scholarly journals The air pressure on a cone moving at high speeds.—II

1933 ◽  
Vol 139 (838) ◽  
pp. 298-311 ◽  
Keyword(s):  
National Physical Laboratory ◽  
Air Pressure ◽  
Research Department ◽  
High Speeds ◽  
Physical Laboratory

Though the calculations are concerned only with the flow in the neighbourhood of an infinite cone, it was thought that the flow near a finite cone or near the nose of a bullet with a conical head might be comparable with the calculations. Accordingly, measurements of two kinds were undertaken. The surface pressures on cones were measured at the National Physical Laboratory, and photographs of a bullet with a 60° conical head were taken at various speeds by the Research Department at Woolwich.

scholarly journals Research Organisations in British Shipbuilding and Large Marine Engine Manufacture (Part II)

2021 ◽  
Vol 30 (2) ◽  
pp. 133-154
Author(s):  
Hugh Murphy
Keyword(s):  
Research And Development ◽  
National Physical Laboratory ◽  
Research Association ◽  
Marine Engine ◽  
Research Department ◽  
Physical Laboratory ◽  
Research Organisations ◽  
Premiere Partie

Cet article fait suite à la première partie, qui traitait de la période 1900 à 1944. Ici, l’auteur étudie l’impact de la British Ship Research Association, de la Parsons Marine Turbine Research and Development Association et, de façon tangentielle, d’un groupe de conseil en recherche privé, le Yarrow Admiralty Research Department (Y-ARD), une filiale de Yarrow Shipbuilders établie dans le district Scotstoun de la rivière Upper Clyde, et le National Physical Laboratory (NPL). Il traite également de William Doxford & Sons, avant d’évaluer l’impact individuel et collectif de ces sociétés jusqu’en 1959, ainsi que la situation générale de la construction navale britannique et la fabrication de gros moteurs maritimes.

scholarly journals 75th Foundation Day of CSIR-National Physical Laboratory: Celebration of Achievements in Metrology for National Growth

MAPAN ◽  
2021 ◽  
Author(s):  
Sanjay Yadav ◽  
Goutam Mandal ◽  
V. K. Jaiswal ◽  
D. D. Shivagan ◽  
D. K. Aswal
Keyword(s):  
National Physical Laboratory ◽  
Physical Laboratory ◽  
National Growth

Comparison of the acceleration due to gravity at the National Physical Laboratory, Teddington, the Bureau International des Poids et Mesures, Sèvres, the Physikalisch-Technische Bundesanstalt, Brunswick, and the Geodetic Institute, Potsdam

1952 ◽  
Vol 213 (1114) ◽  
pp. 408-424 ◽  
Keyword(s):  
National Physical Laboratory ◽  
Absolute Value ◽  
Geodetic Institute ◽  
Physical Laboratory ◽  
The Absolute

The values of gravity at these stations have been compared by means of pendulum observations with Invar invariable pendulums. The observed differences of gravity from the National Physical Laboratory are: B. I. P. M. -256·73 ± 0·49 mgal P. T. B. + 68·68 ± 0·49 mgal Bad Harzburg - 15·68 ± 0·49 mgal The accuracy of the measurements is not so great as has been achieved once or twice previously with the same apparatus, mainly because the changes in the lengths of the pendulums were greater than usual. These differences have been combined with German pendulum observations and with gravimeter comparisons with the following results: Value of gravity at N. P. L. on the Potsdam system: 981196·29 ± 0·3 mgal. Differences between sites of absolute determinations of gravity: N. P. L. - B. I. P. M. +256·45 ± 0·3 mgal N. P. L. - P. T. B. - 68·98 ± 0·3 mgal P. T. B. - Potsdam - 8·95 ± 0·4 mgal ( g at Potsdam = 981274 mgal.) The effects of these results on gravity surveys based on Cambridge and on the absolute value of gravity are indicated.

scholarly journals A standard measuring machine

1912 ◽  
Vol 87 (597) ◽  
pp. 385-390
Keyword(s):  
National Physical Laboratory ◽  
Standard Measuring ◽  
Physical Laboratory ◽  
Accurate Comparison ◽  
Measuring Machine ◽  
Regular Work ◽  
Absolute Measurements ◽  
Line Standard

In some physical researches it is required to measure the dimensions of a regular solid, whether parallel-sided, cylindrical, or spherical-ended, with the greatest possible accuracy. Again, in the regular work of a metrology bureau, accurate comparison of the size of an end-standard of length with reference to a line-standard is required. Until 1906 the only apparatus available for these purposes was the measuring machine made for comparing engineering gauges. In that year the writer described a machine based on the principle of electric touch, which was much more delicate than the older mechanical machines. It also had facilities for exploring the solid under test, to prove its accuracy of figure. This machine has been installed and used in the National Physical Laboratory since 1909. Improvements in it were described later. The present paper gives an outline of an improved machine of the same type embodying the experience gained in using the 1906 machine. The chief novelties are: (1) greater strength in the supporting parts, and consequent rigidity of the whole apparatus; (2) larger and much improved table to carry the solid under test; (3) improved measuring-ends; (4) an innovation for making absolute measurements, whereby the line-standard moves but the reading microscope remains fixed; (5) side girders to relieve the bed of load and so reduce friction, abrasion, and strain.

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