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Limestone Kilns

By Ruth Shireman

Limestone is a secondary rock structure mainly of skeletal fragments of marine organisms of long-extinct sea creatures, such as coral, forams, and mollusks, squeezed over eons into a solid mass of carbon carbonate (CaC03).  When burned at 1652°F or more, it vents carbon dioxide (CO2), leaving behind the volatile Calcium Oxide (CaO) which is “quicklime”, “burnt lime”, or “unslaked lime”. When combined with water the quicklime becomes Calcium Hydroxide Ca(OH)2 and could be put to many uses. 

Lime forms the basis of whitewash for fences and trees to protect and brighten. Whitewash is fundamentally a mix of lime and water, milk, and linseed oil, for waterproofing. Folks would mix horse hair or corn husks for strength. Dried lime was safe to handle and even for animals to lick. But it remained mildly alkaline enough to disinfect barns and dairy walls.

Lime had other uses as farmers rubbed it on their livestock’s feet as an antiseptic, or painted on fruit trees to prevent fungal diseases.  Some would mix a bit of lime into the wells to disinfect the water. Lime was known to preserve eggs for months without spoiling. Tanners used it to remove hair from hides.  Gardeners used it to repel slugs and snails.  Printers used lime to bleach paper. 

Lime’s use in agriculture was so valuable as farmers found that it temporarily “sweetened” or neutralized the acid soil.  Farmers treated the soil in quite a straight forward manner. They would shovel the quicklime straight from the kiln onto a horse-drawn wagon or cart.  They took this to the field and drove the horse back and forth across it as though plowing.  Every several feet the farmer would stop the wagon and throw several shovels of quicklime on the ground.  It usually took 6 to 8 barrels to the acre. 











Transporting the quicklime was dangerous work as it could spontaneously burst into flames and burn the wagon or barns if it wasn’t spread quickly.

Operating kilns needed to be situated close to limestone quarries and the lime’s destination, as possible, so the quicklime could be transported without incident. The kilns were often built into hillsides to allow folks to easily transport limestone and fuel to the open top. 
















The inside of the kiln was usually tapered so that gravity alone fed the fuel downward.  The kiln had to be filled carefully with precisely measured amounts of the materials.  If the limestone did not bake at a high enough temperature or for long enough, the limestone would not transform into quicklime and the work would be in vain.

Lower Swatara Township had ten (10) working kilns in 1875.

A drawing of the internal as well as the external kiln.
Photo of a Limestone Kiln.
Drawing of men working at a limekiln.
Map of where limestone kilns were located in Lower Swatara Township.


Lancaster Farming - June 2012

You Tube : Ken Miller

The Lime Kilns by Hilary Fraley

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