« PreviousContinue »
At the top is an impression of the yellow plate; below it is an impression of the yellow plate and the red plate combined; at the bottom is an impression of the yellow plate, the red plate, and the blue plate combined. See page 481.
HARVARD COLLEGE LIMARY
(N, Y. PUBLIC LIBRARY)
COPYRIGHT, 1913, BY
GEORGE A. HOADLEY.
COPYRIGHT, 1913, IN GREAT BRITAIN.
ESSEN. OF PHYS.
W. P. 7
THE most essential thing in the study of any science is that there should be a thorough understanding of the fundamental principles upon which it is based. In this text experimental demonstrations are used to show the relation between the conditions imposed and the results obtained. These demonstrations lead to the statements of fundamental principles which are here given either as simple formulas or as expressions of these formulas in ordinary language.
It has also come to be generally understood that there is no branch of natural science that has a more direct application to the needs of modern life than Physics. It is for this reason that emphasis is placed in this book upon the things that are essential in understanding the applications of the principles of Physics to that which is a part of our everyday experience. At the end of each section there is a group of questions, which not only serve to recall the principles considered in the section and to stimulate the interest of the pupil, but also suggest directions in which these principles can be applied. Moreover, the problems that are given are practical problems based on conditions that are to be met with constantly.
The general applications of Physics to the doing of things are graphically presented throughout by a series of full-page illustrations. Some of these show the advances that have been made in well-known machines; as an example, the modern locomotive compared with Steven
L L T X 88