Series: Personal Encounters With Primary Resources for Canadian Sci/Tech History 

Sub-Series 1: Exploring Archival Resources at the University of Toronto

First Posted on Friday, August 21, 2020 / Yom Shishi, 1 Elul, 5780
Last updated Friday, August 21, 2020

By: David Orenstein

Once upon a time long, long ago in a country far, far away you could walk into an archive without an appointment or personal protective equipment. Visiting their cozy reading room, you could ask the archivist on duty to get you a box of old letters. These letters would be ready for you to read in just a few minutes.

I used to do that, so here’s such a story from my distant youth, back in 2018:

American as Apple Pie: Stealing Canadian Credit 

“In media res” or as Lucretius would have said, “In the middle of it.” (De rerum Natura / On The Nature of Things Harvard U P, 1992)

On a recent visit to the University of Toronto Archives (UTARMS), I was continuing my pursuit of real-life details for three scientific congresses held in early 1920s Toronto: in December 1921 the AAAS (American Association for the Advancement of Science) and in August 1924 the BAAS (British Association for the Advancement of Science) and the IMC (International Mathematical Congress). To explore the Astronomy angle for the Congresses, I dipped once more into the Clarence Augustus Chant (Professional) Correspondence, Series 1 of the University of Toronto Department of Astronomy Accession 1896-1953  (A1974-0027), part of the larger University of Toronto Department of Astronomy and Astrophysics Fonds (fonds 0031) A finding aid was available in the reading room.

Chant (1865-1956) was the founder of the University’s David Dunlap Observatory in Richmond Hill, Ontario. The Book of its opening is in the Archives and available online.

In the file of correspondence with Edward C. Pickering (Director of the Harvard College Observatory, 1877-1919) I was struck by the exchange of letters, from 1917, concerning Chant’s master’s student Miss Ashall and her work on variable stars. By the way, Chant wrote an obituary for Pickering. It appeared in the Journal of the Royal Astronomical Society of Canada, where Chant served as the long-term editor.

This exchange consists of four letters each, from Chant and Pickering, for a total of eleven pages. Pickering’s being typed and signed originals on Observatory letterhead and Chant’s, carbon copies.

On April 17, 1917, Chant apologises for “an unfortunate accident to one of the multiple image plates on which Miss Ashall is working….[She] was almost broken-hearted over it.” Otherwise, Chant reports excellent progress by Miss Ashall.

Pickering courteously replies on May 8, “Please assure Miss Ashall that the breakage of the plate is not a serious matter. It is always liable to occur in a legitimate use of plates.”

By November 30, Chant is “somewhat anxious to know whether any of [Miss Ashall’s] stars have been verified as variable.” Pickering confirms on December 19, “One object proves of special interest[:]…+37° 4717, …period of 3h50m with a range from about 9.2 to 9.9…. Please give Miss Ashall my congratulations on her discovery.”

“Miss Ashall was delighted it was a good one. She is a very enthusiastic worker,” notes Chant, December 28. Pickering follows up the following in February 9 with a definitive description and the light curve of “Miss Ashall’s Variable”. On Pickering’s covering letter there’s a manuscript note:

“Dear Miss Ashall,-

“You will be interested in the enclosed letter & news. Return it at your leisure.


The star was SW Lacertae, as cited by Leung, Zhai and Zhang in 1984 (Publications of the Astronomical Society of the Pacific 96:634-640):

“SW Lac, first discovered by Miss Leavitt in 1918, is the most extreme of the W type W UMa stars. Its light curve is variable with 0.1-0.2 magnitude changes which is thought likely to be caused by star spots. Its orbital period is also variable. It is thought to be a quadruple system, but that the two smaller bodies have little effect on the light curve or the period, and that the period increase is more likely to be caused by mass transfer from the lesser to the more massive star.”

They are referring to Henrietta S. Leavitt’s June 10, 1918, report in the Harvard College Observatory Circular No. 207:1-4.


“An examination of photographs taken at this Observatory and having several exposures, as described in H.C. 117, has been made by Miss Ashall, an assistant of Prof. C.A. Chant of the Astronomical Observatory of Toronto. On one of those, she discovered a star which shows a marked change of brightness during the exposures and proves to be a variable of unusual interest. Observations made by the writer on numerous photographs show that the range is small, only about 0.7 magn. It is remarkable however, on account of the period of 3h 50m 55s.10, which is one of the shortest known. In the year 1913, it changed suddenly, becoming longer than before by 0s.17.”

From her Table I of Comparison Stars, you can see that Miss Ashall’s Variable had DM +37° 4717, and 1900 Bonner Durchmusterung Right Ascension of 22h 49m.1 and Declination +37° 23¢.

As you can see Leavitt gave Ashall proper credit for the discovery, unlike Leung, Zhai and Zhang.

But who was Miss Ashall?

“But that’s another story”, as they were wont to say on Tales From the Riverbank, also known as Hammy Hamster.

** (See the forthcoming CSTHA Blog Post “Who was Miss Ashall?”, scheduled for posting Friday, September 4, 2020) **

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