WIDTrt OF- JOINTS 

 VARIABLE AVECAGt I " 



-^^m 



VOLCANIC ROCK 



NATUEAL EESOUCCe 



riG. 



COMPARE WITH RG 5 

 OP THIS SMEtT 



UNNATURAL BED 



BAD 



hG 2 



GOOD AND BAD 5TONEWORK 



POR CAMP STOVErS AND P-lRErPLACtS 



WIDTH OF- JOINTS 

 AVERAGE- %" 



CDEErK BOTTOM STONE 



TMIN LAYER GOOD 



ElG.5 



COMPAR.t WITH PIGS 

 OP THIS 5HEE:T 



COBBLE STONE 



BAD 



Fig 4 



WIDTH OF- JOINTS 

 TO 1" 



ROUGH STONE 



GOOD SCALE 



Fig 5 



COMPARE WITH PIG 5 

 OF THIS SMtET 



ROUGH STONE 



OVER.&CALE — BAD 



EiG 6 



PLATE XXIV 



84 



