in the Coal-Measures of Nova Scotia. 221 



which he gathered at the extremity of the delta of the Mis- 

 sissippi or the Balize. He saw a cane-brake (as it is called 

 in the country) of these tall reeds killed by salt water, and 

 extending over several acres, the sea having advanced over 

 a space where the discharge of fresh water had slackened for 

 a season in one of the river's mouths. Tf such reeds when 

 dead could still remain standing in the mud with barnacles 

 attached to them (these Crustacea having been in their turn 

 destroyed by a return of the river to the same spot), still 

 more easily may we conceive large and firmly-rooted Sigil- 

 larise to have continued erect for many years in the carboni- 

 ferous period, when the sea happened to gain on any tract of 

 submerged land. 



Submergence under salt water may have been caused either 

 by a local diminution in the discharge of a river in one of its 

 many mouths, or more probably by subsidence, as in the case 

 of the erect columns of the Temple of Serapis, near Naples, 

 to which serpulse and other marine bodies are still found ad- 

 hering. 



Sir Charles next entered into some speculations respecting 

 the probable volume of solid matter contained in the car- 

 boniferous formation of Nova Scotia. The data he said for 

 such an estimate are as yet imperfect, but some advantage 

 would be gained could we but make some slight approxima- 

 tion to the truth. The strata at the South Joggins are 

 nearly three miles thick, and they are known to be also of 

 enormous thickness in the district of the Albion Mines near 

 Pictou, more than one hundred miles to the eastward. There 

 appears therefore little danger of erring on the side of ex- 

 cess, if we take half that amount or 7500 feet as the average 

 thickness of the whole of the coal measures. The area of 

 the coal-field, including part of New Brunswick to the west, 

 and Prince Edward's Island and the Magdalen Isles to the 

 north, as well as the Cape Breton beds, together with the 

 connecting strata which must have been denuded, or must 

 still be concealed beneath the waters of the Gulf of St 

 Lawrence, may comprise about 36,000 square miles, which, 

 with the thickness of 7500 feet before assumed, will give 

 7,527,168,000,000,000 cubic feet (or 51,136-4 cubic miles) of 



