Symmetrical bending of thin circular elastic plates on equally spaced point supports. A. F. Kirstein, R. M. Woolley.

Ultrasonic measurement of cylinder expansion at pressures to 40 kilobars. P. L. M. Heydemann, J. C. Houck.

A comparison of absorbed dose determinations in graphite by cavity ionization measurements and by calorimetry. B. Petree, P. Lamperti.

Germanium resistance thermometry in the range 2.1 to 5.0 °K. M. H. Edlow, H. H. Plumb.

Least squares technique for the analysis of periodic temperatures of the earth's surface region. T. Kusuda.

A new near-zone electric-field strength meter. F. M. Greene.

Inductance and characteristic impedance of a strip-transmission line. R. L. Brooke, C. A. Hoer, C. H. Love.

Tensor permeability measurements at L-band frequencies using a degenerate mode cavity. L. B. Schmidt, R. D. Harrington, W. E. Case.

Volume 71C (Engr. and Instr.), No. 2 (Apr.-June 1967)

An apparatus for measuring thermal expansion at elevated temperatures. B. D. Rothrock, R. K. Kirby.

Determination and smoothing of Fourier coefficients representing piecewise continuous functions. B. A. Peavy.

A 2:1 ratio inductive voltage divider with less than 0.1 ppm error to 1 MHz. C. A. Hoer, W. L. Smith.

A dual-load flow calorimeter for rf power measure:nent to 4 GHz. M. L. Crawford, P. A. Hudson.

Polymeric materials for dielectric reference specimens. A. H. Scott, J. R.
Kinard, Jr.

The sensitivity of the Dicke radiometer. D. F. Wait.
Sensitivity of a correlation radiometer. J. J. Faris.

Technical News Bulletin. This monthly publication summarizes the current research, development, and test activities of the Bureau. The articles are brief, with emphasis on the results of research and their significance, chosen for their importance to other scientists, engineers, and to industry. Résumés of longer research reports, important national and international conferences on fundamental science in which the Bureau has represented the Nation, and bibliography of all publications by members of the staff as published are included. The Bulletin is designed to give a succinct account of the current work of the Bureau. (Annual subscription: domestic, $1.50; foreign, $2.25.)

Monographs. These are usually contributions to the technical literature which are too lengthy for publication in the Journal of Research. They often provide extensive compilations of information on subjects related to the Bureau's technical program. Until July 1959 most of this type of material was published in the Circular series.

27. Supplement 2. Bibliography of temperature measurement, July 1960 to December 1965, L. O. Olsen and C. Halpern. April 28, 1967. (Supersedes Suppl. 1 to Monograph 27) 35 cents.

61. The solar spectrum 2935Å to 8770Å. Second revision of Rowland's preliminary table of solar spectrum wavelengths, C. E. Moore, M. G. J. Minnaert, and J. Houtgast. December 1966. $4.00.

75. Colors of signal lights. Their selection, definition, measurement, production, and use, F. C. Breckenridge. April 3, 1967. 40 cents.

88. Heat treatment and properties of iron and steel, T. G. Digges, S. J. Rosenberg, and G. W. Geil. November 1, 1966. (Supersedes Circular 495 and Monograph 18) 35 cents.

96. Electrical parameters of precision, coaxial, air-dielectric transmission lines, R. E. Nelson and M. R. Coryell. June 30, 1966. $1.25.

97. Microwave attenuation measurements and standards, R. W. Beatty. April 3, 1967. 25 cents.

98. Abscissas and weights for Gaussian Quadrature for N=2 to 100, and N=125, 150, 175, and 200, C. H. Love. December 28, 1966. 55 cents.

99. Automatic typographic-quality typesetting techniques: A state-of-the-art review, M. E. Stevens and J. L. Little. April 7, 1967. 70 cents.

100. Trace characterization, chemical and physics, Editors, W. W. Meinke and B. F. Scribner. April 28, 1967. $4.50.

Handbooks. These are recommended codes of engineering and industrial practices, including safety codes, developed in cooperation with the national organizations and others concerned. In many cases the recommended requirements are given official status through their incorporation in local ordinances by State and municipal regulatory bodies.

