More below the image ...
There is no photographers stamp on the photograph
The writing on the photograph reads Start of the 1 1/8 mile now from opposite grandstand. Starting wires and boxes are removed after start. I have included this image as it shows two Julius Tote indicator boards the left one a Straight Pool Barometer Indicator and the right a Lamp Box Results and Dividends indicator. Additionally I find the wire starting system shown in the photograph rather interesting.
The barometer indicator on the left is a public display remote output device for the electromechanical mainframe of the Julius Tote. It is continually updated by the mainframe in the machine room. This display would have been driven by the Straight Pool Mainframe. The Show Pool Mainframe is shown in the first of the images in the Hialeah section of the Photo Gallery and the Straight Pool Mainframe looks the same. To view the image of the Show Pool Mainframe, click on the image then scroll up and select the first image thumbnail. In the high resolution copy of this image it is possible to see the sunlight reflecting off the bulbs in the lamp panels of the right hand indicator when zoomed in on it. The information displayed on this indicator was probably manually entered via some form of control console.
Jack Bell wrote the following, which is an extract from his Miami Herald article, in which he mentions the infield odds indicator which probably is the left hand indicator in this image:
You're going to think you're in a weather bureau plant for a few days. The odds on each horse are shown by a device which operates just like huge thermometers. In the win pool, which will be opposite the grandstand, in the infield, each horse will be represented by a "thermometer". Various odds will be listed on the board and as the money is wagered and recorded on the machines, the mercury columns on the board will rise and fall just as they do on a thermometer - only much faster.Jack also wrote the following in the same article which again mentions the infield odds indicator board:
Each "horse unit" (let's say we are talking of the win bets now) sends its bets into a larger computation machine as they come in. This machine continuously adds the money, sends the totals along to still another unit, which deducts 10 per cent for "the grand and glorious state of Florida (and may our taxes decrease!)," and the remaining 90 percent goes on to the machines which show the odds on the big board on the infield. These constantly changing odds, as indicated by the barometric readings on the board, are computed by use of a system of angles too complicated for me-and you, too. But it works.Jack refers to the Win Pool in his comment let's say we are talking of the win bets now, which I deduce is the Straight Pool, hence the word STRAIGHT appears twice below the circular Grand Total indicator on top of the left hand indicator board in the image. My deduction is based on the fact that Jack, in his article mentions three pools Win, Place and Show and my documentation refers to Straight Place and Show pools. Additionally the image prior to this one in the Photo Gallery of this website, shows a large indicator board at Hialeah containing odds for what are identified as Straight Place and Show pools.
To read the whole Miami Herald article by Jack Bell, which has been reprinted with the permission of The Miami Herald, about the Hialeah Julius Tote installation, click on the image above then scroll to the bottom of the loaded page and select Go to the index navigation bar option. Next select the Automatic Totalisators in America Chapter in the Secondly section of the index. The article appears under the heading Hialeah Park's Australian totalizator.
The only thing missing from the image above regarding this being Hialeah, are the famous flamingos that inhabit the lake in the infield, the water of which can be seen in this image. Wherever images of Hialeah Racecourse are found, images of pink flamingos seem to appear.
The cable start system seen in this image looks quite complicated, with the pole on the near side of the runners and its guy wires and suspended cables running across the runners. Judging by the horses not being lined up and there being several hoofs off the ground, the photo was taken an instant after the race started. I have seen photos of this starting system before, showing the result of what happens when things go wrong, where some horses had fallen to the ground and ended up in a tangled mess. I have another close up photograph of the Results Board on the right. From this other photograph it is clear that this is a lamp box indicator and shows the placings 1 to 4, the Straight, Place and Show dividends and the race time in minutes, seconds and fifths of a second. The indicator accommodates a dead heat for the Straight Pool as there are two rows of lamp panels underneath the word Straight on the indicator, to display the two dividends for the runners in the dead heat. Underneath the second dividend lamp panels is the word DEAD_HEAT, which presumably lights up when there is a dead heat.