62 Transactions of the 



the bottom of the shaft, in order to let the loaded trams be drawn 

 down more easil3\ In post-and-stall work, when they take out 

 the coal in the stalls, they fill the vacant places with rubbish, and 

 this is called goaf, or, as the colliers term it, ' gobb.' When a 

 level or heading is driven through hard rock — that is, through the 

 coal-measure sandstone — it is called ' cross-measures ' (written in 

 the Survey-book x measures). The end of the difterent workings 

 is called tlie ' face of the workings.' 



The fossils in this coal-field are very numerous and diversified. 

 The shells in the ironstone are peculiarly abundant, especially the 

 shell Anthracosia. Teeth also of fish are plentiful in the coal- 

 measures. 



To conclude, I will quote a passage from the ' Memoirs of the 

 Geological vSociety of Great Britain ' concerning the conditions 

 under which the coal was deposited : — 



' The sea water must have had frequent access to the coal 

 growths, and, if the beds were not purely marine, they aiust at 

 least have been estuary deposits. Throughout the whole duration 

 of the British coal-measures there were repeated subsidences, with 

 ])eriods of rest (not of elevation). The lower coal-measures of 

 Lancashire contain unmistakable bands of marine fossils — Avicu- 

 lopecten, Goniatites, Nucida, squaloid fish, &c. — while the middle 

 and upper coal-fields are more prolific in JJnio bands and fish. 

 The margin of the sea of this period was occupied by vast marine 

 savannahs of some peat-creating plant, growing half immersed, on 

 a perfectly horizontal plain, and this fringed and interspersed with 

 forests of trees, shedding their leaves upon the marsh. The ancient 

 shore was covered with vast swampy forests of water-loving plants, 

 protected from the tidal action by sandbars, and therefore in the 

 condition of great maritime lagoons. In such putrid seas accu- 

 mulations of black shale and foetid limestone would be a normal 

 state of things ; the carbonic-acid generated by decomposition of 

 the plants would readily unite as a bicarbonate with whatever iron 

 was present in the water, and be precipitated as a carbonate of 

 iron in the form of ironstone. There would b6 sea inhabitants 

 different from those found within tide-marks on ordinary shores. 

 Races of moUusca fitted for burrowing and living in such locali- 

 ties, with annelids to devour the decaying vegetable matter, 

 would be abundant, and perhaps would be the only tenants of the 

 bottom. The epiphytal ferns which grew on the decaying trees, 

 and such water or land insects as could find a home in the hollow 

 stumps, together with a few aquatic, and possibly even terrestrial, 

 lizards, would all find an appropriate residence in the swamp, and 

 contribute their spoils to the future coal-bed.' 



In concluding, I must beg to apologise for the hasty manner in 



