92 THE HON. SIR CHARLES ALGERNON PARSONS : EXPERIMENTS ON 







APPENDIX. 



ABRIDGED SCHEDULE OF EXPERIMENTS. 



(A.) UNDER PRESSURES GREATER THAN ATMOSPHERIC. 



k.w.m. = kilowatt minutes. Nil in Result column means no diamond formed, 



tons = pressure per square inch. 



From every experiment several samples were selected representing different parts of the ingot or mixture 



and analysed separately. 



(See figs. 1, 2, and 3.) 



EXPERIMENT. RESULT. 



4-inch mould ; iron tube core, filled with ferrous oxalate, marble round, Nil. 



iron disc to bring current to top carbon, and graphite on top, 10 tons 



pressure, 100 k.w.m. total heating, heating | minute. 

 2-inch mould ; carbon rod core, layer of silicon carbide, then calcium Nil. 



carbide, then carbon, iron nose piece, 80 k.w.m. total heating, 10 tons 



pressure, heating 2 minutes. 

 4-inch mould; carbon rod core, water round, then marble, 15 tons Nil. 



pressure, 30 k.w.m. total heating, heating minute. 

 4-inch mould; ?-inch carbon rod core surrounded by marble bush-ring Nil. 



with 1^-inch hole and fitting mould on outside, naphthalene and iron 



filings surrounding rod below ring, anthracene and naphthalene sur- 

 rounding rod in hole and above to maintain fluid pressure, iron plate 



to bring in current to top of rod, 10 tons pressure, 70 k.w.m. total 



heating, soft carbon produced, heating 1| minutes. 

 Same as last, but oxalic acid and ferrous oxalate instead of naphthalene, Nil. 



with iron filings below marble ring and also between carbon rod and 



ring. Anthracene above ring as before to maintain fluid pressure, 



| ton gaseous pressure when somewhat cooled and ram released, 



carbon eaten away, 400 k.w.m. , duration 10 minutes. 

 4-inch mould; carbon core, charcoal round, then marble, crushed arc Nil. 



light carbons on top, 25 tons pressure, 60 k.w.m. total heating, heating 



34 seconds, maximum current 14,000 amperes, 11 volts. 

 4-inch mould ; carbon core, marble round lower part, crushed carbon and Nil. 



perforated iron disc to bring current to top carbon round upper part, 



1 Ib. carbon dioxide, snow on top covered with graphite and iron 



chips, 15 tons pressure, 60 k.w.m. total heating, about J ton gas 



pressure when somewhat cooled and ram released, found to contain 



about 50 per cent. C0 2 , 10 per cent. CO, and hydrocarbon burning 



with luminous flame, heating 2 minutes. 

 2-inch mould ; graphite neck, magnesia piece bridge, 100 tons pressure, Nil. 



4 k.w.m. total heating, little gas produced, heating 25 seconds. 



