In regard to geological formation it need only be remarked that the
Berkshire valleys are almost wholly composed of limestone, and the
supply for architectural and agricultural purposes being practically
unlimited, will prove a source of great wealth to that region for many
years to come. The hills, however, are all composed of quartz, gneiss,
talcose slate, or mica slate.

We will now visit the valley of the Connecticut, where is to be found
some of the boldest, and by all odds the most beautiful scenery in
Massachusetts. The broad and fertile plains through which the river
gently flows are, in themselves, charming, but when we add to them the
bordering hills, the scene is one of surpassing loveliness.

Between Hadley and Easthampton, the river runs through a gorge in a
greenstone ridge nearly one thousand feet high. The portion of the ridge
east of the river is called Mount Holyoke, and the portion west of it
Mount Tom. This gorge is very interesting because of showing the amount
of erosion that can be performed by water in long periods of time. In
all probability the bed of the Connecticut was, in remote time, much
higher than it is at present, and the river itself much larger, and the
rich, alluvial plains that border it at the present day were once
beneath its broad waters.

At one point in the gorge a mass of greenstone projects some rods into
the river from the west side of Holyoke, having a perpendicular face
twenty to one hundred feet high. This mass exhibits a columnar structure
similar to that of the Giant's Causeway. The structure is not very
evident above the level of the river, but at low water, by rowing along
the face of this rock one can find the tops of regular columns reaching