OUR PUBLIC SCHOOLS COLUMN

Otago Daily Times, Issue 16288, 22 January 1915, Page 3

OUR PUBLIC SCHOOLS COLUMN

FOB SENIORS AND JUNIORS. (Conducted by Maoister, to whom all communications must be addressed.) [Msglster will be glaa to receive Nature Notes, marked papers containing educational article?, diagrams, details of experiment*, etc., ol scholastjo Interest to teaohers and pupils. Correspondents must use OKL.T o)l SID* ol the paper, anil whether using a pen name or not, must send both MAUI and addbbss.] "HOW A BIG GUN IS MADE." Recently I promised this short article from "The War : Nelson's Picture Weekly.' published at 3d net. A fuller and more elaborately illustrated article appears in on.' of the recent issues—l haven't the date—o. the Navy and Army Illustrated, a -weekly published at 6d. Tho number lor October 17 contains an illustrated article on " lh> ' Soixante-Quinze,' the Wonderful I'rcncli 75-millimetre .Field Gun." Until recently our biggest picce of ordnanco was the 12 n gun, the largest in us> in cither tho naval or land servico of Britain. Starting from the inside we have—(l) the inner A tube, which is rifled; (2) tho A tub?; (3) wire wrapping; (4) the B tube, extending for two-thirds of the length from the muzzle towards the breech; (5) the breech jacket.. , r Tho A Tube.—T he part to be made first is tho inner A tube. For this a huge solid steel ingot is cast, weighing upwards of 30 tons. The cr.ds having been cut off, tho ingot is mounted in a lathe, and a tube-like ''trepanning" borer removes a long core from the centre. The ingot is then dismounted from tho lathe and heated. A long hollow 7 bar, somewhat smaller than the destined bore of lie gun. is passed through tho central hole ; and tho ingot is placed under a 2500-ton forging press, which gradually thins olid draws it out along tho bar, which is kept cool by water circulating through it. The forged tube is next rough-turned outs de and rough-bored msidc. It has then to bo tempered. A huge 100-ton gantrycrane seizes tho tube by one end and lowm it into a vertical furnace heated by gas. Then it is drawn out and dipped into a deep vertical tank filled with many thousand gallons of cotton-seed oil, which gives it the required tornpar. The A tube is made in like manner, and bored to an inside diameter slightly less than that of tho inner tube. Tho inner A tube is let down into a pit, and the other, after being expanded sufficiently in the heating furnace, is lowered so as to slip over it. The heated tube decreases in length as well as in diameter as it cools, and unless great precautions were taken it would naturally cool at tho ends first, and, bv gripping the " inner A" tightly there, cause the central part of the tube to cool in a state of dangerous tension. To avoid Fuch a thing happening, one end is cooled artificially by moans of water jets, while the other portions are heated by gas flames. One Hundred and Seventeen Miles of Wire.—After the A tube has been turned up it is " wire-wound " with a ribbon of steel a quarter of an inch wide and onesixteenth of an inch thick, tested to a tension of 110 tons to the square inch of section. This wire is coiled on a drum supported by a carriage travelling the whole length of the lathe. As the wire comes off on to the gun the carriage is moved along at such q, pace that tho coils touch one another laterally as they are formed round the tube. A 12in gun is wound with 14 layers at the muzzle and 75 at the breech, the total length of wiro used being about 117 miles—the distance from London to Bristol,—and its weight nearly 14 tons. It is necessary that the tension of tho wiro should decrease with every successive layer to avoid undue stress. This is effected by passing the wire as it is unwound from the reel, through dies of hardened steel with slightly curved surfaces. The dies are pressed together by a scries of levers and weights, and by altering the positions of tho weights the tension can bo adjusted exactly. After wiring, the surface undergoes " skimming" to ensure perfect truth, and the B tube, which has been prepared meanwhile, is shrunk on in the manner alreadydescribed; and the breech end is similarly encased in its stout jacket. Tho A and B tubes and' the jacket give the gun longitudinal stiffness, and' the wire greatly increases its strength circumferentially. Rifling.—Having been bored onco more and finally, the gun is fit to have the spiral rifling grooves cut in the bore. These, as you doubtless know, are necessary to give the shell the spin which prevents it froin turning head over heels during its flight through the air. The rifling is done by a long, hollow steel rod, which carries three tools at the end to cut three grooves at once. Tho tools act only as the rod is withdrawn. To impart to them the twist necessary to produce a spiral cut an ingenious device is employed. A gun has, speaking roughly, two grooves to every inch of the circumference of the bore, so that in a 12in gun about 75 grooves would be cut. Eight to a dozen journeys of the tool are required to finish a groove; therefore, the slow-moving cutter may have to bo drawn out and thrust in somo 900 times before the rifling is complete. Worth £10,000. —As the rifling comes so near the end of the manufacture of a big gun, it must be conducted with tho greatest care, for a single badly-cut groove would spoil the gun, now representing perhaps £10,000 in work and material. The bore baing finished, the brecch ond is chambered out, and has deep threads cut, in the rear end l for tho brcecli block to engage with. The block moves on a hinge, and is a very massive affair, though, thanks to the presence of certain levers and the perfection of tho workmanship, anyone who has tie knack can move it quite easily. The pressure of the exploding powder is so great that gas will pass the most carefullymade block unlets it is furnished with an " obturator pad," a flat circular canvas big attached to the inner end.

