382 The N.Z. Journal of Science and Technology. [Nov. 
farmer does not yet know where he can obtain a supply of a good potash 
fertilizer at a reasonable price), it marks a distinct step forward, and is well 
worth careful reading by agriculturists and agricultural chemists. 
G. H. 
The Control of Settlement by Humidity and Temperature, by T. G. Taylor, 
Commonwealth Bureau oj Meteorology Bull. No. 14, 32 pp., 21 figs., 1917. 
In this bulletin Dr. T. G. Taylor has considered the influence of climate 
upon human activity, especially within the British Empire. Huntington 
has concluded from a study of the records of work done, both physical and 
mental, that the physical activity of the races of western Europe is greatest 
when the average temperature is about 60°—that is, on days when the 
thermometer goes down to perhaps 50° or 55° at night and rises to about 
65° or 70° by day. Mental activity, on the other hand, is greatest when 
the average is a little below 40°—that is, on days which may have frost 
at night. Mean temperature is by no means the only important con¬ 
dition ; a moderate degree of dampness—that is, relative humidity from 
65 per cent, in summer to 90 per cent, in winter—is favourable, but when the 
summers are wet or the winters are very dry people do not work so well. 
Dr. Taylor has therefore designed a type of diagram, to be termed the 
“ climograph,” in which are plotted on squared paper, with ordinates and 
abscissae showing the relative humidity and temperature (wet bulb), average 
values for each month. The latter are chosen in preference to the usual 
drv-bulb figures as giving a far truer indication of the sensation of warmth 
experienced. He then takes the records for twelve typical towns in which 
the white race flourishes, so chosen as to show the greatest possible range 
of conditions that may be termed favourable for settlement, and the 
average value from these towns is made the standard climograph—that 
expressing the most favourable conditions for European settlement. The 
towns chosen are Sydney, Perth, Hobart, Cape Town, and Johannesburg 
in the Southern Hemisphere, and London, Aberdeen, Berlin, New York, 
Chicago, and Seattle in the Northern Hemisphere. 
Regions of which the climographs lie beyond the limits of the area 
enclosed by the standard climograph are unfavourable to settlement because 
the climate is too “ scorching, muggy, raw, or keen.” It would have been 
desirable, perhaps, to have included average wind-velocity as an element 
determining the scale of comfort, but it was not found practicable to do 
so. In comparing the climates of various parts of the world with the 
standard climograph, that of the south-east of England from April to 
October, “ which is almost ideal,” lies within the area of the standard 
climograph; but of all the climates considered those of Dunedin and 
Wellington most closely correspond with the ideal standard, while that of 
Auckland appears to be a little on the muggy side. Dr. Taylor remarks, 
The New-Zealanders are to be envied for their climate. The figure shows 
that Wellington and Dunedin lie wholly within the 6 white climogt&ph.’ 
The death-rate (the lowest in the world) and, one imagines, the advanced 
legislation for which New Zealand is famous are correlated with this con¬ 
dition, which makes for the highest mental and physical development.” 
The problem of the white settlement of the tropics is illustrated in an 
interesting manner by a study of climographs, and these lend support to 
Dr. Taylor’s contention that an effective and energetic white settlement 
of the northern coasts of Australia cannot be expected. W N B 
