Science Siftings

New Zealand Tablet, Volume LII, Issue 14, 22 April 1925, Page 62

Science Siftings

(By Volt)

Electric Warning for Motorists. Automatic warning signals to prevent collisions between motor cars at dangerous crossroads have been tested recently near Bordeaux, France.

These signals are operated electrically,. Across each roadway near the intersection is placed a metal plate even with the road level. Whenever a motor car approaching the crossing passes over the plate, it makes an electric contact that releases a danger "i signal at the crossing and on the intersecting i road. At night the signals are illuminated : for several seconds after contact is made with ] the road plate. ' Thus a • driver is warned instantly that another car ,is approaching the intersection. 1 The signal is at a sufficient distance from the crossing to give him time to apply his brakes. ■ Installation of the system is said not to be costly.

’ ' America’s' Latest Marvel: V - The “Telephotograph.” " • ‘Writing from San Francisco, under date , March 3, the, correspondent of the Christ church Press says ; Another chapter in the story of the annihilation of distance by electricity, brains and steel had been made by officials of the American Telephone and Telegraph Company in an announcement that they plan soon to establish a trans-Continental service for the transmission of pictures. Users of the new service will be able to send photographs from city, to city just as they now step up to a counter and send telegrams. The only' difference will be the cost, as it is estimated that the rate for sending a picture from New York to San Francisco will’ be approximately 100 dollars,/ This rate, however, ■ is. expected to be - materially reduced as the service 1 becomes developed. When delivered, the pictures will be practically indistinguishable from the original photographs. A ' new invention, or group of inventions, called by some the “Telephotograph” machine and developed by engineers of the American Telephone and Telegraph Company and the Bell Telephone Laboratories, Incorporated,, transmits the pictures. A photograph bn a film placed in the sending machine at New York is copied in seven minutes in the receiving station in San Francisco. , , A demonstration was conducted on Sunday, March ,1, between Washington/ New York, Chicago, and San Francisco, and one of the photographs sent was of President and Mrs. Coolidge leaving the White ■ House 1 on the Sunday morning for church. The photographs were received in- San Francisco wtih perfect clearness, quite equal to the highest class of photography and :: were published in the San Francisco daily newspapers. By the same system it was arranged to send photographs of the opening of the Presidential in--1 auguration ceremonies so that the pictures might be in the hands of all newspapers in *” the leading American cities long before 'the ) r President had completed delivery of his inauguration speech. •/ ■/./.• j/

Commercial • use of the machines can -be : ' made, officials of the company stated, for not . • only newspaper photographs, but also for. • signatures, bank and legal documents, finger- . prints, and pictures of anything else thatX should be sent. ■ Line drawings can be ss£rc the same as photographs. < ■ '