WHEN, last year, the fleet hydroplane Pioneer of the Duke of Westminster all but won the Harmsworth Cup, and showed a speed of forty miles an hour, American motor boat enthusiasts awakened to the development of the hydroplane. It was apparent that a displacement boat like the Dixie Ill would not stand a chance against a hydroplane, provided the latter had no mishap. As a consequence, a syndicate composed of H. H. Melville and Frederick K. Burnham, the Commodore and Vice-Commodore of the Motor Boat Club of Am8rica, and Mr. August Heckscher, a member, commissioned Clinton H. Crane to design a hydroplane capable of defending the cup Mr. Crane, the designer of the other Dixie designed a single-step hydroplane, and equipped his craft with two 250 horse-power 8-cylinder V-type Crane motors driving twin screws. This new boat, the Dixie IV is said to have made a speed of 45 knots for several miles. Our photograph shows her at 1181 highest possible speed during a private trial before the race. In order to win the trophy this year, it was decided that the vanquishing boat must lead in two out of three races. The first of these races was run on Labor Day, September 4th, under perfect weather conditions. The British team consisted of the Maple-Leaf III a speedy English hydroplane fitted with two 12-cylinder motors of 375 horse-power each, which is claimed to have made 49Y knots over a mile course on the Solent; the Pioneer another hydroplane designed by an American, Mr. Wm. H. Fauber, and ftted with a 12-cylinde-r Wolseley-Siddeley engine of 380 horse-power; and the Tyreless IlL a displacement boat fitted with two Brooke engines of 120· horse-power each set in tandem. The American team, headed by the “Dixie IV.,” also contained the “Disturber 11.” and the Viva,” both of which were chosen at the eleventh hour. The latter is a displacement boat fitted with four 6-cylinder 100· horse-power Emerson two-cycle motors arranged in pairs in tandem, wh ile the ' Disturber E .” is a Faub2r hydroplane, owned by Jam9s E. Pugh, )f the Chicago Yacht Club. She is 31 feet 10 inches in length, and is equIpped with two 8·cylinder Stirling motors of 130 horse-power each. As usual, the 1911 race was held in Huntington Bay over a triangular course of 7% nautical miles. Four rounds of this course were requirEd, making a total of 30 nautical miles. The start of the race is shown in the photograph which heads this article. The “Dixie IV.” led from the start, but was closely pursued by the 'Pioneer.” The powerful “Maple-Leaf Ill.” broke her steering gear near the end of the second round, and was towed to her anchorage. The “Tyreless Ill.” also gave out after covering 18 nautical miles, and she, too, was towed in. As neither of these boats was disabled so that they could not proceed under their own power, they were both disqualIfed, and in the second race the “Dixie” had only the “Pioneer” to vanquish. Throughout the first race on Labor Day, the “Dixie” maintained her lead, and finally crossed the line 59 seconds before the English boat, and more than half a mile in advance. The tme of the “Dix:e” was 511, minutes, and that of the “Pioneer” 52 minutes 14 seconds. The “Disturber” fnished -in 52; 42, and the “Viva” in 1; 04; 12. The average speed of the winIer was 35,12 knots, or 40.38 statute miles an hour. The “Pioneer” averaged 34.42 knots, or 39.62 miles an hour. As the “Dixie IV.” made 39.86 knots, or 45.83 miles an hour, in the elimination race five days previous, it is apparent that she is much the faster boat. It was not found necessary to let her out in the first race, and ev,m less so in' the second. The “Disturber II.” averaged 32.31 knots and the “Viva” 27,97. In the second race on September 5th, the “Pioneer” was sligbtly ahead of the “Dixie” at the start, but the latter overhauled and passed her on the second leg of the course, and at the end of the first round was four seconds in the lead. A heavy wooden packing box in the wake of the “Pioneer” was hit by the “Disturber II.” damaging her severely. Her owner beaehed her sdore she fi:led suffic:ently to sink. Soon after the start of the second round the British boat was obliged to stop owing to engine trouble, and during the 19 minutes she was at rest the “Dixie” lapped her and continued steadily to the finish. The “Pioneer” got under way again and was apparently good for second place; but again the unexpected happened. Her propeller shaft b: oke while on the last leg of th'» final round, and within sight of the finish. Cons2quently the laurels went to the “D:xie,” which was a minute and 32 seconds longer in covering the 30 nautical miles than on the previous day, averaging 33.43 knots; and to the “Viva,” which Lveraged 23.06, Dr 27.5 statute miles an hour. For the first time, in the race th's year, America made an excellent showing both as to speed and .e· liability. All three of our boats fin:shed the first race, and but one dropped out of the second, owing to an unfortunate accident and to no fault of the maehinery or hull. While the Duke of Westminster did not see fit to increase the power plant of