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Astronomy In California 1850 – 1950:
Telescope Makers, Telescopes, and Artifacts
The Porter Garden Telescope
By Russell W. Porter, American Telescope Maker
Manufactured by the Jones & Lamson Machine Co. of Springfield, Vermont
Russell W. Porter (1871-1949) was an Arctic explorer, artist, and innovative telescope maker. The most aesthetically pleasing of Porter's inventions is his Garden Telescope. It is also the best example of his skillful blending of art, science, and engineering. He wanted to create a telescope that would be as ornamental in a garden as it would be utilitarian for observing the surrounding landscape or celestial objects. At the time, he envisioned it as a permanent fixture in the garden like a sundial, ready for viewing at a moment's notice. Because it would eliminate the problem of setting up and dismantling a heavy telescope, the Garden Telescope could help to create and perpetuate an active interest in observational astronomy. In early 1923 the idea for the Garden Telescope passed through the embryonic stage, and the product emerged ready for manufacture.
The Garden Telescope is so different from an ordinary telescope that, on first sight, it might not be recognized for what it is. Gone are the lenses and the long tube of the normal refractor telescope, and gone is the tube of the reflector telescope even though it is of this type.
The six-inch aperture mirror is the heart of the telescope. A bowl of bronze lotus leaves embraces the mirror so that it pivots about itself when the telescope is pointed to different parts of the sky or landscape. Reaching out from the side of the lotus bowl, a slender bronze leaf curves gracefully upward about two feet to a prism and eyepiece. Different eyepieces allow the observer to change the magnifying power of the telescope to 25, 50 or 100 times.
If the telescope is pointed at the sun and the image projected onto white paper, the instrument becomes a sundial, and the sun time may be read from the hour circle that encircles the lotus bowl. A table of numbers provided with the instrument allows the viewer to obtain the standard time. Roman numerals show the proper hour, and graduations divide the circle into ten-minute intervals.
The hour circle, which provides the right ascension of the telescope, has a segment removed so the bronze leaf holding the eyepiece can pass through. This allows the telescope to point to all parts of the sky. Thus, Porter made it possible to have the center of mass of all the moving parts within the mounting points of the instrument, a necessary feature to provide a sturdy, compact, and vibration-free instrument. This was actually an application of the design he had published in Popular Astronomy and Scientific American in 1918 as a new mount for large telescopes. The simplest ideas are always the best, and it was this design that Porter later proposed for the mounting of the 200-inch Hale Telescope built at Mount Palomar in Southern California.
Hidden from view is an adjustment for initially setting the telescope to any latitude between twenty-three and fifty-five degrees. All parts are cast in statuary bronze so the telescope can withstand any weather without maintenance. The names of Kepler, Newton, and Galileo are cast into the base of the telescope, symbols of the solid foundations they created in astronomical thought. The young Wilbur H. Perry, who joined Porter's group of amateur telescope makers, was responsible for parabolizing all the Garden Telescope mirrors, and the making of the prisms and eyepieces was contracted to John A. Brashear.
Because the Jones and Lamson Machine Company's records have been lost, there is no record of the number of Garden Telescopes that were manufactured or of when the product was discontinued. Estimates range from 75 to over 200 sold at as much as $500 each. The highest remaining serial number is 53, so at least that many were made.
Today there are very few Garden Telescopes still in existence. It is a sad end for an ingenious idea.
--Excerpted from Russel W. Porter, Arctic Explorer, Artist,
Telescope Maker, by Berton C. Willard (Freeport, Maine: The Bond
Wheelwright Company, 1976), pp. 159-165.
The Porter Garden Telescope is a 6-inch, f/4 Newtonian Reflector cast in statuary bronze. The optical elements are stored in a box containing the 6-inch mirror, a diagonal prism assembly, an eyepiece tube, and three eyepieces magnifying 25X, 50X, and 100X.
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