“I have intrusted Mr. Winslow Upton with the work of compiling the accompanying circular of information relative to time-balls, and have the honor to present herewith the results of his labor.”
– Cleveland Abbe, “Information Relative to the Construction and Maintenance of Time-Balls.” October 1881.
Winslow Upton was a “computer” (in the sense of one who computes) at the U.S. Naval Observatory in 1880. The following year he went to the U.S. Signal Service where he was tasked with compiling a summary on the practice of using time-balls for the distribution of accurate time.
The practice of dropping a ball at exactly noon every day was used to calibrate the chronometers on ships in a nearby harbor. These accurate timepieces were then used for celestial navigation. The balls were installed on tall buildings within a couple of miles of the docked ships. An example is the Boston Time-Ball. The procedure used in Boston was described by B.M. Purssell of the Signal Corps in Upton’s compilation. Continue reading The Boston Time-Ball→
“This summit is near the intersection of Hope Street and Doyle Avenue. If in existence in 1835, Hope Street was a rough country road known as East Pawtucket Turnpike. Doyle avenue was not laid out until many years later. On this summit stands Ladd Astronomical Observatory of Brown University erected in 1891.”
When the construction of Ladd Observatory began in May of 1890 the area was rural with few buildings nearby. At a distance to the east and northeast of the hilltop were low lying areas that were swampland, as indicated by the blue hash marks on the map above. These marshes were later drained and filled to allow for building the residential neighborhoods that are seen there today. A short distance to the south there was a large reservoir, built in 1875. A steam powered pumping station delivered the water through pipes buried beneath the streets. The former reservoir is now the site of Hope High School and the athletic fields behind the building. Continue reading Development on the summit→
“In Philadelphia I dragged out a colorless and an unhappy existence till September, 1904, when to my delight I was ordered back to New England, and this time nearer the centre of civilization. (Of course by that I mean Boston, which is the “hub of the universe” the “Athens of America”, the “Centre of Culture”, and last but not least, the home of the humble baked bean and the sacred codfish). I was sent to Providence, R. I., and have remained here ever since and hope to continue my residence here. By a happy combination of circumstances I have lived in the classic halls of Brown University ever since my arrival in Providence. The location and environment are eminently satisfactory.”
“This is truly scientific magic. Just think of it! You want to know the true time to the fraction of a second, and all you have to do in order to get it is to open your electric ear to these sounds, which seem to drop out of the sky, as if Old Time himself were speaking to you!”
During 1913 the Washington Naval Observatory and the Observatoire de Paris attempted to exchange wireless time signals. The experiment was used to calculate the difference in longitude between the two locations more accurately than was possible with other techniques. They were also trying to measure the velocity of radio waves through space. The goal was to improve communication with ships at sea which used the time signals to calibrate the chronometers used for celestial navigation. For most of the year atmospheric conditions prevented the reception of the signals sent across the ocean. The conditions improved in November and the two observatories were then in regular contact by radio. Prof. Winslow Upton of Ladd Observatory was listening in on the transmissions.
When news of Léon Foucault’s demonstration of the Earth’s rotation reached the United States in 1851 there was great interest in repeating the experiment in Providence. Two members of the Brown faculty arranged for a public demonstration in the Providence railroad depot. Alexis Caswell was a professor of natural philosophy, mathematics, and astronomy. William A. Norton was professor of civil engineering and natural philosophy. The pendulum bob weighed a little less than 40 pounds and was suspended from the end of a wire 97 feet long. The report on this experiment was published in the Proceedings of the AAAS along with an account of the Harvard demonstration in the stairwell of Bunker-Hill Monument. Continue reading “The pendulum of eternity”→
The site chosen for Ladd Observatory was at the top of the highest hill in the city of Providence. The hill lost that distinction in 1919.
The borders of Providence have changed a number of times. The settlement of Silver Lake was originally part of Providence, but the residents decided that this agricultural community had more in common with rural Johnston and choose to secede in 1759.