The pupils who enter the tobacco service, commence, on quitting the Polytechnic, with the rank of _élève de 2^{e} classe_. They study, in the manufactory at Paris, chemistry, physics, and mechanics, as applied to the preparation of tobacco. They make themselves acquainted at the same time with the details of the manufacture and with the accounts and correspondence. They are generally promoted to the rank of _élevè de 1^{re} classe_ in two years. They rise afterwards successively to the rank of sub-inspector, inspector, and director. After completing their instruction at the manufactory of Paris, the _élevès_ are sent to tobacco manufactories in other parts of France. Promotion in the tobacco service does not follow altogether by seniority. Knowledge of the manufacture and attention to their duties are much considered, as the interests of the treasury are involved in the good management of the service. TELEGRAPHS.--(_Lignes Telégraphiques._) On entering the telegraphic service the pupils of the Polytechnic receive the rank of _élevè inspecteur_. They pass the first year at the central office. During the six winter months they study, under two professors, the composition of signals, and the regulations which insure their correctness and dispatch, the working of telegraphs and the manner of repairing them, the theory of the mode of tracing lines and of determining the height of the towers, electro-magnetism and its application to the electric telegraph. During the summer months they make tours of inspection. They assist in the execution of works, and practice leveling and the laying down of lines. At the end of the year the _élevès inspecteurs_ undergo an examination, and, if there are vacancies, are appointed provisional inspectors. After a year in this rank they may be appointed inspectors either in France or Algeria. Each inspector has charge of a district containing from twelve to fifteen stations. He is obliged to make a tour of inspection once a month of at least ten days’ duration. After a certain number of years’ service the inspector rises to the rank of director. Besides their other duties, the directors exercise a general superintendence over the inspectors. PROGRAMMES OF THE PRINCIPAL COURSES OF INSTRUCTION OF THE IMPERIAL POLYTECHNIC SCHOOL DURING THE TWO YEARS OF STUDY. I. ANALYSIS.--_FIRST YEAR._ DIFFERENTIAL CALCULUS. LESSONS 1-9. _Derivatives and Differentials of Functions of a Single Variable._ Indication of the original problems which led geometers to the discovery of the infinitesimal calculus. Use of infinitesimals; condition, subject to which, two infinitely small quantities may be substituted for one another. Indication in simple cases of the advantage of such substitution.