Science Sittings

New Zealand Tablet, 30 October 1913, Page 57

Science Sittings

By 'Volt.'

New System of Train Operation. Edward Rowe, a resident of Indiana, Pennsylvania, has invented a new system of train operation by means of a telephone working in such a way as to keep the train in touch with the ' block ' office, and through that office with the division dispatcher. In addition to this, the electric connection operates an 'indicator' which shows the position of the train as it completes each one-fourth mile of its trip over the block. As the engine passes each contact rail the contact is recorded on an indicator in the operator's office and shows how far the train has progressed. If the operator desires to talk to the engine-driver all that is needful is for him' to switch on a stronger current, which will ring the bell of the telephone instrument in the cab. The engine-driver will stop his tram and back up to the contact rail, when, lie can talk to the operator. '•...-•. • . - ~

Wind Too Swift to Gauge. The highest velocities of the wind have only been estimated, never measured, for there are no instruments that will measure them. A Eobinson anemometer was blown away when registering 120 miles an hour in Jamaica on November 18th last. -The highest velocity on record is 186 miles an hour, measured by an_ anemometer on Mount Washington, January 11, 1878. An effort has been made to estimate the velocity of the wind in a tornado, basing it on some of its effects. A pine board was driven. through a telegraph pole, another was driven three inches into the trunk of a tree, and it was calculated that such effects could have been produced only by a force little less than a cannon ball of somewhere between 600 and 800 miles an hour. The Milky Way. The Milky Way, or Galaxy, is an apparent ring extending entirely around the universe of stars visible in the largest telescopes. It is composed of suns in literal millions. They are so remote (says G. W. James, m the National Magazine) that as seen from the earth they appear to be close to each other, while really they are separated by millions and billions of miles. To the eye of the belt of soft light looks like a continuous band of cloth of pearl, but telescopes have the effect of bringing objects nearer. This separates the filmy cloud into many millions of glittering but minute points on the black background of space. At a distance, forest trees seem to be closer together, but as they are approached they separate and stand alone. It is next to impossible to describe the matchless beauty of the Milky Way as seen in a telescope of great power. Carpet a large room with black velvet. Throw down and scatter all over the black floor a bushel of minute diamonds, rubies/ pearls, sapphires, opals, amethysts, and other gems. Then turn on the light. You would have a faint imitation of the superficial glories of the galactic hosts. ' . The Latest Photographic Marvel. X-ray photographs can now bo taken at a single ' flash ' by means of an improved apparatus, which embodies all the most recent advances in radio-graphic work. The advantage to medical men of being able to secure a sharp X-ray photograph in the onethousandth part of a second is obvious; it means securing a photographic image in which the maximum of detail is obtained, there being no time for the patient to make any movement during the exposure. It is not many year since exposures had to be so long as 20 minutes and half an hour, frequently causing pain and inconvenience to the patient. Improved apparatus, using large currents, brought down these exposures to a few seconds, but the feature of the new apparatus is that an absolutely instantaneous picture is secured by means of a single brief contact which closes . the electrical circuit.