138 UNDEVELOPED COAL FIELDS OF NOVA SCOTIA—GILPIN. 
deposits, as we are now practically concerned about the size, ete., 
of coal beds, not about their scientific age. 
Leaving the consideration of the productive measures of the 
Sydney coal field out of the question, and adopting the boundary 
there laid down by the Geological Survey between the two sets 
of measures, it may be taken as a fact thatin the Millstone Grit 
in that district there do exist workable seams of coal of which I 
may mention the Mullins, Gardner, Long Beach and Tracey 
seams. It is plain, therefore, that even if exception may be 
raised to the productive age of the rocks holding coal seams else- 
where, we are starting with the important premises that the 
Millstone Grit does hold valuable coal seams in the Sydney dis- 
trict, and that in other districts explorations may show deposits 
of equal value. The following condensed sections will show 
what is so far known of the coal contents of this horizon in the 
Sydney district :— 
In Cape Breton County there extends from the rear of Lin- 
gan Bay and Glace Bay to Mira, aud thence up the river of that 
name and its branch, the Salmon River, as far as Loch Lomond 
on the county line, a large area of Millstone Grit. Seams of coal 
are known throughout this district. Classing the Mullins, 
Gardner and Tracey seams in this horizon the fact is established 
that it presents seams of workable size lying, geologically speak- 
ing, thousands of feet below the seams classed as the lowest of 
the true or productive measures, as shown by the following 
condensed section :— 
In the section showing from the south head of Cow Bay to 
the head of Mira Bay there are, in about 1,900 feet of strata, 
eleven seams of coal, the thickest, the Tracey, being 4 feet. Four 
of them have a workable thickness. 
In the centre of the district, assuming with the Geological 
Survey that the summit of the Millstone Grit begins a short 
distance above the Lorway or Gardner Seam, we have first that 
seam 5 feet 9 inches thick, then in about 700 feet of measures 
there are six coal seams varying in thickness up to two feet. 
