240 Life and Letters of Francis Galton
and listen to-I regret to say without the least reciprocity-with wrapt attention. Even to-day I can conjure up frqm memory's misty deep, that tall figure with its attitude of perfect physical and mental poise, the clean shaven face, the thin compressed mouth with its enigmatical smile, the long upper-lip and firm chin, and as if presiding over the whole personality of the man the prominent dark eyebrows from beneath which gleamed with penetrating humour, contemplative grey eyes. Fascinating to me was Francis Galton's all-embracing, but apparently impersonal beneficence. But to a recent and enthusiastic convert to the scientific method, the most relevant of Galton's many gifts was the unique contribution of three separate and distinct processes of the intellect : a continuous curiosity about and rapid apprehension of individual facts, whether common or uncommon; the faculty for ingenious trains of reasoning; and more admirable than either of these, because the talent was wholly beyond my reach, the capacity for correcting and verifying his own hypotheses by the statistical handling of masses of data, whether collected by himself or supplied by other students of the problem."
The following letters may serve to illustrate and deepen the above very admirable characterisation by a skilful artist in words !
(5) Selected Correspondence between Galton and his biographer,
illustrating the years 1900-1902.
TEWFIK PALACE HOTEL, HELOUAN, CAIRO. February, 1900.
DEAR PROF. K. PEARSON, Thank you heartily for letting me see, as a New Year's gift, the important proof sheets. By much hammering, the bad part of the "law* " will be knocked out of it and the good, if any, will remain. You know probably that India ink (1) in water and common ink (2) may look alike, but if you pass the former through a filter of blotting paper the water alone comes through; not so with regard to ink. Now a mixture of (1) with water is not properly a blend, but a mixture with (2) is. When the particles in any case of L0 particulate" inheritance are small and independent, I do not see any sensible difference (within reasonable limits) between the behaviour of the two. But now comes in the consideration which I take to be the great problem, and that which as I conceive lies at the bottom of stability of type, viz.: regarding the imperfectly explored facts of group-correlation. Let, in a given "stirp," a, b, c, ... be classes of elements which develop in that order, the several classes consisting of
a.,, a21 ..., b,, b2i ..., &c. varieties. Now we find that a certain lineament, or trait, a,, bs, ct, &c.
tends to be inherited. If a, b, c, &c. were independent, the probability against the above particular combination would be enormous, whereas it is found to be frequent. What then is the cause? or, in default of knowing the cause, how can we represent to ourselves the character of the correlation? If a, b, c are developed in that order of succession, the particular and not improbable sequence of a,., b, must make the next step to ct far more probable than if b, had been preceded by say a„ or some other variety of a.
There must be an accumulating correlation of some kind. But how if a, b, c, &c. are simultaneously developed? Here I fail to make any picture to my mind of the way in which the needed group-correlation acts. I often watch the family traits in a party at church, trying to find out the beginnings and the ends in each inherited lineament of resemblance whether to the parents or to one another. They are usually indefinite, I think. My servant writes me word that your "Grammar of Science" has just arrived at Rutland Gate, Thank you sincerely. I must wait till my return, to read it.
We have had a very interesting and healthful journey to Wady Halfa and back, including a week's stay with Flinders Petrie at his diggings. The climate here near Cairo is far from being always benign. There are days of stormy wind with dust, and occasional down-pours of rain. I can't make up my mind as to the best places for an invalid-certainly neither Cairo nor Luxor. I have had two pleasant days in the desert with Prof. Schweinfurth the famous traveller.
I trust you have pulled through the wretched English winter fairly well.
Very sincerely yours, FRANCIS GALTON.
I hope to be back about Mid May.
* The Law of Ancestral Heredity, especially its application to alternative inheritance.