Revisions log for Answer #2638

Almost exactly the right guess. The grid of one eighth of a meter is actually derived from stone measures. Today's brick measurements still build on that, but in earlier decades with solid bricks, a brick was actually (with joint) one brick (25 cm) long and one head (12.5 cm wide). In height, this is eaten a little less hot since the use of jumbo formats, which practically create three old layers in one step.