English: A plan of the East Side fire control building, completed in 1904. The second floor plan is on the left, the ground floor on the right. In the style of the 1900-1920 period, a thick octagonal concrete pillar ran from well underground up to the second floor and had a depression position finder mounted on top of it, in this case at an observing height of 113.94 ft. The site itself was 90.9 ft. above mean low water.

In many other fire control towers of this period (such as one existing at Ft. Strong on Long Island in Boston harbor), all that remains of the structure in 2010 is the huge concrete pillar; the wood or plaster-walled building itself has long since fallen apart.

The plan also shows two less substantial pillars in the observing room, likely for azimuth telescopes used in spotting the fall of fire.