INTRODUCTION:The chalk line is a simple tool that allows a workman to draw a long straight line on a surface to act as a guide for some work to be done. Most commonly used by carpenters or masons, the line might serve as a reference to follow in order to saw a straight line in a board, or to form a true edge on a beam shaped with as adze, or for the mason, to align building blocks in a straight line along a footing. The parts of a chalk box are a long string, a reel on which the string is wound, and a reservoir containing some sort of marking medium or pigment. The principle of all such devices is that the string is drawn through the reservoir and picks up on the surface fibers of the line, the “marking medium.” The most common substances used were powders ground from soft rocks to make chalk (in avariety of natural colors) or black powder pulverized from wood charcoal. Liquids such as ink were also used to wet the line in color in order to “draw”or lay down a visible line. If a ring or a loop in the string is provided at the loose end of the string, in many applications, one man can draw the line himself. A nail would be used to hold one end of the string while the workman would control the reservoir and reel. Quitesimply, the workman un-reels the line. The line passes through the reservoir,and the line becomes coated in the medium. The line is very gently carefully positioned over the board or foundation so as not to dislodge the powder orink. Once the ends of the string are accurately positioned, the line is pulled taught. The string is then plucked, as harpists might play their instruments. “Snapping the line” in this particular way, shakes the medium loose, thus transferringthe powder or ink from the string on to the working surface. Thus, a very useful straight line drawn. Evidence of the development of this system of marking is found in Europe, Japan, China,the Phillipines, then later carried to the Americas. It is impossible to tell if there was just one original invention of this system. One might ask at this point how or why the chalk box is related to the plumb bob, after all, that is the subject of this newsletter. Simply said, some place lateon in the course of the subtile development of the chalk box, it is discovered that if the reservoir and reel of the chalk box are made in a symmetrical and sometimes pointed shape, that the chalk box reservoir can behave as a weight very much like the bob of a plumb bob, and the chalk line can act like the plumb line attached to a plumb bob. Thus, a combination tool of some marketable significance was born. There are notable examples of this combination tool indifferent forms, advancements worthy of letters of patent in the late 19thand early 20th Centuries. Even today, combination chalk box, plumbbobs are a common tool form to purchase in a hardware store.
CHALK LINES, SNAP LINES etc.
CARPENTERS 1531 USING A CHALK LINE GERMANY
CHALK LINE FROM CHINA. See the interesting handle
CHALK LINE FROM CHINA. More pictures and text you can find in the article.