Sent H. Thompson to K. Pearson, 15th July 1895.
15 Jul 1895
Description:

‘Dear Prof. Pearson,

Thanks for your latter of the 13th. I did not mean to say I had taken the German “Länge”, (in relation to the Horizontalabene); but the measurement no.2 in the German paper – which has no reference to the Horizontalebene & is merely the ordinary glabello-occipital maximum length of Prof. Thane & others. The breadth & height measurements are also taken without any reference to Horizontalebene but they are described in the German list under nos. 4 & 7 (I think – I have left the paper at College).

I have been trying capacities today with mustard seed according to Sir W. Flower’s directions: but so far, the results are very unsatisfactory – for instance, in a very good skull, I took a measurement; result 1214 cc. I then asked another man, who had seen me do it, to try – this result was [1?]242 cc. He tried again, result [1?]235 cc. I then tried again, result 1214 cc. (same as before in my case[)] – I called in a third man (a medical student, who had seen me do one or two others), who made two successive estimates of 1186 cc. & 1213 cc. The general result is hopeless & in other cases was nearly as bad, several estimates of other skulls differing by 20 cc – the differences are due to the varying amount of pressure exerted on the seed at intervals during the operation – it “packs together” very much under constantly repeated pressure. Probably after a short practice a simple operator would obtain fairly even results, comparable with each other; but I do not see how the results of different operations are to be compared with much advantage – error (or rather opportunities for difference) creeps in, not only in “packing” the skull, bit to a degree as great or even greater, in settling the seed down in the measuring glass.

Very likely shot would be better in this respect, but I fear the weight would smash up many of these skulls which are brittle.

We will devote tomorrow to further experiments & I will let you know if better results are obtained.

Had the experiments only been satisfactory so that I could start at once, I think I could no doubt have undertaken to do the capacities – since the skulls capable of being measured in this respect probably do not exceed 150, if so many. Each one takes 15 to 20 minutes; but the preparatory cleaning of them sometimes takes some time longer. This however I fear I cannot promise at present. I shall probably be able to see you & talk the question over at the beginning of next week.

Meanwhile I hope you will make your holiday as long as possible & enjoy it thoroughly.

Very truly yours,

Herbert Thompson.’