To the E'ditor of SCIENTIFIC AMERICAN: I shall be infinitely obliged and highly-thankful to you if you will kindly take on yourself the trouble to inform me at an early date as to the truth and accu-| racy of the following incident said to have occurred in Mexico, which has excited the amazement of the people in this quarter of the globe, especially in the absence of any mention of it in your world-renowned paper, the SCIENTIFIC AMERICAN, which I have been an interested reader of; nor do I find any such reliable authority to b© referred to on the topic. The local papers here describe the descent of a man from Mars accompanied with a clap of thunder and lightning whkh put all the people of the locality to flight with the single exception of a scientist, who alone had the courage to proceed to the scene of the occurrence to satisfy his curiosity, and he is said to have described the man to be twenty cubits long, his speech being above the book of the scientist. At last, the man, as is said, after a short stay, flew away. Here I request you to throw some light on the subject which will bring us from the realm of uncertainty to tha't of truth. Your paper has proved very valuable to me. Almost all its articles are intrinsically interesting, opening to me a broad feld of scientific knowledge. It reveals to me a museum of rare objects of curiosity and wonder. I should also thank you warmly if you would inform me through your columns how far the progress of the astronomers has, in counting stars, till now gone. I have much to talk about and many things to converse upon, but the long distance stands in the way, as the paper (which comes to the engineering office and from which source I see it) takes a month to reach the office. ABRAR BAKSH. Cuttack, Bengal, India. [The key to this extraordinary letter from our far-away correspondent will probably occur to those of our readers who may have chanced to be in the locality when “Bud” Mars, the aviator, made his recent flight into Mexico. “With this incident in mind, and allowing for the errors of hearsay and translation of Mexican vernacular into Hindoo, we can see how “the local” papers came to “describe the descent. of a man (from the) Mars,” etc. To the Mexican countryman, who might never even have heard of, much less seen, an aeroplane, the descent out of the heavens of this apparition (with its engine back-firing and shooting out flame and thunder claps) may well have suggested the supernatural. In some such fashion, doubtless, were founded and perpetrated many of the llyths of ancient Greece and R ome.-ED. ] To the Editor of SCIENTIFIC AMERICAN: I was glad to see in your issue of October 7th the very clear and forcible statement of J. B. Wells in opposition to the proposed safety stop locomotive throttle. Two possible solutions of the problem present themselves. What happens when a man suddenly loses consciousness from any cause? He collapses. Must we not look to this fact for our solution of the question? It is quite possible to require an engineer to perform his regular duties standIng within a light, semi-circular guard. His collapse in any direction would immediately throw a considerable pressure upon the upper rail of this guard, which would result in the operation of levers shutting off the engine and applying the brakes. Or perhaps a preferable mode of achieving the same desirable end is by a footplate upon which the engineer stands. His collapse would remove all, or in any event most, of the pressure from this plate. This is infinitely better than having the pressure at the throttle and brake valve handle, and leaves the hands of the engineer free to perform any duties he may find neces£ary. An) difficulties pre- senting themselves may, I am convinced, be met and mastered with comparative ease. Bridgeport, Conn. ARTHUR POWELL. EThe Battleship “Orion" (Ooncluded i,om vage ML) cent” (21.9) and the “Superb” (21.62); while the four completed battle-cruisers, designed for 25 knots, have all made well over 27 knots. Principal interest in the new ship naturally centers in her armament. First of all as to its disposition: and here it is to be noted that the British Admiralty has been slowly working round for some years toward the consistent American principle of the all-center-line arrangement, which is, after all, as essential to the ideal dreadnought as unity of caliber. The second turret from aft, which in previous ships is on the same level as the aftermost, was raised so that the aftermost turret could be brought up under its guns. There is a general impression that the object of this arrangement was to increase the astern fire, but that is not so. The primary object was to save length; and although the special trials which the “Neptune” carried out in the Mediter-, ranean showed that the superposed guns •could be fired directly astern if needed, they also showed that such