It was super clever. The rear brake was on a spring loaded mount. When it clamped down the caliper would travel a small distance to the rear before hitting a stop. It is pulled by the wheel it is grabbing. Attached to that traveling caliper is a cable to the front brake so the motion of the rear caliper would activate the front one. Neat trick effect of all this is it is near impossible to flip over the handle bars. As soon as the rear wheel leaves the ground the spring return on the rear brake pulls the rear brake forward releasing the front braking pressure. The effect is you can potential get max front braking power automatically using a simple purely mechanical system.
https://books.google.ca/books/about/Bicycling_Science.html?i...
To illustrate this point further: the common setup is to have the rear break on the right hand side of the handlebar. But some people ride it the other way around. If you are used to one way and then have to ride the bike that is set the other way (say, a borrowed bike), it completely messes up your riding.
>I was always told you want to brake both the front and back at the same time
This isn't true at all. And even when one does use both brakes, pressure on each is not the same.