in Massachusetts. 



77 



perpendicular^ sometimes seventy feet high. Its width is 

 upon an average, about fifty feet ; though for a consider- 

 able part of its course, large fragments of gneiss occupy 

 much of the fissure. The dip and directions of the slate 

 that form its sides, correspond with those of the rocks 

 generally, in that vicinity ; and hence it is difficult to im- 

 pute its origin to a subterranean upheaving force ; for had 

 the sides of the fissure been removed by such a force, we 



should expect the strata to have somewhat of a quaqua- 

 versal dip ; or at least, that the fissure would coincide 

 with our anticlinal axis ; which is so far from being the 

 case, that the basset edges of the strata cross the fissure 

 nearly at right angles ; and they dip in only one direction. 

 In the southeast part of Newport, Rhode Island, (or 

 perhaps in the southwest part of Middleton,) the coarse 

 conglomerate rock contains numerous fissures, crossing 

 the seams of stratification nearly at right angles, run- 

 ning parallel to one another, as w^ell as perpendicular 

 to the horizon. In a high rocky bluff on the coast at 

 the spot above named, two of these fissures occur, not 

 more than six or eight feet apart ; and in the course of 

 ages, the waves have worn away the intervening rocks, 

 so as to form a chasm about seven rods in length, and 

 sixty or seventy feet deep ; the sides being almost exactly 

 perpendicular. This is called Purgatory ; and the sea 

 still continues its slow work of extending the chasm 



farther into the clifF- 



On the south shore of Newport is a similar fissure, in 

 granite. It is not so extensive as that in the conglome- 

 rate, being about twenty feet deep. During a southerly 

 wind, the waves are forced into it with great violence ; 

 and on reaching its extremity, are driven upwards in 

 spray to the height sometimes of thirty feet above the 



VOL. I. PART II. 



11 



