involved in the Construction of Artillery. 435 



SECTIONS. PA.^E. 



303, 304 Recapitulation of the advantages of built-up artillery of wrouglit-iron ; better 

 material, better applied ; 36-incli mortars designed by the author for British 

 Government, 300 



305 Remarks in refutation of the chief objections urged against wrought-iron as a 



material for guns, against built-up guns of v^rought-iron; American Govern- 

 ment Reports, 3(11 



CHAPTER XXXVI.— Particular Conditions of Wear of Gun3 in Service. 



306 General forms of wear, 302 



307 Particular forms of wear observed in the United States; " Columbiads," their 



explanation, 303 



308 Stellilbrm enlargement of vents; its explanation, 303 



309, 310 Burnishing of the lower side of chase ; its explanation ; economy of wear induced 



by sabots, 30 4 



311, 312 The wear is, in part, of the nature of abrasion by friction; Morin's constants; 



application, 3O5 



313 The wear in relation to charge, velocity, caliber, and weight of shot; wear of 



wrought-iron 6-pounders in America; of Colonel Simmons' 32-pounder, . . 305 



314 Ballotage; what its conditions; maybe least in wrought-iron guns; wear by atmo- 



spheric corrosion, 3O6 



315 Further objections to wrought-iron guns stated and answered, 306 



316 Special objections to built-up guns, answered, 307,308 



CHAPTER XXXVH.— Resume and Conclusion. 



317, 318 Precise scope of the work, not mechanical operations, but physical and mechanical 

 science applied to form, fabric, choice of materials, and modes of application in 

 ordnance, 3O8 



319 Recapitulation si^ubjects discussed, and conclusions arrived at under twenty-one 



lieads, 309-311 



320 Wrought-iron substituted for cast in civil structures ; why not in artillery; con- 



clusion, 3J2 



CONTENTS OF NOTES. 



PAGE. 



Discovery of gunpowder, and of artillery, 3I3 



Size of artillery ; power of shells, 339 



Distress from modern powder, 34c) 



Maximum pressure on elongated shot guns, 352 



Molecular arrangement of crystalline bodies under constraint, 353 



Fracture of cylinders, 357 



Effects of remelting cast-iron, 353 



Limits of malleability ; zinc, cast-iron, 361 



Swedish cast-iron; relation between volume and strength, 361 



Baltic mortars; sulphur in iron; cold- blast and charcoal-iron, 362 



Mechanical effect of expansion, 3'j2 



Refers to Note C, Section 2 373 



German steel, and refers to Note, O, 373 



Refers to Note S, Section 265, 373 



Cast-iron field-guns, 374 



