8 



9. Muffle furnace. Price 40s. 



1884. Exhibited by Thomas Fletcher. 



10. Gas muffle furnace, requiring neither blast nor at- 

 tention ; for temperatures up to fusing point of cast iron. 



1876. Exhibited by Thomas Fletcher. 



11. Patent injector gas furnace, with blower, for the 

 treatment of refractory substances at very high tem- 

 peratures. 



1876. Exhibited by Thomas Fletcher. 



This furnace will burn perfectly in the same space any avail- 

 able gas supply from 10 to 50 ft. per hour, or more, if required, 

 giving temperatures in exact proportion. With \ inch gas 

 supply, day pressure, starting with a cold furnace, silver can be 

 melted in three minutes, cast iron in eight minutes, and cast 

 steel in 25 minutes. The highest temperature obtained is 

 2,500 Fahrenheit. Although a foot blower is used, it must not 

 be classed as a furnace, for the air supply required is very small. 

 Owing to the great heating power of London gas, furnaces stated 

 to give certain results are not verified elsewhere. 



12. Gas crucible furnace for temperatures up to white 

 heat, and requiring neither blast nor attention. 



1876. Exhibited by Thomas Fletcher. 



IB. Draft crucible furnace, to melt two pounds of 

 brass. Price, 30s. 



1884. Exhibited by Thomas Fletcher. 



14. Set of apparatus for the estimation of carbon in 

 steel (Eggertz colour test). Price, 91. 



1879. Exhibited by J. Preston, late Cubley 8f Preston. 



Balance with agate centre, knife edges, and agate planes, in 

 glass case, to take 20 grammes, and turn to one milligramme. 



Copper carbon bath, with thermometer and tripod stand. 



Three dozen test-tubes accurately picked to one size. 



Test-tube stand for 24 tubes with draining pegs. 



Three burettes to hold 30 c.c. divided in -^ c.c., with three 

 tubes matched to same size, and with the same graduations. 



Screen of finest ground patent plate glass on stand. 



Set of weights in polished mahogany case, 10 grammes to one 

 milligramme. 



Two Bunsen burners. 



Archimedian drill for sampling. 



Hydrometer and hydrometer tube. 



