Speaking of the study of human life and society, Professor Karl Pearson is clear that both thorough training as well as sound theories are needed if research is to be fruitful. In the course of a letter to the Carnegie Institution, he says:--“Biological and sociological observations in too many cases are of the lowest grade of value. Even where the observers have begun to realize that exact science is creeping into the biological and sociological fields they have not understood that a thorough training in the new methods is an essential preliminary for effective work, even for the collection of material. They have rushed to measure or count every living form they could hit on, without having planned at the start the conceptions and ideas that their observations were intended to illustrate. I doubt whether even a small proportion of the biometric data being accumulated in Europe and America could by any amount of ingenuity be made to provide valuable results, and the man capable of making it yield them would be better employed in collecting and reducing his own material.” Professor Edward C. Pickering, Director of the Harvard Observatory, has suggested that astronomers the world over resolve themselves into a committee of the whole for the attack of great questions, the work to be duly parcelled out among the observatories best placed and equipped for specific tasks, to the end that repetition be avoided and a single, comprehensive plan be pursued. Not only in astronomy but in every field of science such concerted attack would have great value. In engineering, for example, there are questions as to the durability of steels and other building materials, which when investigated would yield rich harvests to every practicing engineer on the globe. It may be expected that in effecting co-ordinations of this kind the Carnegie Institution will play a notable part in the science of the twentieth century. CHAPTER XX OBSERVATION What to look for . . . We may not see what we do not expect to see . . . Lenses reveal worlds great and small otherwise unseen . . . Observers of the heavens and of seashore life . . . Collections aid discovery . . . Happy accidents turned to profit . . . Value of a fresh eye . . . Popular beliefs may be based on truth . . . An engineer taught by a bank swallow. Ability to observe is an unfailing mark of an inventor or discoverer: it is quite as much a matter of the mind as of the eye. A botanist, keenly alive to varieties of hue, of form in leaves, tendrils, and petals may not give a second glance to stratifications which rivet the gaze of a geologist for hours together. Each sees what he knows about, what he is interested in, what he brings the power and desire to see. When Faraday was asked to witness an experiment he always said: “What is it that I am to look for?” He knew the importance of concentrating his attention on the very bull’s eye of a target.