CAMBRIDGE: Printed at the Riverside Press, AND FOR SALE BY HURD AND HOUGHTON, NEW YORK. 1870. Entered according to Act of Congress, in the year 1870, by H. O. HOUGHTON AND COMPANY, in the Clerk's Office of the District Court for the District of Massachusetts. RIVERSIDE, CAMBRIDGE: STEREOTYPED AND PRINTED BY H. O. HOUGHTON AND COMPANY.