From first to last a 67-ton gun takes about a year to construct. The mountings, which are made simultaneously with the gun, are of too complicated a nature to bs described here in detail. When all the parts come together the gun undergoes a firing test, and if these are satisfactory is handed over to the purchaser.

MADE. IN THE BRITISH EMPIRE. ■Some time ago a reader sent me the Ten Commandments, as compiled in Germany, 'iney were written from a commercial poult of view, and made it appear as if it were high treason to buy alien goods as long as it was pcesible to procure German. I'iie table i 3, sunpiy, ''Support local industry, ' "writ large." I intended publishuig tlie table, but toave misplaced it. 1 ao not know mat there has been a corresponding Ten Commandments lor Great .Britain, or, better still, for the Empire; if there is not sucii a table, then, we must compose one, and take it as our guide. Teachers should study this, as other questions, dealing with the solidarity of the Empire and its development, and educate children to see that any commerce given to a rival, if it is possible to develop that commerce within the Empire, is a source ot weakness to us, and of strength to the alien. Until the war is over, and a working agrceinen has been urriced at between the units of the Empire, we may take the following as our creed —I think it was Chamberlain who enunciated it:—l believe in the British Empire. . . . I believe in the British race. I believe that the British racc is tho gPsatest of governing races that the world hav ever seen."

The present wax has startled many by showing them how dependent we have been upon Germany for many of our supplies, requiring high technical skill to producc—l am speaking, of course, of the Empire, not of our dommionette. And what is the result? Frectrade Britain is now engaged in subsidising industries, and in some cases is uctually controlling them. Frectrade may be the correct policy for the Homeland, but", looking back now and counting up what the loss of industries has cost us, what it is nowcosting through high prices and dislocation of trade, one wonders whether Britain would not have consulted her own interests by retaliating upon Germany, Austria, and other countries crushing her industries bv their bounty-fed and othewise protected manufactures. These nations may bo injuring themselves; but they may have injured us, also, by extinguishing our industries and in wiping out capital. Further, in times of stress, like the present, when we wish t-o resuscitate an old industry or est.iblish a new one, wo find we have not the capital to spare, or. if we have, that wc have not the experience or the experts to make the industries successes. Think it out. In a smaC way we are doing this when supporting local industries. The Canterbury Industrial Association suggests tho as an educational factor, of a pamphlet, to be circulated in our schools, recommending the use of dominion goods. Why not go a step further and organise a crusade in favour of Empire productions? Two points must rot be forgotten, however. We should not. attempt to establish hot-bed industries, unci manufacturers should always aim at producing the best, and be in no way beat'n bv aliens.

The w;.r has certain!" undo the Honi" folk think-. I.et us buck them up. and lyf us give one instance of how we can do it. Next, year, for instance, buy British-made toys. Up to now 75 per oont. of the toy? soid in the British Empire have been foreign make, mainly German, nr l>ought through German agencies. Birmingham and other British centres are now attacking this problent- The other day .1 saw samples of toys produced at the Chad Valley work ,

