36 Life and Letters of Franr'iM Galton 



Galton's first considerations on climate sprang directly from his geogra- 

 phical work and were closely associated witli the relation of the health of 

 the explorer to the climate'. Thus we have already referred to his little 

 table of climate in Zanzibar in the lecture of 1861. I'wo yeara later he pre- 

 pared a table giving the "Climate of the countries bordering Lake Nyanza, 

 1861-2." He published it in the Royal Geogrnp/iical Suciftj/ Proceedings, 

 Vol. VII, 1863 (pp. 225-8), in a paper entitled "On the Climate of Lake 

 Nyanza": it gives with the exception of the middle fortnight of November 

 meteorological details for every 'week' of every month'. The mean tem- 

 perature for the week, the maximum and minimum and the extreme ranges 

 are provided. The rainfall in inches is given where available, the number of 

 rainy days j)er week, the numl)er of davs per month of rain .sutticient to be 

 measured, and the total number of tiays per month of rain and slight 

 showers, also the prevalent wind for each month. The whole of the mate- 

 rial Wii8 due to Speke and Grant, but it obviously required much 'dressing,' 

 i.e. smoothing and interpolation, etc. It was based on observations taken at 

 Karagwfe (5100 ft), Uganda (3400 ft.), Unyoro (3200 ft.) and in a camp 

 3400 ft. above sea-level, so that there is considerable heterogeneity in the 

 data. Speke's original log is among the Galtoniana. 



The tables thus formed led Galton to consider the possibility of maps 

 combining at a single glance much meteorological data. This occupied his 

 mind largely in 1861-2, and there is no doubt that Galton was the tirst to 

 publish meteorological maps of Europe, possibly of any country at all. He 

 uuluced his friend W. Spottiswoode, the nead of the great printing firm, to 

 cast movable types which were u.sed in Galton's fii-st maps. These repre- 

 sented by shaded rectangles llain. Snow, Dull and Overcast, Overcast, 

 Mostly clouded. Half-clouded, A few clouds, Clear blue sky; the direction 

 and force of the wind were given by another series of .symbols, and finally the 

 height of the barometer and the temperature — ordinary and wet bulb — were 

 printed in figures. Thus a rectangle 8"5 ram. high by 5'5 mm. broad contained 

 the information as to rain and cloudiness, intensity and direction of wind, 

 state of barometer and thermometers at a given meteorological station, and 

 these rectangles were placed centrally to each station on a map of the 

 stations at which observations had been made. Galton's first map' is 



' The efft-ct of climate on the tniveller luid Ijeen ))rouglit lioine to Galton very emphatically 

 by his own ex|ierience of the after-t'tfects of his travels in .Syria and tropical Africa. 



« Ist to 7th, Hth to 1.5th, 16th to 23rd, 24th to end. Thus the first 'week' was 7, the 

 second and third 'weeks' each 8, and the fourth 'week' 7 or 8, or in the case of February only 

 5 days. 



' Among Galton's papers is another "Weather Map of the Hritisli Isles for Tuesday, 

 Sept .3, 9B.m " No year is stat^ni, hut I should think it was more prolwhly Tuesday, Sept. 3, 

 1861, than Tuesday, Sept. 3, 1867. In this map five conditions of wind int^-nsity, five conditions 

 of sky (clear, def-achwi (-loud, overcast or fox. showers, rain) and three pressure conditions 

 (barometer falling, stationary, rising) are indicjitj-d by no less than 75 circular 'stamps.' The 

 direction of the wind is given by the direction of the arrows which measure wind intensity and 

 the circular stamps are rotated to give this direction. A map is printed with the names of the 

 60 to 70 recording stations, and underneath these names the appropriate stamp is affixed with 

 the right orientation. 25 copies of tiiese attachable stamps for the case of rising barometer 



