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98 to one of scores meeting in its own home; it has a neat building free of debt; it pays a curator a regular, if small, salary; it has something toward a permanent endowment fund; with six creditable volumes of Proceedings, it has a permanent invested fund of ten thousand dollars to perpetuate their publication; it owns a valuable museum, which is open free to the public, and acts as a constant incentive to develop scientific interest. And all this has been done by the academy in a small town in the West, without the assistance of any particularly wealthy patrons.



SYCHOLOGY did not begin with the development of its own methods or in the psychological laboratory; on the contrary, it has been largely the product of other sciences. In most cases the first impulse to the investigation of psychological phenomena was given by the discovery of sources of error in the other sciences which were due to the scientist himself.

In astronomy Tycho Brahe did not accept his instruments as being correct, but determined their errors; it was not, however, until centuries later that a suspicion arose concerning the possibility of errors in the observer himself.

Astronomers have to record the time of the passage of heavenly bodies across parallel lines in the telescope. When the star is about to make its transit the astronomer begins counting the beats of the clock. As the star approaches and passes the line he fixes in mind its place at the last beat before crossing and its place at the first beat after. The position of the line in respect to these two places gives the fraction of a second at which the transit occurred.

In 1795 the British astronomer royal found that his assistant, working with another telescope at the same time, was making his records too late by half a second. Later on, this amounted to 0.8 second. This difference was large enough to seriously disturb the calculations, and, as the astronomer did not suspect that he himself might be wrong, the blame was laid on the assistant. In 1820 Bessel systematically compared his observations with