a maneuver was not at all advisable. In the case of the “Orion,” no attempt has yet been made to fire more than two guns (those of the first and fifth turrets) forward or aft, nor is it likely to be. So far as the arrangement of the turrets is concerned, the new ship has no exact counterpart in any fleet. She most nearly resembles the “Delaware” class, with, however, the following difference: In each case there are two turrets forward and three aft of the superstructure; but instead of the third turret from aft being raised above the two farther astern as in the “Delaware” class, the “Orion” has the second (or middle) turret so raised. In other words, the forward turret arrangement is repeated astern, and a fifth turret is placed just abaft of the superstructure, on the same level as the a ftermost. Each turret contains two 13.5-inch guns, of whose ballistics little is known outside the gunnery circles of the fe t itself. The weight of the gun, usually placed at 80 tons, is 76 tons, and its length is 45 calibers, while the weight of the projectile is 1,250 pounds. The muzzle energy, firing with full charges, is believed to be 69,000 or 70,000 foot-tons (as compared with 53,400 foot-tons for the latest 12-inch model in the British service); and the perforations of 26 inches of Krupp cemented steel at 3,000 and of 22 inches at 5,000 yards (with capped armor-piercing shot in each case) are believed to be reliable but must be accepted with reserve. For purposes of comparison it may be stated that the 13.5-inch guns mounted in the obsolete battleships of the “Royal Sovereign” class (now being sold out of the service) are 30 calibers in length, weigh 67 tons, and fire a l,250·pound shell with a muzzle energy of 35,230 foot-tons, or just ab out h alf the power 0 f th e new weapon. The penetration of the old gun (Krupp steel) at 3,000 yards is 11 inches. The following table shows the increase in the size and power of successive types' of British all·big-gun ships: ] Broad-Com- Length sid e, pleted. Type Ship. Feet. Tons. Pounds. 1906 “Dreadnought” 490 17,900 6,800 1909 “Bellerophon” 490 18,600 6,800 1910 “St. Vincent” 500 19,250 6,800 1911 “Hercules” 510 20,000 8,500 1911 “Orion” 545 22,500 12,500 The anti-torpedo armament of the “Orion” consists of twenty 4-inch 31-pounder rapid-fire guns, mounted in two groups, each of ten guns, disposed as shown in the illustrations. In the firing of the heavy guns several of the mountings of the smaller weapons were started, and .so seriously that it is understood some new arrangement for them will be found. The following sister ships to the “Orion” are approaching completion: "Thunderer,” “Conqueror,” “Monarch,” to be. completed by March 31st, 1912. “King George V.,” “Centurion,” “Ajax,” “Audacious,” to be completed by January 16th, 1913. The last four will be slightly larger-about 24,000 tons-due to better protec- .arn Repairing Watches le Teid you how WE WILL HELP YOU START IN BUSINESS This is not a correspondence school. It is a big watch repairing and jewelry concern. We give you actual practice. You can stay at home and continue your present occupatlon. You make money while you learn. WE GIVE INSTRUCTIONS FREE BECAUSE WE WANT YOU TO REPRESENT US. We mean just what we say. We will furnish you, free of cost” text-books, clear, simple illustrated lessons and photo prints showing exactly how to do each job. 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Addres8 Nearest Office, Dept. 22' National Salesmen's Training Association Chicago New York Kansas Cily Se_lIle New Orleans November 11, 1911 SCIENTIFIC AMERICAN 439 tion for the anti-torpedo guns and possibly to the mounting of larger weapons for this purpose. Of the ships of the 1911-12 programme, for which tenders have just been asked, no details are known, but it is believed they will he similar to the “King George” class. It is probable that next year's ships will be of an entirely different type-smaller, and armed with six 15-inch and a number of 9.2-inch guns. Simple Tests for Food Purity (Ooncluded from page M2.) harmful if it is present in large quantities. Further, nearly all the adulterants employed present a shiny appearance, whereas coffee always looks somewhat dull. A more rapid way of testing any kind of ground coffee is that pictured in an accompanying illustration. Take a tumbler of water nearly full to the brim and scatter about half a teaspoonful. of the grains upon the surface of the liquid. Pure coffee contains a large amount of oil and on this account the grains will float with a very few exceptions. Practically all the adulterants in use will sink to the bottom of the tumbler. The presence of chicory in the sample is at once known by the almost instant coloring of the wat"r a deep brown shade. If the tinting is very intense chicory has been added to a positively unwholesome extent. Pure coffee grains will