SCIENCE NOTES.

Otago Witness, Issue 2399, 22 February 1900, Page 58

SCIENCE NOTES.

—No field presents a broader range for inventive genius than electricity. But a few years ago electricity was little known, and but trivial application was, made of the subtle force which to-da> is seen everywhere. Step by step it has gone onward, each new success inspiring the tireless woi'kers to new and greater endeavour. In more than one city of the United States, says the Mining and Scientific Press, fortunes were sunk in the earliest electric railways, which were unsuccessful. Now this means of applying power to city railways is all but universal. The fiist transmission plants were disappointing and far more expensive than the instalment of similar capacity under like conditions at the present time. Forty thousand volts are now to be transmitted over 90 miles, and it is not unlikely- that not only the amount of pow&r, bm also the distance over which it may be transmitted, will soon be greatly increased. What may come of experiments in wireless telegraphy can only be surmised.

—Mr G. J. Symons, the eminent meteorologist, appeals for additional rainfall observers in the United Kingdom, so as to make the records of the next decade even more valuable than those which have been kept 'during the last 40 years. There are already 3500 observers at work, but this is not sufficient it our knowledge of the rainfall and water supply of the British Isles is' to be full and exact. It is mostly in the remote districts of Ireland and Scotland that the need for new (stations is felt.

. — "It is very hard to realise that the voice one hears over the telephone is not the voice of the pirson who is talking," raid an electrician, chatting about the oddities of the Vmsiness to a reporter of the New Orleans Times-Democrat. "It seems exactly like t':e real tones, drawn out thin and small and carried from a long distance by some mechanical means, but it is not. When one speaks into the inji rumonl, a little diaphragm, like a drum-head, begins to vibrate, and each vibration send° a wave of electricity over the wire. These waves set up a mimic vibi_atuni in another diaphragm at the opposite end. which jnrs tho air and produces an imitation of the original That's not a very scientific exnlanation, but it's accurate. The autograph-telegraph, which makes a fa'ceimile of handwriting, is a fair paiallel. You ■write your message with a pen. atiuehed lo a special electric 1 apparatus, and i licilo i"Jr Fyphor. n rV> oHier end of the Yir.o exactly initat"- -'-v dot nnd cuno, The irt.ul',. Beem« lite the real thing, hvt it is lrcroly a first cla-?-; counlerfpit. It's the same way exftcMv vitb th" voicT in thp 'phono."

— Engineprivg gi'-cs a description of the most powerful ]ncoaioHvp in the world. It ha= a total eight of 232,00011). or ibout 103 tons. The tolal whenl-baso ol the enginp is 26ft 6in, of which 15ft Qin is the dm ing wheel-base. The total wWeel-Laso of entrine

and tender is 55ft 2iin, and the total length over engine and tender 65ft 7|in. The centre of the boiler is 9ft Bin above the rails. The height of the funnel above the rails is 15ft sin. This engine was built at the Brooks .Locomotive Works, in America, and will run on the Cairo Division of the Illinois Central railroad between Carbondale and Fulion. The steam pressure is 2101b per square inch, and is generated by 3500 square feet of heating surface, of which 5237 square feet are in the tubes, and 263 square feet in the firebox. This latter is 132 in long, 42in wide, and 90in deep in front, and 81^in at the bar 1 ':. The grate area is 37.5 square feet. The steam is u. c ed in two cylinders, each 23in in diameter by 30in stroke. The cylinders drive four coupled axles, on which are wheels 57in in diameter. The tender has a capacity of 7000$;al of water and 12 tons of coal.

— Magr.alium, says the Electrical Review, London, is the name of a new alloy of aluminium and magnesium, discovered by Dr L. Mach, which is said to possess valuable properties. The addition of magnesium in quantity not exceeding 30, and not le»s than 10, parts by weight to 100 parts by weight of aluminium imparts to the latter metal properlies which, in the puro condition, it does not possess, without raising its specific gravity (2.64-) — on the contrary, slightly lowering it, since the specific gravity of magnesium (1.74) is even less than that of aluminium. The addition of magnesium produces an alloy which is harder and is easier and cleaner to work than pure aluminium. Turning produces a purface as bright as a mirror, and shining like salver, the metal coming off in long spiral turnings. The alloy files clean and regular ; without, tearing, or choking the file, as aluminum does. Deop and sharp S!tpw threads can bo ciit on it, and very clean holes can be bored out. The colour of the metal resembles silver more than aluminum, and it takes a high polish. The hardness and strength of the alloy are considerable; the hardness can be varied by varying the proportions of aluminium. An addition of heavy metals is not only unnecessary, Irat is positively injurious, since this deteriorates its working properties and increases its specific gravity. Previous attempt-s to make useful alloy? of aluminium and magnesium are said to have iailed owing to the aluminium not being pure. This point, i? of great importance, and aluminium made by an electrolytic process mu&t be used.

— Industrial strikes generally do far more harm than good, and represent a lojs to the community which cannot be recovered. But occasionally a strike will lead to the introduction of new processes and methods which prove to be of value. The leeent plasteiers' stiikc in England has, for example, called attention to a method of employing metal fronts to house?, and as a substitute for lath and plaster ceilings, which has already been employed successfully in America. The British consul at Philadelphia expresses the hope, in which all will concur, that this new application of steel will be taken up by manuf.'icburers in Great Britain.

—Mr Thomas Edison, jun., thinks that he and a friend of his have solved the problem of telephoning acroos the ocean. To a representative ot the New York Commercial he if reported as sa}*ing: "Contrary to the general impression, we have found that it will not bake a very powerful current Io send a message aoro-s the ocean. AYe have taken more than 3000 miles of wnc and subjected it to the same pru.-aure and wmo conditions as nearly as possible a<> those of the ocean, and we found that our devices were successful. We submerged the spindle on which the wire was, and subjected the wire to a heavy pressure, and at the same time made the swindle revolve at tha rate of 10 or 12 revolutions a minute. 'It v. k-s found that the «oiii>ds •>vorp carried "'cry distinctly. Of course wo do not fxocct to send °. mc>'a»o s>irninlit nrn,s>s -virhovit sinv delay, for that would be hnpo-wble with ovr prc-cnt conditions of el' cirical device?. II has bee.) decided that ore relay in die ocean will be sufficient, and there the moj-sage will bo ic. a ent by :> nKcV>-i:iical device."' It will be noticed that in tlr- above interview Mr Editor. ]un., dort not -late how he pvopo^p^ to overcome the difncultios that have lior^loforo mads long distance ocean telephony impossible. With but on. lelnv station, loented in mid - ocean. a nicbiitse would have

io travel a distance of about, 900 miles, whereas, up to the present time, owing to static induction in long submarine telephone cables, which, as is well known, changes the quick, short sound wave-; into long, slow vibrations, impossible for the human ear to detect, it has been found impracticable to make use of telephone cables over 30 miles in length. Possibly Mr Edison, iun., has discovered a new force, Oi some properly of electricity heretofore unknown, for. as his father once said, "'Nobody will be able to telephone directly from Europe to America until some force more powerful than electricity has been discovered." Is it likely thai: the son will succeed Mhere the father freely acknowledges he ha? failed ? — From Electricity.