102. ASTM metric practice guide. March 10, 1967. 40 cents.

Miscellaneous Publications. As the name implies, this series includes material which, because of its character or because of its size, does not fit into any of the other regular publication series. Some of these are charts, administrative pamphlets, Annual Reports, Weights and Measures Conference Reports, and other subjects appropriate to the Miscellaneous series.

236. 1967 edition. NBS Standard frequency and time services Radio stations WWV, WWVH, WWVB, WWVL, 1967. 15 cents.

240 Suppl. Publications of the National Bureau of Standards, July 1960 through June 1966 (includes papers published by others 1960 through 1965). Together with subject and authors indexes, B. L. Oberholtzer. April 3, 1967. $4.00. 260-11. Standard Reference Materials: Viscosity of a standard lead-silica glass, A. Napolitano and E. G. Hawkins. November 7, 1966. 25 cents. 260-12. Standard Reference Materials: Homogeneity characterization of NBS spectrometric standards III: White cast iron and stainless steel powder compact, H. Yakowitz, D. L. Vieth, and R. E. Michaelis. September 19, 1966. 20 cents.

260-14. Standard Reference Materials: Determinaiton of oxygen in ferrous materials SRM 1090, 1091, and 1092, O. Menis and J. T. Sterling. September 23, 1966. 30 cents.

262-2. Legibility of alphanumeric characters and other symbols. II. A reference handbook, D. Y. Cornog and F. C. Rose, February 10, 1967. $4.25.

265. Dimensional metrology. Subject-classificed with abstracts, I. H. Fullmer. August 1, 1966. $3.00.

273. Critical phenomena. Proceedings of a conference, Washington, D.C., 1965, Edited by M. S. Green and J. V. Sengers. December 1, 1966. $2.50

274. Periodicals and serials received in the Library of the National Bureau of Standards as of October 1965, N. J. Hopper. July 1, 1966. (Supersedes Monograph 57) 50 cents.

280. Hydraulic research in the United States 1966, Edited by H. K. Middleton and G. Kulin. September 8, 1966. $1.50.

281. Bibliography on flame spectroscopy analytical applications 1800-1966, R. Mavrodineanu. February 23, 1967. $2.00.

282. The National Bureau of Standards 1966. November 1966. 35 cents.

283. Technical highlights of the National Bureau of Standards, Annual Report 1966. April 1967. 60 cents.

284. Technology and world trade, proceedings of a symposium, Edited by R. L. Stern. 1967. $1.25.

285. Nuclear science and technology for ceramists. Proceedings of the American Ceramic Society Symposium, Washington, D.C., April 7-12, 1966. May 26, 1967. $1.75.

286. Units of weight and measure. International (metric) and U.S. Customary, L. J. Chisholm. May 1967. (Supersedes Miscellaneous Publ. 233) $1.50. 289. Bibliography of low energy electron collision cross section data, L. J. Kieffer. March 10, 1967. 50 cents.

290. Report of the 51st National Conference on Weights and Measures 1966, L. J. Chisholm. May 15, 1967. $1.00.

National Standard Reference Data Series. NSRDS provides quantitative data on the physical and chemical properties of materials, compiled from the world's literature and critically evaluated. Reports will fall into eight categories: general; nuclear properties; atomic and molecular properties; solid state properties; thermodynamic and transport properties; chemical kinetics; colloid and surface properties; and mechanical properties of materials.

5. The band spectrum of carbon monoxide, P. H. Krupenie, July 8, 1966, 70 cents. 6. Tables of molecular vibrational frequencies, Part 1. T. Shimanouchi. March 1, 1967. 40 cents.

7. High temperature properties and decomposition of inorganic salts, Part 1. Sulfates, K. H. Stern and E. L. Weise. October 1, 1966. 35 cents.

