56 THE CRUISE OF THE BETSEY ; OR, 



other, and separated by deep square ditches exactly parallel 

 in the sides, traverse the irregular level in every direction. 

 The ditches vary in width from one to twelve feet ; and the 

 ramparts, rising from three to six feet over them, are per- 

 pendicular as the walls of houses, where they front each 

 other, and descend on the opposite sides in irregular slopes. 

 The iron block, with square groove and projecting ears, that 

 receives the bar of a railway, and connects it with the stone 

 below, represents not inadequately a section of one of these 

 ditches with its ramparts. They form here the sole remains 

 of dykes of an earthy trap, which, though at one time in a 

 state of such high fusion that they converted the portions of 

 soft sandstone in immediate contact with them into the con- 

 sistence of quartz rock, have long since mouldered away, 

 leaving but the hollow rectilinear rents which they had oc- 

 cupied, surmounted by the indurated walls which they had 

 baked. Some of the most curious appearances, however, con- 

 nected with the sandstone, though they occur chiefly in an 

 upper bed, are exhibited by what seem fields of petrified 

 mushrooms, of a gigantic size, that spread out in some places 

 for hundreds of yards under the high-water level. These 

 apparent mushrooms stand on thick squat stems, from a foot 

 to eighteen inches in height : the heads are round, like those 

 of toad-stools, and vary from one foot to nearly two yards in 

 diameter. In some specimens we find two heads joined to- 

 gether in a form resembling a squat figure of eight, of what 

 printers term the Egyptian type, or, to borrow the illustra- 

 tion of M'Culloch, " like the ancient military projectile 

 known by the name of double-headed shot ;" in other speci- 

 mens three heads have coalesced in a trefoil shape, or rather 

 in a shape like that of an ace of clubs divested of the stem. 

 By much the greater number, however, are spherical. They 

 are. composed of concretionary masses, consolidated, like the 

 walls of the dykes, though under some different process, into 



