Mr. Buddie's Synopsis of the Newcastle Coal Field. 239 



For a more particular account of this seam, I beg to refer to Mr. 

 Button's excellent paper on the New Red Sandstone of the county of 

 Durham, below the Magnesian Limestone, published in the first half 

 volume of the Society's Transactions, page 72. 



In the description of the several Sections of the strata, I have not 

 entered into detailed descriptions of the several Slip Dykes, which cross 

 their respective lines of direction. I have abstained from this because I 

 am persuaded that the Society will consider the investigation of the 

 several Slip and Whin Dykes which occur in our district, not only a pro- 

 per subject for geological investigation, but also of great utihty to the 

 land and mine proprietors of the present day, as well as to posterity. 



As far as our Coal district has been explored, the lines of direction, 

 the throws,* and other circumstances of the several Dykes, are well 

 known. But on contemplating the nature of the several seams of Coal, 

 which extend through the district, it is obvious, that, considering their 

 various thicknesses, qualities, and depths from the surface, they cannot 

 be worked in regular succession. 



The order of succession in which they will be worked, will be regu- 

 lated by their relative value — hence, the best and cheapest working 

 seams will be first exhausted. And the seams of inferior thickness and 

 quality, and the most expensive to work, will be the last worked, and 

 each seam will naturally be worked in succession as its relative value 

 as an article of commerce, will entitle it to be carried to market. 



It is, therefore, obvious, that many collieries which are now open, 

 will, sooner or later, be shut up, and lie dormant for various and inde- 

 finite periods, dependent on, and regulated by, the circumstances above 

 stated And the probability is, that in many cases all knowledge of the 

 Dykes which intersect them may be lost, and that the parties having to 

 re open them, may be as ignorant, or even more so, than those who first 

 opened these mines. 



It is not necessary that I should dwell on the extent of the loss of 

 property and of lives, which may result from such a state of things. 

 My object is to draw the attention of the Society, and of the public, to 

 the means of avoiding it. 



VOL. I. K k 



