1

ON THE

PRINCIPLES AND PRACTICE

OF

LEVELLING,

SHOWING ITS APPLICATION TO PURPOSES OF

RAILWAY ENGINEERING AND THE CONSTRUCTION OF ROADS, &o.

Falter

BY

FREDERICK W. SIMMS, F. G. S., M. INST. C. E.,

CIVIL ENGINEER.

FIFTH EDITION, REVISED AND CORRECTED.

WITH THE ADDITION OF

MR. LAW'S

PRACTICAL EXAMPLES FOR SETTING OUT RAILWAY CURVES.

With three Lithograph Plates and several Wood-Cuts.

NEW YORK:

D. VAN NOSTRAND, PUBLISHER,
23 MURRAY STREET AND 27 WARREN STREET.

1870.

TABLE OF THE DIFFERENCE OF THE APPARENT AND TRUE LEVEL FOR DIS-

28

ON THE PRINCIPLES OF THE TELESCOPE, AND OF THE LINE OF COLLIMATION. 25

ARRANGEMENT OF LEVELLING OPERATIONS..

PART II.

28