ON MAGNETICAL AND METEOROLOGICAL OBSERVATIONS. 45 
and reducing the latter to six-hourly or even eight-hourly records, which would 
materially lessen the personal staff and therefore the expense. But whether 
such reduction may take place yet, or whether only at the end of some years 
longer, is a question concerning which for the reasons already given I can 
pronounce no decided opinion at present. 
The principal employment at each observatory, in addition to the daily 
observations at equal intervals of six or eight hours, will be to make, several 
times a year, absolute determinations with the most extreme care, and this 
without prejudice to other work which the directors of the different establish- 
ments may concert together; among which, frequently-repeated interchange 
of magnetic bars and apparatuses will give many instructive results, and will 
also keep up and check the activity and the skill of the directors in many 
ways. Ishould also think it very advisable that those directors who have 
shown in a suitable manner their talents and their zeal, should be allowed 
somewhat freer scope for their activity. 
The reasons for continuing such establishments are so direct, that it seems 
unnecessary to develope them at much length. Our knowledge of terrestrial 
magnetism is but a fragment, so long as we confine it to one period of time 
only, and do not follow with equal care and interest those secular changes 
which make themselves felt even in the course of a few years. There is in- 
deed required the concurrence of very many friends of science at very many 
points on the earth’s surface ; and half a dozen, or even a dozen observato- 
ries scattered over the whole earth can, if taken alone, give only a small con- 
tribution. But these normal observatories may at the same time be schools 
for many good observers, who will extend their activity over a wider range. 
They will also afford to travelling observers the opportunity of testing and 
correcting their instruments, and keeping up and perfecting their skill in ob- 
servation, and they will contribute to arouse, to nourish, and to extend to 
other parts of natural knowledge that desire for the greatest possible accuracy 
in observation which was formerly met with only in astronomy and the higher 
geodesy. 
Private activity in the field of magnetic observation has, it is well known, 
existed for several years in Germany and the adjacent countries; but though 
it cannot be said to have been first awakened here by the British under- 
takings, since it existed before them, yet they have caused its further exten- 
sion. It cannot be doubted that if the British government were now to dis- 
continue its extra-European-establishments, this would have a discouraging 
influence on the existing establishments in Germany and elsewhere; the more 
so, as the publication of the organ of their activity (the ‘ Resultate des Magne- 
tischen Vereins’) has been indefinitely suspended since the removal of Pro- 
fessor Weber from Gottingen. 
XII. M. Kreil, Director of the Magnetical and Meteorological Observatory 
at Prague, to Lieut.-Colonel Sabine. 
VEREHRTER Herr, Prag, 23 Marz, 1845. 
Ich erhielt vor wenigen Tagen die werth vollenmagnetischen und me- 
teorologischen Beobachtungen von Toronto 1840-41-42, und beeile mich 
nun das Schreiben zu beantworten, womit mich unterm 5 Dec. 1844, das 
magnetische Comité beehrte, und in welchem meine Ansicht uber einige 
dort vorgelegte Fragen gewiinscht wird. 
Mit grossem Vergnigen durchblatterte ich den Band, so wie auch den 
schon friiher erhaltenen der ‘ Observations on days of unusual disturbances; 
