Every ledge of stone is different. It has its on character, faults, hard spots and grain structure. Every piece of stone will break differently based on these characteristics. Before drilling, stonecutters took the time to study the stone they planned on cutting and removing. Was it solid or full of seams? Was it stratified horizontally or vertically? Early cutters learned to work with the rock, not against it.
Marking the marble before beginning the drilling process
Stone usually will break at the first horizontal seam below the point of the bit or plug. By placing the line of holes based on the character of the stone, the cutter can determine that the stone will break away at the proper angle, dimension and in the right place using the least amount of work.
After the stone has been studied and a determination made as to where to place the holes, the drilling begins. Using a star bit and hammer, the hole is drilled. With each blow of the hammer, the concussion of the bit against the stone caused it to chip.
There are two methods for hand drilling – single jacking and double jacking. In single jacking a single cutter works both the bit and hand hammer. In double jacking, one cutter holds the bit and one or two drillers hit the bit with large sledge hammers. Double jacking is more efficient and will break out larger ledges of stone but is more dangerous for the cutter holding the bit.
Drilling by hand in 1900. This shows Double Jacking with center man holding bit and two other men swinging hammers. Note the background channel cut. A row of holes was drilled close together and then broken out or broached. 40 to 50 feet of drill holes was a day’s work.
In rural areas where quarrying operations were small, the quarry owner would often used family members to hold the bits. Charles Bauer, Appleton City, Missouri, recalls his father telling him that at the early age of five, it was his job to sit cross-legged holding the large star bit firmly in both hands while his father swung the sledge. After each blow, the bit would be turned one-eighth turn and then it again.
This process would occur until the hole was deep enough to accommodate large plug and feathers or until the series of holes themselves caused the stone to break away.
A side process of drilling was the production of “drilling dust”, the small stone chips in the bottom of the hole caused by the bit cutting into the stone. It could build up in sufficient quantity to interfere with the efficiency of drilling or even cause the bit to “lock up” and become unable to be rotated.
Drillers would add small amounts of water to the holes. In some stone this would create a mud that would stick to the bit which could be lifted then from the hole. In other types of stone, a “miners spoon” was used to dip out the mud. The “miners spoon” was forged from an iron rod. One end became the handle, the other end was flattened and curved slightly. These spoons were also used to remove black powder from blast holes that failed to fire.
Sharpening Drill Bits
Blacksmiths made most of the early tools. Frequent sharpening was needed and this too was done by the local blacksmith.
First the drill bit or star drill was forged back to the proper shape and given new edges. The hammering would give the sharp edge. Some smiths would then finish the edge using a grindstone or file.
When the degree of sharpness was obtained, the point of the bit was heated to a glowing red and then plunged into a bucket of cold water. This would harden the point. The smith would then run the bit with sand to clean it.
The color would then be checked. It should be a dark blue to make a tough point. If the proper color wasn’t there, then the smith would reheat the bit and repeat the process until the proper blue color for tempering was present. The bit would then be dipped into cold water for tempering and left until cool.
Source: Interviews with Charles Bauer, Frank Simpson, Melissa Phillips, Bates County, MO. Photographs – Through the Ages, Vol. 2.