22 ANNUAL REPORT OF THE 
reconnaissance was made of the country from Fort Edwards 
southward, mainly along the west side of the Hudson River to 
Copake lron Works, in search of postglacial faults in the bed- 
rock, and during the winter a paper was prepared embodying the 
results of this investigation. Much time was also given to the 
reading of the proof of two reports named in the appended list of 
publications. 
Instruction was given to Radcliffe students in two half-courses 
and one full course, in which work Dr. Smith assisted in the field. 
Professor Jaggar was granted leave of absence from September 
Ist, 1904, to give instruction in the Massachusetts Institute of 
Technology and to take charge of the Department of Geology in 
that institution. He continued to teach two advanced courses of 
Field Geology in Harvard University, Course 22 in this Depart- 
ment and Mining 28, both of which use the advanced laboratory 
of the Geological Section of the University Museum. These 
courses were given together in the first half-year to twenty-one 
students; in the second half of the year the nine members of 
Geology 22 worked independently over areas south of Boston. 
The method pursued was the same as in former years. Certain 
members of the class made discoveries which will lead to publica- 
tion. Mr. G. R. Mansfield was associated with Dr. Jaggar in 
conducting the work, and also prepared a paper on the Quater- 
nary Gravels of the Northern Black Hills. Mr. F. E. Matthes 
made an extended study of the structure and distribution of eskers 
south of Weymouth. Mr. I. Bowman co-operated in this work, 
and also discovered glauconitic clays and found more of the lignite 
first reported by Upham in the cliffs of Scituate which may 
prove to be of pre-Pleistocene origin. Mr. H. E. Simpson, in 
collaboration with Mr. G. F. Low, finished a topographic model 
of Crook Mountain, a laccolithic dome in the Black Hills. 
Professor Jaggar continued his experimental studies of erosion, 
for which purpose a pneumatic spraying apparatus was installed 
in the basement of the Museum. He made anew model of the | 
sclerometer, an instrument for testing the hardness of minerals, 
and also constructed a telemeter-alidade designed for reconnais- 
sance mapping. Experiments with these instruments are in | 
progress. 
Mr. Francois E. Matthes, U. S. G. S., gave a course (Geology 
13) in topographic work for the instruction of students in geologi- 
cal surveying. 

