ONE BY ONE.

Auckland Star, Volume LXVII, Issue 143, 18 June 1936, Page 9

ONE BY ONE.

STAMPS FOR PENNIES.

P.O. VENDING MACHINES.

ANNUAL SALES WORTH £38,000

The extent to which automatic stampvending machines are meeting the convenience of the public in New Zealand is demonstrated by the fact that last year £38,000 worth of penny stamps went out into circulation through the tiny these devices, pulled out one by one by people who had put in a pejiny.

It will be interesting to those who use the machine to learn something of its construction and method of operation. They ha.ve probably discovered that the penny has to be pushed into the slot firmly, the reason being that sufficient pressure must be exerted to lift a light weight which, in its suosequent fall, provides the power necessary to actuate the machine to the point of producing one stamp in return for the penny.

There is a very simple, but cleverly designed, mechanism within the machine which prevents the stamp feed from working unless a bona fide penny has been inserted to start operations. Lead discs, half-crowns, and the circular tops of match boxes have been tried, the general result being that they are thrown out through the • lowest slot on the face of .the instrument. But if a penny is inserted the mechanism works smoothly, revolving a small drum which carries tiny pins fitting exactly into the perforations of the stamp. A slight pull by the intending purchaser enables the stamp, which appears outside the slot to be detached from a continuous roll lying behind in the recesse of the machine.

Great accuracy is needed in constructing the moving parts of the mechanism, the stamp drum being machined to limits ' of l-1000th of an inch. The preparation in the Government Printing Office of the stamp rolls, carrying 480 penny stamps, involves use of a specially designed machin

Comparatively few complaints are received of the machines failing to function, a tribute to the excellence of the workmanship at the Department's workshops in Wellington, where they are manufactured. Dampness has to be guarded against in machines having very fine adjustments, so as to avoid risk of failure or the gum 011 the stamps being affected.

In some instances a low-power electric light is kept burning inside the machine, but in the majority of cases a small tin of powdered calcium chloride placed in the base of the machine is sufficient to extract the moisture from the air and enable the mechanism to function efficiently in all weathers.