Midlothian, 3360 feet, contains 38 seams, and gives an aggregate thickness of 135 feet.

Lanarkshire, in 3000 feet, contains 27 seams, and gives an aggregate thickness of 67 feet.

The district to be described is situated between Bathgate and Whitburn, and between the Morningside Railway and the march between Linlithgowshire and Lanarkshire. Vertical Section No. 1 shows the strata of the Lanarkshire coalfield from Wishaw to Shotts, or the upper series, the coals marked alphabetically. Section No. 2 shows the arrangement of the strata as generally found in this Bathgate district, though there are many great variations in thickness, and other details. The first seam found in the deeper part of the basin is G, or the

Rough Parrot, from 14 to 18 inches thick, poor in quality,

and sometimes interstratified with thin laminæ of slate; but all the coals, down to the Torbanehill parrot or gas-coal, are of poor quality, contain much earthy matter, and are unfit for house use. From 19 to 21 fathoms below this rough parrot lies H, or the

Mill Coal, averaging 27 inches thick. About 8 fathoms below this is found I, or the

Wee Coal, 2 feet 2 inches thick, with a stratum of clay ironstone balls in connection with it; extremely variable in thickness, but it is worked at various points by three iron. companies. Five fathoms below this lies J, or the

Main Coal, 3 feet 3 inches thick, with a 3-inch stone in it. And from 6 to 10 fathoms below this we have K, or the

Colinburn Coal, 2 feet 6 inches thick. And from 2 feet to 3 fathoms below this we find L, the

Boghead Gas-coal and the Slaty Blackband Ironstone, a mineral of value, which has been most earnestly and indefatigably searched after by many parties, and the position of which is thoroughly determined and admitted in the mining world. It is, however, a most erratic deposit, occurring only in small patches and islands, and these vary much in thickness and quality.

No continuous stratum of it has been discovered north of the fault CD (Plate II. fig. 1), although nearly fifty bores have been put down by four iron companies in the ground between the Bathgate gas-coal field and this fault, and all who had trialleases have given them up. The last company, after spending a large sum on a pit about the point X, only got about halfway down, when they encountered so large a flow of water (1600 gallons a minute) that the engines were overpowered, and it was abandoned about two years ago. The strata of the Slatyband and Boghead gas-coal district give off water in immense quantities; the largest pumping engine in Scotland, a direct acting one, with 80-inch cylinder and 12-feet stroke, working 27-inch pumps, delivering 1750 gallons per minute, is required at Crofthead, at a joint fitting by Mr Dixon of Govan, and the Coltness Iron Company. There are two other engines of the same kind in this Bathgate field, one with 22-inch and the other with 21-inch pumps.

I have been thus particular about the ironstone on account of its being an important feature, lying immediately below the famous gas-coal (sometimes in connection with it), forming as it were an index to it; every bore or pit which has reached this slaty blackband passes through the position of the Boghead gas-coal.*

The rough map on the wall copied from the Ordnance map on the 6-inch scale, but deprived of much of its topographical detail, exhibits this coal field, and its relation to the Shotts and Benhar field, with the principal faults and slips shown in white lines; the adjoining trap rocks are also shown, and the gas-coal field in black. It crops out from Inchcross at the Chemical Works, away round, a little to the south of Torbanehill House, shown by the letters B F (Plate II. fig. 1). That part with a bold edge has been correctly ascertained; where the black is washed off, shows the parrot thinning to such a degree as to be unworkable, or going into common coal.

The extent from south to north, or from the Torbanehill crop to the Couston tramway, is two and a half miles, and from east to west, or from Inchcross to the boundary of Lanarkshire, is two and a quarter miles, making an area of about four square miles, say 2500 acres, and the deepest position is somewhere between 70 and 75 fathoms.

There are no protruded masses of igneous rock near enough to harm the coal, except a whinstone dyke, which seems to emanate from the whin at Westcraigs (part of which is shown on map), trains east by Polkemmet Cottage on to the Chemical Work, destroying the coal for a few fathoms on each side of it, and almost turning it into shale. There is a sample marked C of the coal so destroyed. The ironstone, on the other hand, is improved and made denser nearer the dyke. Neither is the coal overlying any sheet of igneous rock near enough to cause any alteration on it for good or bad, as many bores have gone far enough below it to prove. Boghead, No. 2 of my section, goes 4 or 5 fathoms deeper, and Barbauchlaw, No. 8, about 8 fathoms deeper.

It was also hinted in the evidence at the first trial, that

It is situated well down in the upper coal series, within 80 to 100 fathoms of the first limestone, or beginning of the lower series.