29. Tracing of the chamber and of its junction with the bore. 30. Thickness of metal around the chamber. 31. Chase and reinforce. 32. Determination of the angle of sight. 33. Vent and base ring. 34. Minimum weight of the piece for the resistance of the carriage. 35. Approximate calculation of the weight given by the profile previously obtained. Modification of this profile, if there is any. _Fourth Section.--Trunnions, Breech, and Handles._ 36. Dimensions of the trunnions and of the shoulders. 37. Tracing of the breech. 38. Base rings and other moldings. 39. Object and fixing of the preponderance of the breech. 40. Exact settlement of the position of the trunnions, definitive length of the reinforce. 41. Center of gravity of the piece; dimensions and position of the handles. 42. Means of executing the calculations indicated in the two preceding articles. 43. Table of the dimensions of the piece. C. FIRE OF THE HOWITZER. EFFECTS OF THE PROJECTILE. _First Section.--Elements of the Charging of a Howitzer._ 44. Tracing of the shot bottom. 45. Tracing of the fuse. 46. Diameter of the cartridge (or of the bag.) 47. Charge of powder for firing with ball. _Second Section.--Laws of the Motion of the Projectile. Establishment of Practice Tables._ 48. Preliminary calculations. 49. Trajectory. 50. Curve of the inclinations. 51. Curve of the remaining velocities. 52. Curve of the durations of the passage. 53. Determination of the elevations for the fire at different distances. 54. Angle of fire, corresponding to the different distances of the object aimed at. 55. Angles of descent. 56. Résumé of the laws of the motion and of the practice tables. _Third Section.--Effects of the Projectile._ 57. Depth of penetration in the media indicated by the programme. 58. Effects of explosion in earth. 59. Résumé of the results relating to the effects of the projectile. NOTE.--The formulas cited in the memoir need not be accompanied by their demonstration, except in the case of the latter not having been already developed in the lessons of the artillery course. It will be sufficient to insert in this notice only the final result of the calculation relating to each formula, without entering into the details of such calculations. The study of the design for ordnance is preceded by four lessons intended to make the students acquainted with all the details of its execution, and the substance of which is indicated in the programme of the memoir. III. APPLICATION OF THE THEORIES OF THE ARTILLERY COURSE (6 DAYS.)