Measuring shadows

Several weeks ago I ran across a new website called Suncalc. Using this site I was able to configure it for downtown Tulsa, 1 June 1921, and start looking at the shadows in the photos. Part of the problem we’ve had with measuring the shadows previously has been that 24.5 degree shift from north to northwest that downtown has. The reasons for this rotation has to do with the establishment of the city along the railroad where it curves around to line up with the river crossing. Add to that, the latitude, the season, and the other factors that have moved these measurements beyond my mathematical skills. This web site makes this process much easier.

Take a look at the photo in the banner. The building shadows on the streets seem to run down the street from east to west, with a slight shift to the north of about 5%. That makes this picture being taken about 7.45 am. According to the Timeline of the riot, about 7.30 “Everything on Archer from Boston east to Elgin is on fire. The fire department says “the mob” shoots at them when they try to put out the fire (Tulsa Tribune, 1 June 1921).” The Bessemer Gas Engine company is at 201 E. 1st (or the NE corner of 1st and Cincinnati). Considering that Boston had started burning early in the morning the lack of burning here does seem within limits of verifying the news report. Also we can see in this photo some serious fire along the east side of Detroit, and some serious smoke billowing up from the area of Elgin.