Charts For Use Research Articles

Hyperbolic Projections

The introduction of radio aids to navigation of the hyperbolic type, such as Decca, Gee and Loran, resulted in the need for special charts. These charts, which are usually of the scale and projection appropriate to the occasion, have overprinted on them red, green and purple lattice lines, representing the families of confocal hyperbolae drawn with respect to the Master and Slaves of the radio system. The production of these lattice charts was extensively developed during the war, both in Great Britain and the U.S.A. To provide the mariner with satisfactory marine charts for use with the English Decca Chain, the Hydrographer of the Navy has latticed all the principal coastal charts of England and Wales, and the Danish Hydrographer has similarly latticed the Danish coastal charts.

Magnetic work of the United States Coast and Geodetic Survey From April 1944 Through March 1945

The facilities of the Section of Geomagnetism of the United States Coast and Geodetic Survey were devoted largely to obtaining and furnishing magnetic information for charts for use by the military services.The close cooperation maintained in former years with, the Department of Terrestrial Magnetism of the Carnegie Institution of Washington was continued, by temporary loans of certain field and observatory instruments and by exchange of data obtained in repeat surveys of the United States, Alaska, Central America, South America, and elsewhere.

Growth charts for use in pediatric practice

10. Ronchese, F.: Arch. Dermat. & Syph. 47: 613~ 1943. 11. Brown 7 E . L . : Arch. Pedlar. 61: 233, 1944. 12. Connor, A., and Gonce, J . E . : J. PEDIAT. 23: 335~ 1943. 13. Freud, P.: Monats chr. f. Kinderh. 51: 28~ 1931. 14. Freund~ H~: Dermat. Wehnschr. 98: 52, 1934. 15. Friihwald, R.: Dermat. Wchnschr. 99: 922, 1934. 16. Bentley, F. l~.: Brit . J. Dermat. 52: 222, 1940. 17. Platou, E .S . : Am. J. Dis. Child. 48: 333~ 1934. 18. Brain, R. L., and Lewis, B.: Brit . J. Dermat. 49: 551, 1937. 19. Seidenberg, S.: Schwelz. Ztschr. f. Path. n. Bakt. 4: 398~ ]941. 20. Strickler, A.: Urol. & Cutan. Rev. 48: 340, 1944. 21. ~Wenner, H . A . : Am. J. Dis. Child. 67: 247, 1944. 22. Barton, 1~. L , and Brunsting, L . A . : Proc. Staff Meet., l~ayo Clin. 18: 199, ]943; Arch. Dermat. & Syph. 50: 99, 1944. 23. Blattner~ R. J., }teys, F. 1VI., and Harrison, 1~. L . K . : Science 99: 432, 1944. 24. Blattner, R. 5 , t teys, F. M., and Go]lub~ S .W. : J. Immunol. 46: 207~ 1943. 25. Lane, C. W., and Herold~ W. C.: Arch. Dermat. & Syph. 50: 396, 1944.

The forecasting significance of anticyclonic eddies on the isentropic chart

The fundamentals of isentropic analysis of flow‐patterns within the atmosphere were set forth last year in a paper presented before the meteorological section of the American Geophysical Union by C.‐G. Rossby [see 1 of “References” at end of paper]. Since that time a considerable amount of research has been directed to the application of these charts for use in helping to explain certain weather‐phenomena and to develop new tools for use in weather‐forecasting. While the technique of constructing these analyses has been appreciably improved within the past year, the underlying procedure and suggestions made by Rossby have been found to be substantially most effective, and for this reason they are being carried out at the Massachusetts Institute of Technology.

An Analysis of Lateral Stability in Power-off Flight with Charts for Use in Design.

An Analysis of Lateral Stability in Power-off Flight with Charts for Use in Design.

A Surface Landmark Chart for Use in X-Ray Examinations of the Trunk

THE ability to place patient, x-ray tube, and film in such relationship that some selected anatomical structure in the chest, abdomen, or pelvis shall appear at the center of the finished roentgenogram is an accomplishment much to be desired in a roentgenologist or his lay helper. Two general problems are involved: first, one must line up tube and film until the target lies perpendicularly above the center of the film; second, one must know what point on the skin of the patient's body lies directly above the anatomical structure selected for examination. The first of these problems is more or less time-consuming if commercial types of apparatus are employed. In this particular laboratory it has been disposed of by equipping all exposing tables with special tube arms similar to the one on the obstetrical table described by Hodges and Ledoux. When these tube arms are locked to the Potter grid and are made to stand at 90° to the table top, the target of the x-ray tube lies perpendicularly above the center of the film. The second problem is the subject of the present dissertation. Sitting Height.—The sitting height of a subject is obviously closely related to the length of his spine and so this measurement was the first one used. Subjects were made to sit on a stool, their backs against a standard height board, and then, after sitting height had been measured, they were placed back down on the x-ray table. Measuring downward from the vertex along the anterior surface of the body in a plane parallel to the table top, a point was located halfway from crown to rump. The patient was now arranged on the table so that this ½ S. H. (half sitting height) point lay along an imaginary perpendicular joining the target of the x-ray tube and the center of the film, and the exposure was made. In six adults ranging in build from short and fat to tall and lean, this one-half sitting height point was found to correspond to that portion of the spine bounded above by the center of the eighth thoracic vertebra, below by the center of the ninth thoracic vertebra. In one eight-year-old child it corresponded to the body of the eighth thoracic and in another, six years old, to the seventh thoracic vertebra. However, sitting height does not lend itself well to such work because the measurement cannot be made as the patient lies on the table ready for examination. S. S. Axis (suprasternal notch—symphysis pubis axis).—Obviously the measurement of choice should be related to landmarks on the anterior surface of the body. Several such landmarks on examination proved unsatisfactory: the umbilicus did not have a constant relationship to spinal segments and the costal margin, iliac spines, and iliac crests could not be palpated with sufficient precision.

