STALACTITES UNDER THE LINCOLN MEMORIAL, Science & Mechanics, August 1968.

(This is the same issue that carried Part 2 of the series, _Ithaca's
Terrifying Flying Saucer Epidemic_, featuring Jimmie Orr in the swampy area
behind the house of Mrs. Anna "X", that is, before he became a local cop. I'm
looking for a July 68 copy of S & M.)

Few, if any, of the hundreds of thousands of annual visitors to the Lincoln
Memorial realize that just a few feet below them, within the underground
concrete foundation of the Memorial, is a scene reminiscent of the scenic
caverns of the world.

Scientists of the Department of the Interior's National Park Service, and
Geological Survey report that stalactites -? deposits of calcium carbonate
normally found in caves -? are growing down from the foundation ceiling.
Also, short, stubby stalagmites rise a few inches from the foundation floor.

According to William Newman and Charles Withington, geologists of the U. S.
Geological Survey, and Maurice Sullivan, and Ellsworth Swift, naturalists of
the National Park Service, "the icicle?white stalactites range in length from
a few inches to as much as five feet or more. Their diameters are generally
less than an inch; most are a half inch or less. A few of the stalactites
have grown sufficiently long to connect with their corresponding stalagmites,
forming a continuous mineral link between ceiling and floor."

The best display of stalactites is in the farthest reach of the foundation,
particularly in the general area beneath the surface steps that rise from the
roadway. "The foundation area, however, in which the phenomenon is observed,
is not open to the public," the, Park Service said.

"Although the growth rate no doubt varies from year to year, and from place
to place beneath the Memorial (completed in 1923), some stalactites appear to
be growing at an average rate of more than an inch a year," Newman and
Sullivan said.
Explaining the processes that form the "dripstone" features, geologist Newman
said that "the stalactites and stalagmites beneath the Lincoln Memorial form
in a manner similar to those found in natural caverns in many parts of the
world. Water, carrying calcium carbonate in solution, percolates through
cracks in the concrete slab and support?works upon which the Memorial rests.

"As the water drips along the cracks and evaporates," Newman continued,
"calcium carbonate is deposited around the margin of the drop in the form of
a zing. Successive drops make additional minute deposits which grow downward
to form a hollow tube. If a stalactite is sliced into disks, the cross
sections show concentric growth rings that resemble the layered structure of
an onion."

The source of the calcium carbonate, according to ?the Survey and Park
Service spokesmen, is difficult to pin down, but there are several
possibilities: the marble flooring and the trim of the Memorial itself, or
the mortar used in its construction; the concrete forming the massive
underground foundation; or the cement matrix of the cobbled steps and walkway.

Continuing studies by naturalist Ellsworth Swift, of the National Park
Service, are being made to determine accurately the growth rate of the
curious stone "Icicles."

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