In the meantime, a kind and helpful reader named Ron has provided a great explanation for the purpose of the "stars" that have been observed on the brick walls of several sugar factories, including the factory in Longmont:
The “decoration” on the outside of a brick building signifies the need for additional support for the floors inside where a machine or other load makes vertical support beams impractical. They come as stars, squares, circles and other shapes which may be plain or highly embellished. They are used in place of a nut and washer which could pull through the relatively soft material in a masonry wall.
Ron notes that the sketch is just one possible configuration of the rods, cables, and turnbuckles, and that there could be others.
In this sketch in cross section A is the decorative plate which is attached to a rod, H. This is in turn is attached to a turnbuckle, J, after crossing the spacer, I, in this simple example and then a mirror image to the opposite wall. The beam, G, which holds up the floor joists, F, and the floor itself, E, rests on the inner portion of the support column, D, which is built in one piece with the outer portion, B. and shows as the raised portion of the outer wall where the stars are. The walls, C, are built with openings as needed for windows and doors. Without this sort of device, too heavy a load could cause the floor to fail or in extreme cases cause a wall to blow out. By tightening the turnbuckle an equal amount of upward pressure can be achieved allowing a much heavier load than would otherwise be possible without vertical support beams.
Thanks for the great information, Ron!
Many of the Colorado sugar factories were built by the Kilby Manufacturing Company from Cleveland, OH and using this device must have been part of their standard practice. The second floor of the factories usually held a number of evaporators, weighing twenty tons each, so you can understand why the additional support was necesary.