

264 

tion, when it met at York in the year 1831 :—“In addition to 
other more direct benefits, these meetings [of the British Asso- 
ciation]. I hope, will be the means of impressing on the 
Government the conviction, that the love of scientific pursuits, 
and the means of pursuing them, are not confined to the 
metropolis; and I hope that when the Government is fully 
impressed with the knowledge of the great desire entertained 
to promote science in every part of the empire, they wilt see 
the necessity of affording it due encouragement, and of giving 
every proper stimulus to its advancement.” 
Besides abstracts of papers read, and discussions held, before 
the Sections, the annual Reports of the British Association 
contain a large mass of valuable matter of another class. It 
was an early practice of the Association, a practice that 
might well be further developed, to call occasionaliy for a 
special report on some particular branch of science from a 
man eminently qualified for the task. The reports received 
in compliance with these invitations have all done good ser- 
vice in their time, and they 1emain permanently useful as 
landmarks in the history of science. Some of them have led 
to vast practical results ; others of a more abstract character are 
valuable to ths day as powerful and instructive condensations 
and exposi ions of th: branches of science to which they relate. 
T cannot better illustrate the two kinds of efficiency realised in 
this department of the Association’s work than by referring to 
Cayley’s Report on Abstract Dynamics,* and Sabine’s Report 
on Ferrestrial Magnetism + (1838). 
To the great value of the former, personal experience of benefit 
received enables me, and gratitude impels me, to testify. Ina 
few pages full of precious matter, the generalised dynamical 
equations of Lagrange, the gr-at principle evolved from Mau- 
pertuis’ ‘least action” by Hamilton, and the later develop- 
ments and applications of the Hamiltonian p.inciple by other 
authors are described by Cayley so suggestively that the reading 
of thousands of quarto pages of papers sc ttered through the 
Transactions of the various learned societies of Europe is rendered 
superfluous for any one who des res only the essence of these 
investiga ions, with no more of detail than is necessary for a 
thorough and practical under-tanding of the subje.t. 
Sabine’s Report of 1838 concludes with the following sen- 
tence: ‘‘ Viewed in itself and its various relations, the mag- 
netism of the earth cannot be counted less than one of the most 
important branches of the physical history of the planet we 
inhabit ; and we may fee! quite assured that the completion of 
our knowledge of iis distribution on the surface of the earth 
would be regarded by our contemporaries and by posterity as a 
fitting enterprise of a maritime people, and a worthy achievement 
of a nation which has ever sought to rank foremost in every ar- 
duous and honourable undertaking.” An immediate result of 
this Report was that the enterprise which it proposed was 
recommended to the Government by a joint Committee of the 
British Association and the Royal Society with such success, 
that Capt. James Ross was sent in command of the Z7edus and 
Terror to‘make a magne ic survey of the Antarctic regions, and 
to plant on his way thiee Magnetical and Meteorological Ob-er- 
vatories, at St. Helena, the Cape, and Van Diemen’s Land. A 
vast mass of precious observations, made chiefly on board ship, 
were brought home from this expedition, To deduce the de- 
sired results from them, it was necessary to eliminate the 
disturbance produced by the ship’s magnetism ; and Subine 
asked his friend Archibald Smith to work out from Poisson’s 
mathematical theory, then the only available guide, the formulz 
required for the purpose. This voluntary task Smith executed 
skilfully and successfully. It was the beginning of a series 
of labours carried on with most remarkable practical tact, 
with thorough analytical skill, and with a rare extreme of 
disinterestedness, in the intervals of an arduous profes-ion, 
for the purpose of perfecting and simplifying the correction of 
the mariner’s compass—a problem which had become one of 
vital importance for navigation, on account of the introduction 
of iron ships. Edition after edition of the ‘‘ Admiralty Compass 
Manual” has been produced by the able superintendent of the | 
Compass Department, Captain Evans, containing chapters of 
mathematical investigation and formule by Smith, on which de- 
pend wholly the practical analysis of compass-observations, and 
rules fur the safe use of the compass in navigation, I firmly be- 
* Report on the <ecent Progress of Theoretical Dynamics, by A. Cayley, 
(Report of the british As-« ciation 1857, p. 1). 
+ Repor on the Variations o' the Magnetic Intensity observed at different 
points of the Earth’s Surtace, by Major Sabine, F.R.9, (forming part of the 
7th Report of the British Association). 
NATURE 

