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From the Library: Colossal NYC Potholes

NYBG pothole

Of course, we’re not referring to the potholes you might encounter this spring on the Mosholu Parkway or the Cross Bronx Expressway. We’re a botanical and horticultural research library after all, far more interested in natural history, so when we say potholes we mean glacial potholes.

This enormous one was photographed in 1913. Originally it would have been twelve feet deep, four to five feet in width, tapered at the bottom. And its earliest published description might have come from Nathaniel Lord Britton, first Director-in-Chief of The New York Botanical Garden, in the proceedings of the New York Academy of Sciences.

Dr. Britton told a meeting of the Academy, on June 5, 1882, that the above as well as other potholes were “brought to my notice by the late Professor A. Wood. They are located on the western bank of the Bronx River, about midway between Bronxdale and Williamsbridge…near the western end of a now dismantled and impassable bridge, with stone abutments, and in the northern part of a hemlock grove which fringes the stream for about a mile below. It is one of the most picturesque spots in the vicinity of New York City, and a walk along the little river from Bronxdale to Williamsbridge is always enjoyable.”

Housed in the archives of The LuEsther T. Mertz Library, this historical photo also accompanied “Pot-holes in The New York Botanical Garden”—an article by paleobotanist Charles Arthur Hollick, in the September 1913 issue of the Journal of the New York Botanical Garden, page 157.

“Pot-holes are bowl- or basin-like depressions in rock,” Hollick wrote, “caused by the abrasive action of gravel or cobble stones when churned around in the depressions by rapidly moving water. A pot-hole has its beginning in an irregularity or inequality in the rock bed of a stream, in which gravel or perhaps a single cobble stone or other rock fragment finds logdment. If the conditions are favorable, so that the foreign material is free to move and the current of the stream is sufficiently rapid to churn or swirl it around, the original inequality in the stream bed becomes deeper and more or less circular in shape, from the abrasive action of its contents, and a pot-hole is formed. A pot-hole, therefore, no matter where it may be located, is definite evidence that the rock in which it was excavated must have been, at some time, a part of the bed of a rapidly flowing stream.”

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