|About the Book|
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1862 Excerpt: ...conditions which should regulate theMoreThis historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1862 Excerpt: ...conditions which should regulate the shading of maps and their reduction. They immediately precede the exercise to which they relate. Lecture 1 relates to small maps, copies, and reductions of these- and it explains the object of topographical maps, the various kinds and the different scales generally used. The manner in which the form of the ground is represented by equi-distant contour or level lines is also explained, and mention is made of the conventional tints used, and the species of writing and value of the BOale employed. Lectures 2 and 3 relate to the execution of shaded plans by the brush and the pen, under different circumstances of light and shade. Lecture 4 explains the different methods for reducing topographical maps, also the description, mode of using, and verification of pentagraphs. Second Section.--Exercises. These exercises are intended to teach the students the conventional signs used in topographical drawing, and to give them facilities with the pencil and brush for producing shaded maps, and in reducing them from one scale to another. SECOND PART.--INSTRUCTION IN TOPOGRAPHICAL SURVEYING. This instruction comprises: 1st. Lectures given in amphitheatre. 2d. Practical lectures or exercises. 3d. The execution of topographical surveys. First Section.--Oral Leciures. These lectures are divided in two classes, which comprehend: --1st. Those relating to the description of the instruments, and of the methods used in topography. 2d. Those which have reference to the manner in which the students should proceed in the execution of the work, and principally of surveys of limited extent. Eight lectures are devoted to the description of the various instruments, the method of adjusting their errors, and the manner of using them, as well as to the di..