288 IETS IOI INAVE (QUE (GAXOMOG IW. 
Another method, which yields average velocities, is to determine 
the position on the ice of some prominent bowlder which is 
marked, so that it can be recognized after one or more years, 
and the distance it has moved measured. A very good way is 
to lay out a line of sheet-iron plates, say, three inches square, on 
which is painted the date when, and the position where, they are 
placed. These will sink slightly into the ice, will not be blown 
away by the wind, and will not roll or slip, as bowlders may. 
They can be recovered and the distance moved over determined 
by a future observer. Stones are used in this way for the obser- 
vations on the Rhone glacier. 
Rate of melting.—At the lower end of glaciers, when the ice 
is somewhat disintegrated and will not in general hold water, 
the melting can be measured by boring an auger hole in the ice 
and putting a stick in it; the apparent rise of the stick out of 
the ice will be the measure of the melting. If the ice is compact 
enough to hold water, this method may yield inaccurate results ; 
it is better then to bore two holes starting from the same point 
on the surface of the ice and making an angle with each other 
of 45 to 60°, put a stick in each hole and where they cross 
bind them firmly together with wire. The ice will melt around 
the sticks, but each will prevent the other from sinking into its 
deepened hole. The wire may be used as an index, and its 
increasing height above the ice will measure the melting. 
All photographs and observations sent me* will be carefully 
filed away and preserved as the record of the history of the 
glacier in question; they will be considered as the property of 
the Geological Society of America. A poor photograph is much 
better than none. Prints should be mounted on linen or 
unmounted. On each should be marked the glacier depicted 
the date, the station from which the picture was taken, the direc- 
tion in which the camera was pointed and whether or not the - 
lens used was rectilinear (or give the name of the lens), If its 
focal length is known, it should also be given. 
Harry FIELDING REID. 
t Address Johns Hopkins University, Baltimore, Md. 
