It was rather commonplace (at least here in the Boston area) before around 1900 to cut a notch into a crossarm and put another crossarm into it for 90-degree connections. I assume this this method did not pass the test of time too well owing to decaying wood, storms, wire straining, etc. No doubt this led to the new era of iron brackets and other hardware that secured crossarms a lot better to poles or other arms where a line wire turn was needed.

Click "Next" for a closeup view of the top of this pole.