[The editors are not responsible for statements made in the correspondence column. Anonymous communications cannot be considered, but the names of correspondents will be withheld when so desired.] Octave Chanute and H. T. Ricketts-A Sidelight To the Editor of the Scientific American: The very appreciative article on Octave Chanute by Prof. Zahm, in your issue of May 13th, recalls an interesting coincidence occurring not far from the commencement of certain close relations between the writer and Mr. Chanute during the last eighteen years of his life. One morning in the early summer of 1896 Mr. Chanute inquired, somewhat quizzically, but in his usual serious and methodical manner, as to a young doctor who might not be too busy or too dignified to accompany him-for a consideration-on an expedition where he, the doctor, would be expected to do cooking during the few spare moments when he was not engaged in the professional duty of setting broken limbs. This inquiry was typical of Mr. Chanute's customary way of launching an enterprise-foresightedness, economy of service, shrewd calculation of adequate margins of safety, were but outcomes of his instinct and distinguished training as a bridge engineer. Having tried out his air planes and kites among tne tin cans and sand lots at the foot of Huron Street, he was preparing for his gliding experiments at Dune Park, Ind. With the fate of Otto Lilienthal fresh in his mind, he did not propose to let the members of his little company smash their 'bones without having some representative of the coroner available. It was a part of his spirit of cautious frugality that had he been spiritually minded he would have proceeded just as methodically to secure the services of a chaplain willing to take on a side line of washing while waiting for emergencies. I knew Mr. Chanute too well not to receive his request in the same spirit of courtly gravity in which it was made. And here is where the coincidence came in-l sent with him a solemn-faced conscientious student of medicine then helping me in my ofce, who was as single-minded a crusader in his own sphere of science as was Octave Chanute in his. What Howard Ricketts did not know about cooking, his temporary employer-a Frenchman and an epicnre-informed me, would have flled a large Creole cook book, and as a snrgeon he never had a tryout on Herring's or Avery's legs. But locked up even then in my young friend's breast was the purest, most deeply religious and unselfsh love of science with which I have ever been privileged to come into intimate contact. Ricketts had no money; he cared nothing for it except as a means toward achieving his ambition to become an independent thinker in the sphere of pathological biology. He sat up nights with his ideas until his health was ruined, and his friends began to think him obsessed; perhaps he was a little so on commonplace subjects, but it was the obsession of preoccupation with connected thought, a form of mental peculiarity uncommon enough to seem queer to most of us, who are willing-post hoc-to admit that genius is usually a form of successful queerness. Curious, was it not, that the lives of these two great serious and clean·minded scientists should have touched thus semi-comically and casually, only to drift presently apart again without infuence upon or understanding of each other. Ricketts always thought “fying” was the one really jocular event of his life, and expected to eventually hear of his patron's incarceration for too lavish expenditure of money on box kites. Mr. Chanute associated Ricketts with nothing but spoiled meals, and pursued the disagreeable subject no farther-of what use was biology to the mathematician? And so each of these productive nineteenth century materialists thought the other a hopeless, useless visionary! Yet Ricketts, like Chanute, “dreamed true,” and his brief life with its tragic end-a last willing ofering to his great goddess-was crowded full of those un-dramatizable epics of the modern laboratory that recall to us, if we have but the logical imagination to see them in their true stature, the heroic lives of early explorers, patriots, or religious enthusiasts. Pasteur and Metschnikof gave him of their inspiration and technique. Animated by their methods, he struck out into new-world felds and returned with or fnally sent back fresh contributions to science, destined also to prove of inestimable practical value to humanity. His original studies in pathological biology have never been equaled on th is continent. His discoveries in blastomycosis gave him early recognition, and won for him an appointment at thf University of Chicago. He spent three years studying the hitherto SCIENTIFIC AMERICAN mysterious “tick fever” of the Rocky Mountains, and placed its etiology and pathology on a firm foundation. His experimental work in the immunity of 'organs received world-wide recognition and won for him in 1910, when barely thirty-eight years of age, the appointment to the chair of pathology at the Uni-elsity of Pennsylvania. As an especial mark of honor, the appOintment carried with it a year's preliminary freedom for research work at a full salary, before entering upon active teaching service. As his final tribute to science he gave his life at its meridian in exchange for a knowledge of the secret sources of Mexican typhus. But not before that knowledge had matured from theory into fact, and the life history of the micro-organism of the disease lay unfolded beforE' him under the microscope and in the culture medium. The Mexican government co-operated liberally with him during his work, and since his death in 1910 has given him unstinted recognition in an appreciative state paper transmitting his records to this country. We have now for the first time a complete biological and morphological history of the bacillus of typhus fever-a filth disease transmitted from human to human through the intervention of the body louse as an intermediate host. These records, with others of importance made by the same hand, have just been edited and published for the University of Chicago” and the Chicago Pathological Society. I is not difficult for one who knew both of these natures well to see why they repelled and misunderstood each other. Their method in dealing with, and their mental attitude toward, facts were from opposite poles. Ricketts's method was intuitive and highly imaginative-an old-fashioned dreamer working hackward from theories and ideals to facts. He saw the truth correctly but intuitively, the facts came inevitably but later. Chanute collected facts during a lifetime of mature and precise mathematical thinking, and by methods of pure induction arrived step by step at correctly demonstrated conclusions, eventually beyond even the insane dreams of Daris Green. And yet he also was an unselfsh idealist, as is abundantly evidenced by his refusal to accept the commercial advantages which his basic patent on the biplane undoubtedly gave him. The several hundreds of unpublished letters, full of technical details and mathematical calculations, which passed between