March 25, 1909] 



NA TURE 



109 



THE XATIONAL PHYSICAL LABOR ATORY 

 DURIXG 1908. 

 T^HE annual meeting of the general board of the 

 •'■ National Physical Laboratory was held at Tedding- 

 ton on the afternoon of Friday, March iq, when the 

 report of the executive committee for the year 1908 was 

 formally presented, and the various departments of the 

 laboratory were thrown open for inspection. The fifth 

 volume of the " Collected Researches," which is now 

 ready for issue, was also laid before the general board, 

 and includes the results of the more important investiga- 

 tions recently carried out at the laboratory. 



In connection with this year's gathering, the absence 

 of Lord Rayleigh from the meeting cannot be allowed to 

 pass without remark. Lord Rayleigh has always taken 

 the warmest interest in the development of the laboratory ; 

 he has been from the first, and is still, chairman of the 

 executive committee, though during his temporary absence 

 abroad his duties have been undertaken by Sir John Wolfe- 

 Barry, and this is the first occasion on which he has been 

 prevented from being present at the annual inspection. 

 His absence was de- 

 plored by none more ^ 

 than the staff, by 

 whom his appreciation 

 and his ready counsel 

 on innumerable matters 

 of detail are especially 

 valued. Sir Archibald 

 Geikie, as president of 

 the Royal Society, 

 acted this year as 

 chairman of the 



general board. 



The report of the 

 executive committee 

 gives some particulars 

 as to the expenditure 

 during 1905-8 on new- 

 buildings. These com- 

 prise buildings for 

 electrotechnics, i n - 



eluding photometry, for 

 metrologv, and ' for 

 metallurgical chemistry, 

 as well as an extension 

 of the engineering 

 building. They havi- 

 been erected at a cost 

 of about 25,000/., and 

 an additional 8000/. has 

 been spent on equip- 

 ment. This latter 

 amount, however, does 

 not include what has 

 been provided out of 

 annual income, nor the 

 many gifts of apparatus. Of the total thus expended, 

 25,000/. has been provided bv the Trcasurv. The grants 

 promised by the Treasury for 'building purposes have,'^how- 

 ever. now come to an end ; no new buildings have been 

 added during 1908. the funds available being devoted to 

 equipment, which is still by no means complete. 



There is thus, unless funds are provided from other 

 sources, no immediate prospect of anv considerable 

 extension of existing departments, though the rapid 

 development of the work has shown clearlv that the need 

 of further accommodation must shortlv become urgent. 

 The department of metallurgy, which 'is doing work of 

 the gre.-itost value in connection with the most important 

 of British industries, is at present quite inadequatelv 

 housed in the old kitchen and a few scattered rooms in 

 the basement of Bushy House. Plans have alreadv been 

 prepared for a new building, which would be an extension 

 of that devoted to the Indian railwav test-work, but the 

 committee is unable at present to do 'more than commend 

 the importance of such a department to the attention and 

 generosity of those to whom metallurgical research is of 

 interest and value. 



The only development of first-rate importance immedi- 



ately in prospect is thus the experimental tank for investi- 

 gations on ship models, building operations for which will 

 be commenced in the spring. The construction of the tank 

 has been rendered possible by the munificence of Mr. A. F. 

 Yarrow, who has placed 20,000/. at the disposal of the 

 Institution of Naval Architects for the erection at the 

 laboratory of a tank of the most modern type, under the 

 proviso that a sufficient sum be found to provide for 

 maintenance during the first ten years. The guarantee 

 fund has now reached a total sufficient to warrant the 

 work being begun, and another department of great public 

 interest and utility will thus be added to the laboratory. 



Turning now to the details of the work carried out 

 during the year by the several departments, reference may 

 first be made to the re-organisation of the thermometry 

 division of the physics department. Arrangements have 

 been made for transferring to Teddington some of the 

 thermometer testing at present undertaken by the observa- 

 tory department, and at the same time it has been found 

 necessary to provide increased facilities for the rapid and 

 accurate verification of high- and low-range thermometers, 

 as well as of standards and thermometers of special types. 



Fin. 



NO. 2056, VOL. So] 



Baths for Verificaticn of Ordinary and Standard Then 



For this purpose the old chemical laboratory, v.icated by 

 the transfer of the chemical work to the new building for 

 metallurgical chemistry, has been re-fitted with a new 

 and special equipment for the testing of mercury thermo- 

 meters, designed by Dr. Harker and Mr. W. A. Price, a 

 description of which is given as an appendix to the report. 

 The chief requisites in connection with baths for thermo- 

 meter comparisons are efficient stirring, convenient and 

 rapid heating, and satisfactory temperature regulation, 

 with arrangements for avoidance of emergent stem errors, 

 .^t the same time, suitable provision must be made for the 

 rapid recording of observations. The type of bath and the 

 general arrangements adopted are shown in Fig. i. The 

 containing vessel of the apparatus consists of two flat boxes 

 of cast brass, the larger containing the thermometers to 

 be tested, while the smaller is occupied by the stirrer above 

 and the electric heating appliances below. The stirrers in 

 .•ill the baths are driven with endless cord and pulleys from 

 an electric motor. The heating is effected by means of 

 special resistance units, each of 400 watts capacity, con- 

 structed of " Eureka " strip. The baths are well lagged, 

 and the temperature can be run up very quickly to any 

 desired point. A desk is provided for the observer, above 



