SCIENCE and INVENTIONS.

New Zealand Herald, Volume LVII, Issue 17651, 11 December 1920, Page 2 (Supplement)

SCIENCE and INVENTIONS.

sound RECORDS. " ' A process for producing sound records has been patented in which, a "fine modelling clay is substituted for the usual wax base materials employed for recording sounds. When the record is made the clayis dried so that the . exact character of impression made by the recording needle is retained. The disc is then fired in a pottery kiln and a metal matrix from which records for sale are made in the usual manner, is prepared from this pottery disc. It is also claimed that plaster of paris or other cement just about to set may be employed. PURIFICATION" OF OIL. For many. years there has been in use in most of the large engineering works of America, a centrifugal separating machine which removes the oil from iron and steel turnings or borings, and thus permits it to be used again. The idea which underlies this machine has now been carried further and applied to the removal of the dust and dirt which unavoidably collect in oil used in the lubricating systems of marine and other large engines. The new

machine is very similar in form and operates on the same principle as the ; now ■well-known centrifugal cream separator. The foul oil .is fed continuously into the machine through a strainer which catches any gross particles, precisely as milk is fed into the cream'separator. The purified oil escapes Continuously, ; while the dust and dirt collect ;©a the : inner surface of the separating drum. ■'*- Provision is made by which the attendant can instantly tell when the machine : is* choked with the do, posited impurities. LIGHT ALLOYS. It is interesting to note that the majority of the- light alloys in the United States are aluminium-copper, whereas abroad aluminium-zinc is more often found. This is said to be due to the American lack of information regarding the aluminium-zinc series, and to supply the missing information, extensive research work has been undertaken on this class of materials by one of the large zinc-producing companies. The. production of aluminium is rapidly increasing in r the United Slates, and it is predicted r that by 1930 the total production will equal, if indeed it does not exceed, that of- copper. Aluminium as an element in J "3ie-castihg has caused a number of difficulties, which are, however, being gradually overcome, and at: present 150,000 castings can be made from" a' single die. There is no question but that aluminium has come : to,,stay :*as- r an engineering material,, the possibilities .of; which j jhavo bj| not" mean* bees «xhsmts3«