NOTES ON THK PkOI.ONM ;i:i) KROSI', 189O-9I. 67 



In the case of the dead fish, when the tliaw set in the surface o( the ground 

 would be the first disturbed and that possibly to such an extent as to bring a laj-er 

 of eai th over the pond ice, which would eventually sink and entomb the dead 

 organisms. Similar denudation attending the break up of the frost can now lie 

 observed at the bottoms of fields which have a slight inclination. The result is a 

 layer of brick-earth deposited, similar to that following a heavy rain, only ^ery 

 much greater in quantity ; as we have before observed, the work of seasons is here 

 done in a few weeks. 



One other possible case of fossilisation is presented by the dead rooks in tlie 

 wood. Suppose, instead of carting away those looks to manure the field, as w.is 

 actually done, they had been allowed to remain. Their desiccated carcases would 

 have held out but little temptation to the returning rodents and carnivores of the 

 summer. When the autumn arrived they would have received a coveting of 

 leaves and so easily have passed to the first stage of preservation. The present 

 speculative position of the conditions under which organisms are entombed is my 

 apology for venturing upon these suppositions. 



The rapid work of the frost in disintegration has been forcibly brought to 

 notice in the following instance. Some Boulder-clay of a very chalky character 

 had been thrown out last autumn. Ordinarily the lumps of chalk would have 

 wasted ver^^ slowly under exposure from year to year. Now, the appearance of 

 the heaps is that of a mass of white slimy clay, the lumps of chalk having quite 

 disappeared. As bearing upon the work of decalcification the instance is 

 instructive. That work must now proceed there with greatly accelerated velocity. 

 Of the effect of the frost in splitting rocks we have also one instance. A pa\ e- 

 ment in this village (Felstead) is laid with flags of an indurated sandstone.- Some 

 two or three of these flags are broken by the frost, not into laminae, but quite 

 through the substance splitting the flag. The whole pavement, too, is disturbed. 

 As to the penetrating character of the frost in different soils accounts vary 

 greatly. Some pipes were found choked with ice at a distance of more than two 

 feet under ground. Yet there was no good evidence of the frost having penetrated 

 the soil to that depth. In compact soil and closely pressed gravel there is good 

 evidence of a penetration of frost of one foot and some cases are quoted much in 

 excess. 



In passing over some stubble fields a few days after the thaw, I found many 

 small weeds, notably Cudweed and Pimpernel, looking green and vigorous. 

 Beneath their roots there was still a frozen pan of ice and this proves that at one 

 time the plants were completely frozen. It is not easy to see how they emerged 

 from that state unharmed. Problems affecting the natural transport of plants, not 

 well understood, might perhaps be helped to a solution by noticing their behaviour 

 under prolonged frosts. 



The varied phenomena attending this great frost serve as an object-lesson to 

 illustrate the ciianges brought about by the severity of early post-Glacial times. 

 Assuming the frosts more severe and prolonged, and the thaws to be of rare occur- 

 rence, our deaths and migrations of plants and animals would be proportionate!}- 

 increased, and the erosion accompanying one of those rare thaws would be so 

 tremendous as to seem perfectly' incredible to ordinary readers ; nevertheless tract s 

 of all such changes are legacies remaining with Essex folk to this da}:. 



P.S. — Since writing the above I observe a letter in "Nature," of January 29th, 

 by Professor T. G. Bonney, referring to the destruction of fish by the frost in 

 Regent's Park Canal. He also asks whether " such a cause may have acted in 

 the geological history of the globe." I n Nordjenskiold's " Arctic \'oyage " there is 



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