THEORETICAL AND PRACTICAL TREATISE

ON THE

STRAINS, DESIGNING, AND ERECTION OF

WORKS OF CONSTRUCTION

BY FRANCIS CAMPIN, C.E.

PAST PRESIDENT OF THE CIVIL AND MECHANICAL ENGINEERS' SOCIETY; AUTHOR OF
"IRON BRIDGES, GIRDERS, ROOFS, ETC.; "MECHANICAL ENGINEERING,"
ETC., ETC., ETC.

186.
g. 167.
д

LONDON:

PRINTED BY VIRTUE AND CO., LIMITED,

CITY ROAD, LONDON.

PREFACE.

IN writing the present treatise, my object has been to produce a work dealing comprehensively with the subject of materials and their use in certain branches of constructive art, viz. the massive works usually intrusted to civil engineers and architects, and throughout I have carefully avoided the introduction of the higher branches of mathematical investigation; and in so doing I have not omitted problems of the classes usually treated by high mathematical processes, but have substituted simpler, but equally convincing, lines of argument for the more abstruse processes of analysis.

It will be found that algebraical arithmetic, or simple forms of equations, supply the basis of calculation, and this basis is indeed amply sufficient for all the theoretical reasoning that is called for in the consideration of the practical problems engaging our attention.

From the above remarks it will be seen that the work is designed especially for all those readers who desire to become thoroughly acquainted with the theories of structures and the practical application of results in the simplest way, and not as a mathematical exercise. It may be advisable to say a few words in explanation of the stress I lay upon the importance of this simplicity of calculation.

There are comparatively few of those entering upon a
mechanical profession who are thoroughly accomplished
mathematicians, and once launched upon the business of
life—or what is equivalent to it, the probationary term
which precedes actual remunerative employment-the tyro
will not desire to give time to the study of abstruse
science, beyond the point where it ceases to be absolutely
necessary for his purposes; and there are many who have
only learned these exact sciences bit by bit as they have
found them necessary.

Another matter of common consideration is, that even in
those who have become proficient at school and college in
pure mathematics, this knowledge, unless sedulously main-
tained and reinforced by after-study, rapidly decays, and
is often only with great difficulty revived; and the time
absorbed by this reinforcement or revival is generally
required for the purposes of more directly practical study.

Although all structures should combine in themselves
both strength and stability, I have, for the sake of clear-
ness, separated the two classes as far as can conveniently
be done for theoretical investigation; showing, however,
their necessary connection in suitable places.

In the examples taken to illustrate the methods of
calculation, I have carefully selected cases such as occur
in every-day practice, and carried them through, in order
to leave no doubt or difficulty as to the practical applica-
tion of the formulæ.

In conclusion, I would add that this work is not intended
in any way as an elementary introduction only to the
science of construction, but deals fully and finally with all
the subjects included in its syllabus.

FRANCIS CAMPIN.