Regarded as a school for the scientific corps of the army, its peculiar mode of uniting in one course of competition candidates for civil and military services, has probably raised scientific thought to a higher point in the French than in any other army. Regarded as a system of teaching, the method it pursues in developing the talents of its pupils appears to us the best we have ever studied. It is in its studies and some of its main principles that the example of the Polytechnic School may be of most value. In forming or improving any military school, we can not shut our eyes to the successful working at the Polytechnic of the principle, which it was the first of all schools to initiate, the making great public prizes the reward and stimulus of the pupil’s exertions. We may observe how the state has here encouraged talent by bestowing so largely assistance upon all successful, but poor pupils, during their school career. We may derive some lessons from its method of teaching, though the attempt to imitate it might be unwise. Meanwhile, without emulating the long established scientific prestige of the Polytechnic, we have probably amongst ourselves abundant materials for a military scientific education, at least as sound as that given at this great School. NOTE. In addition to the Schools of Application for Artillery and Engineers at Metz, and of Infantry and Cavalry at St. Cyr, of which a pretty full account will be given, the following Public Services are supplied by the Polytechnic School. GUNPOWDER AND SALTPETRE.--(_Poudres et Salpêtres._) In France the manufacture of gunpowder is solely in the hands of the Government. The pupils of the Polytechnic who enter the gunpowder and saltpetre service, are sent in succession to different powder-mills and saltpetre refineries, so as to gain a thorough acquaintance with all the details of the manufacture. On first entering the service they are named _élèves des poudres_. They afterwards rise successively to the rank of assistant-commissary, commissary of the third, of the second, and of the first class. NAVY.--(_Marine._) A small number of the pupils of the Polytechnic enter the Navy. They receive the rank of _élève de première classe_, from the date of their admission. They are sent to the ports to serve afloat. After two years’ service they may be promoted to the rank of _enseigne de vaisseau_, on passing the necessary examinations, on the same terms precisely as the _élèves de premiere classe_ of the Naval School. MARINE ARTILLERY.--(_Artillerie de la Marine._) The French marine artillery differs from the English corps of the same name, in not serving afloat. Its duties are confined to the ports and to the colonies. It is governed by the same rules and ordinances as the artillery of the army. The foundries of La Villeneuve, Rochefort, Ruelle, Névers, and Saint Gervais are under its direction.