Tag Archives: telescope

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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Mid Brunswick Green

“During the greater part of the year the 3-inch transit instrument has been in the hands of the maker, Mr. G. N. Saegmuller. This instrument, while a fairly satisfactory instrument, was not of such superior excellence as the builder expected it would be. He therefore, without any suggestion on my part, offered to rebuild it without expense, which he has done at considerable cost to himself, and it is now a very superior instrument.”

―Prof. Winslow Upton, Report of the Professor of Astronomy and Director of Ladd Observatory, 1895.

transit telescope
The transit telescope as it looked in the 1890s.

During the 2010 restoration of the transit room we went to great lengths to ensure that the colors used were historically accurate. The George N. Saegmuller transit telescope had been painted black at some point. We suspected that this was not original but it is impossible to tell from the black and white archival photographs.

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