MR MILNE ON THE MID-LOTHIAN AND EAST LOTHIAN COAL-FIELDS. 



255 



flanks rise perhaps as high above the sea as the valley of the Esk ; but its trough 

 is much higher, being 300 or 400 feet above the sea. The only river which wa- 

 ters it, is the Tyne. 



In my account of the rocks which occm* in the district, I shall describe first 

 those that are stratified, and next those that are unstratijied. 



I. STRATIFIED ROCKS. 



I. The stratified rocks consist of the following strata (and I mention them in 

 the order of their relative quantities): 1. Sandstone; 2. Shale; 3. Limestone; 

 4. Coal ; 5. Argillaceous strata. I am enabled also to give some notion of the 

 absolute quantities in depth of these several strata, for the greatest number have 

 been bored through, and the thickness of each particular stratum nearly ascer- 

 tained. All the coal-seams in the district above 6 inches in thiclmess have been 

 precisely ascertained ; and similar information has been procured with regard to 

 more than one-half of the other strata which lie between the coals. The whole 

 strata, of all kinds, form together a series of layers about 1000 or 1050 fathoms 

 in thickness ; and of this deposit there are between 500 and 600 fathoms in which 

 the relative quantities of all the several different kinds of rocks may be pretty 

 accurately stated. In the following calculation, therefore, I at present throw out 

 of view the coals, in that half, the component parts of which are unknown. In 

 the other half, which is entirely known, the following is the aggregate thickness 

 of the several strata : 



1. Sandstone, 



286 fathoms 



2. Shale, .... 



188 ... 



3. Lime, .... 



27 ... 



4. Coal, .... 



21 ... 



5. Clay, .... 



12 ... 



534 



The aggregate thickness of coal-strata in the whole deposit, above 6 inches 

 in thickness, is about 34 fathoms. This I have ascertained from measurements 

 of each particular seam. If it be assumed, that the other strata maintain the 

 same relative proportions to each other throughout the half which is unknown, 

 as they do in the other half, then the aggregate thicknesses of these several de- 

 posits, in the entire basin, would be as follows : 



1. Sandstone about 



2. Shale, 

 8. Lime, 

 4. Coal, 

 6. Clay, 



550 fathoms. 

 360 ... 



51 ... 



30 ... 



22 ... 



1013 



