Of course, these oil changes & valve adjustments are relative to the life expectancy of the engine. I think (hope) Jims 600 hr est is conservative, my oil ch schedule exceeds OEM specs, I am ballparking the depreciation factor to 900 hrs @ 150 hrs per year = 6 years.
The 4th-century Tomb of the Lionesses consists of a small chamber with gabled roof. The painting depicts flying birds and dolphins and scenes from the life of the Etruscan aristocracy. The 6th-century Tomb of the Hunting Pavilion shows the view seen through the transparent fabric of the pavilion.
This is more of an archeology question, but hopefully someone here can help explain. I've always been kind of puzzled thinking about how ancient cities or ruins get buried. More specifically, I have a few questions. How deep down are most ancient remains when they are found (depends on age and location, of course)? What is the natural rate of sediment deposit and where does it come from? How do cities that are continuously inhabited (like Rome) get buried? In the past people have told me that when buildings fell down, it was common practice for people would fill them in with dirt and build over them.