M.T Buck 
Exercises in Practical Astronomy [PDF ebook] 
Using Photographs

Offering a series of well-defined problems supplemented by solutions, Exercises in Practical Astronomy: Using Photographs presents meaningful practical work in elementary astronomy and astrophysics. The book provides authentic astronomical photographs of very high quality on which different types of objects can be studied with equipment as simple as rulers and protractors. In addition to photographs and a set of exercises that cover 12 topics, the coverage includes ample hints and worked solutions that are designed to enable students to work independently. SI units are used for physical data and in conversions of astronomical quantities. This book is one of the few to use real rather than idealized or simplified data in the problems.