1182 REPORT—1885. 
Section G.—MECHANICAL SCIENCE. 
PRESIDENT OF THE SEcTION—B. Baker, M.Inst.C.H, 
THURSDAY, SEPTEMBER 10. 
The PrestpEnT delivered the following Address :— 
GrnrLEMEN,—Two hundred and fifty-seven Presidential Addresses of one kind and 
another have been delivered at meetings of the British Association since the 
members last mustered at Aberdeen. I need hardly say that the candid friend who 
informed me of this interesting fact most effectually dispelled any illusion I may 
have previously entertained as to the possibility of preparing an address of 
sufficient novelty and suggestiveness to be worthy of your attention, and I can 
only hope that any shortcomings will be dealt with leniently by you. One com- 
pensating advantage obviously belongs to my late appearance in the field—I have 
two hundred and fifty-seven models of style upon which to frame my address. 
My distinguished predecessor, Sir Frederick Bramwell, has a style of his own, in 
which wit and wisdom are combined in palatable proportions; but were I to 
attempt this style I should doubtless incur the rebuke which a dramatic critic of 
Charles the Second’s time administered to a too ambitious imitator of a popular 
favourite: ‘He’s got his fiddle, but not his hands to play on’t.’ I must search 
further back than last year, therefore, for a model of style, and the search reminds 
me that I labour under a double disadvantage: firstly, that only two addresses 
intervene between the present one and that of my partner, Mr. John Fowler, 
with whom I have so long had the honour of being associated, and whose 
professional experiences, as set forth in his address, are necessarily so largely 
identical with my own; and, secondly, that within the same period I have read 
before this Section two somewhat lengthy papers on the work which is at present 
chiefly engaging the attention of Mr. Fowler and myself—the great Forth bridge. 
Although, for the reasons aforesaid, I am conscious that my address may fail in 
novelty, I cannot honestly profess to feel a difficulty in preparing an address of 
some kind, for the subjects embraced under the head of ‘ Mechanical Science’ are 
so inexhaustible that even the youngest student might safely accept the responsi- 
bility of speaking for an hour on some of them. Professor Rankine, addressing 
you thirty years ago, said it was well understood that questions of pure or abstract 
mechanics form no part of the subjects dealt with in this Section. With character- 
istic clearness of conception and precision of language, he told you what the term 
«Mechanical Science’ meant, and, after thirty years’ interval, his words may be re- 
called with advantage to everyone proposing to prepare an address or report for 
this Section, ‘Mechanical Science,’ said Professor Rankine, ‘enables its possessor 
to plan a structure or machine for a given purpose without the necessity of copying 
some existent example; to compute the theoretical limit of the strength and 
stability of a structure or the efficiency of a machine of a particular kind; to 
ascertain how far an actual structure or machine fails to attain that limit, and to 
discover the cause and the remedy of such shortcoming; to determine to what 
extent, in laying down principles for practical use, it is advantageous for the sake 
of simplicity to deviate from the exactness required by pure science ; and to judge 
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