Category Archives: history

Clock vaults

“Owing to the courtesy of Prof. Upton, the laboratory has now the advantage of a set of time signals.”

―Carl Barus, Report of the Professor of Physics. Annual Report of the President to the Corporation of Brown University, June 18, 1896.

The masonry pier that supports the Ladd Observatory’s main telescope contains two clock vaults. These are very small rooms (4 by 4 feet square inside) that contain precision pendulum timepieces called regulators. The purpose of a clock vault is to provide a vibration-free and temperature-stable environment for exact timekeeping. The main clock vault is located in the entrance foyer on the first floor of the Observatory. The basement level vault has not been used in many years. Professor Winslow Upton calibrated the regulators using observations of stars starting in the 1890s.

clock vault
A regulator made by Robert Molyneux in London during the 1850s can be seen inside the main vault on the first floor.

The double doors to the vault seal out drafts and have windows through which the regulators can be observed without disturbing the environment inside. The brick walls are two feet thick which provides insulation to prevent fluctuating temperatures which could cause inaccuracy. There are  telegraph wires to send time signals from the regulators to other locations around Rhode Island. Starting September 12, 1893 and continuing until as late as 1973 the Observatory also transmitted time signals to City of Providence fire stations. Every day at noon and 8:30 p.m. signals sounded on the fire-alarm bells allowing residents and businesses to set their clocks to the correct time. Public time signaling was a common practice during this era.

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Chromospheric lines

“These are some of the problems in connection with the sun which are being investigated at the present time. Their complete solution will help to interpret the mystery, not only of the sun itself, but also of that type of stars of which the sun is a representative.”

―Frederick Slocum, The Study of Solar Prominences. Popular Astronomy, July 12, 1912.

Frederick Slocum (Brown University undergraduate class of 1895) received the first Ph.D. in astronomy at Brown in 1898 and served as assistant professor of astronomy from 1899 to 1909. He then became professor of astronomy at Wesleyan University in 1914 where he planned and supervised the construction of Van Vleck Observatory. The image below shows Slocum observing with a spectroscope attached to the main telescope at Ladd Observatory.

observing with a spectroscope
Observer Frederick Slocum using a spectroscope on the 12″ refractor at Ladd Observatory. March 15, 1905.

This spectroscope was made by the scientific instrument maker John Brashear of Pittsburgh in 1891. It is used to study the spectrum of colors in starlight. It could also be mounted on a table top to examine the spectrum of a chemical which is done to calibrate the instrument. During this era professor Winslow Upton used it in an attempt to predict rain.  It uses a prism or diffraction grating to disperse the light into a rainbow pattern of colors. This reveals dark Fraunhofer lines in the spectrum that can be used to identify the chemical elements present in the Sun or a distant star. Each chemical element has a unique pattern of these dark lines where specific colors are missing.

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“An excellent apparatus”

“Connected with this school is an excellent apparatus, including a telescope, which we understand to be among the largest in the State; this, however. is owned by the Principal, Mr. J. M. Ross.

―”Town of Smithfield.”  Twenty-First Annual Report on Public Schools, January 1866.

The School Committee of the Town of Smithfield submitted a report to the General Assembly of the State of Rhode Island for the school year ending May 1, 1865. One of the challenges conveyed was poor attendance by pupils “… who were suffered to be roaming the streets and fields, when they should have been at school.”

Map of Lonsdale
Map showing the location of the village of Lonsdale in the southeastern portion of Smithfield. From Map of the State of Rhode Island and Providence Plantations by Henry F. Walling, 1855.

The Committee highlights the success of the school at Lonsdale, the only high school in the town at the time. The principal is praised for his work and it is mentioned that he lends his own personal telescope for use by the students. The school is seen as a model that other school districts should emulate.

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The observatory that wasn’t

“The writer of this sketch has been there when the building was thronged with guests; some of them in the upper story enjoying the breezes, and the delightful views far and near; some below were at the billiard or card table; some in the nine-pin alley; some in the saloon; and some in the refectory. The hill itself has utterly disappeared and the neighboring houses have all been either removed or torn down, and all that now remains of this once noted scene of fashion, amusement, gayety and dissipation is this picture of the observatory and of several other buildings,—a picture that was taken near the close of the first third of this century.”

― “Fox Point Observatory.” Publications of the Rhode Island Historical Society, April, 1895.

This is not what I was expecting to find when searching for information on the Fox Point Observatory. It was named for the scenic views of Narragansett Bay, rather than for astronomical viewing which is what I was looking for. The only telescope used here appears to be a spyglass for viewing the sailing ships approaching the port by an observer on the deck, as shown below.

Fox Point Observatory.
“The Observatory” as it looked in the early nineteenth century. By Edward Peckham as reproduced in “A Painter of Old Providence.” The Journal of American History, 1912.

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Fellow Travelers

“The radio signals of the satellite [Sputnik II] were followed and recorded on tape frequently by Mr. C. Newton Kraus, an outstanding radio amateur of Touisset Point, R.I. He had followed Sputnik I signals for the three weeks that the transmitters continued to function.”

―Charles H. Smiley, The First Artificial Earth Satellites, August 1958.

On October 4, 1957 the Soviet Union launched the first artificial Earth satellite which was called Sputnik I. The word Sputnik simply means “satellite” or, more generally, “fellow traveler.” The quotes from Prof. Charles Smiley, director of Ladd Observatory, are from a report published in The Hinterlands, the Bulletin of the Western Rhode Island Civic Historical Society. He describes how Sputnik I could be seen from all parts of the Earth and reports on the local observations of it: “In Rhode Island, between October 12 and November 27, it was observed at Ladd Observatory of Brown University on 13 different passages for a total of 33.2 minutes.” The observed positions and motion were plotted on a star map.

Observations of Sputnik I
Observations of the Sputnik I rocket body from southeastern New England. October 12-17, 1957.

The satellite itself was only 22 inches in diameter and would have been difficult to see from the ground. Instead, they were observing the rocket that launched the satellite which also entered orbit. The second stage of the rocket was 92 feet long and 9.7 feet in diameter. Sunlight reflecting off the rocket body was much easier to see. Notice that observers in Providence RI, Nantucket MA, and Mansfield CT saw the rocket in a slightly different position against the background stars due to parallax.

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