the “Pioneer,” and even was willing to wager $100,000 that she would win, the men who built the cup defender doubled hel” power plant and installed two 8-eylinder V-type fourcycle motors of 250 horse-power each. The motors have a bore and stroke of 7^4 inches, and make a maximum speed of 950 revolutions per m:nute, although, in the race, they ran at only about 800 revolutions per minute. The “Dixie IV.” has twin screws, one propeller shaft being directly coupled to the forward motor, while the other is driven by spur gears from the rearmost motor. This was made necessary on account of the steep inclination of the boat and propeller shaft when under way. A novel feature of the “Dixie IV.” is the attach:ng of a metal step bs-neath the hull directly under the forward engine. ''his arrangement makes it possible to build as staunch a hull as is obtained with any displacement boat, and the action of the single step is certainly very satisfactory. The “Pioneer,” it w:1I be remembered, has multiple steps according, to the Fauber patent. In all there are five of these steps constructed in the bottom of her hull. The fact that none of the American boats gave out on account of engine trouble speals well for American motors, which have heretofore not shown up to good advantage in international or other races. The “Viva” was equipped with Emerson standard 6-cylinder, two-cycle motors, and she ran very regularly in both raee,s. This is the first ere that a two-cycle motor has been used in an international motor boat race. Despite the fact that the “Viva” is a hydroplane equipped with four 100 horse-power, extremely 1ight weight, two-eycle motors, she did not at any time develop a speed of much more than 30 miles an hour, although her regularity was very good. The “Disturber 11.” was equipped with two standard four-cycle motors of the 8-cylinder V-type, and th's boat also demonstrated the reliability of the engines besids showing fairly good speed. True to her name, she disturbed the water to a great extent, and made much more fuss than any of the other craft. Now that America has won the Harmsworth trophy for the third time in succession, it is to be hoped that our motor boat enthusiasts will keep it here permanently by build:ng other higher-powered and more advanced types of boats for the future annual races. September 16, 191 J SCIENTIFIC AMERICAN 2,5 Halos and Rainbows THE correspondence columns of the scientific jour.. A naIs are overburdened with letters from persons who have witnessed one or another of the optical phenomena of the atmosphere, and who describe the same in such a way as to give the impression that they have never opened a book on optks. Strange to say these letters frequently come from men who are more or less prominent in the sc:entific world. One can hardly escape the conviction that a large number-perhaps the majority-of physicists, meteorolgists and astronomers have profited little by the researches of Monge, Biot” Brava:s, Mascart, Pernter and other students of atmospheric op.cs. There is, for example, a particularly beautiful form of halo-the “drcum zenithal arc"-which is nearly always deseribed by persons who thus report their experience as if the phenomenon in question was one of whieh they had never heard, and which they are ('onsequently unable to eall by its correct name or bring into relation with other luminous meteors. A description of this kind appeared in Natttre for May 11th, 1911 (p. 349). The writer, who obviously had not the slightest acquaintance with the terminology of optics, referred to what he had seen as a “rainbow,” Strange to say, the editor naively concurred in this ignorant dia gnosis, and puhlished the letter under the 'eading “A Zenith Rainbow;” notwithstanding the f,act that, in a note appended to the :etter by a well known meteorolog:st the correct name was applied to the phenomenon. Several forms of halo are decidedly common, though they often escape the attention of the casual observer. At the Observatory of lontsouris, near Paris, where h2l0s are systematically watched for, the circumzenithaI arc was seen on 111 days in ten years; an aver age of one day in 33. The Saharan traveler who has ocoasion to mention a crmel does not call it “a large brown quadruped with a hump on its back.” He saves times and obviates misunderstandings by saying “camel.” On the other hand persons constantly report that they have seen in the sky a luminous appearance of such and such as size and shape along with otler particulars bhat may or may not possess real scientific interest; the gist of which is merely th:t they have witnessed the tangent-arc of a halo, a sun-pillar, a lunar cross, a parhe:ion, or some other luminous meteor that ought to be, but is not, perfectly weIl known to the majority of educated people. The Scn:NTIFW AlmKA' believes that its readers wi!! welcome the appearance in its columns, in the near future, of a series of illustrated and plain·y.. worded artIcles on the optical phenomena of the ati1osphere. The “ Mouth-organ “ Industry TROSSINGEN, in the Black Forest of Germany. is the center