Paragraph 27. In stating the dimensions of lumber, the thickness is always given first, then width, and last, length. Instead of writing out the word inches, the sign - two dots (written ") - is generally used, and for feet, one dot (written ')• Instead of writing the word "by," as in the expression 2" by 4", the sign x is used, and it should be written 2"x4". Thus, in describing a piece of material which is l/2-inch thick, 3 inches wide and 23 inches long, it will be written 1/2"x3"x23". The expression would be read, 1/2-inch, by 3 inches, by 23 inches. This rule of giving first thickness, then width and then length is universal in all lines of woodwork; always name dimensions in this order.