Asian Influences

This koi, a domesticated variety of the common carp Cyprinus carpio was photographic in the section of the creek between the Covered Bridge and the Rex Avenue Bridge. Consulting an online guide to koi fish, this appears to be of the Kararimono variety, which upon further investigation appears to be the generic name for koi that do not quite match more carefully specified types. From colored carp originally bred in China, koi can trace their lineage to Japan of the 1820s, and somehow found their way into Wissahickon Creek.

This Chinese Goose was photographed downstream from the Rex Avenue Bridge. The name "chinese goose" is an official designation of American Poultry Association's Standard of Perfection. Bred from the Swan Goose Asner cygnoides, it is of Chinese origins and can easily be identified by the strong basal knob on the upper side of the bill.

A less benign residents of the park is a copse of Trees of Heaven Ailanthus altissima located between the Pro Bono Publico Fountain and the Valley Green Parking lot. An invasive tree brought here in the 1740s a period of chinoiserie excess from China where it enjoyed a medicinal reputation for curing mental illness and baldness, its ability to thrive in harsh environments became the central metaphor for the book A Tree Grows in Brooklyn.

An attempt to eradicate the tree in the past only seems to have inspired vigorous new growth. Its flower, notably malodorous, can be seen in bloom, whence the scent may soon be experienced by the casual stroller, who can determine whether the name "stink tree" is applicable.

Source

Ice Age

The blue shows the scope of the most recent Ice Age, the Wisconsinan (17,000 - 22,000 yrs.).

The green shows the edge of the Late Illinoian (132,000 - 198,000 yrs.) ice cap.

The orange shows the edge of the of the Pre-Illinoian (>770,00 yrs) ice cap.

The yellow shows the stratified drift, the outflow resulting form the melting of the last two Ice Ages.

The position of the ice cap can be determined by the till—the debris resulting from the grinding of the surface rock as the massive ice shelf moved over the it. From the maps, it is clear that the most recent Ice Ages never reached the Wissahickon Gorge.

Source

High Water!

Saturday's rainstorm produced an usually large flow of nearly 5,000 cu.ft./sec down the creek.

This is a map the of rainfall over the last seven days in the watershed. Most of the rain fell in a single day, with a total in the range of 4"- 6" judging by the color code.

Scholar's Stone

A short distance from Horse Head Rock, another element in the Park landscape seems worthy of naming: Scholar's Stone. The shape of this feature suggests a mountain in miniature. Not in the tradition of Fairmount Park, where scholar's stones are more often in gardens, one might find beauty and inspiration by happening upon this outcropping in the Park.

Portland Classical Chinese Garden, with the pleasant name of The Garden of Awakening Orchids. Portland, Oregon.

Scholar's Stone is suggestive of the Asian appreciation of rock of the geological sort, as shown by the Chinese artist Xia Gui during the Southern Song Dynasty.

Bells Mill Road Bridge

Built in 1820, the Wissahickon Creek is spanned by the closed spandrel stone arch Bells Mill Road Bridge. With a total length of 66.9 ft. and a deck width of 24.3 ft., the span of the longest arch is 29.9 ft. Above is the upstream view and below is the downstream view.

The guard house has fallen into disuse and distance marker is no longer accurate.

The superstructure and substructure are generally considered to be in poor condition. The bridge has been appraised as being structurally deficient. Note how nearly 200 years of debris flowing through the arch at times of high water have chipped away at the voussoirs.

Horse Head Rock

While all the bridges over the Wissahickon Creek have names, many other features seemed to have escape notice and demarcation. This particular rock, coincidentally near the Equestrian Center, looks enough like a horse's head to be worthy of this name. It is also located at the exact spot where the creek turns into the gorge with the hill of Chestnut Hill on one side and ridge of Ridge Avenue on the other.

Not as dramatic as Old Man of the Mountain, seen here in a picture from Belknap College, which is a composite showing the ghostly Old Man before his tragic demise on May 3, 2003.

The clarity of perceiving Horse Head rock is hampered by the leafing of trees in Spring.

The simple glare on the water surface can be remedied in a pinch by shooting the picture through the lens of polarizing sunglasses.

Construction Begins on Bio-Composting Toilet

New life for the long-closed toilet on Forbidden Drive near the Rex Avenue Bridge. Construction has begun on a much needed 'green' facility. This follows on the first bio-composting toilet built near the Kitchen's Lane entrance to the park.