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NIE IEG Tate ON USOSsVESw7, 
FaciLities for the measurement of gravity by means of the 
pendulum have been greatly improved in recent years. The 
apparatus devised by Dr. Mendenhall for the Coast Survey not 
only affords results of high precision but enables an observer 
traveling from point to point to make at least one measurement 
each week. During five months of 1894 Mr. G. R. Putnam, of 
that survey, occupied twenty-six stations, a greater number than 
has previously been successfully occupied in North America. 
The measurements have the further advantage that they are 
homogeneous, being all made by the same observer with the same 
apparatus; and as it is understood that the work is to be con- 
tinued, American geologists and geodesists may confidently look 
forward to such a knowledge of the distribution of mass in the 
continent as will materially clarify conceptions of the inner earth. 
A brief report of Mr. Putnam’s results was communicated by 
Dr. Mendenhall to the National Academy of Science, and printed 
in the American Journal of Science for January. A fuller account 
of the work and a discussion of the results were presented to the 
Philosophical Society of Washington by Mr. Putnam, and have 
recently appeared in the Bulletin of the Society. Under the 
same cover also are comments by the present writer.7 While 
these discussions are merely tentative, and were undertaken 
primarily for the purpose of indicating the most advantageous 
directions for future work by the Coast Survey, certain of the 
inferences drawn are of such importance and so little liable to be 
overthrown that their presentation to the readers of the JoURNAL 
seems warranted. 
"Results of a Transcontinental Series of Gravity Measurements, by GEORGE 
ROCKWELL PUTNAM; and Notes on the Gravity Determinations reported by Mr. G. 
R. Putnam, by GROVE KARL GILBERT. Bull. Phil. Soc. Wash. Vol. XIII., pp. 31-75. 
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