April I, 1865.] THE TECHNOLOGIST. 



CAMBRIDGE COPROLITES. 423 



feet below the surface of the ground (similar to geological strata), and, 

 when washed and pulverised, are largely xised in all kinds of nitrate, 

 super-phosphate, and other chemical manures. The advantages gained 

 by using such are too well appreciated by the agricultural community 

 to need any further favourable notice from me. The largest works or 

 diggings for obtaining these valuable fossils are at the little village of 

 Abington (of which Mr. Charles Cooper is manager), about thirteen 

 miles from Cambridge, and four miles from the little town of Eoyston. 



Here was a trast of country nearly two hundred and fifty acres in 

 extent, some parts of it submerged in large lakes of limpid mud, the 

 refuse of the numerous washing mills by which the works are studded ; 

 around could be heard the labouring groan of the steam-engines, the 

 unceasing flow of water, and the merry hum of the voices of nearly four 

 hundred men at work, whilst the musical din of the engineers 1 and 

 blacksmiths' hammers at the repairing sheds adjacent, made a pleasant 

 addition to the busy and interesting scene. Here may be seen thirty 

 or forty men stripped and hard at work in deep trenches, digging the 

 precious coprolites, whilst others are in constant attendance, ready to 

 convey them to the washing-mills. 



The method of preparing the coprolite for market may be divided 

 under four heads — viz., digging, washing, grinding, and mixing. On 

 these works the coprolites are only dug and washed, ready for the grind- 

 ing-mills, the latter process being carried on at Ipswich. It may be 

 necessary for the reader to understand the process of digging and wash- 

 ing, as carried on at Abington, before he can enter thoroughly into the 

 subject. 



The men are divided into gangs, one portion digging, the others 

 filling, washing, and loading. The strata are found about nine inches in 

 thickness ; a party of men carefully remove the top soil, which is after- 

 wards replaced, and then dig a trench about six feet wide and eighty or 

 ninety feet long, until the strata of coprolites are reached ; these are 

 then removed in small and peculiar trucks especially constructed for the 

 purpose, several of which are attached to each pit, or gang of men, and 

 drawn by a horse on a line of tramways to the washing-mills. A brief 

 description of these trucks may not be uninteresting. They are 

 mounted on four (flanged) wheels, with a body independent of the 

 frame or carriage, and connected only by a rod running completely 

 through and uniting th^e two parts ; the top or body when loaded is kept 

 in its upright position by means of a small catch, or bolt ; the truck 

 is then run abreast of the washing-mills ; a boy draws the bolt or catch, 

 and the body of the truck turns over and discharges its contents into the 

 ring of the mill. Simple as this may be, it tends to show how nicely 

 time is calculated on these extensive works. When the men have 

 removed the fossils from their bed, the land is undermined, and large 

 iron crowbars or levers are inserted on the surface, by which means the 

 whole mass is thrown over the ground already dug ; by these simple 

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