172 



!Mr. RIallet on the Physical Conditions 



Table III. 

 General Classification of the principal Makes of British Cast-Irons as applicable to Artillery. 



Class of Iron. 



Apcdale, 



Hwrdest procurable, . . . 



Oldberry, 



Ponkey, 



Peutywn, 



Calder 



Shotts, 



Doulais (Finely Pig), . . 



Arigna 



Burchill's, 



Muirkirk, 



Peutwyn (peculiar), . . . 



Arigna, 



Apedale (Cylinder Iron), . 



Peutwyn, 



Calder, No. 1 + Peutwyn, 



No. 2 + Scrap, 



Gray Cast-iron (Blacnavon, 



No. 2 + Scrap), .... 



Monkland, 



Clyde 



Parkfield 



Apedale, 



Devon, 



Calder, 



Arinnai, Scrap i, . . 

 Calder J, Scrap }, . 



Gartsherry, 



Low Moor, 



Shotts, 



Elaina, 



Arigna, 



Gartsherry, 



Shotts 



Varteg Hill, 



Calder, 



Summerlie, 



Madeley Wood, . . . 



Elsecar 



Cinderford, 



Carron, 



Gartsherry, 



Muirkirk, 



Klonkland, 



Doulais, 



Arigna, 



Shotts, 



Lillieshall, 



Shotts, 



Caedtalon, 



BufTcry 



Caedtalon, 



CaiTon, 



Doulais, 



Doulais, 



Blacnavon 



Muirkirk 



Milton, 



Calder, 



Calder J, Peutwyn J. . 

 Arigna i, Peutwyn j. 



Cold. 



Hot. 

 Cold. 

 Hot, 

 Hot. 

 Hot. 

 Hot. 



Cold. 

 Cold. 

 Hot. 

 Hot, 



Cold. 

 Hot, 

 Hot 



Hot. 

 Cold. 

 Cold. 

 Hot. 

 Cold. 

 Hot. 



Hot 

 Cold. 

 Hot 

 Cold. 

 Cold. 

 Hot 

 Hot 

 Hot 

 Hot 

 Hot 

 Cold. 

 Cold. 

 Cold. 

 Hot 

 Hot 

 Hot 

 Hot 

 Hot 

 Cold. 

 Hot 

 Cold. 

 Hot 

 Hot 

 Hot 

 Cold. 

 Cold. 

 Cold. 

 Cold. 

 Cold. 

 Cold. 

 Hot. 

 Hot 



Com- 

 mercial 

 No. 



No. 2. 

 Scrap. 

 No. 3. 

 No. 3. 

 No. 2. 

 No. 4, 

 No. 4. 

 No. 4. 



No. L 

 No. 1. 

 No. 2. 

 No. 1. 



No. 3. 

 No. 2. 

 No 2.' 



No. 4. 

 Na 1. 

 No. 1. 

 No. 1. 

 No. 3. 

 No. 1. 



No. 2.- 

 No. 2. 

 No. 2. 

 No. 3. 

 No. 3. 

 No. 1. 

 No. 3. 

 No. 2. 

 No. 3, 

 No. 2. 

 No. 1. 

 No. 1. 

 No. 1. 

 No. 2. 

 No. 3. 

 No. 3. 

 No. 3. 

 No. L 

 No. 2. 

 No. 1. 

 No. 1. 

 No. 2. 

 No. 2. 

 No. 1. 

 No. 2. 

 No. 2. 

 No. 3. 

 No. 1. 

 No. 1. 

 No. 2. 

 No. 1. 



Silvery. 



Bright Gray. 



Dull Gray 



Dark Gray. 



Characteb in Working. 



w. 



Xeast fusible; thickening rapid-' 

 ly when fluid by a spontaneous 

 "puddling;" vesiculai', often 

 crystalline, incapable of being 

 cut by cliisel or file; ultimate 

 cohesion a maximum ; and 

 elastic range generally a mi- 

 nim imi. 



er>' soft ; feels creasy ; peculiar* 

 micaceous appearance, gene- 

 rally owing to excess of man- 

 ganese; soils the lingers 

 strongly ; crj'stals large ; nins 

 verj' fluid ; conti'action large. 



Tough and hard; can be mth 

 difliculty filed or cut; crj'stals 

 large and small, mixed : some- 

 times runs thick ; contraction 

 on cooUng a ma:iinium. 



Toughness and hardness most 

 suitable for working ; ultimate 

 cohesion and elastic range 

 gencnilly are balanced most' 

 advantageously ; crystals uni- 

 form, verj' minute. 



Less tough and hard than the 

 preceding ; other characters 

 alike; contraction on cooling' 

 generally a mininium. 



Most fusible, remains long fluid; 

 exudes graphite in cooling ; 

 soils the fingers ; cn-stals 

 large and lamellar; ultimate, 

 coliesion a minimum, and 

 elastic range generally a mas 

 imum. 



Physical 

 IklAxiMA AKD Minima 



Maximum density. 

 Coefficient E, nearly as in No. 22. 

 Maximum ultimate strength and 

 value of T^, nearly as in No. 40. 



Full of microscopic vesicles. 



Maximum contraction in cooling. 



Coefficient £, maxim, but T^ small 

 Minimum densitj'. porous, as No. 8. 



;Value of Te, maximum. 

 Minimum density, solid. 



Minimum ultimate strength. 



Note.— All deduced from equal pieces, cast one inch thick and five inches square. 



