TO THE REY. ANDREW P. PEABODY. MY DEAR SIR: When I first mentioned that I had undertaken a Research into the Laws of Force, you encouraged me to follow up the investigation; and from that time you have constantly extended to me your sympathy, and have manifested a kind interest in the result of my labors. Thus you are intimately associated in my mind with the work, though it is but just to say that you are in no sense responsible for the correctness of any of my deductions. I dedicate the book to you as an acknowledgment of your kindness, and as a manifestation of my respect for the power of mind which has not only given you your eminent position in your profession, but is conspicuous in every department of learning to which your attention has been directed. With sincere regard, Your friend, SAMUEL E. COUES. ERRATA. Page 107, line 30th ~~~ read, descends to a lower level. "163, line 8th ... for bury, read buoy. "258, line 4th ---- for their, read these. ❝263, line 2d for common, read coming, #272, note—omit the quotation marks in the second paragraph. ** 250, line 6th - insert the before work-next line, omit the before law. PLANETARY MOVEMENTS. FORCE FROM THE Fall of BodIES. HEAT. ACTION AND REACTION. REACTION AS REACTION AS A PROPELLING POWER. GO INTRODUCTION. THESE outlines of a System of Mechanical Philosophy are the result of a research made by the author, for his own. instruction. In the research he attempted to separate sup position from fact, the questionable from those things necessarily taken for truth by the laws of the mind. The inquiry took the form of snythetical reasoning, proceeding step by step, deducing the unknown from what appeared self-evident, taking nothing as truth on authority, however great the name which had given currency to the theory; thus shutting out all sources of error except such as resulted from the weakness of the individual mind. Arriving by this process at conclusions, the very opposite of thoso taught in the schools of science, these conclusions were tested by an appeal to the phenomena of nature. Both, the reasoning without the phenomena, and the phenomena without the reasoning, pointed to the same general truths. Thus are presented opinions which appear to be sup ported both by reason and by observation, and presented in the order of their development. The writer feels confident, that, however defective may be his logic, however imperfect may be his statement of the facts of science, however crude may be his application of the truth to the |