llarborne. iuid Birmingham, a company specialising m Toddy boars, stool drawing pins—tho latter were all produced in 'Germany before,—erasing rubber, tin toys, and wood blocks. Until olio has a chat with a representative of an industry one has no conception of what is involved. For instance. in the making ;>f a penny tin toy, it is ncccssary to have a sot of dies, perhaps half a dozen, any one of which may cost £20 or more, unci before any profit can |x>ssibiy accrue 1000 gross of Ibis particular toy must be marketed. Sometimes the material u«i'd is comparatively expensive - that used in tho making ofTeddy bears, as an example. Hero, the initial cost is very groat, because employees must bo paid while learning what is a new industry, ami in becoming proficient. they waste a considerable amount of material. The making of toys may appear to be a minor industry to take to " illustrate my point, but, under tho auspices of the Board of '1 ra.de, there is about to be hold in London nn exhibition of toys and games previously made in Germany, but. now made in England by about 500 firms —thai, is the number exhibiting, though there may be other firms manufacturing but not taking pari. I might add here that the representative of the Chad Valley Works showed mo a large appropriately designed and coloured cardboard placard coated with washable gelatine and announcing that "We sell British-made goods." I hope no wholesale house or retail establishment will exhibit that placard as a cover to sell alien manufactures. GERMAN CHEMICALS. But the making of toys 16, after all, but a minor industry, and not requiring a lifelong technical training. Toys can be done without, but not so dyes, chemicals, and special medical preparations. The making of these means years of specialised preparatory work, and always progression. In Britain many large industries almost came. to a standstill 'because of the cutting olfl of supplies of Gorman chemicals and dyes. The following taken from the Now York Times of November 15, gives a slight idea of what the German dye industry is. Hie consignment left Rotterdam, October 30, and arrived at Jersey City on November 14. Tho Matanzas's tonnage is 3200 tons. I am leaving in tho names of importers to show how largely the foreign element enters into the commercial life of tho United States: —

Tho Matanzas's cargo, which is practically a capacity one for this ship, represents tho first large dircct consignment of colours to be sent to this country from Germany since tho outbreak of tho European war, and was arranged for by a special committee of dyostuff importers. Tho committee had the co-operation of the Department of State and tho German authorities, who expedited tho passage of the goods out of Germany, via the Rhino to Rotterdam, where they were put aboard the Matanzas.

An inspection of tho Matanzas's manifest shows that, she brought good-sized quantities of almost all tho colours and ingredients so urgently needed by manufacturers in this country. While the consignment of indigo paste is not as largo as had been hoped for by some of the colour handlers, a sufficient quantity was received to help out until the arrival here next of tho steamer Sun, which is following the Matanzas.

Altogether, about 12 firms engaged in the dyestuffs importing business in this city, were the consignees. The Cassella Colour Company was the largest individual beneficiary, this firm receiving 3984 casks manifested as "coal tar dyes." The Farbwerkc Hoechst Company came next with 3,489 casks and packages of dyestuffs of all kinds, while William A. Mitchell, acting as agent for the Badischo Company, followed with 2229 packages. Other consignments were as follows:— Geigy ter Meer, 625 casks and packages aniline colours; William F. Wiener, 459 packages aniline colours and 10 casks metachrome mordant; Edgar Fischer, 626 casks coal tar colours; Geisenheimer and Co., 3 cases and 496 casks aniline colours; C. Bischoff and Co., 29 casks aniline colours; Heller and Merz Co., 107 casks anilino colours, and Bayor and Co.. 1900 casks aniline colours. The goods consigned to Bischo and Co., a banking and commission house, are understood to be for the account of one or more textile manufacturing plants who bought dircct. The Farbwerkc-Hoecbst Company's consignment is typical of the rest of the cargo carried by the Matanzas. This firm's consignment contains such items as 206 casks or sulphur colours, 200 casks dyeing materials, 148 casks alizarine colours, 335 casks dyeing materials and allied products. The Cassella Colour Company received 1054 packages of indigo paste which, so far as could he learned, was the largest single lot of this class of merchandise brought over by the dyestuffs ship. Other firms received smaller lots. There were goodsized lots of alizarine paste, the Cassella Colour Company taking 524 packages, wISi other firms importing smaller quantities. The same concern received 214 casks of dry alizarine paste. The indications are that from now on fair quantities of dyestuffs will roach here from Germany in monthly instalments based on the average American consumption per month, the nast five years being taken as a basis for the allotment to be made by Germany to this country. The dyestuffs must be brought here in a vessel flying tho American flag, as was the case in the Matanzas's shipment. Tho German Government further requires a guarantee from the importers that none of the colours of materials shall be re-exported. Unloading of the cargo will begin to-morrow morning. This illustrates another point. Patriotism and the war cause us to give up Gorman good.i. We are blocked from using "German chemicals, biit Germans are selling to other Germans in the United States, and possibly to companies or men having liiuri cial interests in Germany, so we deprive ourselves of these goods and at the same time are helping other rivals—indeed, possibly buying from tho United States what otherwise we might have got from Germany. for the Americans—l don't like the "word ; Yankees,' but Americans is too embracing—are slim enough to outwit the Boers. "MADE IN AMERICA."

