Science Notes.

New Zealand Mail, Issue 1032, 11 December 1891, Page 6

Science Notes.

■To make white roses blue, water the trees throughout the winter with a solution of Prussian blue, and-if you want them to be green use sulphate of copper.

Besides the large planets which revolve about the sun, over two hundred and fifty others have been discovered and catalogued, and science is daily adding to this list.

Telescopic steel masts or rods are to be used in lighting the public squares in Brussels. The object of this system is to preserve the beauties of the parks in the daytime.

The steam power of the world is placed at 49,000,000 horse-power. This is equivalent to the working capacity of 1,000,000,000 men, which is more than double the total workiug population.

Moulds for casting iron can only be' 1 made in sand. Iron or other metallic moulds chill the iron and it does not fill well. The great heat at which iron melts will burn any other material or will stick so as to break the mould.

Oxygen is a gas whose presence is necessary before the phenomenon of burning can take place, aud hydrogen is a gas that burns with a pale blue flame* and yet the combination of these two gases form water, which is the opposing element of fire.

Dr D’Abundo has published the result of some researches on the markings on the tips of the fingers. He examined the. fingers of seven idiots, and founi that, the markings on the tips of all thefingers on each hand were identical, thus, showing a marked difference between, those ot idiots and of sane people.

Dr Gill, the Astronomer-Royal at tlio Cape of Good Hope, is reported to have said that a plan for universal time has been officially proposed to his Government, by which there will be one time for the whole world, starting from the meridian of Greenwich, and changing local times at longitudes separaled by an even number of hours frem Greenwich.

Some remarkable armour-plate tests have just been completed at the Annapolis proving grounds of the United States Government. Three plates manufactured of a steel containing but 25 per cent of carbon, but with the face made extremely hard by the Harvey cementation process were fired ot with a Hotchkiss sixpounder quick-firing gun. The projectiles used were of the armour piercing type, and the striking velocity was upwards of 1800 feet per second. Every one of the projectiles broke up against the hard faces of the plates, none of which were cracked or even penetrated to any depth, there being only a slight indentation made in the surface.

Herr Julius Schnelke, of Berlin, has recently constructed a petroleum lamp which is similar in workiug to the Wenham and Clark Gas lamps. The petroleum is evaporated in a chamber, and after having passed through a ring of small tubes, is burnt as a gas without a wick, and produces an inverted flame. The production of serve for the heating of a system of baffle plates by means of which the air necessary for combustion is well heated before reaching the burner. The flame ia perfectly white, and the regulation of the oil, which flows from a reservoir above, is easily effected by a needle valve, which at the same time secures the entrance of clean oil into the lamp. The heating of tbe evaporating chamber is effected by a small flame which is fed by petroleum or by spirit, and ia automatically extinguished a 3 soon aB the evaporation of the oil has commenced, and the lamp ia in working order. Photometric trials show that the lamp has a high illuminating value per unit of oil consumed.

The Folk-lore Society of Massachusetts haviug sent a delegate to Col. Gouraud, asking his assistance in obtaining records of the ‘ street sounds ’ of London and the capitals of Europe, Col. Gouraud has put a phonograph at the society’s disposal, while a photographer will photograph the subjects simultaneously with the phonographing of their ‘ sound waves.’ This secures the ‘coincident reproduction’ of both sights and sounds—by means of the lantern and the phonograph combined. New material indeed, for the lecture platform.

Interesting experiments have recently been made on the Lake of Zurich with a boat built entirely of aluminum. The boat weighs only about half a ton—viz., about half the weight of ar. ordinary boat of the same size. It carries eight persons, and, with a petroleum engine of only two horse-power, easily makes six miles an hour. Aluminum not "being subjected to rust, the permanent colour of the boat is a beautiful dull white, while the chimney, being of polished aluminum, shines like silver. The trial trips of the bout wore eminently successful, and it is anticipated that the construction of aluminum steamers, having the same capacity and only half the weight of the iron one now used on Swiss lakes, has a great luture before it.