4 
NATURE 
[NMov. 3, 1870 

undertaken to examine the records from these various 
outlying observatories before they are sent to the central 
office. Nor is it necessary to detail the other steps which 
have from time to time been taken by the Meteorological 
Committee to insure instrumental and observational 
accuracy ; for men of science have only to examine the 
various publications of the office to be convinced that a 
large amount of accuracy has been already achieved. 
In addition to the observations from self-registering in- 
struments, other records of a less complete nature come to 
the office in continually-increasing quantity ; for,evidently, | 
. | 
the records from only seven stations, however completely | 
equipped, are insufficient to give us a true view of the 
very complicated meteorology of these isles. It is, there- 
fore, an important duty of the chief officer of the Com- 
mittee so to increase this stock of observations as to 
obtain in time a complete and trustworthy meteorological 
record. There seems reason to believe that this will ulti- 
mately be done, and it will be a great boon to meteoro- 
logical science when it is accomplished. 
But, if the observational system is important, the method 
of reducing observations is a point of equal importance. | 
The condensed account of the quarter’s weather, and of 
its easterly storms, by Mr. Scott, are exceedingly useful 
summaries, and form, as it were, the first step of the 
ladder which leads from facts to laws, and it is hardly 
necessary to state that such summaries have a practical as 
well as a theoretical importance. 
We pass on from these to consider next the tables of 
averages for the year 1869, which have been given in this 
Quarterly Report. As far as the air-temperature and pres- | 
sure are concerned, there can be no objection to tables 
giving average results. These are two meteorological ele- 
desirable ; and the five-day means of those elements given 
in page 41 form, perhaps, the best way of accomplishing 
this. But surely the readings of the wet-bulb thermometer 
do not represent any simple meteorological element ! 
The moisture is best represented by ascertaining the 
mass of vapour present in a cubic foot. of air, this 
forming its legitimate expression in terms of mass and | 
volume, which are fundamental physical conceptions. On | 
the other hand, the temperature of the wet bulb, while it 
forms the easiest and best observational method of ob- 
taining continuous information regarding moisture, is yet 
in reality a very complicated joint function of the tempera- 
ture of the air, of its pressure, and of the mass of vapour 
present in one cubic foot. To give five-day readings of 
; 
the wet-bulb thermometer cannot, therefore, we think, lead | 
to any good result. 
We are just beginning to knowa little about the motions | 
of the atmosphere and its variable components, and if we 
wish to extend our knowledge in this direction, it seems 
perfectly essential that the physical meteorologist should 
choose proper methods of reduction. 
not to be one which, when accomplished, may possibly 
increase our knowledge, but one which, from its very 
nature, must necessarily do so, He ought to seek to have 
the same certainty which the astronomer possesses, that 
in treating his observations after a particular method, the 
results will infallibly extend his knowledge of celestial 
motions. 
We have dwelt so long upon this part of the labours 
His method ought | 
of the Meteorological Committee, that we can only briefly 
allude to their system of publication. The reduced graphi- 
cal representations of the observatory records given at the 
end of the volume, while hardly enough for the wants of 
meteorologists, are yet extremely valuable and useful. It 
is impossible to say what benefit to science may not re- 
sult from bringing before the public such a speaking 
epitome of weather, and we owe many thanks to Mr. 
Francis Galton, the member of the Meteorological Com- 
mittee who invented the instrument which has given us 
these admirable plates. BALFOUR STEWART 

BEET-ROOT SUGAR 
On the Manufacture of Beet-Root Sugar in England and 
Ireland. By William Crookes, F.R.S., &c., Editor of 
the Chemical News. Illustrated with ten engravings. 
Pp. 290. (London: Longmans, 1870.) 
HIS work is founded on a series of articles by M. 
Julien M. Deby, C.E., published about a year ago 
in the Scéentific American ; these articles have, however 
been very much extended, and much new matter added, 
in order to bring the subject down to the present date, 
and so increase its usefulness in assisting those who may 
ie i te tril 
oe 
wish to establish beet-root farms and sugar factories in~ 
this country. The experiences obtained abroad, and in- 
vestigations made in England and Ireland, show that it 
would be quite possible to grow sugar-beets with profit in 
the United Kingdom. The beets might be used as fallow 
crop and cultivated, instead of the roots grown in such 
great quantities as food for cattle, since the beet-root pulp 
after the extraction of sugar is even more valuable for 
; : . | this purpose. 
ments of a nature sufficiently simple to render averaging | Be 
During the year 1867, beet-root sugar of the value of 
1,600,000/, was imported into this country, and it would 
appear that this might readily have been produced here. 
Inthe first chapter we have a description of the beet, 
and of the qualities that can most profitably be used for 
sugar making ; the weight of each root should not be less 
than r}lb., nor more than 2lbs. ; smaller roots are fre- 
quently woody, while larger ones are watery and poor in 
sugar. The juice should have a specific gravity between 
1‘o60 and 1070, though sometimes, when very rich in 
sugar, it rises to 1075 or 1:078. The percentage of sugar 
in the roots varies considerably, the minimum quantity 
given in a long list of analyses being 3°62, while the 
maximum is 13°47. The next number below this maxi- 
mum is 13°19, and is interesting as representing the 
amount of sugar found in red beet manured with London 
sewage. Peligot obtained as much as 18 per cent. from 
some French beets, and some American specimens have 
produced 17°6 per cent. 
that from 16 to 4o tons of roots may be grown on 
one acre, so that satisfactory results might be anticipated 
in that country. Chapter II. treats of the culture of the 
beet, the climate, kinds of soil, manure, and all the neces- 
sary directions to the agriculturist to ensure a profitable 
return. Chapters III. to VII. contain a detailed descrip- 
tion of the mode of extraction of the sugar, and a 
very useful statement of the cost of the different pieces of 
apparatus required for working up 150,00olbs. of beet- 
root per twenty-four hours during five months, which 
It has been found in Ireland 
