Termites, tree, box ways

I took a look at the pictures of the Tree mill, that is one mongo piece of
iron, any clues as to the weight? Is there any major advantage of box ways
over dovetails? I saw on the Beaver mill I am looking at they use one
slightly raised ridge as one the ways on the x axis and then the other is
much higher. Is this idea to limit the amount of delicate cutting needed
with dovetail mills? I was thinking perhaps the more substantial raised way
is used to carry the load and the other is just a guide. Are the designs
actually based on any physical properties of how they'll behave or is it
more just how they can be bothered making them?

John H.

> Tree made a few milling machines, somwhat similar to the Bridgeport
> design. Apparently, from the above info, they also made one a bit bigger
> than a Bridgeport Series II. Some people feel that a Tree is far superior
> to a Bridgeport. I think they may have box ways, not dovetail. I have
> only seen one or two, and not the bigger ones.
> Jon