Below are two cropped views of "Johannes Hevelius's 8 inch telescope with an open work wood and wire "tube" that had a focal length of 150 feet to limit chromatic aberration." from Harvard University, Houghton Library, pga_typ_620_73_451_fig_aa (found here) the first of which I've zoomed and enhanced the contrast.
I've used these images in two other questions in Astronomy SE:
- How did Johannes Hevelius' long telescope work? Why all the round holes?
- How does making a refracting telescope very long reduce the chromatic aberration of an uncorrected lens?
However, the structure itself may be familliar to engineers. I'm getting the feeling that the series of square blocks with round holes and string or lines connecting them (presumably under tension?) have no specific optical function, and are purley part of a system to keep the long "telescope tube" stiff.
Is this combination of blocks and lines a recognizable implementation of some named structure or technique?