19. Dr. Weidlein has been prominently and actively identified with the Institute for over 40 years, serving as a senior fellow 1912-t6, and then as an executive staff member from 1916 to 1951, when he was made President. He is noted internationally as a scientist, research administrator, and author. Following his retirement he will spend several months in Europe on a Federal Government mission. Dr. Weidlein will continue to serve the Institute as a member of the Board of Trustees and will be available in an advisory capacity in the administration of research programs.ALBERT H. COOPER has joined the American Hard Rubber Co., New York City, as assistant to W. M. Bergin, Director of Research & Development. A well-known authority on organic and inorganic chemicals, Dr. Cooper will devote the major part of his time to furthering American's accelerated chemical research and allied production programs. He is the owner and manager of Pilot Engineering Co., industrial consultants on plant design and production problems; he also is head of the Dept. of Chemical Engineering at Pratt Institute in Brooklyn. J. J. LANDER has resigned as chemist with the Naval Research Lab., Washington, D. C., to assume the position of Director of Research of the Storage Battery Division, Electric Auto-Lite Co., Toledo, Ohio. J. S. DEWAR recently was promoted to President of National Carbon Co. Ltd., Toronto, Ont., Canada. He has the distinction of being the youngest chief executive in the history of the company.

Seven resistance thermometers (six Pt; one 90Pt:10Rh alloy) have been calibrated on the thermodynamic scale by comparison with a helium gas thermometer. The boiling point of oxygen was taken to be 90.19° K, and computations were made in such a w ay as to secure continuity between the International Temperature Scale and the scale being established. On the latter scale the triple point of normal h ydrogen was found to be 13.96° K and the boiling point 20.39° K. Tables have been prepared by means of which temperatures corresponding to observed resistances may be obtained by linear interpolation.

Vapor-pressure measurements on oxygen covering the entire range from the triple point to the critical point are reported. By measuring short sections of isotherms, the critical temperatu re and pressure were found to be 154.78° K and 50.14 atm, respectively. The triple point temperature and preSSUle were found to be 54.363° K and 1.14 mm Hg respectively. The two solid-solid trans ition s were found to be at 43.800° and 23.886° K respectively. Meas ure ments were made of the heat capacity of oxygen in t Il e c ritical region at s ix different filling densities . A comparison of the temperatu re scales of three d ifferent laboratories is made, based upon reported values of the fix ed points o f h y clrogen , nitrogen, and oxygen .

The vapor pressures of H 2 , ED , and D2 have been measured from near the ir t riple p oin t s to their critical points. The H 2 and D 2 sampl es were catalyzed to or tho-para equilibrium at 20.4 0 K. Tables suitable for in terpo lation have been p r epared to r epr esen t t he r es ul ts both in centimeter-gram-second and in engin eerin g units.MeasUl"ements of d ew-point pressures of sever a l binary mix tu res have been made at several pressu res below atmospheric. Obse rved pressures were about 3 percent above those predicted by the law of ideal solution s.

When an equation is to be fitted to a set of data by least squares, it is often much more difficult to minimize the sum of squares of the residuals of the independent variable than those of the dependent variable. This article presents a procedure that greatly simplifies the fitting of the independent variable. Given y=f(x) it permits not only y and x, but also y2 , x2 , ln y, ln x, and similar simple functions to be fitted almost as easily as y. It is shown that the residuals change significantly when the quantity fitted is changed. Five different equations representing the R(T) relations of thermistors are examined and their ΔT residuals for the same set of experimental data are shown; three of these fit the data more closely than the often-used cubic equation in ln R.