326 



NATURE 



[June 27, 19 18 



The case ajjainst the rook is not yet proven, but 

 the evidence should be collected together and submitted 

 to the consideration of a scientific jury. 



Sydney J. Hickson. 



The University, Manchester, June 22. 



Dr. Long (Nature, June 20, p. 304) raises a point 

 which I think must appeal to many. The potential 

 damage, represented by the 23-9 per cent, of injurious 

 insects, is surely the one factor upon which every- 

 thing depends ; and, difficult though it is to see just 

 how the necessarv information is to be acquired, ^ye 

 are scarcely justified, so I am inclined to think, in 

 arriving at any conclusion without it. 



Is it not a fact that the Hungarian Central Office 

 for Ornithology reached the conclusion, after careful 

 investigation, that the rook is of service both to agri- 

 culture and to cattle-breeding? 



H. Eliot Ho\vard. 



Hartlebury, June 22. 



" Harbour Engineering." 



Lest it should be assumed that I tacitly acquiesce 

 in certain sins of omission alleged in the review of 

 the second edition of the above book, which appeared 

 in Nature of June 13, may I point out that the matters 

 in question (slipway construction, durability of con- 

 crete in sea-water, mechanical handling of material, 

 etc.) are discussed so fully in the companion volume 

 on "Dock Engineering," to which they are equally, 

 if not more, appropriate, that it seemed undesirable 

 to include any extended notice of them in " Harbour 

 Engineering " ? Reference to this fact is to be found in 

 several places (pp. 147, 265, etc.). 



Brysson Cunningham. 



June 20. 



VNITS AND UNITY. 



THE note that appeared in Nature of March 7 

 (p. 14) about the nomenclature of tempera- 

 tures in centigrade degrees measured from a zero 

 273° below the normal freezing point of water in- 

 vited further contributions on the subject of units, 

 and other circumstances transform the invitation 

 into an imperative demand. The report of Sir 

 J. J. Thomson's Committee on Science Teaching, 

 without making a definite recommendation for the 

 adoption of metric units, deliberately adjusts its 

 scheme of education in such a way as to make 

 familiarity with metric units a part of general 

 education. What is the use of doing so if metric 

 units are not to be used for the practical affairs 

 of life? Our present situation is ridiculous. 

 Every boy and girl at school who "does science " 

 now learns that metric units are the universal 

 medium of scientific expression, and is practised 

 in their use. At the same time, we cry out for 

 more science in our practical life. What can we 

 expect from our appeal? A boy goes home at the 

 end of term and tells his father that he has been 

 doing science, weighing in grams, measuring 

 lengths in centimetres, pressures in millimetres of 

 mercury, and temperatures in degrees centigrade. 

 Surely the most natural remark for any naturally 

 minded parent to make is that his bov need not 

 pay any attention to that, because, if it had any 

 NO. 2539, VOL. lOl] 



bearing at all upon practical life, he would cer- 

 tainly have been taught to use pounds or grains^ 

 inches, and Fahrenheit degrees, and not the out- 

 landish things that nobody uses after he has left 

 school. There is a story told of Adams, the astro- 

 nomer, who, in a Swiss hotel, asked for a bath, 

 and was particular that the water should be at 

 100°. After a long time, the maid came and said 

 she had done her best, but she could not get it 

 above 95°; and I doubt if, even at this day, 

 the President of the Royal Society himself uses 

 the same unit for his bath-water and his water- 

 bath. 



If science is to be a part of practical life, the 

 units of science and the units of practical life 

 must be the same. One thing or the other : either 

 practical folk must learn to use metric units, or 

 British men of science must use British units in 

 their laboratory courses. The present divorce 

 between education and practice is ruinous for both. 

 If we want instruments according to metric 

 measures, we get them from instrument-makers 

 who understand such measures, not from those 

 who do not — that is, we tend to get our scientific 

 instruments mostly from abroad — and so on in 

 everything. Hitherto men of science have 

 not cared, because we can use either measure 

 with equal facility, and we take a little 

 pedantic pleasure in being bilingual in that 

 sense. It is the same with our language. We 

 take a tiny pride in the small difficulties of pro- 

 nunciation that stand in the way of its being a 

 lingua franca; we sneer at any attempts to bring 

 spelling into agreement with pronunciation ; we 

 advocate the learning of Esperanto or Ido instead, 

 to avoid international jealousy, forsooth. Shake- 

 speare wrote "Gloster," but we lose marks if we 

 do not write "Gloucester"; classical authors 

 wrote "gage," but we must write "gauge," and 

 we chuckle inwardly when our friends write 

 "guage." There is a ton of "the high life" 

 in knowing that " C-h-o-l-m-o-n-d-e-l-e-y " is pro- 

 nounced "Marchbanks" which we are all proud 

 of ; and meanwhile English is set down as impos- 

 sible for the use of the world at large. 



The attitude of mild complacency with our own 

 superior knowledge runs through everything. I 

 have heard it said quite recently that meteorology 

 stands in the way of the adoption of metric units. 

 Certainly that is not true ■ of the Meteorological 

 Office. . Since May i, 1914, we have gone a step 

 further than most people in using C.G.S. units 

 for pressure, millimetres for rainfall, metres per 

 second for wind velocity in the Daily Weather 

 Report, and we use absolute temperatures 

 wherever we dare. We have even gone so far as 

 to use milliwatts per square centimetre for solar 

 radiation, instead of the preposterously unscien- 

 tific unit gram-calories-per-square-centimetre-per- 

 minute. But it is difficult to keep these things 

 going without the support of those who could 

 help. The United States \^^eather Bureau and 

 the French Meteorological Service, and " some 

 others outside, have gone with us. In this country 

 nobody but the Meteorological Office appears to 



