Re 
Reference is further made to the late floods. Within 
last fortnight a great calamity has befallen us. Inun- 
ions to an extent unknown in the colony for a long 
es of years have inflicted serious though only temporary 
ge on a large tract of country. The loss of life, so 
as I can ascertain, has been but small, considering the 
denness and extent of the floods ; but many houses 
e been swept away, and a large amount of native pro- 
destroyed.” 
_ It appears that a bridge on the Randy railway, that 
‘over the Hanwella road, was broken down by the flood, 
id at the time the Governor spoke traffic with the Central 
vince was interrupted. Three persons employed in the 
ment were drowned when the railway bridge was 
away. Science is evidently not likely to suffer in 
ie hands of Mr. Gregory. 
EAN METEOROLOGICAL OBSERVATIONS 
rks to accompany the Monthly Charts of Metcoro- 
logical Observations for No. 3 Square, extending from 
the Equator to 10° N., and from 20° to 30° W. (Printed 
for private circulation, by authority of the Meteorologi- 
cal Committee of the Board of Trade.) 
HIS portion of the Meteorological Committee’s workin 
the discussion of Ocean Meteorology has been printed 
he Committee for distribution among meteorologists 
others, with the view of eliciting their opinions on the 
ty of the method adopted, together with any sugges- 
s they may have to offer. The chart issued with the 
marks gives the results of the discussion of No, 3 
uare of Marsden’s numbered squares for the month of 
January. This square has been selected as the one of 
eatest importance, and in which the largest number of ob- 
ervations have been collected. It is divided in the chart 
into 100 squares of 1° each, in which are set down, ina 
mpact form, the results of the discussion as respects 
wind, variation, atmospheric pressure, air and sea tempe- 
rature, humidity, the currents and specific gravity of the 
sea, and, in the margin, weather and cloud. 
~ In attempting to give the results of so many subjects in 
a small space, and with one printing, not a little has been 
sacrificed to clearness. The chart has considerable merit 
is an ingenious and compact tabulation of results ; but 
ittle praise can be awarded to it as a chart or diagram 
telling its own story at once clearly and readily to the eye 
—a characteristic which charts specially addressed to 
eamen ought to have. Printing in colours would intro- 
luce some improvement, but as regards the important 
subject of the winds more will be required, if the present 
ethod of presenting the results be adhered to. By 
this rnethod the arrow representing the largest number of 
vind observations extends to the centre of the circle in- 
sluded in each square ; and hence the arrows represent- 
ng the winds of difzvent squares cannot be directly com- 
gared together. Since such comparisons can only be 
made by the arrows of each square being drawn to show 
by their lengths the percentages each wind direction is of 
the whole number of winds observed in the square, a 
separate wind chart will be necessary in the text accom- 
nying the charts. 
Three small charts are given with the Remarks (p. 43), 
showing the pressure and temperature of the air and the 
_ NATURE 
43 
temperature of the sea. These have been constructed by 
grouping the roo squares into twenty-five squares of 2° 
each. As respects pressure, the isobarics are drawn for 
every two-hundredths of an inch of mean pressure. The 
outré forms of the isobarics are such as to suggest the idea 
that the method of discussing the barometric observations 
is faulty. An examination shows it to be so on two im- 
portant points, which will appear from the following 
extract from the chart of the observations of the four 
contiguous sub-squares (Nos. 59, 58, 49, and 48), of which 
the mean pressures are stated in inches, the number of 
observations in each case being printed within brackets :— 
ON, 
29'882 29.963 
(3) (14) 
SN. | l 
| 29°870 | 29°939 
(2) | (15) 
4°N. 
30° W. 29° W. 28° W. 
In the small isobaric chart these four results are treated 
as of equal value, and the average of this 2° Square is 
calculated by taking their simple arithmetical mean ; 
accordingly 29’914 inches is entered as the mean. Now 
a little reflection shows that the averages 29882 and 
29°870 inches, based respectively on 3 and 2 observations, 
are very faulty as approximations to the true averages of 
their squares. In such cases the method of discussion is 
to deduce the new averages not from the averages of the 
four sub-squares, but from the whole of the observations 
added together and divided by 34, the number of the 
observations. By doing so we obtain in the above case 
the average 29940 inches. Similarly we have dis- 
cussed the whole of the 100 squares, and the result is the 
disappearance of several of the anomalies in the new 
isobarics drawn from the twenty-five new averages thus 
calculated. 
But other anomalies remain, which lead to the second 
point on which the method of discussion is defective. 
The method is thus described in the Introductory Re- 
marks (page 1) :— 
“The various hours at which the observations were 
taken may not give the mean result for the twenty-four 
hours ; still,as the same hours have been generally ex- 
tracted, we may confidently hope that the temperatures 
and pressures obtained from the means of the whole will 
give very good relative results for comparing the meteoro- 
logical state of one part of 10° square with that-of another. 
In making the extracts the hour of each observation has 
been recorded, so that any inquiry depending on the 
hours might be carried out if thought requisite.” 
The confident hope here expressed is very remarkable 
in the face of the averages printed on the chart, of which 
an example is given above. The truth is, comparable- 
ness of the results of the different squares is not to be 
looked for except in cases where the observations are 
numerous. Since the daily range of the barometer is 
large in these regions, averages based only on a few 
observations—regarding the hours at which they were 
made we have no information—are worthless in every 
inquiry in which comparisons require to be made. Now 
looking at the squares, we find from the chart that there 
Cae Tad et ae 
pen 
