lems or other constructive work which would tend to strengthen the science among the sciences and in the esteem of those who mold our educational and national life. The practical aspects of our science, its values in the conduct of life and its direct bearings in education, medicine, treatment of the unfortunates and in social reforms, its influence upon the development of other sciences, such as biology, anthropology, sociology, logic and ethics, and its aid in the pursuit of art, history and literature, have been clearly affirmed by five presidents, denied by one, and practically ignored by the rest. Only one, I believe, has seriously touched the question of the teaching of psychology to our student body. Which type of a president derived by compositing all these contrasts is the more desirable and the more useful in our leader ship in view of the present needs of psy chology, is a query that must be referred to each one by himself. THE MEMBERSHIP. The structure of an association organized in the interest of the advancement of science finds its efficiency not so much in the cortical officials who annually declare their views, as in the interest and efforts of its members, who actively explore the psychological field, offer intelligent criticism of past returns, and otherwise increase its content of fact and in general advance its repute. The scientific and professional aims of the association have been safeguarded within itself, at least, by that modern form of predestination which makes the psychologist's 'calling and election sure.' We have already given an impersonal summary of the work yielded by the elect. We have yet to consider its distribution among the individuals. The fourth, fifth, sixth, seventh and eighth headings in Table I. present the aggregate facts to be considered in detail. Beginning with twenty-six original members, the association has grown annually, having admitted in the ten years one hundred and forty men and eight women to membership. One man has been elected twice to membership, and seven of the women abide with us still. The present roll includes one hundred and twenty-seven names, showing a total loss, by death and voluntary cessation, of twenty-one members during the ten years. In the matter of attendance, the showing is not as satisfactory as one would wish for the efficiency of the association. The average attendance of members at each meeting has been nearly thirty-five, which is but slightly above the membership at the first annual meeting. Reasons geographical and financial, not to mention others more temporary or personal, must not be overlooked in interpreting for psychology's fellowship, the percentage the attendance at each meeting has been of the total elections indicated above. It is, however, in place to ask, why has the association apparently lost its hold upon our psychological nestors, who have seemed ready to give place to the younger men? This may indicate a lack of interest on their part in the scientific details that legitimately find place in the proceedings, or it may betoken a change in the community of interest in the unified development of inquiry and criticism. Psychologists above all others are least apt to misinterpret the significance of mere numbers, popularity or enthusiasm. But those who wield greater influence in shaping the association's affairs can well take into consideration the causes of the lessening grip upon many of the more mature and industrious of our coworkers, and seek to promote the faith within ourselves. The most noticeable feature in the comparative exhibit in Table I. is the contrast between the steady increase in member- A more forceful, and thus a more interesting, way of showing the aggregate individual distribution of the industry that has found place among us annually is given in the following summary, which includes two or three instances of joint authorship. Eighty-nine members have been the total contributors, of whom thirty-four have presented one unit, as paper, report, etc., each; twenty-three have presented two units each; ten have presented three each; eight have presented four each; five have presented five each; three have presented six each; two have presented seven each; one member has presented fourteen, one seventeen, one nineteen and one twenty-three units. The remaining fifty-nine members have been inactive, silently paying their annual dues. It is, indeed, a serious question whether the association can hasten its realizations by carrying forty per cent. empty baggage, or whether this phase of the situation should not be radically changed. Almost twenty-six per cent. of the total contributions offered has been the work of four members, who are laboratory men. It will not be overlooked that they have simply stood as sponsors mostly for the No work done by the student body of research- There is one function which the association can properly undertake more seriously, which would tend to secure a steady advance in the value of the newer material psychological researches may bring forth. At present the indefinite and uncertain method of 'natural selection' or mere survival of interest in individual cases is the only mode of checking off results. An improvement over this method would be a planful arrangement whereby the association could see to it that the annual output of new conclusions and formulæ is intelligently and critically evaluated. This would effect a great saving of individual labor on the part of each psychologist. EDWARD FRANKLIN BUCHNER. UNIVERSITY OF ALABAMA. (To be continued.) PROFESSOR ALEXANDER GRAHAM BELL ON KITE-CONSTRUCTION. IT is fortunate for those interested in aeronautics and the exploration of the air that Professor Alexander Graham Bell has joined the band of experimenters and is lending his inventive genius to the cause. Professor Bell has been for several years experimenting with kites, led to this line of experiments, he thinks, because of the intimate connection of the subject with the problem of the flying machine.