596 



NATURE 



[May 6, 1922 



of the fat-tailed ancestry of present-day sheep, 

 Prof. Ewart noted some time ago a Border-Leicester 

 sheep with the tip of the tail turned up following 

 the lines of the tail of the fat-tailed sheep. Thus 

 it would appear that the nine brief statements 

 with which the report starts are of quite extra- 

 ordinary interest, and in addition may usefully be kept 

 in mind when studying present-day types of sheep. 



Mendelian principles — particularly involving the 

 reshuffling of " characters " — are then insisted on 

 and the value of crosses beyond the first cross 

 emphasised. This is really essential, as so many 

 breeders fail to realise the importance of the Fg 

 cross. Australian sheep-breeders, however, say " three 

 generations to obtain the cross and thirty to fix it " ! 



The report is then divided into two sections : 

 (i) experiments with Highland blackface and other 



modern breeds^; and (2) experiments with primitive 

 breeds. It is pleasing to note the assistance accorded 

 by the Duke of Richmond and Gordon and his agent, 

 Mr. R. A. Dawson, Mr. R. Macmillan, Captain J. 

 Stirling, Mr. Dyson Perrin, Sir John Ramsden, Sir 

 Malcolm Macgregor, Mr, Gordon, and the veteran 

 of experimental sheep-breeders, Mr. J. Elwes of 

 Colesborne, Cheltenham. 



The Scottish Board of Agriculture is also taking a 

 deep and broad interest in experiments here partially 

 recorded. Ten photographs of typical sheep and 

 their crosses add materially to the value of the report. 



The report concludes with references to the experi- 

 ments in progress under the direction of Prof. White 

 in Wales and to the experiments on British wool 

 characteristics at present being carried out at the 

 University of Leeds, A. F. B, 



r^URIOUS reflections- on 



^-^ scientific knowledge are suggested by the 

 extraordinarily interesting address of Dr. F. L. 

 Hoffman to the social and economic science section 

 of the American Association, at the Toronto meeting 

 last December, on " The Organisation of Knowledge," 

 published in Science of March 10 and 17. Dr. Hoffman 

 has been for thirty years a very practical organiser 

 of knowledge in connection with his management of 

 the Prudential Insurance Company of America. 

 He has been reading Prof. Whitehead's " The 

 Organisation of Thought," and it seems to have 

 impressed him with a sense of the remoteness of 

 mathematical principles, mathematical methods, and 

 mathematical research from any organisation of 

 science which is serviceable in practical life. 



The problem Dr. Hoffman deals with is a profound 

 one, and carries us back to the old distinction between 

 truths of reason and matters of fact which in some 

 form has been the problem of modern philosophy 

 since it first arose with Bacon and Descartes. It is 

 interesting to look back on the confidence with which 

 some of the leaders of philosophic thought in the 

 nineteenth century supposed they had solved it. 

 The confidence appears first in Comte and afterwards 

 in Spencer, who devoted a great part of his intellectual 

 energy to an attempt to give it practical effect. It 

 rested on the idea of a division of labour. It was 

 to be the business of scientific workers to observe and 

 coUect facts, guided of course by certain rules of 

 classification and arrangement, but it was to be the 

 special business of philosophers to systematise and 

 generalise. An amusing illustration is a story related 

 to the present writer many years ago by the late 



The Organisation of Knowledge. 



the present state of Dr. Williamson, professor of chemistry in University 

 College. Herbert Spencer had written to him to ask 

 him whether certain specified chemical experiments 

 could be relied on as correct. In his reply he added 

 to the information asked for his own interpretation, 

 only to receive by return a sharp rebuke pointing 

 out to him that his business was to observe and report 

 facts ; it was for the philosopher to theorise con- 

 cerning them. It is perhaps needless to add that the 

 narrator saw no humour in the stor3^ 



The fact gatherer. Dr. Hoffman tells us, should be 

 the fact user. It is the reason he gives for this, 

 however, that deserves particular attention. Fact 

 gathering is impossible without imagination, and 

 imagination is what the mathematician is ever trying 

 to get rid of. The ideal of science is forecasting, and 

 in the business of insurance we have the most 

 complete development of it. In the organisation 

 of knowledge for insurance the whole principle is 

 that all facts are regarded in their interrelation or 

 interdependence for useful purposes. Dr. Hoffman 

 contrasts this with Prof. Whitehead's appeal for a 

 first-hand knowledge which has " never been scared 

 by facts." Progress and discovery depend upon a 

 disciplined imagination, and Dr. Hoffman quotes 

 Karl Pearson, " the man with no imagination may 

 collect facts, he cannot make great discoveries." 

 What we want to forecast are the sort of things 

 mathematics is helpless before, things like the inter- 

 national war, or the influenza epidemic. 



Dr. Hoffman concludes his address by outlining 

 the general scheme of his own organisation of the 

 library and information service of his business 

 office. 



T TNDER this title an interesting paper was read 

 ^ at a meeting of the Newcomen Society on 

 March 30 by Engineer-Commander Edgar C. Smith. 

 Among other matters treated was the development 

 of paddle-wheel vessels, and a notable feature is 

 presented by two tables giving particulars of steam 

 vessels added to H.M, Navy during the period 1820- 

 1850. 



During the first twenty years all Navy boilers 

 were of the flue type and were box -shaped. 

 Leakage was very frequent ; Dinnen remarks on 

 the numerous " weeps " of which no notice was 

 taken. These boilers were suitable for low pressures 

 only, and it was forty years before the working 

 pressure increased from 3*5 to 20 lb. per sq. in. 



Great care was necessary for working these early 

 boilers with salt water. Ships at sea put out the 

 fires every third or fourth day and emptied the 

 boiler. Afterwards, blowing down every two hours 

 became the rule. If the blow-down cocks jammed, 



NO. 2740, VOL. 109] 



The Centenary of Naval Engineering. 



the water could be blown through the hand pump, 

 according to Murray, " a usual plan is to knock 



out a rivet from the bottom of the boiler." Feed 

 heating came into use early, an annular tank being 

 placed round the funnel. 



The first vessel in the Navy to have a surface 

 condenser was the Megaera. She had the five-fold 

 combination of an air-pump, a circulating pump, a 

 surface condenser, an evaporator, and a steam saver. 

 This vessel was wrecked in 1843. The oscillating 

 engine was invented by Murdock, improved by 

 Manby, taken up by Maudslay, and its final success 

 was due to Penn. Since all warships had to retain 

 their sailing qualities, special attention had to be 

 paid to devices for preventing interference from the 

 paddle-wheels whilst the vessel was under sail. 



We are indebted to the Engineer for the foregoing 

 details, and trust that the author will complete his 

 work by another paper dealing with the development 

 of screw propulsion. 



