4th. The orientation of the triangulation.
5th. The calculation of the co-ordinates of the points and their construction from the minutes of the survey.
6th. The geodesical and barometrical leveling.
The first lecture is devoted to the explanation of the different kind of signals used under various circumstances; on the method of measuring bases and angles, and the principles on which these operations are performed; and concluding with the description and mode of using certain instruments for measuring angles.
The second lecture continues and enlarges on the subject of the measurement of angles, horizontal and vertical, with different kinds of instruments.
The third lecture relates to the corrections and reductions which must be made to observed angles, such as the correction for the eccentricity of the instruments, to the reduction of the angles to the horizon, and to the center of the station, and also on the adjustments of the instruments, or the application of corrections for certain errors.
The fourth lecture discusses the calculation of the triangles and their errors, and points out the best organization that can be given to the triangulation, and the exactitude which can be expected from it.
The fifth lecture also relates to the calculation and the development of the triangulation, and explains the nature of the geodesical operations for the map of France.
The sixth lecture explains the manner of observing for, and determination of the azimuthal bearing, for the orientation of the triangulation.
The seventh lecture has reference to the convergence of meridians, calculation of rectangular co-ordinates, sundry problems, and geodesical leveling.