NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXIII, Issue 7758, 2 October 1886, Page 4 (Supplement)

NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

A NEW HYDRAULIC MOTOR. Tap utilisation of hydraulic power for domestic and other purposes is not a- new "if but the invention made by Mr. H. D. Pearsall, C.E., in this direotion has the advantage of greater economy than any other M yet suggested. On a small scale this invention is known to engineers as the com. HQpn hydraulic ram. Mr. Pearsall's machines are also oalled " rams" by that gentleman, out their action is so superior to that of the Machines known by that appellation, and they are available under such very different firoumstances, that they should really receive a distinot name. The maohine consists ?JV lr ? n pipe ending in an air 'vessel,, with which the pipe communicates by some ordinary valven. Immediately -under the air .Vessel there is a hole in the pipe (extending oound the whole peripheri), which is alternately opened and closed by a hollow sliding cylinder, moved up and down by a small motor worked by the air from the air vessel. _ This is the whole of the maohinery, -and with any water power which may be available any kind of pumping can be done by this simple maohine alone. The water power is oaused , by means of Pearsall's rams (without any pumps or any additional maohinery whatever), to compress and force si*| instead of water through small pipes, Habere the compressed air is used in the same way as steam to drive dynamos. 51 The appli< cations of this machinery are various, such as, for instance, for water supply for a town, water-saving apparatus on locks, and com* pressing air for working rock drills, etc. > LONG-DISTANCE TELEPHONY. At the meeting of the Society of Telegraph Engineers and Electricians held recently, Mr. "V H. Preece, F.R.S., read a paper on distance Telephony.." The papeu dealt with the question of working at a •distance between town and towns for commercial purposes, as distinguished from mere distance speaking with the view of seeing how far one could speak. Speech has been transmitted over 1000 miles of open wire, but it was difficult to speak over twenty miles of cable. The development of telephones in the United States has been enormous. At the present time 325,574 instruments were in use, while in England there are only 13,000. London was not even the chief centre in Europe. Berlin exceeded it, while Stockholm had nearly 'as many subscribers. New York and its neighbourhood alone had as many instruments as the United Kingdom. The disturbances to which telephones are liable, and their remedies, Were fully detailed in the paper. Speech , was now perfectly practicable to distances of 100 miles. Inter-urban connections in the United States were very extensive, from the 42,461 miles of' wire, and they earned £107,600 a year. v The longest distances were about 100 miles; the toll was Is for five minutes''conversation. This business did not pay of itself, but it paid indirectly by attracting subscribers to local exchanges. he greatest development of the system in this kingdom had been in Lancashire, and also in the neighbourhood of Glasgow, where the local telephone companies had been very enterprising. In Europe it had been principally adopted in Belgium, where all the large centres were in communication with each other on M. Van Rysselberghe's system, which utilised the telegraphic circuits for the purpose. The Post Office had carried out a large inter-urban system in the neighbourhood of Newcastle, and in South Wales very great improvements had been effected. The author remarked strongly on (the policy that had restricted so closely the development of telephony in England, and expressed the opinion that if it had been under the control of the Post Offioe, there would have been a very different tale to tell, ' A POCKET SEWING MACHINE. A number of gentlemen interested in mechanical engineering attended at the offices of Invention to examine a novel and ingenious invention, the work of a German gentleman, which, from its portability and the cheapness with which it can be produced, is doubtless destined to become exceedingly popular. The invention takes the form of a lockstitch sewing machine, working with the same rapidity of the ordinary treadle maohine, feud turning out well-finished work. The peculiar features of this little wonder are its weight, size, and simplicity. The maohine is totally unlike any sewing machine hitherto invented, and, strange to say, does not contain a single wheel in its composition. In form it somewhat resembles a mechanical hand stamp; it measures Sin.