SCIENCE AND INVENTIONS.

New Zealand Herald, Volume XLVI, Issue 14133, 7 August 1909, Page 4 (Supplement)

SCIENCE AND INVENTIONS.

SELF-HAIRCUTTING MACHINE. Mr. Felix Brown, of Chicago, has invented an appliance by means of which a man may cut his own hair.

MOVABLE KITCHENS FOR ARMY.

Two thousand movable kitchens have been ordered for the Austrian army. The equipment of each includes four coppers, an oven, cupboards, tables, and various other facilities for cooking in the field.

TANNING WITH FORMALDEHYDE.

Leather can be tanned very quickly with formaldehyde. A few hours' immersion in a 40 per cent, solution products a tough, well-tanned leather, which Inay be made more flexible by adding 5 or 6 per cent, of soda to the bath. Trioxymethylene may be substituted for formaldehyde.

SPECTACLES FOR SEEING BEHIND

There are many occasions on which it would be an obvious advantage to see what is going on behind one. Especially, it may be supposed, for a policeman in' the discharge of his duties. And Commandant Souie, of the Paris police, has just invented a pair of spectacles for his subordinates which enables them to do this. This is accomplished by the. simple device of placing a pair of small and very accurate concave mirrors on the outer edges of the spectacles. In this can be seen the reflections of what is happening behind. It is claimed that this does not interfere with the forward view.

1 NEW FERTILISER PROCESS. A German patent has been granted for a process of making fertilisers by the combination of lime with materials containing silica . and alumina. Either natural materials (clay, loam, marl, etc.), or artificial materials (household refuse, rubbish, soft coal ashes, etc.), kiln-dried if necessary, are mixed with slaked, or unslaked lime and, in some cases, treated with superheated steam. Compounds of potash, phosphorus, and nitrogen are also added, according to the character of the other materials and the kind of fertiliser desired. The advantage claimed for the process is the cheap production of certain compound silicates which greatly increase the fertility of the soil.