not color cold water, at any rate not until the passing of a considerable interval. In these experiments it is interesting to inelude a few samples of the so-called coffee substitutes, many of w h ich WI·ll be shown to contain a large amount of coffee and this in spite of the assertions of the manufacturers. The only means by which illicit additions to tea can be detected is by an examination of the dried leaves after one has become fully acquainted with the genuine article. Leaves of many kinds of plants have been employed in this connection, of which those of the wild plum are perhaps the most commonly used. Nowadays, however, at the place of its production tea is so cheap that it scarcely will pay the manufacturer to do much in the way of adulteration. Cocoa is rather different, however, and there is little doubt that huge quantities of this substance are sadly behind what they should be in the way of quality. Some form or other of starch is a very favorHe adulterant with certain sections of the trade. This may be at once detected if about a teaspoonful of the powder is placed in a cup and boiling water is added. If any starch is present the liquid shows a very marked thickening, a happening which should not be noticeable to any extent in the genuine cocoa essence. A much more harmful adulterant is the addition of cocoa shell; un fortunately the presence of this is not very easily discovered save by the help of a microscope. If the powder has been carelessly ground it may impart a slight grittiness to the mixture, though of course the skilful manufacturer will take great pains to avoid this. There are perhaps no articles of food which are more commonly adulterated than jams and jellies. It is not an exaggeration to say that very little of the material sold of this nature is simply the -fruit named on the label embodied with pure sugar. Most of the adulterants, such as those used for coloring and adding to the bulk of the jam, are fairly harmless, though none is of course desirable. Starch is a very common adulterant in jam though owing to the cloudy properties which it would give to a clear jelly it cannot be used with much effect in this article. In the case of jam it is impossible to detect its presence without a small test. Dissolve a teaspoonful of jam in half a teacupful of hot water. Through a piece of muslin strain away any solid matter which is left. Now add drop by drop a solution of potassium permanganate until the mixture is practically decolorized. In some cases of artificially colored jams the decoloriza-tion may not be very complete, but this can hardly affect the final stages of the test. When the liquid has quite cooled down add a single drop of tincture of iodine and if any starch is present the solution will turn a decided blue color. Even more commonly used than starch is | glucose, and to determine the presence of this adulterant a slightly different test is necessary. Again the same quantity of jam or jelly should be dissolved in warm water; in the former instance it will be necessary to strain away the insoluble matter as before. Now allow the solution to become quite cool and then add an equal amount or possibly a little more of strong alcohol. In order that the subsequent stages may be closely observed it is as well to carry out the experiment in a glass vessel. If the sample is a pure fruit one there is very little precipitation except perhaps the smallest amount of proteid bodies. On the other hand should glucose have been employed in the manufacture a cloud of dense whiteness separates from the rest of the solution, and finally settles down at the bottom of the tumbler. This may be taken as condusive evidence that glucose has been used as an adulterant. In order to render the appearance of the pickles more attractive copper, to a greater or less extent, is frequently emplayed in the preparation of pickles. This may not have been directly added in every case, for the practice of boiling the pickles in copper jars is quite suff-cient to aecount for its presence. Scalding . vinegar has a powerful effect upon copper a fact that should be noted by every cook. Even when only present to a small extent this mineral is highly injurious as of course it is a rank poison. Pickles of a very bright green color should always be suspected and put through the following test. Mash some of the material with a fork until it is well crushed, and then place the material in a stoppered bottle. Add to this a solution composed of ammonia and water in equal 1)arts and shake the whole well. If there should be the smallest trace of copper the ammonia turns a blue color. Copper is often used to deepen the green of imported canned goods such as peas, beans, spinach, etc. In some articles of this nature it has been found to a really alarming extent. A very interesting experiment to detect its presence is one involving the