CONTENTS. Vil 
Some Problems About to Confront Astronomers of the Twentieth Cen- 
heEye slsee. Science, Maye 25, LSOG. Vis. ccc scccatadeses oc owa sawccacss send dans 146 
(1) The Harvard College Observatory Photographs of Star Clusters, ~ 
Planets, Variable Stars and Stellar Spectra. (2) Prof. J. E. Keeler’s 
iEhotostaphs- of Planetary; SpCebra...sccsscessteateacer=s-ssecccrcr~vonese sees 147 
HEINRICH RIES. 
The Geology of Orange County, New York.................seense00 ere 70 
A Visit to the Bauxite Mines of Georgia and Alabama....................2+5 143 
Notes of a Trip Through the Marble Quarries of Western New England 
NCP HASERUPING Wa VOU Kees ce tscs cslecsccneescc ce seece ct aa ieee taecene pte sat iam 188 
W. L. ROBB. 
Apparatus for Showing Vibrations of @ Cord...................sceeseeseeceesceees 135 
C. H. SMYTH, JR. 
The Origin of the Talc Deposits near Gouverneur, N. Y. (See School of 
MW RES QUGTHAAM), ANG; INEEIS) yspcpoconscoseedonesoos osc BeDonasoonocnasqduocasoone: 154 
0. S. STRONG. 
Bese Gh ormalin, im Injecting Medias «...2.00.:000s.sesscescscssescecncsoesers 99 
A Case of Degeneration of the Optic Nerve in the Brain of the Skate, 
ee PU RACCH A DY, GUEIG cred vsmneeouce ses «scnttarinvancsoe dtc sas vactiacsecebces scccex 148 
C. C. TROWBRIDGE. 
The Use of the Hair Hygrometer (by title, see these Trans. XVI. 2)...... 157 
CORNELIUS VAN BRUNT. 
The Natural Flora of Bronx Park (Public Lecture)...................ss0+++ 62 
R. 8S. WOODWARD. 
Results of Experiments on Metallic Spheres Falling in Water............ 2 
Systems of Mechanical Units (abstract)........0<0.r0srsersconscsevenssusensedennse 34 
J. L. WORTMAN. 
The Expedition of 1895 of the American Museum of Natural History... 67 
LIST OF PLATES. 
Plate I. Geological Map of the Vicinity of Glacier Bay, Alaska. 
Plate II. View of Sherman Falls, Kauya Hoora Gorge. Trenton Falls, N. Y. 
Plate III. Fig, A. Undulations in layer (D 15) between lower and upper 
portion of the Great Fall, Kauya Hoora Gorge. Trenton Falls. Fig. B. 
Overlap structure of bedding of Trenton limestone,‘on east bank of West 
Canada Creek in Kauya Hoora Gorge. Trenton Falls. 
PlateIV. Fig. A. Blue-black layer (D11) with adjacent layers above 
Sherman Falls. Kauya Hoora Gorge. Trenton Falls. Fig. B. Example of 
