First published in 1953, as the second edition of a 1951 original, this book was written for the general reader by the renowned Scottish astronomer William Marshall Smart (1889-1975). The text presents an accessible account of the history of earth, incorporating the contributions of astronomy, physics, chemistry, geology and biology within the main theme. Numerous illustrative figures are also included. This book will be of value to anyone with an interest in the development of earth and the history of science.

In many of the sciences there is no means of ensuring absolute accuracy in the measurement of a particular quantity. The difficulty can to some extent be overcome by making several independent sets of observations and by combining these to give the most probable result. This done, the degree of precision of the calculated value can in its turn be assessed. It is seldom a straightforward matter of taking the average reading, and in many cases a knowledge of the theory behind the methods of combining observations becomes essential. It is this knowledge that Professor Smart provides.

This new revision of a standard work gives a general but comprehensive introduction to positional astronomy. Useful for researchers as well as undergraduates.