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A Carious Traveling Nest To the Editor of the SCIENTIFIC AMERICAN: Your very interesting article on Nests and Nurseries of Insects in the last SCIENTIFIC AMERICAN reminds me of a curious traveling nest that I saw last summer, which may interest your readers. It was also a remarkable example of protective imitation. The creature when I first saw him was crawling rapidly along a dusty road; but the instant I disturbed him all signs of life ceased, and I picked up what seemed at first glance to be a head of wheat, or large grass. On closer examination it turned out to be an artificial head. There were no grains in it, but little bits of straw and chaff ingeniously arranged around a central tube, all pointing in one direction, and simulating very closely the husks and short beard of some kinds of wheat. Where the stem of the wheat-head should be, the mouth of the tube was drawn tightly shut, so that no one at first glance would suspect that a living creature was therein. When left alone long enough, however, the little door opened, and revealed the mouth of a well-made silken tube, which formed the core for the artificial head of wheat. Soon a worm's head protruded, followed by the thorax, with several pairs of legs, and worm, nest, and all began to hurry away. When I touched him again, however, he instantly disappeared in his hole, and, literally, pulled the hole in after him, leaving only the head of' wheat. Unfortunately, this time the worm outwitted me, so that I failed to get his photograph. He tired me out waiting for him to reappear, and then, when I left him for a few minutes, he made off so successfully that I never saw him again. On only one other occasion have I seen this kind of creature, and never heard of it elsewhere than in this region. HENRY H. RIGGS. Harpoot, Turkey, December 31, 1907. Balloon Varnish. To the Editor of the SCIENTIFIC AMERICAN: The matter ofballoon varnish seems to be giving a lot of trouble. It always has, more or less, as commercial varnish manufacturers do not make balloon varnishes, and none of the ordinary varnishes serve well for balloons. What is wanted is an elastic, non- adhesive, and enduring varnish that will not heat or spontaneously decompose. Pure boiled linseed oil comes tIre nearest to these requirements. The difficulty is in getting it pure to begin with, and keeping it unmixed with oxides or dryers when boiled. Any such admixtures lay the seeds of destruction, for oxidizing, if once started, ' is kept up continuously till the mass is rusted or rotted finally, and the fabric made brittle or sticky, and soon useless. Balloon varnish is not a matter of formula or recipe, but a process or system of preparation, and thus requires experience, judgment, and to some extent courage, as it is more or less dangerous to produce good linseed oil varnish cooked at a high temperature. I have known one large varnish factory to be entirely destroyed in attempting to make balloon varnish, and I have seen over a hundred conflagrations of more or less magnitude result from boiling oil to make balloon varnish. [ only make balloon varnish once a year, in considerable quantities, requiring weeks with special apparatus, on a manufacturing scale, and I aim to keep a year's supply on hand,' and use the oldest and best. My varnishing is done by patent machinery permitting the use of pure linseed oil varnish too thick to spread by hand brushes. One thousand yards of surface requires about one hour's work, all superficial varnish being removed by the machines, after which the fabric is dried spontaneously in the hot sun without oxidizing dryers. This process is repeated several times till seven to nine films are superimposed with increased thickness appreciable by a micrometer caliper after the first coat is applied. The microscopic pores in each film do not coincide, or are plugged up, resulting in a practically hydrogen-proof fabric, of light weight and thickness, which can be folded or rolled repeatedly without fracture of the films at ordinary temperatures, and which never decomposes or sticks or becomes rotten when packed. This fabric in 100-yard rolls, of various grades, I keep for immediate use by myself. There is only a limited demand for this or my varnish besides, the prevailing. impression being that any one can make varnish from a formula, or the secret recipe, just as any one can tan hides and make shoes if told how. I have tried very many preparations and found them mostly disgusting for continued usefulness. The best of these include good boiled linseed oil as a basis, thinned with best spirits of turpentine or stove gasoline for use with hand brushes. Dryers to be used are chiefly