PHYSICAL LABORATORY OF GREAT BRITAIN. 357 



In iUK)th(n' direction a wide field is offered in the calibration and 

 standardization of glass measuring vessels of all kinds — flasks, burettes, 

 pipettes, etc. — used b}' chemists and others. At the request of the 

 board of agriculture we have already arranged for the standardization 

 of the glass vessels used in the Rabcock method of measuring the butter 

 fat in milk, and in a few months man}' of these have passed through our 

 hands. We ai'e now being asked to arrange for testing the apparatus 

 for the Gerber 6c Leffman-Beam methods, and this we have promised to 

 do when we are settled at Bushy. Telescopes, opera glasses, sextants, 

 and other optical appliances are already tested at Kew, but this work 

 can and Avill be extended. Photographic lenses are now examined l)y 

 eye', a photographic test will be added, and I trust the whole may be 

 made more useful to photographers. 



I look to the cooperation of the Optical Society to advise how we 

 may be of service to them in testing spectacles, microscope lenses, and 

 the like. 



The magnetic testing of specimens of iron and steel again offers a 

 fertile field foi- inquiry. 



If more subjects are needed it is sufficient to turn over the pages of 

 the evidence given before Lord Ra^deigh's commission or to look to 

 the reports which have been prepared by various bodies of experts 

 for the executive committee. 



In electrical matters there are questions relating to the fundamental 

 units on which, in Mr. Trotter's opinion, we ma}' help the officials of the 

 board of trade — standards of capacity are wanted; those belonging- to 

 the British Association will be deposited at the laboratory; standards 

 of electromagnetic induction are desirable; questions continually arise 

 with regard to new' forms of cells other than the standard Clark cell, 

 and in a host of other ways work could be found. Tests on insulation 

 resistance were mentioned by Professor Ayrton, who gave the result 

 of fais own experience. He had asked for wire having a certain stand- 

 ard of insulation resistance. One specimen was eight times as good as 

 the specification; another had only one one-hundred-thousandth of the 

 recjuired insulation; a third had about one three-hundredth. 



Mr. Appleyard again gave some interesting examples, the examina- 

 tion of alloys for use for resistance measurements and other purposes, 

 the testing of various insulating materials, and the like. 



1 have gone almost too nmch into detail. It has been my wish to 

 state in general terms the aims of the laboratory, to make the advance 

 of physical science more readily available for the needs of the nation, 

 and then to illustrate the way in which it is intended to attain those 

 aims. I trust 1 may have shown that the National Physical Laboratory 

 is an institution which may deservedly claim the cordial support of all 

 who are interested in real progress. 