* long by 2in. wide, and weighs but 10az. To work it, it is only necessary to fix the clamp attachment ■to the edge of an ordinary table ; and having placed the material to be worked in position, to ; press the head of the sliding bar at regular intervals. Apart from the exceeding ingenuity of the invention, which comprises the entire working principle of a full-sized machine, the "Moldacot" sewing machine points to a little short of a revolution in the production of domestic machinery, and nerves as an instance of what can be done in this way at a price which seems almost marvellous, the retail coat of the machine being only half a guinea. THE HFBEKLEIN BRAKE. A number of gentlemen interested in the question of safety in railway travelling visited the Colne Valley Railway recently to witness a series of experiments with the continuous and automatic Heberlein friction brake, which has been adopted on that line. There were present, among- others, Colonel Le Meaaurier, R.E., and Messrs. Burnett, Imray, Walmisley, Ridley, Merton, Colam, Lennox, Macao lay, etc., together with the Hon. W. : Massey Mainwaring, Captain Fairholme, , R.N., and Mr. A. G. Fenn, C.E., as repre- | renting the Heberlein Brake Company. Mr. Nasford. the general secretary, and several , of the officers of the Amalgamated Society of Railway Servants, by which the questions of i improved couplings and efficient brakes have > of late been taken up in so praiseworthy a [ manner, also attended the trials, which com- , prised, amongst others, the following :—A bridge, supposed to have been carried away, . and the danger only observed by the driver on rounding a curve at high speed at a disl tance of about 150 yards. The train was t stopped by the driver alone about 30 yards 1 short of the bridge. An axle, supposed to . have been broken, and only remarked by the » guard in the rear van, who stopped the train ; at once, without the steam being shut off. j Supposed rupture of a coupling, when the train stopped automatically on the brake cord ■. giving way. The train of carriages, with the ' engine attached, was then worked down an ' incline of 1 in 75, by the guard in the post 4 van, who regulated its speed at pleasure. | A WIBE TESTER. A wire tester has been constructed by i Messrs. W. H. Bailey and Co., of the Albion 1 Works, Salford, for the use of the South Australian Government Telegraphic Depart- • ment, on an improved principle, especially 3 designed by Mr. W. H. Bailey. The tensile r strength of the wire ib tested in an ingenious 1 manner by means of a column of mercury, • and when the wire breaks a back pressure 3 valve prevents the return of the mercury, 1 . ( so that the breaking strength of the wire iB , thus exactly indicated. There is also a t diagramic attachment used with the machine, i which indicates on metallic paper the , elongation of the wire before the maximum 5 breaking strain of the wire iB reached. _ Tho arrangements of the machine are so simple - that levers and springs are entirely dispensed • with. [ MISCELLANEOUS. . 1 Dr. Fothergill, a greatly respected English f authority on dyspepsia, speaks strongly in b favor of milk puddings and stewed fruits for i tho dyspeptic, the bilious, and the gouty. He I says " Sugar is undoubtedly objectionable , to many, but it is by no means necessary to j add sugar to stewed fruit. If the acidity be 3 neutralised by a little bicarbonate of soda, the natural sweetness of the fruit will be r brought out, and the dish be made more j agreeable than though artificially made sugar r were added." , ~ _ . j The following is given by the Boston - Journal of Commerce man . excellent cement for leather- belting Common glue and 1 isinglass,; equal partu, soaked for ten hours 1 in just enough water to cover them. Bring r gradually »to a boiling heat and add pure • tanning until the whola becomes ropy, or i appears like the white of eggs. , Buff off the I surface.l to be joined, apply this cement warm,. , .and clamp firmly. 4. ■ : .,. t - ' 1 Toothache often anses from acidity of the I saliva," which causes irritation and inflamma- ; tiod of the exposed nerves. A strong solution ' of bi-carbonate of soda will generally remedy > thia kind of toothache. , The mouth should i be well rinsed with the solution, and it m&y , be also applied to the teeth and gums with a - mSqer'atwy hard tooth brush. Oven three; hundred volunteer observers , arc now investigating thunderstorms in New i England in connection with the United . States Signal Service. ■