litharge or 'japan and chrome yellow. Bird lime and rubber are sometimes mixed in small quantities with linseed oil varnish, and are of doubtful value. Raw or half-boiled linseed oil will never make other than a sticky coat, necessitating frequent dusting with talc, chalk, or other similar preparations, and will inevitably ruin any balloon coated with it. While almost . any varnish in repeated layers will serve to hold gas temporarily, or for immediate use on a balloon, such vessels are short-lived, heavier than desirable, and not satisfactory for airships or vessels required to hold hydrogen for a long time. Balloon Farm, Frankfort, N. Y. CARL E. MYERS. Identification 01' Neptune. To the Editor of the SCIENTIFIC AMERICAN: Fearing that many young amateur' astronomers who read the February astronomical article might obtain an exaggerated impression of the difficulty of ideni fying Neptune for themselves, I will try to tell how I succeeded in obtaining my first sight of that faint member. The method is very well known among many amateurs for locating the inferior planets in daytime. Granting that the observer possesses a small telescope (two-inch aperture is sufficient) mounted upon some kind of a stand, I will explain my- method by taking the actual conditions for the middle of March. The amateur should provide himself with the ordinary star atlas, without which he can hope to do very little, also something that will give him the positions of the planets. The American Ephemeris and Nautical Almanac for the current year will supply all the data needed. The Ephemeris will also give him the position of any lucid star whose declination is within the desired limits (the list of stars occulted by the moon is just what we want). Thus: Neptune's R. A. 6h. 52m. 14s. a Geminorum R. A. 6 46 2 6m. 12s. From this we see that a Geminorum precedes Neptune by 6m. 12s. Declination of Neptune 22 deg. 05m. Declination of d Geminorum 21 52 13m. From this we see that Neptune is 13m. north of d Geminorum or 36 Geminorum, as it is called sometimes. So we set the telescope with the center of the field of view 13m. north of d Geminorum. After waiting 6m. 12s. Neptune will occupy the center of the field. Now carefully chart all the stars seen in the field, and repeat the observation' in a few days, and Neptune will betray its identity by its motion. (Neptune will be one of the brightest stars in the field.) This method will be found very useful in locating any other faint object such as comets, nebul, and star clusters. WILFRID GRIFFIN. Pittsfield, Mass., February 24, 1908. The Recent Criticism 01' Our Navy. To the Editor of the SCIENTIFIC AMERICAN: I would like to say a few words in regard to Mr. Van Brimmer's letter of recent date. I think he will find , that he has stirred up a hornet's nest, and it seems' impossible to me for anyone that read your article to come to the conclusion that he did. He points out the five great charges against the navy, which are as follows: (1) Faulty distribution of armor. (2) Low free board as a distinguishing feature of our battleships. (3) Open turret communication with the magazine. ( 4) Archaic system of selecting men to command our fleets. (5) Lack of sufficient battle practice. Here I will quote a few lines from Mr'. Van Brimmer's letter, which runs as follows: Now in regard to the last four of these charges, what have you to say? Only this: That they are faults--serious faults--f:mlts that are found to a far greater extent in our navy than in the British navy or in the French navy. I can not find any place in your article where you admit any of these faults but No. 3--open turret communication with magazine; and this one you state is being remedied in our latest ships. Your article proved that charges Nos. 1 and 2 are entirely, false or greatly exaggerated. I can not find any place in your article where you speak of the selection of men to command our fleets, neither of the lack of sufficient battle practice, but I believe the American seaman gets as much training as the average seaman - of foreign navies. Mr. Van Brimmer speaks of your reviling Mr. Reuterdahl, but I find no place in your article where you revile him in the least. One would be led to think from Mr. Van Brimmer's letter that the American navy was the only one that had any red tape connected with it, that the foreign navies were perfect in every detail. If the French ships are armored so well, why was it so many of the Russian ships, which are of the French type, were sunk in the Russian-Japanese war? I wonder if Mr. Van Brimmer would kick any worse if the United States should throw away a few million dollars on a worthless invention. If our battleship'! were never any good, why was it