ROUGH WAYS MADE SMOOTH

A SERIES OF

Familiar Essays on Scientific Subjects

BY

RICHARD A. PROCTOR

NEW IMPRESSION

LONGMANS, GREEN, AND CO.

39 PATERNOSTER ROW, LONDON

NEW YORK AND BOMBAY

1903

All rights reserved

'Let knowledge grow from more to more'
Tennyson

PREFACE.

It is scarcely necessary for me to explain the plan of the presentwork, because I have already—in introducing my 'Light Sciencefor Leisure Hours,' my 'Science Byways,' and my 'Pleasant Ways inScience'—described the method on which, as I think, such treatises asthe present should be written. This work deals with similar subjects ina similar way; but I think the experience I have acquired in writingother works on the same plan has enabled me to avoid some defects inthe present work which I have recognised in the others.

The list of subjects indicates sufficiently the range over which thepresent volume extends. Some of them might be judged by their names tobe in no way connected with science, but it will be found that nonehave been treated except in their scientific significance, though infamiliar and untechnical terms.

RICHARD A. PROCTOR.

S.S. 'Arizona,' Irish Sea
October 18, 1879.

CONTENTS.