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and in the past some of these have been dug for fuel. This is 

 especially true of Tucker's Swamp, west of Beal Street and 

 Hockley Lane, where the digging of peat was at one time an 

 important industry. In connection with the peat-bogs I have 

 learned of no deposits of diatomaceous earth ; but it is very 

 probable that such exist. Bog-iron ore is forming in many 

 places, the most important occurrence that I have happened to 

 notice being on the farm of David Breen, in the meadows west 

 of Downer Avenue and north of Lincoln Street. It forms a 

 layer from one to two feet thick beneath a similar thickness of 

 peat. A beautiful orange sand, that is, a sand strongly impreg- 

 nated with limonite, was exposed in a ditch dug to drain the 

 swamp on Lincoln Street west of Squirrel Hill. 



