‘Mr dear Mr Galton,

...

Yours always sincerely,

Karl Pearson.

Dr Franz Boas has sent me two batches numbering altogether about 1000 sets of measurements on Indians & half-castes. The series is not very long or good but we are working out all the relations for cephalic index which alters little for growth. We have got almost 100 of each relationship, e.g. father, daughter, brother, sister, etc. I will send you a note of the results when complete.’

‘My dear Mr Galton,

...

Your horse photography seems to be a great success and opens up wonderful vistas for inheritance. Could not your photographer have a card with a variety of graduated shades of horse coat hair, numbered 1 to 16 say & note on the photograph the coat colour by a number? A standard graduated card ought to be kept for reference.

...’

‘Dear Mr Galton,

I wanted to write you a few words as to yesterday’s meeting [at the R.S.]...

All the problems laid down by you in your printed paper seem to me capable of solution, and nearly all of them in one way only, by statistical methods and calculations of a more or less delicate mathematical kind. The older school of biologists cannot be expected to follow these methods – e.g. Ray Lankester, Thistleton-Dyer, etc. A younger generation is only just beginning its training in them.

I believe that your problems could be answered by direct & well devised experiments at a ‘farm’ or institute under the supervision of some two or three men who appreciate the new methods. I think you were entirely right in the idea of a committee to carry out such a [sic] experiments. But I venture to think that the Committee you have got together is entirely unsuited to direct such experiments. It is far too large, far too much of the old biological type & far too unconscious of the fact that the answers to the problems required are in the first place statistics & in the next place statistics & only in the third place biology. It was the idea of a committee so constituted endeavouring to make experiments that had me support Professor M. Foster’s motion, that the Committee should not experiment but assist experiment, and also object to his words “under the committee”. Fancy the attempt to make real experiments on correlation or heredity coefficients “under a committee” of whom I shrewdly suspect, only the chairman [Galton?] & secretary [Weldon?]  know the significance of the terms!

Hence, to sum up, your method seems to me the right one – a committee to undertake experiments of a definite statistical character. But your committee is quite a wrong one. It would be a good committee to press the public with subscription lists, but it is, I believe, a hopeless one to devise experiments which will solve in the only effective way these experiments [i.e. questions].

Yours always sincerely,

Karl Pearson.’

‘...

I hope you are keeping well. They are establishing an anthropometric statistical bureau in New York on the Carnegie Trust, and write to me for a man who know[s] the new methods & is keen. I think we could find the right person, but I have written for further particulars meanwhile the matter is confidential. I wish Carnegie would establish a Biometric Institute here – farm & botanic garden & statistical laboratory. What a lot one could find out, if such a place were set going with a good income & a band of keen workers! It would do much more good than free libraries which he now seems [to be] scattering up & down the country.

Yours always sincerely,

Karl Pearson.’

‘My dear Mr Galton,

I have received today the stature packet, following the great book on anthropometry which reached me yesterday. Many thanks for them both. The book interests Weldon as well as myself. The skewness of the stature curves confirms my view that for a growing population even about one age, skewness is an essential feature. I take it that the conscripts about 18 years old have not done growing. The head indices are also racially most interesting. By the by the copy you sent is inscribed by the author to the “Anthropometrical Institute.” Was this the one you wished to send? Eventually the book shall find its way into our library.

Yours very truly,

Karl Pearson.’

‘My dear Mr Galton,

...

If I am not troubling you too much I should like to refer to one or two points.

Thoroughbreds. The Racing Guide & Studbook give no information except amount of money won and age at death of stallions. The former did not seem to me a possible measure of quality, - the number & value of races changes so considerably = and the latter, which I proposed to deal with for equine mortality was complicated by the number of horses meeting with accidents, going abroad, or disappearing into [illeg.] – (? Hansom cabdom). I knew one large stud very well years ago,- but no measurements I am certain where [sic] then ever taken beyond vague statements of colour for the sale-catalogues. I shall, however, write to the Editor of the Field in the hopes that he may put something in my way.

I think I follow your view as to fraternal regression & should thoroughly agree in the statement that it must be referred to statistics for settlement. But it is just here the difficulty comes in...’

‘Dear Mr Galton,

Please excuse a very hurried line to enclose the accompanying letter from Prof. Petrie. I trust the R.S. Committee will see its way to helping in the cost of carriage. Kindly return the letter ultimately.

[re: P’s criticisms of Weldon at R.S.]’

[re: Huxley’s proposal for new university in London, his part in this]

‘...

I have put in six more lines [in a proof of a biography of Weldon] about the Evolution Committee emphasising what your aims were & how they were rendered unavailing by the numbers pulling in different directions & the struggle of different schools. To my mind the absence of such an experimental farm as you suggested has been the great drawback of the past years. We want a land “Marine Biological Association”. But it would never have been possible to combine the thoroughness of Weldon with the slipshod character of the rival school. Friction would have destroyed everything. The only hope is that a Dhorn may arrive some day with the energy & force of character to carry it out which marks him.

The worst is that the Americans have already got it under the Carnegie Institution, but so far they have done nothing profitable with it because our friend Davenport is not a clear strong thinker. The success of these things always lies in the strength of the individual who determines the whole. Dohrn must have been splendid.

...’

‘...

I am very distressed about these heredity results. I hardly see my way further now than a simple statement of observed values – the theory seems [to be] slipping away from me. I shall have to modify much of what I have said in the last two proofs of the Grammar of Science. Further I have found a possible arithmetical blunder in my paper on the law of Ancestral Heredity. In fact the constant Y must be increased, not reduced to get values above .3, .15 etc., as I want them.

I have worked out as far as I could the correlation between sire’s sire and sire’s dam and again between dam’s sire & dam’s dam for the Basset Hounds. They come just like the others – practically all of them insignificant! But terrible to narrate my assistant blindly working at my numbers correlated dam’s dam & sire and found a high correlation! I have been through it all again myself and unless Table I has got the sire’s & dam’s sire & dam somehow interchanged there must be a custom among breeders to very generally get a double strain, of the same blood, on the sire’s side & on the dam’s side, so that the sire is correlated closely with his mother-in-law!! – you see I am very deep in the mire & see no daylight. What between the Boers & the Bassett Hounds I don’t get much sleep o’nights!

Yes, I should much like the original documents as to the Hounds, if you can spare them for a time. They shall be safely returned. With the best wishes for your voyage. I am,

Always yours sincerely,

Karl Pearson.’