Scientific Notes.

Horowhenua Chronicle, 4 October 1911, Page 4

Scientific Notes.

RUBBER PAYING

The prophecy of the president of the Kubber Exhibition; held at the Agricultural Hall, London, recently, that the time will soon come when tho price of rubber would be low enough to mako rubber paving an accomplished fact in titoa streets, is excellent 'hearing. 'Whenever out comes across one or another of the few .specimens of rubber paving which at present are to be found in London (says the Globe , ), one experiences a seii-so of grateful relief. But up till now a wider uise of this material for such a purpose ilvas been prohibited by the question of expense, although iit has been thoroughly recognised that as a, substitute for the ordinary materials used in paving tihe streets rubber offers enormous" attractions. If it could be employed in large quantities in certain localities, London, one imagines would bo a happier' pb.ee.. Koi there is no doubt that, a.s things a.re. the increase of traffic must be attended with increase of noise .and that, though Londoners may become dulled, by painful ihibit, to the ceaseless roar, the nerves of the community are certainly, even is uncon--1 sciouslv. in a state of tension.

WATER I'IIOOFIXG FABRICS. The .French army is interested in a new method for waterproofing fabrics which is claimed to be superior to the. usual processes. English manufacturers .have- been in the lead in bringing out waterproof fabrics for many years yeans past. Besides rubber, for fabrics-, wo have the use of insoluble gelatine-, bailed linseed oil, shellac., metallic .soaps and others, which have had more or less success. It appears that the best product for waterproofing is acetate of aluminium, and when applied to t'he fabric it ca.n bo made to form alumina, in a gelatinous state, and volatile acetic acid'. When such fabric, is dried it is waterprcM, but .has not the, objectionable feature of rubber and similar material, as it allows the air to circulate through it. Till© fabric is also quite supple, and this is especially necessary, so that clothing can bo mado of it. As the French army department is looking for the best method of waterproofing which can be used for military cloaks 'as well as for touts, some experiments were made, and it was found that the above process was the best, according to the opinion of the best authorities. This is especially true now that acetate of alumina solution can 'be found k>n the market and does not need to be prepared especially. M. Balland recommends a bath of o<ne part acetate (Tdc'g. B.), 'and forty parts water. Fabrics are soaked in it for 24 hours, and are then dried in the air. This method is being used in the army ■headquarters at present. AUTOMATIC STOKERS.

A pamphlet issued by the British Xiclausse Jioil&r Company gives details of the Xiclausse automatic stoker, wdm-h is claimed to mix the fuel to assure equal thickness of it over the gvn.te, to prevent the formation of holes, and to detach tiro clinker. The .stoker consists of «. number of "elements, ' eacli of \rhicli is formed by two steel plates about Bft long, bnited together at the ends, with distance pieces, so that a channel.about one inch wide is provided! between the plates which carry cast-iron stepper lire .bars. A number of these elements, depending on the width of the grate, are placed side by side at an j-.nrrlo of about 9deg. from tihe horiKf'-iti'l, sufficient space being left for tho admission of air, and each of them receives a gliding motion from cams on a. rotatng-abaft. The ibars at tihe front of the grate, where the coal is admitted, dlo not admit air, and act as a dead-plate. "The middle part of the bars, where the largest amount of air is required, is designed to form the air passage, tihe air being reduced towards tihe .bade 'until at the end of thle grate none is .'ittlmitted. The pit for tihe reception of the ashes is situated at "the'end of the grate, from whcli they may be removed either by band' or hy mechanical means.