* Professor Bell began his experiments with the boxkite of Hargrave, whom he recognizes as the pioneer in modern kite-construction. His objections to the box-kite are that, "It requires additions to the framework of va even if made of the finest wire, so as to be insignificant in weight, all comes in the way of the wind, increasing the headresistance without counterbalancing advantages.' These remarks of Professor Bell concerning guys, etc., do not apply to the original Hargrave kites which have no guys, but only to a style of Hargrave kite invented and patented by me. This style is the one which has come into universal use under the name of the Hargrave kite, and is the one with which Professor Bell rious sorts to give it sufficient strength to hold the aeroplane surfaces in their proper relations and prevent distortions of the kite-frame under the action of the wind. Unfortunately the additions required to give rigidity to the framework all detract from the efficiency of the kite: first, by rendering the kite heavier, so that the ratio of weight to surface is increased; and, secondly, by increasing the head-resistance of the kite. A rectangular cell like A (Fig. 1) is structurally weak, as can readily be demonstrated by the little force required to distort it into the form shown at B. In order to remedy this weakness, internal bracing is advisable of the character shown at C. This internal bracing, * His experiments are described in a communication made to the National Academy of Sciences, in Washington, D. C., April 23, 1903. Also National Geographical Magazine for June, 1903. The numbers of the figures differ from the original because many of the figures are omitted here. FIG. 2. began his experiments rather than with the original Hargrave structure, few of which have been made. Continuing, Professor Bell says: "In looking back over the line of experiments in my own laboratory I recognize that the adoption of a triangular cell was a step in advance, constituting indeed one of the milestones of progress, one of the points that stand out clearly against the hazy background of multitudinous details. The following (Fig. 2) is a drawing of a typical, triangular-celled kite, made upon the same model as the Hargrave box kite. * A triangle is by its very structure perfectly braced in its own plane, and in a triangular-celled kite, like that shown in Fig. 2, internal bracing of any kind is unnecessary to prevent distortion of a kind analogous to that referred to above in the case of the Hargrave rectangular cell (Fig. 1). The lifting power of such a triangular cell is probably less than that * * cellular kite (Fig. 3, 4) which flies perfectly well. The weight of the compound kite is the sum of the weights of the three kites of which it is composed, and the total aeroplane surface is the sum of the surfaces of the three kites. The ratio of weight to surface, therefore, is the same in the larger compound kite as in the * Some experiments, made by us at Blue Hill in 1896 with some of Hargrave's models of triangular-celled kite, led us to think the rectangular cell much superior in efficiency to the triangle, owing to the sheltering of the upper surface at the corners of the triangular-celled kite. smaller constituent kites, considered individually. "It is obvious that in compound kites of this character the doubling of the longitudinal sticks where the corners of adjoining kites come together is an unnecessary feature of the combination, for it is easy to construct the compound kite so that one longitudinal stick shall be substituted for the duplicate sticks. For example: the compound kites A and B (Fig. 3) may be constructed, as shown at C and D, with advantage, for the weight of the compound kite is thus reduced without loss of structural strength. In this case, the weight of the compound kite is less than the sum of the weight of the component kites, while the surface remains the same. If kites could only be successfully compounded in this way indefinitely, we should have the curious result that the ratio of weight to surface would diminish with each increase in the size of the compound kite. fortunately, however, the conditions of stable flight demand a considerable space between the front and rear sets of cells; and, if we increase the diameter of our compound structure without increasing the length of this space, we injure the flying qualities of our kite. But every increase of this space in the fore and aft direction involves a corresponding increase in the length of the empty framework required to span it, thus adding dead load to the kite and increasing the ratio of weight to surface. Un "While kites with triangular cells are strong in a transverse direction (from side to side), they are structurally weak in the longitudinal direction (fore and aft), for in this direction the kite frames are rectangular. Each side of the kite A, for example, requires diagonal bracing of the character shown at B, in which the framework forms the outline of a tetrahedron. In this case the aeroplanes are triangular, and the whole arrangement is strongly suggestive of a pair of bird's wings raised at an angle and connected together tip to tip by a cross bar. "In the tetrahedral kites, shown in the plate (Figs. 4 and 5), the compound structure has, itself, in each case the form of the regular tetrahedron, and there is no reason why this principle of combination should not be applied indefinitely so as to form of some new metal or some new force.' The process of reasoning by which Professor Newcomb arrived at this remarkable result is undoubtedly correct. His conclusion, however, is open to question because he has drawn a general conclusion from restricted premises. "He says: "Let us make two flying machines exactly alike, only make one on double the scale of the other in all of its dimensions. We all know that the volume, and therefore the weight, of two similar bodies are proportional to the cubes of their still greater combinations. The weight relative to the wing-surface remains the same, however large the compound kite may be. The four-celled kite (Fig. 4), for example, weighs four times as much as one cell and has four times as much wing surface. "This, at first sight, appears to be somewhat inconsistent with certain mathematical conclusions announced by Professor Simon Newcomb in an article entitled, 'Is the Air-ship Coming?' published in McClure's Magazine for September, 1901conclusions which led him to believe that 'the construction of an aerial vehicle which would carry even a single man from place to place at pleasure requires the discovery FIG. 5. Sixteen-celled tetrahedral kite. dimensions. The cube of two is eight: hence the larger machine will have eight times the weight of the other. But surfaces are as the square of the dimensions. The square of two is four. The heavier machine will therefore expose only four times the wing surface to the air, and so will have a distinct disadvantage in the ratio of efficiency to weight. "But Professor Newcomb's results are probably only true when restricted to his premises. For models exactly alike, only differing in the scale of their dimensions, his conclusions are undoubtedly sound; but where large kites are formed by the multiplication of smaller kites into a cellular structure the results are very different." |