humbled valiant wrote:
I have designed, built and tested a telephone/intercom circuit for 4
buildings, and got everything to work.

http://www.stonetabernacle.com/compound_circuit.html

Next I have to connect 4 cables (6 pairs of wire per cable) in the shop
(central location) and hook in the other buildings (house, barn and machine
shop)

I just don't understand how the clips on a 66 block are connected to each
other. Are the rows connected?
Are the rows split? Are the columns connected? Are the columns split?

A standard 66 M block has 50 rows of 4 columns making for a total of 200 connectors. They do have
ones with 6 terminals across, all connected, but that's less common outside of ancient phone
systems. I've not seen one in years that was still in use.

Electrically, there are only two columns. The left and right side of the block are split. If you
wiggle the outermost connector on any row you'll see it's the same piece of metal as the one
directly next to it.

There are two ways to use a 66 block.

1) use it as a way to connect upto 50 pairs (100 conductors) together. The very left and very right
terminals are for either the inside or ouside of the wiring and the inner connector are for the
opposite side of the wiring. There are no connections across the block.

2) use it as way to connect 25 pairs for 50 conductors, across the entire block. To connect the gap
"bridge clips" are used. You'd usually only use the outer terminals in this configuration. This is
the more serious way to wire things up.

In your case, if you want to connect 4 or more lines together you'd weave a common conductor in and
out of, or across multiple points on the block, the connect into that. That's why 66 termination
tools have a cutting side and a non-cutting blade. Never double connect any one connector either.