For many of us, the moment we learned that a 2×4 board is actually 1.5 inches x 3.5 inches was simply mind-blowing. The reason for this apparent contradiction is that the board has been planed down to eliminate irregularities. At one point, many years ago, 2x4s actually were 2 inches x 4 inches, but their rough surfaces made them difficult to stock and handle. The old terms, such as 2×4 or 4×4, are still used, and are known as the “nominal” size of the board. These nominal sizes are used because they are easier to say and they stick to tradition. Now, thanks to a lawsuit, most big box stores list the nominal and actual sizes of lumber.
Woodworking was essential to the Romans. It provided, sometimes the only, material for buildings, transportation, tools, and household items. Wood also provided pipes, dye, waterproofing materials, and energy for heat.:1Although most examples of Roman woodworking have been lost,:2 the literary record preserved much of the contemporary knowledge. Vitruvius dedicates an entire chapter of his De architectura to timber, preserving many details. Pliny, while not a botanist, dedicated six books of his Natural History to trees and woody plants, providing a wealth of information on trees and their uses.
With a pencil and a protractor, divide the larger disc into 30-degree wedges to create 12 center lines for the bottle indents. Center and trace the smaller disc on top of the larger disc. Next, with a drill press, drill 3/8-in.-deep holes on the 12 center lines with the 1-7/8-in. Forstner bit, spacing them between the disc’s outer edge and the traced circle. Next, divide the smaller disc into 60-degree wedges and drill six more 3/8-in.-deep holes with the Forstner bit.