Friday, April 22, 2016

Lime Kilns


When the first colonist came to Delmarva there was a lack of mortar to build with.  Fireplaces and the chinks between logs and board walls were filled with mud.  This was short term, however, as when the next rain came it would wash out the mud.  What was needed was lime to created cement, plaster, whitewash, etc.   With no natural stone and certainly no limestone available on Delmarva the Colonist turned to oyster shells and other sea shells. 

Exposed to high heat the calcium carbonate in the shells would make calcium oxide or “quicklime”.  This was slaked in water prior to use in mortar and plaster.

Stacks of logs were put on ground or in a pit and shells were stacked on top of the logs.  This created a lime rick.  The fire had to reach 1800 degrees and the burn would last for about 24 to 36 hours. 

 




It was very hot work and considering the caustic effect of lime on human skin it made for very unpleasant work. The long term effect on one's lung most have been horrible.

The finished lime from the ricks were hauled to where the construction required it. 

At first the lime ricks were placed near the Indian middens of shells (those massive piles of discarded shells bones and other detritus built up over hundreds of years by local Indians ) and they continued to be placed near the source of the shells as the oyster industry took off.  Seaford had a large lime kiln.  The map of Fairmount shows they also had a lime kiln. It was located over by the ice house and packing sheds.



When the railroad line to Crisfield was built it changed things.  Crisfield with its huge piles of discarded oyster shells supplied many oyster kilns that were placed near to the rail lines such as the one in Fruitland in the 1920s.  

While all lime used for building purposes had to be thoroughly burned, it was not crucial for mortar lime to be pure, and it was  commonly known as “lean lime”.  However plaster lime was known as “fat lime” which required a higher calcium content.  Thus partially burned shells may be present in shell lime mortar but seldom will be found in shell lime plaster.

Because burned lime absorbs water over time, it is considered as a perishable product that must be used in a set period of time or it becomes useless for construction purposes.  By adding sand to the lime the bonding between the sand and lime creates a hardened product (mortar or cement).

Lime kilns went from being the simple lime rick to lime kilns where a tower with an inverted cone shape inside the tower and a firebox at the bottom would generated more lime than the simple rick.

Altho there were a number of Lime Kilns on the Eastern Shore about the only remains of them are in the name of roads or geographic points. 

Above notice from the Salisbury advertiser 1888

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