The eighth lecture shows in what manner the barometer is made use of for the determination of differences of altitude, the nature of the corrections to be applied to the instrument, and the degree of exactitude to be found in the results of this process.
The ninth lecture points out the order in which geodesical calculations should be performed and the verifications which should be exacted.
The Second Section contains five lectures or exercises, and they have for their object to familiarize the students with the use of the various kinds of instruments employed in carrying on the operations which have been shortly described in the first .
The Third Section relates to the practical application of the preceding principles, and mostly consists of geodesical applications.
[SECOND PART.—COMMON TO THE ARTILLERY AND ENGINEERS.]
The First Section consists of lectures given in the amphitheatre, and relates to reflecting instruments, such as the sextant, reflecting circle, and the method of using them, and also on the principles of dialling, and its connection with various problems in astronomy; describes also the different kinds of dials.
SECOND SECTION.—PRACTICAL EXERCISES.
In which the students are called upon, in the presence of the Professor, to adjust the sextant, and to use it in connection with an artificial horizon for the measurement of the angle between any two objects of the altitude of these objects above the horizon, and also the same altitude.
Third Section contains the practical application of the principles enunciated in the preceding s, in the preparation by the students of two drawings, in which they will exhibit the graphical representation of the hour in terms of the altitude of the sun previously observed, and show the various constructions of a sun-dial, according to the specified conditions based on the observation of the hour angle.