leve that it is to the thoroughly scientific method thus adopted 
by the Admiralty, that no iron ship of Her Majesty’s Navy has 
ever been |i st through errors of the compass. The “ British 
Admiralty Compass Manual” is adopted as a guide by all the 
navies of the world. It has been translated into Russian, Ger- 
man, and Portuguese ; and it is at present being translated into 
French. The Briish Association may be gratined to know that 
the possibility of navigating ironclad war-ships with safety de- 
pends on application of scientific principles given to the world 
by three mathematicians, Poisson, Airy, and Archibald Smith. 
Returning to the science of terrestrial magnetism we find in 
the Reports of early years of the British Association ample evi- 
dence of its diligent cultivaion. Many of the chief scien ifie 
men of the day from England, Scotland, and Irelan1, found a 
strong atiraction to the As-ociation in the facilities which it 
afforded to them for co-operating in their work on this subject. 
Lloyd, Phillips, Fox, Ross, and Sabine made magnetic observa- 
tions all over Great Britain; and their results, collected by 
Sabine, gave for the first time an accura‘e and complete survey 
of terrestrial magnetism over the area of this island. I am in- 
formed by Prof. Phillips that, in the beginning of the Associa- 
tion, Herschel, though a ‘‘sincere well-wisher,” felt doubis as 
to the general utility and probable success of the plan and pur- 
pose proposed ; but his zeal for terrestrial magnetism brought 
him from being merely a sincere well-wisher to join actively and 
cordially in the work of the Association. ‘‘In 1838 he begin 
to give effectual aid in the great question of magnetical observa- 
tories, and was indeed foremost among the supporters of that 
which is really Sabine’s great work. At intervals, until about 
1858, Herschel continued to give effectual ai'.” Sabine has 
carried on his great work without intermiss‘on to the present 
day ; thirty years ago he gave to Gauss a large part of the data 
required for working out the spheri al harmonic analysis for the 
aitered state of terrestrial magnetism over the whole earth. A 
recalculation of the harmonic analyss for the altered state of 
terrestrial magnetism of the present time ha, been undertaken by 
Adams. He wries to me that he has *‘already begun some of 
the introductory work, so as to be ready when Sir Edward 
Sabine’s Tables of the Values of the Magnetic Elements deduced 
irom obs-rvyation are completed, at once to make use of them,” 
and thit he intends to take into account terms of at least one 
order beyond those included by Gauss. ‘The form in which the 
requisite data are to be presented to him is a maznetic Chart of 
the whole surface of the globe. Materials from scientific travel- 
lers of all nations, from our home magnetic observatories, from 
the magnetic ob-ervatories of St. Helena, the Cape, Van D e- 
men’s Land, and Toronto, and from the scientific observatories 
of other countries, have been brought together by Sabine, 
Silently, day a'ter day, night after night, fora quarter of a cen- 
tury he has toiled with one constant assistant always by his side 
to reduce these observations and prepare or the great work. At 
this moment, while we are here assembled, I believe that, in 
their quiet summer retirement in Wales, Sir Edward and Lady 
Sabine are at work on the Magnetic Chart of the world. If 
two years of life and health are granted to them, science will be 
provided with a key which must powerfully conduce to the ulti- 
mate opening up of one of the most refractory enigmas of cos- 
mical physics, the cause of terrestrial niagnetism. 
To give any sketch, however slight, of scientific investigation 
performed during the past year wouid, even if I were competent 
for the task, far exceed the hmits within which I am confined on 
the present occavion. A detailed account of work done and 
knowledge gained in science Britain ought to have every year. 
The Journal of the Chemical Society and the Zoological Record 
do excellent service by viving abstracts of all papers published 
in their departments. The admirable example afforded by the 
German “Fortschritte” and ‘‘Jahresbericht” is before us ; but 
hitherto, so far as I know, no attempt has been made to follow 
it in Britain. It is true that several of the annual volumes of 
the Jahresbericht were translated ; but a translation, published 
| necessarily at a considerable interval of time after the original, 
| 
cannot supply the want. Anindependent British publication is 
for many obvious reasons desirable. The two publications, in 
German and English, would, both by their differences and by 
their agreements, illustrate the progress of science more correctly 
and usefully than any single work could do, evea if appearing 
simultaneously in the two languages. It seems 10 me that to pro- 
motethe establishment ofa British Year Book of Science isan object 
to which the power‘ul action of the British Associauuon would be 
thorougnly apprupriate. 
