362 



REV. A. W. KOWE ON THE 



152. Besides these, many lamps of hard chalk occur in the 

 drift, some of them as rounded boulders with distinct striation. 

 ~No. 169 is a section of this hard chalk, and is full of circular 

 organisms of which little but the form can be detected. Mr. 

 Keeping identified a specimen as being exactly similar to the 

 hard chalk of Cambridgeshire. There remain only the flints and the 

 Boulder-clay itself to be considered. The flints are by far the most 

 abundant of the rocks in the drift, and sometimes are in blocks of 

 very considerable size ; two great blocks which were dug out of the 

 Boulder-clay in making a very deep drain measure respectively 

 22 in. Xll in., and 19 in. X 11 X 7 in. In examining some Boulder- 

 clay within two miles of Eelstead in a disused clay-pit, I dug out 

 several large flints, which were so highly polished on all sides that 

 the surface was quite transparent ; there were a great number of 

 them lying in this clay at a depth of from four to five feet from 

 the surface • but though apparently whole as they lay, yet, when 

 taken out, they were all without exception found to be sharply 

 cracked in one or two places without being at all splintered, and 

 the clay itself was quite undisturbed. Of the chalky Boulder- 

 clay itself three slides will be found numbered 170 ; they were taken 

 from a mass of this clay exposed in an open grip close to Eelstead, 

 and they contain great numbers of very minute Eoraminifera, many of 

 them in perfect preservation, mixed up with particles of quartz- 

 sand. 



I fear that this investigation into the character of the rocks 

 of the Essex drift has so far been productive of little, if any, 

 practical result ; but it is possible that the mere description of the 

 rocks may lead to some important results as regards the general 

 question of the glacial drift. In taking it up, I hoped to discover 

 some of the localities from which the different rocks had come, 

 and it is possible that further investigation may be productive 

 of more definite results ; but at present I feel that the difficulties of 

 actually identifying these fragments with the rocks of any special 

 locality are so great that I am not myself capable of coming to any 

 definite conclusion upon such a question. I have to thank Professor 

 Bonney and Mr. J. J. H. Teall for so kindly examining many of 

 the specimens and sections, and for several valuable suggestions. 

 My thanks are also due to Professor A. Geikie and Mr. Clement 

 Beid for kindly inspecting the specimens, and to Mr. H. Keeping 

 for identifying several of the sandstones and the fossils in the 

 limestones. 



Discussion. 



The President said the author of the paper had shown how much 

 might be done by a petrologist even in so unpromising a region as 

 Essex. Most geologists had experienced the difficulty of identifying 

 rocks transported from a distance. Unless, however, the fragments 

 are actually found in situ in the Boulder-clay, it is well to beware 

 of concluding that they have not been brought to the spot. He 

 related a case in which a Mexican carving was picked up in a Bom an 

 encampment in Devonshire. 



