SCIENTIFIC AND USEFUL

New Zealand Graphic, Volume XII, Issue XIII, 31 March 1894, Page 296

SCIENTIFIC AND USEFUL

THE ‘ELVAKTA.’

This in the name of an inkstand which operates on a perfectly new principle. In the centre is a glass tube, containing a leaden ball ; this tube is enlarged at the upper end, and fits into a guide formed in the cap. The bottom end is provided with a rubber cup. By applying a slight pressure with the pen the glass tube is depressed, and the ink flows to supply the pen ; the ball preventing the ink being rapidly sucked back when the pen is withdrawn, and the right supply of ink is obtained, the surplus ink slowly passing back into the pot through a small hole provided in the tube, and the ciiculation of ink is thus effectually maintained so as to prevent the usual deposit of sediment. The ink is kept free from dust, and, while the ball valve prevents spurting, it retains the ink long enough to allow a proper supply of ink to be obtained by a single dip of the pen. EXTINGUISHING FIKES. From Salem, Massachusetts, comes news of a novel experiment in fire extinguishing. A sheet iron cylinder, about 3in in aiameUr and 16in long, was charged with gases and chemicals sufficient to throw a stream half the size of an ordinary lead pencil to a distance of about 12ft for five or six minutes continuously. Then a box Bft long and 4ft high and 4ft wide was smeared on the inside with tar, and a halfgallon of kerosene oil was sprinkled over it, and the whole thing set on fire. After the fire had burned the boards nearly half through the contents of the little c.r Under were turned on to it, and the flames are said to have been extinguished in something less than a minute. PAPER HOSIERY. Paper hosiery yarns have been lately invented by an ingenious American. They are made entirely of paper, shear flocks and loose fibres, but so closely resemble good woollen yarns that, at first sight, it is stated, one is easily deceived. The objection to these yarns seems to be that they fail to pieces as soon as they become damp, and that they have no elasticity, durability, or in fact, any of the qualities of good yarn, except appearance. The inventor, says an indignant Canadian journal, has the audacity to devise a means by which he can form a strand of paper, polish it, cover it with cheap flocks, give it a coating of fibre, knit it into goods, and then palm it off on the hosiery trade. We do get some queer * yarns ’ of one sort and another from America now and then, and it looks as if this was an exceptional specimen of quite a new kind. THE PUGNACITY OF THE HUMMING HIRD.

A correspondent of Science writes of the bravery shown by humming birds in attacking other birds much larger than themselves. He has seen a rufous-hummer attack and put to flight a wren and another and larger bird that had been having a spirited dispute. Tiring of their noisy warfare, or thinking them too near his chosen haunts, be made a dash first at one and then at the other and quickly put them to flight. The wren he chased into a brush pile, buzzing vigorously about its ears until it sought the seclusion of the interior of the pile. All who have spent any time in the country are aware that a crow can chase a hawk, a blackbird a crow, and a flycatcher in tuin put a blackbird to flight ; but few know that this driving power increases in exact ratio with the diminution in the size of the bird ; so that the flycatcher yields to the sparrow and the sparrow to the hummer. The latter is, as far as I know, the only bird that can always put an English sparrow to flight. I have seen our little Eistern ruby-throat break up a group of sparrows that were chattering too loudly and too near a clump of flowers in which he was busy. In Jamaica the ‘ doctor bird,’ a long-tailed species of hummer, so named by the natives because they go around presenting very long bills, are most fierce, even in attacking men. Having, after infinite pains, followed one of these creatures to its nestingplace, and reached a most perilous position in a silk cotton tree, I was driven to retire in self-defence. Both birds, as I got near the nest, flew directly against my face. Had I not been a spectacle weaier it would have been difficult to keep them out of my eyes ; as it was, they several times knocked my glasses awry. AN ARTIFICIAL LARYNX. Dr. Pebier, of Laribosiere, France, has constructed an artificial larynx, which enables the patient to speak by means of air supplied to it by a pneumatic appliance fastened on his chest. The larynx is of silver tubing, and contains a reed which gives to the artificial voice a uniformity of tone. The air pump, if we may call it so, consists of two indiarubber bulbs, communicating together and with the larynx by flexible pipes ; and it is actuated by a collapsing bulb held in the hand. The bulbs serve as reservoirs for the air, like the bag of a bagpipe, and the other bulb is used to fill them and keep up the supply.