Tuesday, November 23, 2010

Sundials at Haverford College, Then and Now

Posted by Darin Hayton on 11/23 at 10:56 PM

Sundials are ubiquitous in gardens and on lawns. It seems that every garden shop and nursery sells an array of cheap sundials, often given a patina classical ornamentation or styling. At times gardens have been designed so that the plants themselves are a sundial—Longwood Gardens in Kennett Square, PA, has a topiary garden designed to function as an analemmatic sundial. First laid out in 1939, it reportedly took eight years of observations to adjust the plants so that the sundial was accurate.

But sundials have not always been horticultural kitsch. In the second century A.D. the Greek astronomer Claudius Ptolemy wrote one of the foundational texts for constructing sundails, his Analemma. This text explained in general terms how to find on a plane the arcs traced by specific points on the celestial sphere. The shadow cast by a gnomon projects the position of the sun as it moves across the sky. Ptolemy’s text provided the methods to construct the various lines that can be used to mark the hours.

While sundials of various sorts were constructed and used throughout the middle ages, the 15th and 16th centuries witnessed incredible developments in their accuracy, their ornamentation, and their function. Regiomontanus, who seems to have contributed to nearly every development related to astronomy, developed a universal dial that functioned at all latitudes. He first described his “Quadratum horarium generale” in his Kalendarium (1474).

Regiomontanus’s universal sundial from his Kalendarium (1474) (Source: Bayerische Staatsbibliothek, BSB-Ink 4 Inc.s.a. 1552)

During the 16th century sundials enjoyed incredible popularity, particularly with princes, rich merchants, and powerful patrons. Nuremberg became an important center for the production of sundials (see the Georg Hartmann Diptych Dial here). These dials were not merely pretty objects to be admired. As Bruce Moran has argued, German princes often commissioned these instruments in order to display their mathematical skills. Horologia of different types were important technical, astronomical devices that reflected a growing princely concern with precision instruments. Princes used such precision instruments to help realize their political and economic goals, including centralizing and extending their authority by imposing metrical standards, controlling territories, and extracting revenues at the local level.1

In addition to the proliferation of sundials, makers often wrote treatises on the construction and use of dials. Hundreds of volumes were published tracing the history of sundials, describing innovative new designs for sundials, and explaining their uses. These texts often drew attention to particular noteworthy sundials that had been designed for princes or town councils. In the mid-16th century Andreas Schöner noted in his Gnomonice … hoc est: descriptionibus horologiorum sciotericorum omnis generis … libri tres (Noribergae, 1562) that Johannes Stabius, imperial mathematician and historiographer to Emperor Maximilian I, had designed a particularly ingenious sundial for St. Lorenz’s church in Nuremberg.

Andreas Schöner praises Johannes Stabius’s sundial that he erected on the side of St. Lorenz’s church in Nuremberg (Source: Andreas Schöner, Gnomonice digital copy)

Sundials still occupy a strange place between kitsch and science. To be sure, considerable science—e.g., astronomy and methods of projection—undergirds sundials. More generally, they also continue to be associated in various ways with science and knowledge. Sundials seem to be a sort of scientific accoutrement. Three examples from Haverford College illustrate this connection. The first and oldest is a broken sundial that marks the site of the original observatory at Haverford.

The column with its broken sundial that marks the site of the original observatory. The plaque reads: “This stone marks the site of the Observatory of John Gummere (1784-1845). Erected about 1834.” (Source: Author’s photo)

The observatory was moved from this site sometime before 1870, when this column with its sundial was installed to mark the site:

The plate of the sundial clearly missing its gnomon. Apparently the gnomon has been missing since at least the mid-1960s. (Source: Author’s photo)

A slightly later sundial hangs on the front of Founders Hall. This sundial, erected in 1918, is an analemmatic dial (as noted across the top), which explains the curving lines across the face the instrument. Analemmatic dials take into account the fact that the sun traces a figure-8 as it moves through the heavens throughout the year. Consequently, the numbers of the face of an analemmatic dial are arranged not in a circle but along ellipses. These dials also often include the declination lines marking the declination of the sun through the year. The sundial on the front of Founders includes declination lines for the sun’s entrance into each sign of the zodiac.

The Analemmatic Dial on the front of Founders Hall at Haverford College. “Pereunt et impuntantur” from the Roman poet Martial. This motto—“They vanish and are reckoned by us”—is commonly found on sundials.(Source: Author’s photo)

The front of Founders faces slightly south east, which explains the slight angle to the lines on the face of the sundial. The motto across the bottom, “Pereunt et impuntantur,” is a quotation from the Roman poet Martial and commonly decorates sundials.

As if harkening back to the original observatory, the newest science building on campus has a sundial installed on one wall. A rather plain sundial with a decidedly unscientific, though classical sounding, motto, it is located high up on the south wall of the chemistry wing of the Integrated Natural Sciences Center. It seems an odd little flourish, out of the way where few people seem to notice it or know that it is there.

Haverford’s newest sundial. The motto this time, “Horas non numero nisi serenas,” comes from the English author William Hazlitt’s essay “On a Sun-Dial” (1827). Hazlitt claimed to see this motto on a sundial near Venice.(Source: Author’s photo)

This last sundial perhaps reflects the odd relationship sundials have with modern science. No longer seen by scientists as a key marker of science, sundials retain some historical connection to the sciences. Perhaps the sundial is like like the old scientific instruments and glassware that scientists often collect to decorate their offices and homes—artifacts from some scientific past, scientific ornamentation.

On the south wall of the Union Music Building there is a fourth sundial that might actually be the second oldest dial on campus. The Union Music Building was constructed in 1909, nearly a decade before the analemmatic dial on the front of Founders. Like the newest of the dials on the end of the INSC, the sundial on the music building is built into the stone wall itself. And like the newer one, it bears the same motto from William Hazlitt: “Horas non numero nisi serenas.” In this case, the fact that the Union Music Building houses the music department and practice rooms, the motto seems vaguely more appropriate than it does at the end of the sciences building. Like its older relative across the main quad, this dial too is missing its gnomon. One report suggests that it is in the music library inside Union.

Haverford’s second oldest sundial (?) on the south wall of the Union Music Building (Source: Author’s photo)

Tucked in behind a tree, this sundial too escapes the notice of most passersby—not one of students who passed by it this afternoon had previously noticed this sundial.

1The best collection of essays on the role of precision in politics is Norton Wise, Values of Precision, esp. K. Alder’s essay “A Revolution to Measure.”

Tags: andreas schoner, haverford college, johannes stabius, regiomontanus, sundials