Dvorine Animated Fusion Training Chart.

This set of 101 charts for use in the stereoscope is similar to the Wells series. The chief point of difference is that some of the charts used for developing dormant vision have safety movie films mounted on disks. When one of these charts is held toward the light the film is illuminated. The charts for developing macular visual function are printed on both sides so that they may be used for training either eye. All the charts are brightly colored. Those for developing fusion and stereopsis are not up to the standard of the corresponding ones in other sets. The chief advantage of these charts is that they offer a variety of designs for young children. They may be used to supplement the Wells charts.

Chart for Use in the Diagnosis of Bright's Disease

Chart for Use in the Diagnosis of Bright's Disease

A Spherical Projection Chart for Use in the Study of Elliptically Polarized Light

The constants of an elliptical vibration are determined by transforming it either to a rectilinear vibration or to one of small, known ellipticity and then measuring the azimuth of the transformed vibration. From these measurements the constants of the elliptical vibration can be computed or ascertained by graphical methods. For this transformation, crystal plates of known thickness and birefringence are used. In each one of a series of transformations the incoming vibration is referred to the axes (α′, γ′) of the crystal plate along which the vibrations take place on passage through the plate; the phase lag or lead, introduced by the plate, is then added and the form of the vibration emerging from the plate thus ascertained. This procedure is repeated for each crystal plate and for the analyzer. Poincare showed in 1892 how the relations of any given elliptical vibration can be represented by a point on a sphere or in a stereographic projection. His graphical method of representation is now in general use. In this connection a specially prepared angle or stereographic projection chart, as a base, greatly facilitates the graphical solutions. A brief description of this chart and of the methods developed for its use, as applied to the derivation of the equations and to the solution of problems in elliptical vibrations, is presented.Throughout the paper the effect, on a given elliptical vibration represented by a point in the projection, of changing from one set of reference coordinate axes to a second set is obtained in the projection by a rotation about the vertical, N−S, axis through twice the angle between the sets. Similarly the effect of the introduction of a phase angle, ϕ, by a crystal plate on a given elliptical vibration, referred to the vibration axes (α′, γ′) of the crystal plate and represented by a point in the projection, is obtained by a rotation of the projection about the horizontal, E−W, axis through the angle, ϕ.

The Elasticity of Pipe Bends

Abstract In this paper the authors develop in detail mathematical formulas connecting the deflection of different types of pipe bends with the force producing deflection, and also expressing the stress set up as a function of the observed deflection and the constants of the bend. They describe experiments made to check force vs. displacement, and present charts for use in selecting the proper size and shape of bends to take care of a given expansion, and to determine the force exerted by a bend when in a given state of deflection. In general they recommend bends of larger dimensions than are ordinarily used, and their figures are said to lie on the side of safety. In some cases the bends tested showed a greater flexibility than anticipated, due to minute folds formed on the compression side when bending pipe to short radius.

THE SEASONAL DISTRIBUTION OF PRECIPITATION AND ITS FREQUENCY AND INTENSITY IN THE UNITED STATES

SYNOPSIS Much has been written on the subject of precipitation in the United States, and a number of charts have been prepared and published showing its geographic distribution. Most of these, however, have represented the average annual amount, the only other available chart, where more than a very limited number of records were used, being that for the summer-half year. The need for a series of charts based on all available records, showing the seasonal distribution of precipitation in this country has long been recognized, and the accompanying series is presented to meet this need. Those here shown consist of 12 monthly charts, and 1 for each of the 4 seasons, together with auxiliary maps for the seasons showing the percentage of the annual precipitation that occurs in each. The monthly and seasonal charts are based on all available records of sufficient Length for such use, about 3,600 in number, reduced to a uniform 20-year period. There are, in addition, a number of graphs showing for selected stations representing various rainfall types, the total precipitation in each season for each of the 20 years on which the maps are based. These show the relative variations in amount that may be expected from year to year in different sections of the country, and also give an indication of the dependability of the averages. In localities where the dispersions about the mean value are small, the latter is more indicative of the amount likely to he received in a particular year than in those where wide variations are shown by the graphs. Departures from year to year from the average precipitation vary in magnitude inversely with the length of the season considered. The relative variations from the mean for the annual, the summer-half year, each of the 4 seasons, and for each of the 12 months, are graphically shown in figure 1, in such manner as to admit of direct comparison, as the scales are drawn on a comparable basis. In addition to an indication of the variations from the mean precipitation that are likely to occur, it is important in considering the representations of precipitation charts to take into account the frequency with which significant amounts occur, the intensity of falls, and the subnormal frequency and duration. Auxiliary charts for use in this connection are presented as follows: Showing the average number of days annually with precipitation from 0.01 inch to 0.25 inch in 24 hours; the average number of days annually with 0.26 to 1 inch; the average annual number with more than 2 inches; the average annual number with more than 1 inch in an hour, and the maximum precipitation in 24 hours for the entire 20-year period. Also. the percentage of years east of the Rocky Mountains with 30 consecutive days or more, without 0.25 inch of rainfall in 24 hours from March to September, inclusive, and the greatest number of consecutive days without 0.25 inch in 24 hours for the same months. These auxiliary charts are based on the records of all regular reporting stations for the 20-year period from 1895 to 1914.