by Mr. Leo. Scott in the year 1856; it consisted mainly of a conical mouthpiece; attached to the smaller end was a diaphragm of light material, a needle was fixed to and followed every movement of the diaphragm, and traced them on a blackened cylinder of paper, which revolved underneath the needle.
The inventor of the gramophone was the late Mr. Edison, whose death recently was such a blow to the scientific world. The only alteration he made to Mr. Scott's phonautograph was to substitute tin-foil for the blackened paper; and as Mr. Edison said, " No one was more surprised than I when the machine reproduced the words spoken into it."
The working of the phonograph, as it was called, and still is in America, is relatively simple to understand. The needle attached to the diaphragm of the recorder presses into the tin-foil, and impresses it with a series of indentations which vary with the frequency of the sound being recorded; to hear a record thus made, it was only necessary to turn the cylinder back and let the needle follow the track previously made. The records made in this manner were by no means perfect; for one thing, they could not be reproduced many times, because the impressions faded with use.
A further improvement was accomplished by the use of a flat circular plate, with a spiral groove cut, from the outside to the centre. For the final perfection of the instrument, however, we are indebted to Dr. Chichester Beil and Mr. Tainter, who found that better recording could be obtained by using paraffin wax, mixed with other materials, for receiving the impressions ; then they evolved a different method of cutting, by which the fluctuations of the diaphragm were recorded by means of a wavy line, varying according to the frequency of the sound recorded. The numerous benefits which the gramophone has bestowed upon mankind are fourfold. It is the gramophone which enables us to hear beautiful music, and also the speeches of great men. It is a tremendous benefit to those who study foreign languages, and finally, we must not forget that great masterpiece of modern