As I've been browsing through old issues to resurrect sage words from The Old Timer of Royal Oak, I come across other gems that I think are worthy of sharing, and of course, still useful today.
One of these that caught my attention was a filtration system used in a self-propelled howitzer. In the last ten years or so, many companies have come out with breathers that not only filter air drawn into a hydraulic reservoir, but also contain a desiccant to remove moisture from the air. But the article I found, originally published almost 25 years ago, describes a reservoir filter-breahter with desiccant bed to ensure that air drawn into the howitzer's reservoir is not only clean, but dry.
This article also illustrates how much of the technology developed for military and aerospace applications eventually works its way into mainstream applications throughout industry.
I also provided a link to a video showing the M109 howitzer in action and links to related articles on ambient air filtration of reservoirs. You can get it all by clicking here.