XXxil REPORT—1857. 
of so novel a kind, while at the same time the six months’ trial referred to has 
placed beyond doubt the sufficiency of a properly conducted research by 
means of self-recording instruments for the examination of the solar magnetic 
variations.” 
The Committee authorized Mr. Welsh to proceed with the construction of 
the instruments, which have now been completed at an expense not exceeding 
£250, this sum being defrayed from the funds supplied by the Government 
Grant through the Council of the Royal Society, the instruments remaining 
at Kew at the disposition of the Council of the Royal Society. 
With the assistance of apparatus lent from General Sabine’s department, 
the observatory is now possessed of the means of determining with great ac- 
curacy the various constants required in magnetic observation. Some alter- 
ations in the method of manipulation have, it is believed, added considerably 
the accuracy of observation of the absolute value of the Magnetic 
orce. 
At the request of the Foreign Office, Magnetical and Meteorological In- 
struments have been prepared at the Observatory for Mr. Lyons M‘Leod, 
Consul at Mozambique. Mr. M‘Leod attended on several occasions in 
order to make himself acquainted with their manipulation. 
The following correspondence has taken place relative to an application 
from the Austrian Government to be supplied with Magnetical Instruments, 
to be employed in the scientific voyage undertaken by His Imperial Majesty’s 
Frigate “ Novara.” 
(Copy-) 
“ Admiralty, 31st December, 1856. 
“DeEAR GENERAL SABINE,—The Austrian Consul, Baron Rothschild, has 
written a pressing note to the Admiralty to ask where the enclosed list of 
instruments can be procured, and for any assistance we can give in ensuring 
their being the best. Will you be so good as to say what answer shall be 
sent? would it be too much to ask you to see that they are properly sent, 
and as nearly as you can, will you name the time the instruments could be 
ready ? 
“Yours faithfully, 
(Signed) “Joun WaAsuHINGTON.” 
“ Memorandum of Instruments required by His Imperial Majesty's 
Frigate ‘ Novara.’ 
“a, TheAzimuth Compass. 
“b, The Unifilar Magnetometer. 
“¢, Mr. Fox’s‘apparatus for observing the magnetic force and inclination. 
“d. Mr. Barrow’s Circle for observing the magnetic inclination. 
“ To the apparatus 6 belongs also a peculiar apparatus for its erection and 
use on board ship. . 
“ For the further use of these instruments and for taking the observations 
made thereby, it is desired that they may be delivered with the indication 
of their respective constants, as the moment of inertia, the temperature, 
coefficients, &c. &c. 
“ The Consulate-General will apply to the British Admiralty, who will, no 
doubt, kindly give the names of the makers who supply the British Admiralty, 
as it is desired that they be the same instruments as those on board Her 
Majesty’s ships of war.” 
“ London, 29th December, 1856.” 
