Here is the 60 horse power Spencer Orgoblo which supplied the wind to the organ.
This large machine is a series of turbines driven by a 3 phase 60 hp motor ( from 1927). In the photo to the right, you can see the motor for the blower (with what looks like a small hose connected to it), and just above that you can see the high pressure line coming off the blower and going over to the main high pressure regulator. The static pressure before the high pressure main regulator was about 45 inches of water, which the regulator brought down to 40". The high pressure was then distributed to the chambers which had things on 20" pressure or higher.
In the photo on the left, which is the front of the blower, on the left side you can see the corner of on of the "low" pressure main regulators. There were three regulators in the blower room, one high pressure, and two "low" pressure (one for the great side, and one for the swell side). The wind line coming off the side of the blower is 24 inches in diameter. (I have been inside this wind line) The static pressure was about 26 inches, which was regulated down to 22 inches and then distributed to the organ. Just in front of the blower was an oil-bath air cleaner, which was very useful when the organ was installed for removing soot from the air. (we burned a lot of coal when the organ was installed in 1928) The service hatch is open on the shroud of the filter and you can in the blowers intake through the door.