8. Thermal conductivity of selected materials, R. W. Powell, C. Y. Ho, and P. E. Liley. November 25, 1966. $1.00.

Building Science Series. Research results, test methods, and performance criteria of building materials, components, systems, and structures.

5. Interrelations between cement and concrete properties. Part 2. Sulfate expansion, heat of hydration, and autoclave expansion, Section 4. Variables associated with expansion in the potential sulfate expansion test, R. L. Blain, H. T. Arni, and D. N. Evans; Section 5. Heat of hydration of portland cements, R. L. Blaine and H. T. Arni; and Section 6. Variables associated with small autoclave expansion values of portland cements, R. L. Blaine and H. T. Arni. July 1, 1966. 35 cents.

Commercial Standards. Define quality levels for products in accordance with the principal needs of the trade. Their use is voluntary.

259-63. (As amended Feb. 1, 1966). Southern pine plywood. February 1, 1966. 15 cents.

270-65. Acrilonitrile-butadiene-styrene (ABS) plastic drain, waste, and vent pipe and fittings. April 1, 1965. 15 cents.

271-65. Polyvinyl chloride (PVC) plastic drain, waste, and vent pipe and fittings. April 1, 1965. 15 cents.

272-65. Polyvinyl chloride (PVC) plastic drain, waste, and vent pipe and fittings. April 1, 1965. 15 cents.

273-65. Expanded vinyl fabrics for furniture upholstery use. December 31, 1965. 10 cents.

Simplified Practice Remommendations. List staple sizes, kinds, types, and applicable methods for certain commodies produced and stocked in greatest quantity, to aid in holding variety to a minimum. Their use is voluntary.

174-65. Cast-iron radiators. December 31, 1965. (Supersedes R1741-47) 10 cents.

Product Standards. Provide requirements for sizes, types, quality and methods for testing various industrial products. These standards are developed cooperatively with interested Government and industry groups and provide the basis for common understanding of product characteristics for both buyers and sellers. Their use is voluntary. (Replaces the Commercial Standard Series and Simplified Practice Recommendations.)

1-66. Softwood plywood, construction and industrial. November 1, 1966. (Supersedes CS45-60, CS122-60, and CS259-63) 20 cents.

2-66. Standard sizes of blackboard slate. May 15, 1966. (Supersedes R15-35) 10 cents.

3–66. TFE-fluorocarbon (polytetrafluoroethylene) resin skived tape. September 1, 1966. 10 cents.

4-66. Standard stock light-duty 1%- and 14-inch thick flush-type interior steel doors and frames. November 1, 1966. (Supersedes CS211-57) 10 cents. 5-66. Porcelain enameled formed steel plumbing fixtures. November 1, 1966 (Supersedes CS144-47) 15 cents.

6-66. Trim for water-closet bowls, tanks and urinals (dimensional standards). November 1, 1966. (Supersedes CS172-50) 10 cents.

7-66. Wire bar supports for reinforced concrete construction. August 1, 1966. 10 cents.

8-67. Grading of abrasive grain on coated abrasive products. January 9, 1967. (Supersedes CS217-59) 15 cents.

Technical Note Series. This series was initiated in 1959 to supplement the Bureau's regular publications program. Technical Notes provide a means for making available scientific data that are of transient or limited interest.

277. Analytical Mass Spectrometry Section: Instrumentation and procedures for isotopic analysis, W. R. Shields. July 25, 1966. 60 cents.

278. Scanning electron probe microanalysis, K. F. J. Heinrich. February 3, 1967. 30 cents.

290. Information handling in the National Standard Reference Data System, F. L. Alt. July 1, 1966. 25 cents.

292. Procedures for precise determination of thermal radiation properties. November 1964 to Otcober 1965, J. C. Richmond, G. J. Kneissl, D. L. Kelley, and F. J. Kelly, February 10, 1967. 50 cents.

293. Research on crystal growth and characterization at the National Bureau of Standards June 1966, H. C. Allen, Jr. August 26, 1966. 25 cents.

294. Notes on the state-of-the art of benefit-cost analysis as related to transportation systems, J. D. Crumlish. November 1, 1966. 30 cents.