of the foreign harmonica industry, where most of thB world's “mouth-organs” of the cheaper grade are made. One factory alone is said to employ several thousand hands; and the numb3r of harmonicas turned out by aH the factories therB is enormous, amounting to almost a million annually. Although the United States imports a large number of the cheap German “mouth-organs,” the finer grades are made in this country, and these are held to be equal in every way to the more expensive instruments made abroad. The Germans devote some attention to the manufacture of the more costly “mouth-organs,” but their principal output is the cheaper grade. Among the finer grades of harmonicas are the kind known as “concert,” which come in sets of from four to a dozen and sell for sevBral dollars apiece. These are tuned in various keys. In one form they show six harmonicas of different keys grouped about a central stem: Many of the elaborate and expensive harmonicas are handsomely decorated with designs of gold and silver upon mahogany. The wood used in the cheaper grades is pine. Portable Swimming Tanks ALARGE and permanent swimming tank is a costly affair, especially if it is located in the center of a large city, wherB ground is valuab'e. Many German cities are provided with such establishments, but many others have been deterred from following the examplB by the great cost involved, which may be estimated at about $100,000. The swimming bruth in Munich cost more than twice this sum. Attempts to prDvide cheap substitutes for these expensive estab ishments have hitherto been fruitless. The first practical solutiDn Df the problem is exhibited at the International Hygiene Exposition in Dresden this summer and is described in Hygieia, the buEetin of the EXPDsition. This first portable swimming tank was designed by H. Recknagel, a well-known engineer of Berlin, and was opened on the 14th Df May. The basin fDr an Establishment of this kind can be constructed cheaply of concrete on any plot that is likely to remain vacant for a number of years in a centra) and accessible part of the city. The cost of a cheap basin of this kind will be covered -by the revenues in a comparatively short time, and when the land is required for building, the o:sin can be rebuilt on another vacant plot. The water can be obtained from a river, lake or spring, or even from the city mains, as the quantity of water required will not be very great if the English fltration system is employed. By continuous purifcation of the water in this way, the number of bac- teria per cubic centimeter in the bath can be reduced, according to the latest investigations, below the num: ber found in the freshly entering water. A light shed with a canvas roof which wH proteet the bathers both from the heat of the sun and from eold winds can be cheaply erected over the basin. These movable swimming baths are equipped with locomobi es which will be found useful for various purposes, including the heating of the water and the air in cool weather, thus prolonging the bathing season, the operation Df the pumps and filters, etc. The locomobile can also be employed for the production of waves by means of the simple Hoeglauer system, by which it is possible to produce powBrful waves three feet in height. 'Llis wave motion not only increases the p'easure of the bath, but presents a sanitary advantage as, according to Dr. Brieger, it effects a mechanical destruction of bacteria; it also affords an opportunity for practice in swimming in rough water which is a valuable a(:quirement. Such a swimming tank, measuring 40 by 130 feet, with tts shed, etc., can be constructed for about $20,000. Everyday Misnomers A VAST number of incorrect notIOns are acquired by reason of misleading names . . For instance, we ask for a Dutch clock. We get the kind we want, so it really doesn't matter that it is nct a Dutch clock at all, but one Df German man nfacture. Practically all the wooden clocks cal'-ed Dutch are made in the village of Freyburg, in the Black Forest. This misnomer is due to simple mispronunciation-"Deutsch” meaning, of course, German. Nothing is more natural than to assume that India ink comes from India, but it does not, and never did, any more than does India rubber. India ink is” ' Chinese product, and India rubber comes from South America. Camel's hair brushes are not made from the hair of camels, but from the hair Df the tails O Russian and Siberian squirrels. Camel's hair is, however, employed in the manufacture of certain fabrics to be made into shawls, etc., and it is sometimes mixed with silk. French brier pipes are not made from the roots of brier, but from the root of a white heath which attains a considerable size in the south of France, where it is sedulously cultivated for pipemaking purposes. The name is derived from the French bruyere, the dia'ect form of which is briere, meaning heath. We entertain a fixed idea that a centipede has 100 feet, and naturally, but we are misled by the name. As a matier of fact, this insect, taking one of the largest species, shows about thirty feet on each side.