they whipped the fleets of a much older nation in the Spanish-American war? Though I think speed is essential in bat- tleships, it is not for me to condemn the designers, at greater proof is needed of the fact that our navy is equal to that of any foreign navy than the letter from Berlin which you publish? JOHNNIE LYNN. Eldora, Iowa, February 13, 1908. Competition Cor Apparatus or Device Cor the Humane Slaughtering 01' Animals Cor Food Purposes. Painfully conscious of the cruelties inflicted upon animals by the present methods of' slaughtering and desirous of preventing, as far as possible, the suffering of animals at the moment of giving up their lives for the benefit of mankind, the American Society for the - Prevention of Cruelty to Animals, through its Board of Managers, offers a reward of five hundred dollars (500.00) for the device or apparatus, not now in use, which will best accomplish the humane destruction of animals used for food purposes; to be competed for under the following conditions, which constitute an agreement between the society and each competitor who submits a design under its provisions. The competition is open to all without restriction. The society reserves the right to reject any or all proposals. The award will be made by the Board of Managers of the society. The design may be submitted by means either of drawings, or a model, or both, together with such description as may be necessary to a proper understanding of the apparatus. Proposed details of construction may be shown by a supplementary drawing of the section; or by a typewritten description. Each sheet of drawings and each model shall be Unsigned, but shall bear, a device, cipher or emblem for identification; and the same device, cipher or emblem shall be placed on a sealed envelope containing the competitor's name and address. This will not be opened until the award has been made. Drawings and models, with the accompanying envelopes, must be securely packed or wrapped and delivered at the office of the American Society for the Prevention of Cruelty to' Animals, 50 Madison Avenue, New York, before 6 o'clock P. M. on Monday, June 1, 1908. Competitors are requested to call or send for their drawings and models within one week after the award has been announced. The apparatus or device must meet the following requirements: First: It shall, with the least possible suffering, accomplish' the desired object of stunning or killing the animal. Second: Its use shall not occasion any deterioration to the flesh, nor any serious loss in the value of the skin or other portions of the animal's body for commercial purposes. Third: The difficulty, cost, or time required in its practical operation, under all conditions, shall not be so great as to preclude its general adoption. Any inquiries regarding this competition should be addressed to Alfred Wagstaff, President the American Society for the Prevention of Cruelty to Animals, New York. lJIcAdaniite.--A New Light Alloy. A new aluminium alloy named McAdamite, after its inventor, William A. McAdam, has recently made its appearance. In addition to its low specific gravity (3.20), it is wonderfully strbng. Careful tests show that it has a compression strength of 126,000 pounds per square inch and an elastic limit of 84,000 pounds. The cast alloy has a tensile strength of nearly 45,000 pounds to the square inch. Among its other good qualities are its freedom from occluded gases, its homogeneous, close-graineB. structure, the ease with which it can be machined, its low melting point (977 deg. F.), its resistivity to acids, its toughness, and its elasticity. The best brasses and bronzes are decidedly inferior to this new alloy in point of strength, fusibility, and ductility. McAdamite should prove valuable in the construction of automobiles, motor boats, flying machines, and in industries where an easily cast, light, yet strong metal is required. Introducing New Inventions in Foreign Countries. Consul Albert Halstead, of Birmingham, invites the attention of American manufacturers of new inventions to the fact that while they may be satisfactory in the United States, they may not be satisfactory in the United Kingdom, until proved. He cites the case of an English agent who communicated with an American manufacturer of a novel device, informing him that he was ready to purchase six of these articles, for which he would pay in six months, to be placed in industrial centers to prove their worth, and that if the device proved as satisfactory as he thought it would, he would make every effort for its general introduction, The manufacturer would not agree to the terms, but in a year afterward, thus losing valuable time, he opened negotiations with the same agent.