295. Disclosures on: a transrotor engine, high temperature platinum resistance thermometer, dynamic analog correlation system, and combination metering and safety valve for filling sonde ballons with hydrogen, Editors D. Robbins and A. J. Englert. October 21, 1966. 25 cents.

296. A grammar for component combination in Chinese characters, B. K. Rankin, III, S. Siegel, A. McClelland, and J. L. Tan. December 1966. 60 cents. 298. A survey of ionization vacuum gages and their performance characteristics, W. G. Brombacher. February 3, 1967. 40 cents.

299. Calculation of the heating value of a sample of high purity methane for use as a reference material, G. T. Armstrong. December 15, 1966. 25 cents. 343. Temperature-entropy diagram for parahydrogen triple-point region, C. F. Sindt and D. B. Mann. June 22, 1966. 15 cents.

344. A sensitive recording NMR ultrasonic spectrometer, L. W. James. September 7, 1966. 20 cents.

345. A new near-zone electric field-strength meter, F. M. Greene. November 15, 1966. 35 cents.

346. On the natural shift of a resonance frequency, R. J. Harrach. September 29, 1966. 25 cents.

347. A standard for accurate phase-angle measurements at audio frequencies, W. W. Scott, Jr. October 14, 1966. 25 cents.

348. Infrared reflectances of metals at cryogenic temperatures a compilation from the literature, P. F. Dickson and M. C. Jones, October 14, 1966. 40 cents. 349. The design and operation of a high voltage calibration facility, W. W. Scott, Jr. November 10, 1966. 25 cents.

350. The viscosity and thermal conductivity coefficients of dilute nitrogen and oxygen, G. E. Childs and H. J. M. Hanley. October 31, 1966. 25 cents. 351. Discussion of errors in gain measurements of standard electromagnetic horns, R. W. Beatty. March 1967. 30 cents.

352. The viscosity and thermal conductivity coefficients of dilute neon, krypton, and xenon, H. J. M. Hanley and G. E. Childs. March 23, 1967. 25 cents. 353. Connector for saturated standard cells, J. J. Barth. April 21, 1967. 10 cents. 354. The single-engine Claude cycle as a 4.2 °K refrigerator, R. C. Muhlenhaupt and T. R. Strobridge. June 1, 1967. 45 cents.

400. Electrochemical analysis: Studies of acids, bases, nad salts by EMF, conductance, optical, and kinetic methods, July 1965 to June 1966, Edited by R. G. Bates. September 6, 1966. 55 cents.

401. Activities of the NBS Spectrochemical Analysis Section, July 1965 through June 1966, Edited by B. F. Scribner. September 30, 1966. 55 cents.

403. Microchemical Analysis Section: summary of activities, July 1965 to June 1966, Edited by J. K. Taylor. September 1, 1966. 50 cents.

404. Radiochemical analysis: activation analysis, instrumentation, radiation techniques, and radioisotope techniques, July 1965 through 1966. Edited by J. R. DeVoe. September 30, 1966, $1.25.

405. Organic chemistry: Air pollution studies; kinetic behavior of sugars in solution carbon-14- and tritium-labeled carbohydrates; characterization of chemical structures, phenylhydrozone-phenylazo tautomerism; synthesis of research materials, cyclopentitols and related substances; novel research materials; standard reference materials (organic), July 1965 through June 1966, Edited by H. S. Isbell. September 30, 1966. 60 cents.

408. Superconductive materials and some of their properties, B. W. Roberts. September 26, 1966. 45 cents.

409. Fortran programs for the calculation of Wigner 3j, 6j, and 9j coefficients for angular momenta≤80, R. S. Caswell and L. C. Maximon. November 15, 1966. 40 cents.

410. Improved fortran program for single particle energy levels and wave functions in nuclear structure calculations, R. S. Caswell, September 30, 1966. 25 cents.

411. Methods for performance-testing of electromechanical pressure transducers, P. S. Lederer. February 9, 1967. 25 cents.