him and the Wright brothers, and which are now in the. possession of the Chanute estate, would indicate that his interest and his equity in the machine-driven biplane, while not at all tainted with commercialism, were vastly more than passing, and casual. The reported saying that he “turned up” or “happened to drop in” at Dayton or Kittyhawk in 1901 cut him deeply and was scant recognition when viewed in the light of thIs unique and instructive correspondence between two great scientifc men. The secret of this interest is an open one to those who know the mainsprings of his life and character. That secret, after his modest fortune was acquired, was an abstract and impersonal devotion-incapable of jealousy-to the pursuits and achievements of pure science as apart from material gain and advancement. A motive power common enough in the old world, and still more so under the ancien regime-the day of Newton and Franklin, of Laplaee and Priestly, of Humboldt and Goethe, but not commonly to be reckoned with amid the commercialism of present-day American life. In the midst of and a recognized factor in contemporary supply and demand of modern railroad necesstties, he still preserved unchanged the manner and family life of the French gentleman of the eighteenth century. Refnement, honesty, idealism, gentleness, all were his; yet he was full of fre in manner, spirit and inspiration. He was modest, yet he knew anu gave himself his full value and dignity, as many of his letters abundantly show. Tn his seventy-ninth year his keen eyes sparkled like a boy's, and his wit was still as caustic as Montaigne's. On his death bed he corrected letters and telegrams with an enjoyment in the ultimate refnement of words that was altogether French. A many-sided nature in which were joined the pure philosophic altruism of the eighteenth century with the keen love for productive mathematics of the most modern American. An early competence was won by strict business methods; then followed “retired leisure that in trim gardens takes its pleasure,” only the gardens were the Illinois and Indiana sand dunes, and the leisure was an industrious but impersonal life in the fourth foor of a city house, surrounded by models and stufed winged creatures and an abundant library of mathematical and engineering literature. The product of these voluntary labors, which he gave unselfshly to uhe world, showed as a net resultant all that was correct winnowed by patient experiment from a thousand ventures incorrect in their entirety. The ~'Co lO ributioiiB to Med,ieat Science by I. ''. Ricketts, Univ. of Ciucan Press, 1911. '75 Chanute biplane model, in its simplicity of line and principle, is a type of all those products of matured “genius” which are really the resultants of skillful elimination of the unnecessary and illusory. The accident of bodily age prevented personal flight. The accident of five years' delay in the development of the gasoline motor alone prevented the complete equipment of an otherwise perfect model. It has been among the great privileges of my professional life to have had intimate contact with and to have formed an early appreciation of the value of these two great livesIives so unlike in the details of their working out and surroundings, and yet so fundamentally similar in devotion to abstract science and in the altruistic determination to give largely and unselfishly that humanity might be the gainer. Chicago, III. W. H. ALLport, M. D. Why Left-hand Mold-board Plows are Used To the Editor of the Scientific American: The following might be of interest to you in regard 'to the short article about mold·boards for plows in the Scientific American of .une 17th, page 603. As far as the work done by the plow is concerned, there is, of course, no difference between a left-hand and a right·hand mold-board plow. The choice between the two depends, however, on the manner in which the team (two horses or mules) is driven or guided. If a Single line is used, it is customary to connect it to the left (lead) horse, in which case the team is entirely led by this horse and by one line (single connection between the left horse and driver). After the first furrow has been made, it in itself is the best guide for the team, and since the second horse (right-hand horse as seen from the plow) is entirely guided by the “lead” horse, the latter should walk in the furrow. This arrangement. however, is possible only with a left·hand mold-board plow. With one·horse plows, or when the team is driven by a double line, it makes theoretically no diference whatever whether the plow has a left-hand mold-board or a right-hand mold-board. Washington, D. C. F. A. Weihe. Who Saw This Meteor. Train ? To the Editor of the Scientific American: On the night of September 4th, I noticed extending across the heavens at New City, N. Y., what r think must have been a “persistent meteor train” as re· cently described in the Scientific American. It frst attracted my attention at about ten minutes past eight and was then in the northern sky in the form of a large circular arc not unlike a rainbow, but at much great(r radius of curvature and extending almost completely across the sky from west to east. The train drifted rather rapidly in a southerly .direction and apparently straightened out as it reacheu the zenith, remaining perf(ctly straight until it was lost to view at a few minutes after nine. The atmosphere was perfectly clear, the sky absolutely cloudless and the moon, nearly full, shone brightly in the southern sky. At frst I thought it was a peculiar cloud formation, but it apparently had a luminosity of its own and someone remarked to me that, “It looks like the stuf of which the aurora bore-alis is made.” Stars were plainly visible through the luminous mist and as it crossed the Square of Pegasus I noticed that it was almost as wide as the square, its length I estimated was 135 degrees or over. As the streak crossed the moon's disk the section in front of the moon was made invisible by the bright light, but on.each side the segments were still plainly visible although considerably narrower than when at frst observed and still in a straight line. r would be very much interested to know whether this peculiar luminous streak was s(en by other persons and whether it has been reported by anyone who knows what it was. Edgar PfarrE. New York. The National Tree of China THE tung, or iwood-oil, tree is worthily named the national tree of China. It is stately in appearance, with smooth green bark and wide-spreading branches, afording a fne shade. It bears a fruit resembling a sheH bark hickory nut, but as large as a small «range. Each nut contains three triangular seeds similar to small Brazil nuts. The oil is pressed from these seeds, and the refuse is used as a fertilizer. The oil is used principally for polishing wood-work and dressilg leather. Considerable quantities are exported. The wood of the tung tree is used for making musical instruments, fne boxes and the framework of smail houses. I is believed that this tree might fourish in warmer parts of the United States.