22 AERODYNAMICAL THEORY AND DATA
the wall of the tunnel, recording on an alcohol manometer the
difference of the pressure in the room and in the experimental
part of the tunnel. These manometer readings were calibrated
against a standard N. P. L. pitot tube to ascertain the true
velocity.
The aerodynamical balance was constructed by the Cam- bridge Scientific Instrument Company, England, and is a counter-part of the English installation. Most model adjust- ments are possible from the outside without stopping the wind, thus greatly facilitating the experimental work. The balance is arranged so that complete data for the calculation of the stability coefficients for airplanes is obtainable.
While the laboratory is primarily for research work, investi- gations are conducted for private individuals or manufacturers at nominal charges.
It is interesting to note that the Curtiss Company has re- cently erected at Buffalo, under the direction of Dr. A. F. Zahm a wind tunnel similar in construction to that of the N. P. L. and the Massachusetts Institute of Technology.
References for Chapter 1
National Physical Laboratory, Teddington, and Royal Aircraft Fac- tory, Farnborough, England. Publication: Technical Report of the Advisory Committee for Aeronautics, for the years 1909-10, 1910-11, 1911-12, 1912-13.
United States Navy Department Wind Tunnel, Washington, D. C. The Aerodynamical Laboratory of the Massachusetts Institute of Technology, Boston, Mass.
The Laboratoire Aérodynamique Eiffel, Auteuil, France. Publica- tions: "La Resistance de l'Air et l'Aviation," by G. Eiffel, 1912, trans- lated by J. C. Hunsaker. "Nouvelles Recherches sur la Resistance de l'Air et l'Aviation," by G. Eiffel, Dunod and Pinat, Paris, 1914.
Bulletin de P'Institut Aérodynamique de Koutchino, Moscow.
† Göttingen Aerodynamical Laboratory, Göttingen, Germany. The Deutsche Versuchsanstalt für Luftfahrt zu Adlershof, Berlin, Germany.
"Report on European Aeronautical Laboratories," by A. F. Zahm, Vol. 62, No. 3; "Report on Wind Tunnel Experiments in Aero- dynamics," by Hunsaker and others, Vol. 62, No. 4. Published by Smithsonian Institution, Washington, D. C., in Smith, Miscellaneous Collections, Vol. 62.
Bulletin de l'Institut Aerotechnique de l'Université de Paris, 1912- 13-14.
Work published at irregular intervals in standard periodicals and reports, such as: Aeronautical Journal, England; L'Aeroplane, Paris, France; Smithsonian Institution Reports, Washington, D. C.; Engineer- ing, London; Annual Report of the National Advisory Committee for Aeronautics, Washington, D. C., 1915.
† Jahrbuch der Motorluftschiffstudiengesellschaft, Berlin, years 1908-09, '09-10. 10-11, 11-12, '12-13, and Zeitschrift für Flugtechnik und Motorluftschiffahrt (semi-monthly periodical of research work).
