88 



Prof. J. Prestwicb. 



Column 1 of these tables gives the original number of the obser- 

 vation in the general list of Table I. 



Instead of the columns for the height and temperature of the 

 surface, given in Table I, another giving the thermometric gradient, 

 are substituted in the following tables. 



For subjects peculiar to the separate tables, special columns are 

 introduced in each case. 



The gradients for the total depths are given in stronger type than 

 the others. 



Column VIII in Tables II and III gives the temperature of the air 

 in the gallery in which the rock or spring temperatures are taken. 



Table II.— COAL 



In this table there is no separate column for the strata, as they all 



In the few instances where they are overlaid by newer strata, the par- 

 Column IV gives the distance in yards of the place of observation 



the face of the coal. It is, however, not often recorded. 



Columns V and YI give the depth of the hole drilled for the ther- 

 In Column VII, the numbers in brackets show the difference of 



while the rate of increase between these depths is given also in italics in 



depth. 



I 



Number in 

 the general 

 list, Table I. 



II 



Name of colliery and place. 



Ill 



Depth of pit 

 or shaft. 



IV 



Distance of 

 station of 

 observation 

 from shaft. 









Feet. 



Yards. 







England. 









14 





480 







IS 





504 







16 





900 







11 





1200 







ISO 





1365 











1514 











1365—1514 







211 





620 







30 





1584 







116 





1100 



312 









1135 



1935 





