Steward Delaney’s New Clock

“A very valuable Howard clock has recently been placed in the Steward’s office. It is regulated by Ladd Observatory standard time, and is thus kept as near correct as possible. The clock is connected with the bell-ringer’s room, so that now the college bell will be rung at exactly the right time, doing away with the nuisance and inconvenience often caused last year by the bell being rung too soon.”

“In appearance the clock is very attractive. The case is of handsome oak, and is about three and one-half feet high. It will undoubtedly be a great convenience to the students and will be used by many for regulating their own time pieces.”

―”Steward Delaney’s New Clock.” Brown Daily Herald, September 30, 1895

Archibald G. Delaney, 1884
Steward Delaney in his office, circa 1884. This photograph was taken before the new clock was installed.

Ladd Observatory placed an order on behalf of Brown University for one #89 Regulator on Sept. 13, 1895 . The clock was manufactured by E. Howard & Co. at a cost of $100 and was shipped to Providence on Sept. 25 where it was installed in the office of the Steward. The position of Steward was held by Archibald Grant Delaney from 1884-1904. His office was 1 University Hall. A telegraph break circuit connected the clock to the college bell in the tower of the building. It was regulated to the correct time by comparing it to the precision timepieces at the Observatory.

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Development on the summit

“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.”

―Rhode Island Geodetic Survey, COLLEGE HILL, 1935

USGS 1894
Topographic map of the East Side of Providence as surveyed in 1885 & 1887. The small brown oval near the center is the hill where Ladd Observatory was built. USGS, 1894.

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.

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Flight-critical calculator

“In addition to helping the crew organize its time, the second HP-41 computer was kept ready for flight-critical, deorbit-burn calculations. Once during each orbit around the Earth, the shuttle has an opportunity to land at one of six contingency locations. During a routine flight, Mission Control supplies the shuttle crew with deorbit-burn information. Should the shuttle encounter an emergency, however, the astronauts would rely on the HP-41 for these calculations.”

―”HP-41’s Again Aboard Columbia.” HP Key Notes, March-May 1982.

HP-41 advertisement
Hewlett Packard advertisement, 1982.

To prepare an orbiting Space Shuttle for re-entry through the Earth’s atmosphere it is critical that the spacecraft be “balanced” by taking into account the mass of the fuel left in the tanks at the end of a mission. An astronaut would use a handheld computer or programmable calculator to determine how many minutes and seconds of fuel to burn to get the center of gravity correct for a smooth descent and landing. The “personal computing system” used for this was made by Hewlett Packard in the 1980s. NASA donated one of these, a model HP-41CV, to Ladd Observatory after the retirement of the Shuttle program.

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The Weather Bureau in Providence

“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.”

―George Francis Field, “Harvard College Class of 1901.” June 1911

University Hall Weather Bureau
An instrument shelter on the roof of University Hall.

In addition to the weather station at Ladd Observatory there was another on the Brown campus. Located on the roof of University Hall it was operated by the U.S. Weather Bureau. The pole behind the chimney at left was likely used to support the anemometer, an instrument to measure wind speed.

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“The Magic Voice of Science”

“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!”

―Garrett P. Serviss, Wireless Time Signals from the Eiffel Tower. Washington Post, September 7, 1913.

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.

Upton notebook
The notebook of Winslow Upton describes reception of the “Special Wireless Signals from Washington” in November, 1913.

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“The pendulum of eternity”

“The vast cycles of change going on in the heavens seem, as it has been sublimely said, like the recurring beats of the pendulum of eternity.”

―William Augustus Norton, First Book of Natural Philosophy and Astronomy, 1860.

Providence Union Station, 1847-1896.
Providence Union Station, 1847-1896. The Foucault pendulum was suspended within one of the towers at left.

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.

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The highest point in Providence

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.

USGS 1894
The border of Johnston and Providence ran through Olneyville Square. Rocky Hill is in Cranston. USGS topographic map, 1894

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Timing the transit of Mercury, 1907

“About five seconds before third contact a black ligament connected the planet’s disk with the trembling edge of the Sun.”

―Winslow Upton, “Transit of Mercury at Ladd Observatory.” Popular Astronomy, 1907.

1907 transit of Mercury
Chronograph recording of the Transit of Mercury on November 14, 1907.

Prof. Winslow Upton tapped a telegraph key as he watched the planet Mercury transit the Sun. The signal was sent to a chart recorder where an electromagnet moved a pen on a slowing turning drum of paper to record the observation. The instrument is called a chronograph. This one was made by the Warner and Swasey Company of Cleveland in 1890. Primarily it was used for calibrating the astronomical regulators (precision pendulum clocks) to set the time accurately. It was also used for timing events such as lunar occultations of stars.

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Observing the “rain-bands”

The Leonid meteor shower was approaching and as the astronomers prepared cameras to capture the event they must have wondered: will the skies be clear tonight?

Leonids 1898
Astronomers preparing cameras to capture the Leonid meteor shower, Nov. 14, 1898.

Prof. Winslow Upton taught astronomy at Brown from 1883 until his death in 1914. He also had a keen interest in meteorology. He had been a professor of meteorology at the Weather Bureau of the U.S. Signal Survice from 1881 until 1883. In 1884 he was one of the organizers of the New England Meteorological Society and operated a weather station at Ladd Observatory starting in 1890. We can gain some insight into how he might have forecast the cloudiness of the sky by noting a curious instrument to the left of the cameras in the photo above.

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The dark side of the Moon

Automated instruments on the roof of Ladd Observatory monitored the sky during the total lunar eclipse of Sept. 27-28, 2015. First there is a wide field sky camera. It has a fish-eye lens which can capture an image of most of the sky above Providence. The second is a sky brightness meter which is used to monitor light pollution.

Eclipse sky
An image from the sky camera during the total phase of the eclipse. (Click on the image to see a time lapse video.)

The full Moon is usually so bright that it overwhelms the sensitive camera causing the images to be overexposed. During the eclipse the Moon was dark enough that the only artifact in the image above is a thin vertical line where one column of the digital camera was saturated by the moonlight. The camera is more sensitive than the human eye allowing the Milky Way to be seen during the total phase of the eclipse. The time lapse video contains 3,625 still images. Each second of the movie shows about 5 minutes of changes in the sky.

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