1901.] on the National Physical Laboratory. 667 



intended to take up this work, and for this purpose a mercury pres- 

 sure column is being erected. 



Again, there are the ordinary gauges in use in nearly every 

 engineering shop. These, in the first instance, have probably come 

 from Whitworth's, or nowadays, I fear, from Messrs. Pratt and 

 Whitney or Browne and Sharpe, of America. They were probably 

 very accurate when new, but they wear, and it is only in compara- 

 tively few large shops that means exist for measuring the error and 

 for determining whether the gauge ought to be rejected or not. 

 Hence arise difficulties of all kinds. Standardisation of work is 

 impossible. 



In another direction a wide field is offered in the calibration and 

 standardisation of glass measuring vessels of all kinds, flasks, burettes, 

 pipettes, &c, used by chemists and others. At the request of the 

 Board of Agriculture we have already arranged for the standardisation 

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

 fat in milk, and in a few months many of these have passed through 

 our hands. We are now being asked to arrange for testing the 

 apparatus for the Gerber and 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 will, be extended. Photographic 

 lenses are now examined by eye ; a photographic test will be added, 

 and I trust the whole may be made more useful to photographers. 



I look to the co-operation 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 for inquiry. If more subjects are needed it is 

 sufficient to turn over the pages of the evidence given before Lord 

 Eayleigh'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 funda- 

 mental units on which, in Mr. Trotter's opinion, we may 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 will be found. 



I have gone almost too much 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 I 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. 



[E. T. G.] 



