| | | |tered | | | | |off | 12|Medium |Slight |Fairly|Surface | 24 | | |good |white | 13| Medium |None |Excel-|Very | 26 | | |lent |white | 14|Consider- |Medium |Fair |Panel | 28 |able | | |fairly | | | | |white | 15|Slight |Medium |Good |Surface | 30 | | | |quite | | | | |dark | 16|Medium |Very slight |Good |Quite | 32 | | | |white | 17|Consider- |Slight, |Fair |Surface | 34 |able |along | |fairly | | |lateral | |white | | |lines | | | 18|Medium |Slight, with|Good |Surface | 36 | |some scaling| |has be- | | | | |come | | | | |quite | | | | |dark | 19|Consider- |None |Excel-|No black| 38 |able | |lent |coating;| | | | |surface | | | | |very | | | | |white, | | | | |due to | | | | |inert- | | | | |ness of | | | | |pigment | | | | |or pro- | | | | |gressive| | | | |chalking| 20|Medium |Medium |Good | | 40 33|Heavy |None |Fair |White |168 | | | |surface | 34|Consider- |Very slight |Good |Surface |172 |able | | |is very | | | | |white; | | | | |progres-| | | | |sive | | | | |chalking| | | | |may have| | | | |prevent-| | | | |ed for- | | | | |mation | | | | |of black| | | | |coating | 35|Bad |None |Good |Very |173 | | | |white; | | | | |no black| | | | |coating | | | | |evident | 36|Bad |Bad |Fair |Surface |174 | | | |is dead | | | | |black; | | | | |shatter-| | | | |ed in | | | | |places | 37|Extremely |Medium |Fair |Very |175