Index of content:
Volume 14, Issue 10, 01 October 1943
14(1943); http://dx.doi.org/10.1063/1.1714926View Description Hide Description
A HOME office for the American Institute of Physics, as well as a national headquarters for its member societies and for the physicists of America is no longer a dream but a definite accomplished fact. At a fraction of its former value, the Institute has obtained a building eminently suited to its needs. Because of the durable construction and fire‐proof nature of the building, upkeep costs will be reasonably low. This fact together with the tax‐free status of the Institute makes ``home‐ownership'' decidedly a matter of good business.
The suitability of the building for the purposes of the Institute has been emphasized in the appeal for funds. The dignified entrance hall will make physicists proud of ``their building.'' The large member's room on the second floor will provide a place for physicists visiting New York to read, write, telephone, and meet people. In addition, this room will make an excellent board room and meeting place for small groups. The other rooms on the second, third, and fourth floors will provide adequate space for the Director, Publications Manager, and other officers of the Institute, and for the publications staff. Fortunately there is room for the expansion of the activities of the Institute which is sure to come in the near future.
Many of the interior photographs in this issue of the Journal show the furnishings of the building when used as a residence. Naturally when used as an office some of the elegance will be sacrificed for utility. The Institute will of necessity carry out gradually interior decorations adapted to its new use. Since the building has not been used for several years minor repairs and a thorough cleaning will be in order first of all. Although the present appearance of the building inside and out is not as bright as the pictures used here indicate the architectural details are in sound condition underneath the grime.
Dr. Barton has pointed out that the goal of $75,000 which must be raised if this building is to be owned by the Institute free‐of‐debt has not yet been reached. Physicists are asked to send in their contributions soon. Every physicist will want to own a small part of this building. It is to be hoped that everyone will make a contribution even if it must be small so that the Institute will know that physicists are unanimously back of its carefully formulated program for the future of organized physics in America. Great credit is due to the Governing Board and the War Policy Committee, but those close to the Institute know that were it not for the hard work and unbounded enthusiasm of the Director and the Publications Manager, a national headquarters for physicists would not have been possible for a long time to come.
So that physicists may become better acquainted with their new headquarters, a series of articles describing the building is planned. The first of these is concerned with its early history and follows below.—The Editor
14(1943); http://dx.doi.org/10.1063/1.1714927View Description Hide Description
THE following technical applications are dealt with in this chapter: (1) belt drives, (2) clutches, (3) brakes, (4) vibration dampers, such as the Lanchester damper, (5) self‐excited vibrations, such as shaft whipping and sound production in a violin, and (6) grinding and crushing. In most cases a brief outline of the mechanism of operation is given, followed—in the first three of the above‐mentioned applications—by principles of design, chief types of construction, and necessary numerical data on friction coefficients.
14(1943); http://dx.doi.org/10.1063/1.1714931View Description Hide Description
The analysis previously made for the current distribution along a symmetrical center‐driven antenna of non‐vanishing radius, and radiation field thereof, is extended to include long wire center‐driven antennas. The results of this investigation are then applied to obtain an approximate solution for the field of a long wire resonant vee antenna.
14(1943); http://dx.doi.org/10.1063/1.1714932View Description Hide Description
The principles of a short wave dosimetry method, based upon measuring of the electric field strength distribution, are explained. The applicability of this method for measurements outside and inside of the body to be treated is discussed. Measurements in some typical field arrangements are presented.
14(1943); http://dx.doi.org/10.1063/1.1714933View Description Hide Description
14(1943); http://dx.doi.org/10.1063/1.1714934View Description Hide Description
The properties of thermionic emission from a cathode coated with barium oxide are studied. The cathode is indirectly heated and its temperature is measured by a thermocouple. It is found that the emitted electrons have a Maxwellian distribution corresponding closely to the temperature of the cathode. The emission is studied with accelerating voltages up to 1300 volts. The current rises more steeply than predicted by Schottky's theory but begins to bend at the upper end. The variation of the work function and the factor A with the state of the cathode is studied by glowing the cathode at different temperatures. It is found that both the work function and the factor A vary. No appreciable decay of emission with time is observed. The effect of drawing emission on the work function and the factors A is small.