’ 
28 REPORT—1845. 
Disposition des Committee indem ich zugleich mich zu entschuldigen bitte, 
dass ich sie deutsch geschrieben habe, um meine Ansicht mit der Bestimmt- 
heit auszudriicken, wie sie jedem in seiner Muttersprache gegeben ist. 
( Translation.) 
Berlin, 1st March 1845. 
Dear Sir,—I have answered the questions proposed to me by Sir John 
Herschel in German, because every one can express himself with greater pre- 
cision in his native language than in any other. I hope my letter will arrive 
in sufficient time, although all our railways have been for some days buried 
in snow, and are not yet opened even by the exertions of the military. I re- 
turn you my hearty thanks for the to me exceedingly interesting paper, 
é Meteorology of Toronto,’ in which you have so kindly referred to my works. 
Pray also give Mr. Riddell my very friendly thanks for ‘ Magnetical Instruc- 
tions. Iam sorry I have nothing to send in return, as the fourth part of my 
‘ Non-periodic Variations in the Distribution of Temperature on the Surface 
of the Earth between 1729 and 1843,’ will only appear in the course of the 
summer. 
From Sir John Herschel’s letter, I perceive that a volume of ‘ Extraordinary 
Magnetic Disturbances at the British Government Stations,’ and the first 
volume of the ‘Greenwich Observations,’ have been sent to me, and that I 
am to receive the first volume of the ‘ Observations at the British Government 
Stations,’ and the second volume of the ‘ Greenwich Observations.’ Unfor- 
tunately I have received only the ‘ Magnetic Disturbances,’ for which I 
return my cordial thanks. Should it be wished that I should take part in the 
calculations of the meteorological observations, I place my activity entirely 
at the disposal of the Committee. 
In the study of the non-periodic variations, I have often had occasion to 
regret that the journals of observations published in England were not acces- 
sible to me. Would it not be possible that some one should undertake, at 
the request of the British Association, a Climatology of England, in which 
the monthly means of the several years at the different observation stations 
should be printed, for which my work is even already a preparatory work ? 
Would it not further be very advantageous if the meteorological journals 
which are printed to accompany the Transactions of Learned Societies and 
Philosophical Journals had more copies taken off, that they might afterwards 
be bound up in complete and independent years? What an infinity of time 
would be saved if one was no longer forced to look for every single month 
in a different volume, which, if it happens to be lent away from a public 
library, often interrupts a work for months! A proposition emanating from 
the British Association would soon be imitated in other countries as well, and 
we should then be enabled to advance science more quickly. 
I have the honour to be, with the highest consideration, 
Your very obedient servant, 
(Signed) H. W. Dove. 
The problem to be solved by meteorological observations is a threefold 
one: they are to give mean values, empirical laws for the periodic variations 
of these values, and finally, to furnish data for tracing the simultaneous ex- 
tension and the progressive march of a meteorological phenomenon over the 
surface of the earth. 
As the mean quantities can only be obtained after the elimination of pe- 
riodical variations, the determination of the latter is directly demanded for 
both these objects, and hourly observations of temperature, pressure, and hu- 
—" 