Now, what applies to Germany applies to other countr.es, too. Tho British .umpire is so world-embracing, covering all climes and products, and races, that there is no need to go beyond it for all p-ossi ble requirements. There is no reason why wc should not have a preferential arrangement within tho Empire, and a supertax upon alien productions. If the Indians, Canadians, and we- as Australasians, —others within the Empire, too, of coarse—are willing to help to consolidate the Empire, should we not give preference to one another as against outsiders, whose trade with us will weaken us and strengthen them ?

I have just referred to a shipload of dyes—the indigo paste being, no doubt, the synthetic dye the Germans have spent years and hundreds of thousands of pounds in perfecting to make themselves independent of our vegetable indigo—sent irom Germany to America. The dyed stuffs will compete with the British in neutral markets, which Britain is supplying. If, then, the United States are now using tho war as a detriment to our Empire, shouldn't we in self defcrc.e, protect ourselves from the United States? No one can blame us for protecting our own.

I have by ine as I write Collier's Weekly, da-ted December 5. One page has the captions: "Merchants prefer American goods" and " Customers have been the stumbling block." Then follows a full-page article in three or four kinds of prominent type—and underlined iri places, at that —urging the purchase of American goods, but emphasising at the same time tho necessity of produring a superior home product. The following four paragraphs show the line of reasoning adopted. Cannot we substitute British Empire for American? — "A hardware jobber says that his business would be more profitable and satisfactory if he could get everything in this country. Foreign -manufacturers rarely make deliveries in less than five months. Estimating stock demands for half-a-year ahead is difficult even in the most staple lines. The jobbing houses of the West base their trade estimates on crops. Wholesalers of the East add to tlrs factor an estimate of indutrial conditions. Buyers study their markets hard, but they are not propluts. and stocks~ ordered so far in advance are , ; pt to be either too small or too large. "The hardware jobber as well as the wholesale grocer would be glad it all their wants could be supplied in America, liotn of thorn have factories of their own in wh'eh they are already introducing processes for making some of the tilings they have imported, and they are working with

wilier manufacturers to make sure that they can get in this country nearly all of the things that Europe formerly has furnished. " If the public will give American goods a fair trial it will be found that the war lias caused us, as consumers, a very sliglii loss. There are few ot our needs that cannot, be better tilled at home.

'■ It is iiniicc. ;»s -try to develop a prnjudiee against foreign goods. ll is essential only tliut we have no prejudice aga.nst any goods whatever —that we give American goods a chance to show that they are as good as, or better than the things we import—and to prefer them when they are as good or better."

The editor concludes his anpnal in these wo'-d.-;. in extra large type. What do you say about it V —"The whole matter is

squarely up to the American consumer. It is tho consumer who has demanded the foreign label —it jnust be the consumer whu now demands the American label. Lets present, a united front in favour of fanplay for goods made in U.S.A. We must remember that tho Americans contain a largo Gorman and Austrian leaven, and that leaven by its pro-German sympathies is prolonging tho war. Ihe dignity of tho nation was touched when we searched for contraband, but neither dignily nor morality seem to take into account, the largo loss of life and the millions of money wasted through the means of prolonging the war getting into Germany; nor did it strike these hyporsonsitives when tho.ir dollars were endangered, that they might have protested against. Germany violating the neutrality of Belgium, dec-troying universities, cathedrals, buildings, and works of art. that are really world possessions and not national, and mercilessly treating as enomiog an inoffensive people w'ishing to be left alone. If Americans will raise no objections to the disregard of tho elements of the religion they nominally profess, but wax indignant wnoit t heir poeki t.s are touched, then in the interests of civilisation, just, as wo are teaching the Germans that might is not right, so we must teach the Americans dollars aro not to bo the measure of right either.