use of hydrochloric acid, a strong corrosive which of c o urse must be used with extreme care and kept away f r om contact with the skin or clothes. Still the test is so curious that many people will be interested to try it. Mash a sample of the vegetables and place a teaspoonful in a teacup; add thirty drops of hydrochloric acid. Set the cup on the stove in a saucepan containing boiling water, drop a bright wire nail into the cup and keep the whole thing boiling for twenty minutes. Stir the mixture all the time with a splinter of wood. At the end of the time stated drag out the nail, when if copper has been used with the vegetables, the article will be found to be heavily plated with that metal. A final word on the subject of canned goods may not be out of place. These are used so widely nowadays that the laws controlling their preparation are rightly stringent. Still now and again, for no ve ; y clear reason something goeS wrong WIth a tm. of goods. Thl. s is almost always shown by an alt eratIo n m. the external appearance of the package. The ;op or the bottom appears m?re or less , blown out , and when thIS IS the ease even to a sma1I extent the contents should be unhesltat .ngly condemned. There I. S aIways grave the consumption of artIcles contamed m unshapely tms. Major John Burger Waring MAJOR JOHN BURGER WARING, brother of Col. George E. Waring, I died on October 30th at the age of sev-l enty-seven. Major Waring was well] known as a pioneer steel pen maker. The two types of pens invented by him were named the Chase medallion and the Washington medallion. During the civil war he invented an improved device for spiking cannon. Enlisting as a Iieutenant in the Fourth Missouri Cavalry, he attained the rank of major in the Ordnance Division.- After the war he in-1 vented an apparatus for removing silk from the cocoon, also a rock drill and many other mechanical devices. All told he secured over seventy patents. IN 1909, 65,399,889 barrels of cement were produced in the United States, valued at $52,797,973. In 1900 the production was only 17,231,150 barrels. In 1905 it was 31,675,257 barrels, in 1906 it was 51,000,445 barrels, and in 1908 it was 52,910,925 barrels. 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Your last chance to get The Companion for $1.75. Subscribe today. THE YOUTH'S COMPANION BOSTON, MASS. 440 SCIENTIFIC AMERICAN November 11, 1911 Before Subscribing for your periodicals, you should see our Catalog, c0ntaining a list of 3000 magazines and club offers, at prices that will surprise you. IUs the handsomest and most complete Magazine Guide ever published, filled with all the latest and best club offers at rates, lower than you think possible. YOU cannot afford to be without it. In ordering your magazines, be sure you use a HANSON catalog. Accept no substitute. The name HANSON stands for promptness and reliability in the magazine field. It is so accepted by all leading publishers. THIS CATALOG FOR 1912 is FREE for the aSknf. It will SAVE YOU MONEY IPf?* Send us your name and address today. We'll do the rest. J. M. HANSON MAGAZINE AGENCY 240 Hanson Block, Lexington, Ky. FILL IN THIS COUPON AND MAIL TO US J. M. HANSON. Lexington. Ky. Please send me FREE of expense to me, this Catalog fO .r 1912. . NAME.......................... Street Add"ess or Gountv The test of a magazine ' s merit is that its readers tell their friends about it We recently asked our subscribers to send us the names of those whom they believed the Scientific American would interest, and we are gratified to find that so many of our subscribers believe that its merits will appeal to such a large number of their friends. Have you sent a list ? If not, Here is the way: Simply send us the names and addresses ot the people whom you think will be interested and we will do the rest. An accurate record of all names received in this manner will be kept, and for each new subscription we get from any list we will extend the subscription of the person who sent us the list for four months. Thus if we receive three new subscriptions from any one list the subscription of the person who sent us the list will be extended for a full year. Of course you may send as many names as you wish, the greater the number of names you send the larger the number of subscriptions we will probably receive and the longer the period for which your own subscription will be renewed. Be careful to write the names and addresses plainly and don't fail to put your own name and the address at which you are receiving the Scientific American on each list you send. Address all lists to Circulation Department, Scientific American, 361 Broadway, New York. JUST PUBLISHED J . :eu and A uthoritafioe [ook MONOPLANES and BIPLANES THEIR DESIGN, CONSTRUCTION&OPERATION The Application of Aerodynamic Theory, with a Complete Description and Comparison of the Notable Types By GROVER