Up Next

Maker, Unknown, probably English. c. 1890. Movement  5h" x 12" dia. / 11"h x 13" over hexagonal glazed case. Clock work driven orrery with Earnshaw type, split bi-metallic chronometer detent escapement with jeweled potence pivot and driven with chain fusee. Eight day duration. An additional spring barrel drives the orrery with one year duration. It also serves to eliminate the backlash that would be present in a mechanism with so many wheels. Subsidiary dial for the Bisextile, four year (leap year) cycle. Outer ring with year calendar and zodiacal indicators. Orrery with two inner planets, Mercury and Venus with rings to indicate each planet's orbital inclination to the sun. Also a separate tellurian depicting the Earth and moon system, with moon phases, the moon's orbital inclination in relation to the ecliptic represented by a ring around the Earth and a track for the moon to physically rise and fall with respect to the Earth, an indicator to show where it rises and sets relative to the surface of the Earth, below a subsidiary dial for moon's age and phases. The Earth at correct inclination with dial ring above divided into two twelve hour sectors illustrated with Roman numerals rotating with the earth. An apparatus connecting the earth to the Sun to shows the Sun's zenith and declination around the Earth as well as lines showing the approximate areas of sunrise and sunset in the Northern hemisphere. The entire mechanism pirouettes upon its central spindle once per year with indicator hand for outer silvered ring to indicate the position of the sun in the ecliptic as well as the date, month and zodiac house. All subsidiary dials engraved and silvered on skeltonized frame with unique upper and lower plates (not mirrored) held by nine pillars. Total of 45 wheels within the mechanism.

The glazed case has eight sides with metal framing and rests on a painted wooden base. The base shape and colors suggest an oriental inspiration. The entire presentation, including the choice of an Earnshaw type chronometer escapement all contribute to a strong visual impact of complexity. Qualities I found very attractive.

An overall view showing the large, 12" outer silvered ring engraved with a calendar containing the months, days and the associated zodiac and their signs all in Latin. The interior of the base is blue, probably to invoke the color of the sky.

This device is a combination of a tellurian, which shows only the Sun/Earth/Moon system and an orrery which includes also other planets. However it makes no attempt to have a correct scale between the components of the tellurian and the rest of the orrery making this a hybrid. Of course if the correct scale were attempted a pleasing representation would be impossible as the Sun would be huge in comparison to the rest of the celestial bodies and one could not get the detail of the Earth/Moon system one enjoys in this model.

A closeup of the Earth, Sun and inner planets of Mercury and Venus. Notice the apparatus that connects from the top of the sun to a circular harness around the Earth. This give a depiction of where the Sun is overhead on the Earth not only at the point where the the harness is supported, but at any given time by following the harness ring around the surface of the Earth. A brass ring crowns the Earth with two sets of Roman numerals on each semi-circle; each I through XII. This ring rotates with the Earth and indicates the hour of day or night against the pointer just visible in the background.

Up Next