36 REPORT—1845. 
any case, should further data be required, they may be furnished by self- 
registering apparatus. It would, however, be desirable to ascertain, at more 
than one latitude, the inflwence of height upon the temperature and moisture, 
by the means devised by Prof. Wheatstone, and about to be employed at 
Woolwich. To this we may add, as a desideratum, the determination of the 
laws of the electrical changes, taken in connexion with other meteorological 
phenomena. The observatory of the Association at Kew, and that of Green- 
wich, are the only stations which have furnished such results. 
On the whole, I cannot but consider the continuance of the observatories 
for a longer period, if not permanently, to be important to the branches of 
science which they were intended to elucidate, although I believe that their 
number may be somewhat diminished, and that the amount of systematic 
work (and therefore also the observing staff’) may, without detriment, be re- 
duced at all. 
In reply to the second query, I am not able to state any instance in which 
the establishment of the combined system of observation has elicited privae 
research, with the exception of the signal one of the Brisbane observatory. 
The very magnitude of the plan itself is a sufficient reason for this. It is 
however no inconsiderable boon to science that it has enlisted in her cause 
many zealous young men, willing and able to promote it, and whose talents 
probably might not otherwise have received this direction. It may be added, 
that private research may naturally be expected in the theoretical discussion 
of the experimental data. 
The answer to the third query is connected with that already given to the 
first. Assuming that the general features of the diurnal changes are suffi- 
ciently determined, I would recommend the discontinuance of the daily ob- 
servations, except at those hours in which the magnetic elements are in their 
most stable state, whether as respects the influence of the periodic changes, or 
of disturbances. Both these conditions are satisfied for Europe and America 
at the hour of the maximum of westerly declination, and that of the principal 
minimum of the horizontal force. 
I would recommend that more time be allotted to absolute and occasional 
observations, and in particular, that the absolute determination of the decli- 
nation should be made from time to time, like those of the other two elements, 
with a separate instrument. 
I would suggest that simultaneous observations at short intervals should be 
made on one day in each week during the year 1846. The objects which may 
be expected to be attained by such an extension of this class of observations, 
are— 
1. To furnish a record of a sufficient number of disturbances without the 
help of occasional observations. 
2. To supply a number of undisturbed series, sufficient to determine the 
diurnal curves for swmmer and winter from observations at short intervals. 
3. To afford the means of separating from one another the two classes of 
changes. 
4. To supply the simultaneous observations which are required in absolute 
and occasional determinations. 
It would probably in most cases be possible to obtain the occasional as- 
sistance necessary for such observations, without keeping up the whole of the 
present observing staff. 
With respect to magnetic instruments, I am not disposed to recommend any 
considerable alteration in the Declinometer and Bifilar Magnetometer already 
in use. Most of the improvements suggested by experience have been added 
from time to time ; and the advantage of strict comparability in method seems 
