The Department of Geology and Geography announces two short courses of 20 lectures each by Professor Jaggar, open to advanced students. Attendance at which will be voluntary. Thesis work in connection with them may be counted according to the requirements of Geology 20c. One of these courses will be given in each half year. The name of the course for this half year is The Geologic Provinces of the United States. Although the first lecture of the course was given yesterday, there will regularly be two lectures a week on Tuesdays at 4.30 o'clock and Thursday at 8 A. M., in room 53 of the Geological Museum.

The title of the course to be given in the second half year is The Mechanism of Atmospheric Erosion. There will be two lectures a week on Tuesdays and Thursdays at 12 o'clock in room 53 of the Geological Museum. Laboratory work with special apparatus, recently installed, may be taken, with the permission of the instructor, by students wishing to complete a thesis on this subject.