astronomical regulator, no. 103
Date1880-1890
Inventory Number1997-1-0515
ClassificationClock
Subject
Maker
Ballou Manufacturing Company
fl. 1880 - 1890
User
Harvard College Observatory
founded 1839
Cultural Region
Place of Origin
Dimensions163 x 21 x 35.3 cm (64 3/16 x 8 1/4 x 13 7/8 in.)
Material
DescriptionThis astronomical regulator was made by a sophisticated machine shop towards the end of the 19th century. When horologist John C. Losch restored the clock in 1991, he described it as follows in his report:
"The clock embodies the conservative engineering philosophy of most precision clock manufacturers of the last third of the eighteen hundreds. The movement frames are massive and stable despite the fact the pendulum and its supports are independent of the primary frames. All steel is hardened, tempered, and highly polished. Gear-wheels are attached to their hubs with screws, all gears are cut to a high degree of accuracy and precision, and I believe considerable time and apparatus was dedicated to smoothing and polishing working surfaces in order to eliminate marks inevitable from the use of machine tools for cutting gears. With few exceptions, finish work was completed by hand to very high standards.
"Unique, if not exclusive in the design of this piece, is the planetary gear system of maintaining power. Every precision clock has a means to assure the clock will continue to run and measure time even when it is being wound. The system employed in this clock is more commonly found in tower clocks, is rarely applied as in this example, and claim is made that the system has less variable influence upon the escapement than other widely used methods to maintain power.
"The foundation of this device is an internally cut gear. Because of the high cost to produce a gear of this type (in this clock, two of them), I am forced [to] ask why was it necessary when coupled with a gravity escapement? A gravity escapement is virtually independent of its power source concerning its influence on the pendulum.....
"On the top edges of the clock plates, and at a location just below the pivot holes for the gravity arms, the number two is stamped. It is also scratched inside the mainwheels....
"All of the 48 pitch wheels used to transmit power to the escapement are made from two pieces soldered together. It appears teeth were either cut around rings, or, more likely, wheels were cut, then bored out to form rings. These in turn were attached to either other disks which were crossed out to complete the wheels, or to previously prepared, spoked blanks....
"There are two electrical switching devices incorporated in the movement of this clock. Neither is original to the clock and [they] were most likely added at later dates. Both are of different manufacture and finish than the main parts of the clock, and they appear to have been made by separate workmen."
(More details of the conservation report are found in the file.)
Clock is mounted on the wall. There are 2 spare weights on a shelf.
"The clock embodies the conservative engineering philosophy of most precision clock manufacturers of the last third of the eighteen hundreds. The movement frames are massive and stable despite the fact the pendulum and its supports are independent of the primary frames. All steel is hardened, tempered, and highly polished. Gear-wheels are attached to their hubs with screws, all gears are cut to a high degree of accuracy and precision, and I believe considerable time and apparatus was dedicated to smoothing and polishing working surfaces in order to eliminate marks inevitable from the use of machine tools for cutting gears. With few exceptions, finish work was completed by hand to very high standards.
"Unique, if not exclusive in the design of this piece, is the planetary gear system of maintaining power. Every precision clock has a means to assure the clock will continue to run and measure time even when it is being wound. The system employed in this clock is more commonly found in tower clocks, is rarely applied as in this example, and claim is made that the system has less variable influence upon the escapement than other widely used methods to maintain power.
"The foundation of this device is an internally cut gear. Because of the high cost to produce a gear of this type (in this clock, two of them), I am forced [to] ask why was it necessary when coupled with a gravity escapement? A gravity escapement is virtually independent of its power source concerning its influence on the pendulum.....
"On the top edges of the clock plates, and at a location just below the pivot holes for the gravity arms, the number two is stamped. It is also scratched inside the mainwheels....
"All of the 48 pitch wheels used to transmit power to the escapement are made from two pieces soldered together. It appears teeth were either cut around rings, or, more likely, wheels were cut, then bored out to form rings. These in turn were attached to either other disks which were crossed out to complete the wheels, or to previously prepared, spoked blanks....
"There are two electrical switching devices incorporated in the movement of this clock. Neither is original to the clock and [they] were most likely added at later dates. Both are of different manufacture and finish than the main parts of the clock, and they appear to have been made by separate workmen."
(More details of the conservation report are found in the file.)
Clock is mounted on the wall. There are 2 spare weights on a shelf.
In Collection(s)
Signedengraved on the dial: THE BALLOU MFG. CO. HARTFORD, CONN. / No. 103
ProvenanceHarvard College Observatory, Garden Street, Cambridge; transferred to CHSI, 1953.
Historical AttributesUsed at the Harvard College Observatory at its Garden Street site, Cambridge.
John Cuthbertson
Date: 1770-1815
Accessories: brown storage box, descriptive tag, thin strip of paper in box with the inscription "lucernal microscope" in David P. Wheatland's handwriting (which refers to figs. 47-48 and 51 in this series), page from the book "Old Science and Medicine" with a photographic copy of the first print from this series, entitled "The Large Electric Machine at Haarlem."
Object number: 1998-1-1087
William Bond and Son
Date: circa 1864
Accessories: Winding key
Object number: 2502
Synchronome Company, Ltd
Date: circa 1929
Object number: 1998-1-0187b
William Mason Stiles (I)
Date: 1839-1850
Object number: 1994-1-0012
E. Zimmermann
Date: 1890-1910
Accessories: weights, crank, extra tuning fork
Object number: WJ0105