655 INDEX. Glass, strength of: Page. Remarks_______________________________________________________ 635,626 Lights set in frames, tests of_________________________________- - 626 Transverse tests__________________________________________ 627-629,632 Comparison of results___________________________________________ 629-631 Compression tests------------------------------------------------- 631 Gun carriages: Anchor bolts for------------------------------------------------ 377 Helical springs for____________________________________________- 385-392 Piston rods for, proof stresses____________________________________ 378 Retraction chains for— Proof stresses--------------------------------------------- - 378 Tensile tests_____________________________________________ 379,380 Gun, 15-pounder No. 12, recoil mechanism of------------------------ 189-216 Gun, 15-pounder No. 12, double spring for------------------------------- 388 Gun mounts: Steel forgings and castings— 6-pounder— Carrier rings____________________________________________ 99-102 Tabulation_________________________._______________ 102 15-pounder— Carrier ring________________________________________________ 185 Inner bases__________________________________________ 143-160 ' Tabulation_________________________________________ 161,162 Outer bases____________________________________________ 165-180 Tabulation_________________________________________181,182 Pivot sockets__________________________________________ 105-113 Tabulation____________________________________________ 114 Pivot yokes----------------------- -------------------- 117-137 Tabulation____... --------------------------------- 138,139 Gun specimens: 3.6-inch B. L. field mortars— Bodies_____________________________________________-........ 13 Breech blocks___________________________________________________ 13 Obturating spindles______________________________________________ 13 Gas checks------------------------------------------------------ 13 5- inch B. L. siege rifles—‘ Tubes________________________________________________________ 17,18 Jacket---------------------------------------------------------- 19 Tabulation_______________________________________________________ 19 6- inch R. P. guns— Tubes-------------------------------------------------------- 23-26 Jackets--------------------------------!------------------- 27-30 Tabulation_____________________________________________________ 30 7- inch B. L. siege howitzers— Tubes_________________________________________________________ 33,34 Jackets-....________________________________________________ 35,36 Tabulation_____________________________________________________ 36 10-incli B. L. rifles— Tube_______________________________________________________— 39 Jackets---------------------------------------------------- 40,41 Tabulation------------------------------------------------------ 41 12-inch B. L. rifles— Tubes_________________________________________________________ 45-47 Jackets_______________________________,-------------------- 48-50 Tabulation--------------------------------------------------- 50 Gas-check disks----------------------------------------------- 65 12-inch B. L. rifled mortars— Tubes------------------------------------------------------- 53-58 Jackets---------------------------------------------------- 59-64 Tabulation--------------------------------------------------- 65 Heidel’s metal, tensile test and chemical analysis---------------------- 455 Helical springs. (See Springs.) Hooks, retraction and buffer bracket, for 12-inch carriage-------------- 381 Hydrostatic tests of .30-caliber rifle barrels....................... 87-94