618 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
Page. 
United States, Commercial growth and im¬ 
port duties of. H. Farquhar. j. 567 
University, National, Present status and 
prospects for a. J. W. Hoyt. 570 
Van Hise, C. R, elected member... 553 
— Penokee iron-bearing series of rocks. 530 
— Pre-Cambrian rocks of the Black Hills of 
Dakota .. 552 
Walcott, C. D.: Stratigraphic position of the 
ol'enellus fauna in North America and 
Europe... 532 
— Study in .structural geology. 551 
Walling, H. F., Death of... 516, 531 
— Obituary notice of, by C. O. Boutelle. 492 
Ward, L, F.: Remarks on the laws of corra- 
sion. 519 
Warder, R. B., elected member... 515 
Warped polyhedra, with special application 
to the road-cutting solid. C. H. Kum- 
mell. 605 
Water-courses, Relation of surface and cli¬ 
matic conditions to the flow of. 552 
Water supplies, Relation of forests to. B. E. 
Fernow. 552 
— Underground, in Texas and New Mexico. 
R. T. Hill. 571 
Watkins, J. E., elected member. 532 
— Beginnings of engineering. 556 
— Early dividing engines.*. 554 
— Log of the Savannah. 564 
— Origin of the railway systems of England 
and America. 533 
Weed, W. H.: Formation of deposits of lime, 
iron, and silica by plant life... 537 
Page. 
Well, Deep, at Wheeling. W. Halloclc. 571 
Wilder, B G.’ Comparative anatomy of the 
simian and human brain....... 553 
Willis, Bailey: Fault hades. 500 
— Mechanism of the overthrust fault. 529 
Willits, E.: Scientific work of the Depart¬ 
ment of Agriculture. 550 
Wilson, T.: National postal and school sav¬ 
ings-bank system of Belgium. 570 
Wind pressures and the measurement of 
wind velocities. C. F. Marvin. 556 
Winds, Hot, of the plains. G. E. Curtis. 564 
’Winlock, W. C.: Comet 1888 V... 601 
— Secretaries’ report, 1888 . 523 
-- 1889. 544 
-1890...... 557 
-1891... 572 
Woodward, R. S.: Mathematical theory of 
the stratum of no strain and its applica¬ 
tion to the earth. 602 
— Maxwell’s theory of electrostatics. 571 
— Mechanical conditions of the earth’s mass. 532 
— Notes on problems in averages. 605 
— Problem in dynamics. 605 
— Some of the greater problems of physical 
geology .. 537 
— — special laws of the diffusion of heat in 
homogeneous spheres. ; . 607 
— Summation of certain complex series. 601 
— Tisserand’s Traite de mecanique celeste.. 568 
— Variation of terrestrial density, gravity, 
and pressure. 580 
Wiirdemann, H. V.: Color perception. 531 