CLEVELAND LOENING. B.Se, A.M., C L CRITICISMS "The !rst treatise upon aviation which we have seen whicl may be styled really complete.....Actual aeroplane designing is the central themeof the volume.....The prominent types are exhaustively compared..... The illustrations are a notable feature." -Rochester, N. Y., Chronicle. "A very complete account of the theory of heavier than air flying machines with a technical description of nearly all the present types of aeroplanes. .... Presents in compact shape the substance of aerodynamic theory Easily comprehensible to the reader who can concentrate his attention It is the most scientific popular book on the aeroplane that we have come across so far." -New Yorl Sun. .. Many writers have failed to realize the demand which exists for aero literature in which mathematical deductions are a necessary but not predominant part of a comprehensive exposition of the entire subject. For a writer to steer a straight course between the mazes of trigonometry on the one hand. and the superficialities of mere discussion in a popular vein on the other is to accomplish what can be done only by one who is himself a thorough student in the finer details, but who can sufficiently divorce himself from the mathematical atmosphere as to present the whole subject from a broad standpoint, making it readily intelligible and informative to the less erudite seeker after knowledge." -Phla. Inquirer. "Students learned in aerodynamics and laymen ordinarily interested in aviation will fnd equal delight in reading ' Monoplanes and Biplanes.' The book is a welcome addition to the libraries of those who have realized the future of aerial navigation, and desire a work treating solely of the heavier than air machines written by an acknowledged expert and with no hobbies hidden in the discussion." -Boston Journal. ” While enthusiastic in his interest as becomes one who has written so superb a volume, Mr. Loening is also rigidly accurate as the most exacting scientist could demand. Here is a work which is at once a history and textbook which may be depended upon for everything that is within the range of actual knowledge. To say that 'Monoplanes and Biplanes' is at once new and authoritative with reference to the entire subject and that it is practical in the highest degree is tIe just praise due to this volume."-Buffalo News. ” Mr. Loening has written, in fact, for the man who wishes to apply practically the experience that has already been gained.' -New Yorl Times. 12mo. (6x8M inches) 340 Pages, 278 Illustration •• Attractively bound in cloth. Price $2.50 net, postpaid An illustrateJ descriPtive circular will be .en! free on application. MUNN&CO., Inc • 361 Broadwa7 Publishere New York r WOOD DISTILLATION for manufacturing ALCOHOL and other products of the process C Profits from refuse wood and sawdust are in reach of any one who will locate near a sawmill. The Scientific American Supplement files contain a series of valuable articles on this topic which are contained in the following numbers: 1610-A General Review of the Subject of utilizing wood wastes, and the uses to which the wastes may be put. 1684-The “steam” and “destructive” distillation processes, and names the numerous products obtainable from the complete operation. 1661-Distillation of soft wood, and gives the proportions and quantities of each product obtainable, and the various processes used. 1723 and 1724-The general subject of the utilization of wood wastes, giving all the products by a clear and valuable diagram showing their relations to each other, and many illustrations of apparatus. 1592-The manufacture of wood alcohol by a German process which first converts sawdust and scraps to glucose and then to alcohol, leaving the residue of the wood with 75% of its heating value, and in condition to briquette without a binder. 1789-Prof. Ruttau' s article on the manufacture of wood alcohol, a very comprehensive discussion. 1643-Dry distillation of Beech and other hardwoods comparing European and American methods, and giving the quantities of products obtained. 1335-Charcoal manufacture in Germany, with complete recovery of by-products, their description and uses. 1472-” Distillation of Pine Products” refers especially to turpentine manufacture, but covers the by-products as well, and gives information of the profitable nature of the business. 1551-Re£ers to acetic acid, wood spirit and acetone from distillation of wood, and gives a good description of the necessary apparatus, and particularly of the points to be observed in operating the plant. 1736-Production of Alcohol from Cellulose, how wood and wood products may be used. Each number of the Supplement costs 10 cents. A set of papers containing all the articles above mentioned will be mailed for $1.20. Order from your Newsdealer or from us. MUNN&CO., Inc., 'Publishers, 361 Broadway, New York City