B44 Rf^POHTS ON THE STATE OF SCIENCEj 



have carefully avoided indicating to the engineer how and when tliese 

 shapes should be used, or what particular strains should be allowed in the 

 material composing them. The Committee have felt that this is a ques- 

 tion entirely for the engineer, and that he alone must decide what stresses 

 may be allowed in the structures which he is engaged in designing. 



In one instance only have they departed from this principle, and that 

 at the special request of the Secretary of State for India, who desired 

 them to design certain specific types of locomotives for use on Indian 

 railways, which it will be remembered, unlike the railways in this countryj 

 are under direct Government control. 



To give an illustration of the graduation in the standardising of shapfes 

 and forms, it may be mentioned that the Committee have laid down sixteen 

 sizes of equal angles, thirty of unequal angles, twenty of bulb angles, six 

 of bulb tees, seven of bulb plates, eight of Z bars, twenty-seven of channels, 

 thirty of beams, and twenty of tees. In the case of railway rails there 

 are, advancing by 5 lb. at a time, nine sizes of bull-headed rails from 

 60 lb. to 100 lb. per yard, seventeen sizes of flat-bottomed rails from 

 20 lb. to 100 lb. per yard, and five sizes of tramway rails from 90 lb. to 

 110 lb. per yard. Five corresponding sections of tramway rails, having 

 a wider groove for use on curves, have also been designed. 



Slandardisation of Material. 



When the Committee commenced its labours it was not the intention 

 to deal with the standardisation of material, but it soon became evident 

 that assistance of a very real character could be rendered to the manufac- 

 turers of this country if high-class Standard SpeciOcations were issued, 

 covering the materials more generally used in engineering. 



The multiplication of various Specifications for the same subject, differ- 

 ing from one another often in unimportant details, but yet sufticiently 

 divergent to preclude the unification of the process of manufacture, was 

 a. widely experienced difficulty, and one which the Committee sought, by 

 the issue of Standard Specifications, to remove. It was felt that if a 

 liigh-class Standard Specification were generally acknowledged, it would 

 inevitably tend to improve manufacture and assist British manufacturers 

 to meet competition. 



Advantages of Standardisation. 



The advantages accruing from the work which ha.»> been accomplished 

 are now so familiar that we hardly realise their extent, and may be tempted 

 to minimise their value. 



It must, of course, be borne in mind that every advantage is accom- 

 panied in a lesser or greater degree by some disadvantage. For instance, 

 should standardisation be pushed too far, it might in some instances stereo- 

 type design or retard the progress of invention ; but provided that it is 

 clearly understood that special circumstances must exist which warrant 

 special designs, and as long as standardisation is confilied to broad prin- 

 ciples and the standards laid down are sufficiently numerous, the 

 advantages must immeasurably outweigh the disadvantages. Exceptional 

 cases may no doubt exist, for instance, where the use of some particular 

 form of angle or channel is justified, and where the expense entailed in 

 cutting special rolls, and delay in manufacture by the consequent chang- 



