Hi Joe,
You're so right my friend. That's part of the beauty of this forum; it's like an add on to their bio's.
I see your picture of Honest Abe is doing well this week. Ever since I was a kid I found the Mt. Rushmore Presidents fascinating. The work was unbelievable and I was fortunate enough to see it as a kid.
Thought it would be interesting for those that are not familiar with this work of art to know it's history so here's a short article on the subject.
Shalom,
Peter
While working at Stone Mountain in Georgia, Gutzon Borglum had developed what he called the "Pointing Machine." His models in his studio at the bottom of the mountain were carved so that one inch on the model represented one foot on the mountain. Therefore a 60 inch high face on the model would be 60 feet on the mountain.
On the top of the models was what looked like a large protractor and a beam which could be moved around the protractor to different angles where a measurement could be made for the distance out and down to a point on the model.
On each head on the mountain there was a similar protractor and a long beam. They would then duplicate the same angle, distance out, and distance down, and sometimes the distance back to a point on the surface of the granite. Each measurement would be 12 times the size of the measurement on the model. This could be done with accuracies to within a quarter of an inch of tolerance.
In the early stages of construction the workers had to climb a 760 step stairway to get to the top. The workers were then suspended by 300 foot long 3/8th inch steel cables in "bosun chairs" which were similar to the harnesses used on horses for pulling wagons. The workers, who were mostly miners from the area, would use jackhammers and drills run by an 1,800 foot line from compressors at the base of the mountain.
Most of the supplies, drill steel, and dynamite were carried to the top of the mountain by a mine bucket on a steel cable tram. The steel drills would drill about 18 inches and then would be sent back down to a blacksmith shop at the bottom of the mountain where they would resharpened. Many days up to 400 drill would be used.
Eventually a small tram was built to take three and later five men to the top but they would always walk down the steps in the evening.
The stone at the surface which has been expose to the weather and freezing and cracking was too soft to be carved and needed to be remove to get to the hard stone for the final carving. Twenty feet of stone was removed to get to Washington's chin while 80 feet of stone was removed to get to Lincoln's head and 120 feet to Roosevelt's head. Large fissures cutting from the left across the mountain and down to the right determined the final location of the heads. The final location of the heads was determined after most of the excess rock was removed.
About 500,000 tons of rock was removed from the mountain with dynamite. Gutzon Borglum had perfected the use of dynamite while he was working on Stone Mountain in Georgia. He said, "two considerations to be borne constantly in mind - split off just what you want to remove and no more, and second, under no conditions so charge your load as to injure the stone left in place."
At the start Holes were drilled about six feet apart for the placing of dynamite charges and later 15 to 18 inches apart. The dynamite would be placed in the holes and damp sand was then tapped in to surround the stick of dynamite to protect the surface of the stone below. As they progressed they could just use a blasting cap to blow off stone within an inch of the final surface.
When it came time to do the finish work, heavy timbers and scaffolding in eight foot stories were bolted to six inch projection which were left on the granite surface for this purpose. In the winter they were covered with canvas and heaters were built from oil drums for burning wood to keep them warm.
Usually the final six inches would be removed with pneumatic tools by drilling holes downward as close together as possible. The webs between the holes were then knocked out. Then smaller holes were drilled close together and the stone was then removed with hammers an chisels.
The scaffolding was removed for the final stages and the men worked in small cages that were three by four feet for one man or three by eight feet for two men. The cages were hung from the cables and the winch at the top that had once been used for the swing chairs. The cages gave them a better platform for doing the finishing work.
The final finish was then done with a pneumatic "bumper" which would soften or emphasize an area of the surface.