doing we could present the subject in a clearer and more satis factory manner. Throughout the Second Part, which is of a more mixed or practical nature, we have studied to present the whole in a distinct and clear manner, giving in all cases the full and complete work of all examples necessary to illustrate each principle. We would direct the attention in particular to the chapters on Spherical Trigonometry. This subject is generally regarded as intricate and difficult. It is believed the student will find the arrangement and full. development of the different cases as here given, nearly as simple and of as easy comprehension as those of Plane Trigonometry. We might particularize other portions of the work, but will content ourselves by remarking that we have spared no pains to make the whole acceptable to the mathematical student of the present age. How well we have succeeded remains to be shown. UTICA, September, 1854. GEO. R. PERKINS. Proportional lines-properties of the sides of triangles.. PAGE Definition of sines, tangents, secants, etc... To find the sine and cosine of the sum and difference of two arcs |