Science Sittings

New Zealand Tablet, Volume XXXVI, Issue 21, 28 May 1908, Page 35

Science Sittings

Finger Prints. The French ' Academy of Sciences recently received the report of a commission appointed to study the question of the value of finger prints' as a means of personal identification. The report is highly favorable, declaring that the value of the finger print as evidence of identity at least equals that of all other physical characteristics put together. It possesses the great advantage of being applicable at all ages, in infancy, in middle life, and during old age. Every day, the report says, this system is tending more and more to replace the method of anthropometrical measurements. Fuel of the Future. In the opinion of Professor V. B. Lewes, when the existing supplies of fuel become limited, men must rely upon alcohol produced from vegetation of some sort, which, may be produced in any required quantity. Professor Lewes thinks that the alcohol will be manufactured either from potato starch or sawdust, but a writer in ' Nature ' suggests that when the question becomes ' urgent some highly specialised plant will have been brought into existence for the sole purpose .of absorbing the maximum amount of carbon dioxide from the air, and he thinks that the wonderful improvements which hybridisation has already effected save this idea from being regarded as too fanciful. < The First Envelopes. The first mention of envelopes occurs in 1653, when M. de Valayer set up, under royal patronage, a private penny post in Paris, and boxes were placed at street corners for the reception of letters wrapped in postpaid envelopes. The earliest uses of the word in England were by Bishop Burnet in 1714 and Dean Swift in 1726. That the ' little bags called envelopes,' as Rowland Hill described them, were nothing but a revival, and were in use as a covering for postal purposes long before 1840, when his postal reform was established, is evident from the following : Under date July 21, 1627, Secretary Conway gives an account of his opening a letter in the presence of the king, which contained a blank sheet. Lamb mentions them in 1825, and in ' Harry Lorrequer,' published by Charles Lever in 1837, we find, ' The waiter entered with a small note in an envelope.' The early covers were probably rude enough, as machine-made envelopes were unknown before 1810, and the ' lick of the gum ' did not make its appearance till the succeeding year. Fireless Stoves in Germany. Fireless stoves, or self-cookers, as they are variously known, have been in use in Germany for a number of years, so that they may now be declared a success. The earlier types were merely boxes constructed with double walls, or by secret processes built so as to retain heat when sealed. These cookers, which are still on the market, are used as follows : After a thorough heating, food to be cooked (stewed or boiled) is placed inside the box, sealed and left for a sufficient time, when it is opened, and the food, cooked by the retained heat, is ready to serve. Recently a company has produced a fireless stove that fries and roasts. Profiting by past failures and successes, the company has perfected a cooker that, although on the market but a year, has already proved very popular. Frying and roasting are accomplished in the new cooker by the use of a heated stone. The stone is thoroughly heated in an oven, over gas or any fire, and placed in the cooker with the steak or roast. The box is sealed up and left for an hour or so, as required, then opened, and the food is fully prepared and hot. In the double boxes all three processes may proceed at one time without care or difficulty. The. owners of the patents of this latest apparatus claim that the sales in the coming year will exceed 50,000 cookers in Germany and Switzerland.