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In the Typographical appearance of the work neither expense or trouble has been spared, and it is hoped that the Diagrams and Plates drawn on Stone, and struck off separately after the printing of the text, will be at least equal in clearness and precision to the wood cuts of an English volume. The employment of two distinct presses has of course caused infinite trouble and delay, but the art of wood cutting in Calcutta, is still almost unknown, and it was therefore hopeless to carry out the design by any other means than those adopted. In the correction of the Press the utmost pains have been taken, and although the Errata in the first few pages are more numerous than could be desired, the latter part of the work will, it is believed, be found as correct as it is possible to print such difficult matter in this country. Most of the computations have been reworked after the figures were in print, and every proof has had five or six readings.

The preparation of the work has been carried on under a press of engagements, and merely at moments of leisure after other arduous duties of the day had been attended to, which has caused the time of its publication to be very much protracted. That it contains many defects, the compilers are fully sensible of— there is much which in the arrangement and the matter


they would willingly alter if in their power. They only desire to remind their readers, that the space devoted to certain subjects precluded the possibility of entering into them more fully; in some single Chapters are condensed, what might with ease be extended into a volume. It is not professed to treat of the higher branches of Geodesy, for instance, the Measurement of Base Lines, by Compensation Bars,-the Treatment of observed angles according to the Theory of minimum squares, so as to satisfy the Geometrical conditions of the figures to which they may appertain, -or all the refinements necessary to carry out an important Trigonometrical Survey, such as that now in progress in this country. The object has been to include so much merely, as may be useful and necessary for ordinary Topographical or Revenue Surveyors, and if the materials thus thrown together have the effect of maintaining a high standard of accuracy in whatever Survey operations may be undertaken, to keep pace with the refinements of the present day, and to the benefit and extension of our geographical knowledge, the labor expended in passing such a volume through the Press, will be most amply repaid.

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Definitions-Table of Square Measure-Method of de-
termining the Area of Triangles, Trapeziums, &c.,
and of Irregular Polygons.


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Directions for using the Chain-Of the Cross Staff
and Offset Rod-Method of Measuring Offsets-
Of the Perambulator-The Madras Pattern 8-mile
Perambulator-Lieutenant Colonel Everest's 6-mile
ditto-Lieutenant Colonel Waugh's 10-mile ditto.


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Description of the Instrument and Method of using it
-Of the Surveying Compass-Of the Circumferen-
tor-Of the Plane Table.

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Adjustments and method of using the Instrument-
On the Sextant-Principle of its Construction-
Description of the Instrument-Adjustments of
ditto-Of the Artificial Horizon-Method of using
ditto-Remarks on Parallax and Refraction.

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Method of testing ditto-The Y Level-On fixing
the line of Collimation-Adjustments-Method of
examining and correcting the Collimation—
Troughton's Level-Gravatt's Level.


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Drawing Compasses-Hair Compasses-Compasses
with movable points-Proportional Compasses and
their use-Beam Compass-The Drawing Pen-
The Straight edge-Of Parallel Rulers-The Com-
mon Parallel Ruler-The double ditto-The Cross-
barred ditto-The Rolling ditto.

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Simple Divided Scales-Diagonal Scales-Their Con-
struction and use-Vernier Scales--On the Pro-
tracting Scales—Construction-Marquois' Scales-
Plotting Scales-Remarks on Scales.

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