The New York Times, November 29, said that on January 15, there was to bo an international Socialists' gathering at Copenhagen. "London is market for fighters' needs is a caption in the same puper. In tho article it says that "tho combined purchases of those commissions | Britain, Franco, Belgium, Servia, Russia] make London to-day tho greatest market in the world for practically everything that fighting nations neod. The weekly total of sales is already colossal, and, over any week ond almost the wreck of war may prostrate somo Continental commercial centre and thereby swell this total by millions of pounds. And the part, which tho United States plays in this titanic buying has passed from an open secret to an obvious fact." It seems that, tho United States wants not only all she can get of the trade of the Allies, but. squeal if wo do anything to lessen their trade with the enemy. Tho Americans aro out for tho golden eagles every time. Last week I askiyl if any reader could supply me with a copy of Bernard Shaw's paper "Common Sense About the War." and am much obliged to " Old Boy" for sending me a copy. In the meantime, howover, I got it in throe instalments in tho New York Times of the date November 15, 22, and 29. "Old 1 Boy's" copy is issued as a supplement to The New Statesman, November 14. I always like to read the other side. I haven't yet rea<l Barnard Shaw's paper, but a cursory glance at it appears to show that in this instance, as in others, he has a mental obliquity which warrants one in ignoring him. Unfortunately he can bo quoted in Germany to give Germans a wrong impression of the attitude we have taken up, and a wrong impression of British public opinion; whereas those in Britain holding his socialistic opinions do not back him up. I may give a synopsis of the paper in a week or two; but he misrepresents so much or gives so many not half —but hundredth— truths, that, to quote and to correct would occupy too much space. A fortnight ago I promised some notes on tho making of big cannon. All being well they will appear to-dav. Next week may give somo notes oil tho French 75millimetre field gun, and the mitrailleuse, in each case culled from articles in tho Navy and AVmy Illustrated.

The other day I saw somewhere a refer once to Robert Blatcliford's reply to Bernard Shaw. Can anyone oblige me with tho reply in full? Some afternoons ago Mr Clegg, who with two young iadies had such an anxious and exciting time when returning from Europe, gave me somo most interesting notes which I hopo to reproduce next week. The brief outline in tho Times a week or two ago show that very few would care to repeat their experience.

The New York Times of November 29 contains a fairly full bibliography of the war. Copies aro procurable in Dunedin.

A book all should read who have not read Bernhardt® " Germany ar.d the Next W r ar and even if they have—is "Britain as Germany's Vassal." It, was Bornhardi's last work,l think, and appeared in Germany iust before his death in 1913. The title, however, in tho original was "Our Future—e — a Word of Warning to the German Nation." The change of title is duo to the translator. In tho book Bornhnrdi adversely criticises both Emperor and Chancellor. THE YATERLAND. Tho Hamburg-American liner, the Vatorlam], which was launched late in 1913, is tho finest specimen of ship-building in tile German mercantile marine. As soon as war was declared »he took refuge in New York Harbour, and has stopped there over four months, paying harbour dues. Recently we read that a London firm of furnishers had supplied a great proportion of the fittings, but had not been paid, so now a writ of attachment has been posted on the mast. It. is thought by many that the war will probably last- through the coming summer in the Northern Hemisphere, in which c-aso before the ship gets free it, will have eaten up a large proportion of its value in interest, harbour dues, insurance, and debt obligations. The following particulars of her are taken from the Navy Leicue Quarterly, for .Tuly :—■ i

"The Vaterland, built bv Blohm and Voss. of Hamburg. has much iri ooramon with the Impcrat-or, wh'eh ha? been running' for about, a year, but is over, bigger than the latter, having a length of 9C6ft as against the 85:0 ft of the Imperii tor. beam 100 ft against 93ft, and gross tonnage 58,000, being 6000 tons more than the Imperator. The Vaterland lias four turhines of 60.000 h.p , and 46 water-tube boilers. On her steam trials she did 25.84 knots, with 90,000 shaft h.p.. and it is expected that she will maintain a speed of 24 to 24£ knots. The Vaterland is therefore not only the largest, but also th''> fastest ship of the German mercantile marine. " The coal consumption for these giant liners is about i:000 tons. The internal arrangements and fittings of this new ship, which in all represents a value of £1.750,000, are as practical as they are sumptuous. " Particular attention has also been given to safety arrangements against dangers by water and fire, und buoyancy, in case of danage to hull, is insured by watertight bulkheads. Danger from ice. particularly to ihe bows, is guarded against by dividing the forward cargp space into several watertight decks, while the rest of the forward space back as far as the engine-room has been fitted with a double watertight hull and deck. Anti-i'oiling tanks increase the passengers' feeling of safety in this floating city, which is capable ot carrying in all more than 5000 persons. '