SCIENTIFIC NOTES.

Akaroa Mail and Banks Peninsula Advertiser, Volume 2, Issue 134, 30 October 1877, Page 3

SCIENTIFIC NOTES.

The composition of wood is 49.1 carbon, 6.3 hydrogen, 44.6 oxygen ; of coal, 82.6 carbon *, 5.6 hydrogen ; 11.8 oxygen. . Iron wire conducts electricity four hundred million times better than water and four million times better than sea water. Astronomy was cultivated in Egypt and Chaldea 2800 B. C,; in Persia 3209 B. G; in India 3101 B. C, and in China 2952 B.C.

If a recent discovery turns out to be as valuable as it is claimed to be, iron will find a far wider employment in art and industry than at present, and be capable of resisting the corroding effect of moisture. When hot iron is placed in a chamber of superheated steam, it is found to take on a black coat of magnetic oxide. This oxide protects the iron from rust, and supersedes the use of the various substances that have been tried to secure that most desirable end.

In Vienna all the public clocks are moved in practical synchronism with an astronomical time-piece by means of pneumatic tubes. Every minute a wave of compressed air is sen; along the tubes, causing the hands on the large dials set up at various parts of the city to move a distance corresponding to that division of time. The troublesome and expensive electric system has been superseded by this plan, which is the invention of the Austrian engineer, M. E. Mayrhope. In the New York Aquarium, blue-glass sides have been placed in some of the tanks containing the lower order of animal ■and vegetable life. After a few weeks' trial, Professor H. D. Butler, the Superintendent, states that it has been of material benefit,'softening the rays of light and giving the water its natural color beneath the surface of the ocean. It was noted that the anemones leaned toward the blueglass sides when they expanded their tentacles, and the hermit-crabs and other shellfish were oftener found near those sides than elsewhere.