way in which this particular project, and similar ones to it, could not only be expeditiously conducted, but so as to realize the chief objects of the work. Judging from individual expressions received from scientific men everywhere, they appear in agreement with u.s. This policy, briefly stated, is: To make, with the aid of the friendly and harmonious cooperation of all concerned, a rapidly executed magnetic survey of the greater part of the globe, so that a general survey, all-sufficient for the solution of some of the great and world-wide problems of the earth's magnetism, will be completed within a period of ten to fifteen years. At a smaller number of points, selected in consideration of the prime questions at issue, the observations are to be repeated at intervals of five years or less, in order to supplement the rather sparsely distributed magnetic observatory data. Thus the determination of the corrections for reduction of the general work to any specific date is continuously provided for.
Now, had I the time or were this the place, I should like to add a paragraph regarding the needful accuracy and the prime questions to be considered in the conduct of such a piece of work. Permit me to say that the most evident result of all magnetic work in the past is that, for the purposes of a general survey, it is far better to make some sacrifice in accuracy if thereby it is made possible to secure observations at another point. In other words, the errors due to local disturbing conditions are far greater than the purely observational ones. Hence multiplicity of stations rather than extreme accuracy and laborious methods of ohservation and reduction is the prime requisite in magnetic survey work.
Stimulants to Research Work
Dr. Gilman, in his charming reminiscences of the non-resident lecturers of the Johns Hopkins University, related the following of the great mathematician Sylvester:
These anecdotes will serve to recall similar ones of noted men.