Rudi Paul Lindner is a professor of History at the University of Michigan. He is writing a book about the astronomy program at Michigan.
As the nights lengthen and the temperatures drop, let us remember what it was like to observe here a few generations ago. When W. J. Hussey and Ralph H. Curtiss set up the “great reflector” next to the refurbished Fitz refractor, they were both highly pleased at the performance of the new equipment. A stellar spectrogram of the same quality as those coming from the 40” refractor at the Yerkes Observatory took only one third the exposure time, which meant that Michigan’s telescope was far more efficient and productive, at ten to fifteen minutes per exposure. Curtiss kept a running record of spectrograms and, whenever Hussey was away, sent along the latest totals.
But the Observatory was only some hundreds of yards east of Ann Arbor High School, then located in what is now the Frieze Building of UM, and the school’s heating system was coal fired. Smoke, soot, and heated air, drifting east with the prevailing winds, occasionally affected the seeing on the hill. But this was only the prelude to the planning of a great heating complex for the central campus, set in motion after 1913. A tug of war began between the University’s engineers, headed by Professor Cooley, and Hussey’s benefactor, Robert Lamont, and his consulting engineers. Cooley wanted to place the stacks in the “cat-hole,” a low-lying valley between North University Street and Palmer Field. Lamont favored a site down by the railroad tracks and the river, with longer pipes carrying steam south towards the University. The battle went on for a year, with Cooley the ultimate victor. You may admire his vision as you drive east on Huron or northwest on Washtenaw.
In those days there were no scrubbers, no internal means of halting the flow of soot and smoke, much less the heated exhaust. And the prevailing winds kept sweeping east, across Palmer Field and the observatory hill.
The effect of the “Cooley Memorial” was immediate. One of the great American observational astrophysicists of the next generation, Paul W. Merrill, was in his second year at UM, and his comments on the disappearance of good seeing were pithy and provocative; in two years Merrill himself had left for the National Bureau of Standards. Ralph Curtiss began planning for a new site on Huddy Hill, farther from the soot but too close to the railroad. And the smoke stacks in the cat-hole led to Michigan astronomers spending more time in their beds on cloudless winter nights.