THE ESSEX NATURALIST: BEING Journal of the Essex Field Club FOR 1887. ON THE SUBSIDENCE AT LEXDEN, NEAR COLCHESTER, IN 1862.1 BY T. V. HOLMES, F.G.S., M.A.I., (Read May 24th, 1884.) Having accompanied Messrs. Meldola and Cole on their visit to Colchester, to witness the effects of the earthquake, I resolved, before leaving that neighbourhood, to endeavour to ascertain the exact position of the Lexden Subsidence, with a view of marking it on the six inch Ordnance map, if nothing more. Accordingly, Mr. Cole and I went to Lexden on the morning of Monday, May 5th, 1884, and fortunately found a labourer who remembered the occurrence of the sinking twenty-two years ago, and who conducted us to the exact spot. The hole has long since been filled up, and it would have been impossible to have found out its position without his help. This Lexden subsidence formed the subject of a paper by the Rev. Osmond Fisher, F.G.S., and of a letter from Mr. F. Rutley, F.G.S., both of which appeared in the "Geological Magazine" for 1865, pp. 101 and 231. As Mr, Fisher and Mr. Rutley arrived at totally opposite conclusions with regard to the cause of this strange sinking, and as I am myself in favour of a third and wholly distinct explana- tion, I will first of all give a brief account of the views of the two geologists I have named, and then state my own. Mr. Fisher remarks that he did not hear of this subsidence till 1864. It took place suddenly, some workmen, who were in the 1 The date given in the "Geological Magazine" is 1861, but this, as will shortly be shown, is a mistake. It is worth noting specially, lest the local historian of the future should be in doubt whether two sinkings occurred or only one.