THE PICTOU COAL FIELD — POOLE. 229 



fore, thought better to leave the report as it is and review it 

 from page to page in such parts as the light of later operations 

 hy miners and observers seem now to warrant alteration or 

 criticism. With the report in question was given the first com- 

 prehensive geological map of the coal basin and to date no 

 revision has been published.* That which accompanies these 

 notes and comments is necessarily based on it, but altered in such 

 parts where it is believed data more correct warrant. The topo- 

 graphical woi'k is, however, all new, from replottings and from 

 mining plans reduced by Mr. Hugh Fletcher, of the Geological 

 Survey and Mr. J. G. Eutherford. The map owes much to 

 the accurate survej'ing and neat and careful draughting of Mr. 

 Rutherford. 



On comparing this revised map with that of 1(SG9 it readil}' 

 will be seen in what respects structural modifications have been 

 suggested especiallj" in that portion of the Held which Sir W 

 Logan was careful to refer to as " wholly connnitted to Mr. 

 Hartley." For many years the Survey map had been accepted as 

 correct and no one thought of seriously questioning its accuracy. It 

 was not until in the ordinary course of working one of the Albion 

 seams of coal that it became a matter of moment to the writer to 

 verify the assumed position of one of the known faults, and then 

 on a comparison of several mining plans and reports being made it 

 became apparent not onl}' that the Survey map was incomplete 

 but that it had inaccuracies which a full accjuaintance with the 

 records available at the time of its preparation might liave 

 avoided. This awakening of doubt led to further study and in- 

 dependent investigation stimulated by Mr Fletcher who work- 

 ing in the neighbourhood took a deep interest in the questions at 

 issue, and to whcnn an indebtedness is due that only those who 

 know him well can fully estimate. As investioation proceeded it 

 became evident that some local knowledge of the structure sur- 

 rounding the coal field was desirable for the better understand- 

 ing of the conditions which effected its partial destruction, or if 



*The map referred to is on a scale of 20 chains to an inch, but it is not yet completed. A reduction 

 from it to a scale of one mile to the inch is here given for comparison with the Survey map of 1869, 

 on the same scale. 



