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Mount Rushmore

Creating Giants in the Black Hills

President Lincoln"More and more we sensed we were creating a truly great thing, and after a while all of us old hands became truly dedicated to it and determined to stick to it."

-Red Anderson, former Mount Rushmore carver


Sketches in Plaster

Borglum knew portraiture. In his youth he studied art in Paris with sculptor Auguste Rodin. He boasted a roster of memorias to famous Americans, including Gen. Philip Sheridan Gen. Robert E. Lee, and Abraham Lincoln. Having read avidly about Lincoln and been personally acquainted with Theodore Roosevelt, Borglum was thoroughly prepared when the Mount Rushmore commission came his way in 1925.

He based the models on life masks, paintings, photographs, descriptions, and his own interpretations. Plaster copies were always displayed on the mountain as a guide for workman. But Borglum did not merely transpose the models directly into granite. The differences between the models in the sculptor's studio and the heads on the mountain show how Borglum fine-tuned the four granite giants into true works of art.

Inches to Feet

How to transfer the models to the mountain? Borglum's answer was his "pointing machine": the models were sized at a simple ratio of 1:12 - one inch on the foot of the model would equal one foot on the mountain. A metal shaft 1 was placed upright at the center of the model's head. Attached at the base of the shaft was a protractor plate 2, marked in degrees, and a horizontal ruled bar 3 that pivoted to measure the angle from the central axis.

A weighted plumb line 4 hung from the bar; it slid back and forth to measure the distance from the central head point, and raised and lowered to measure vertical distance from the top of the head. Thus, each point on the model received three separate measurements. The numbers were then multiplied by 12 (angles remained the same) and transferred to the granite face via a large-scale pointing mechanism anchored at the top of the mountain.

Sketches in Plaster Diagram
Sketches in Plaster Inches to Feet

 

The Faces Emerge

The only shaping technique available to the carvers was the removal of the stone. No material could be added. With such an unforgiving medium, Borglum at first ruled out dynamite. He quickly changed his mind; the rock was so hard that blasting was the only practical way to remove the huge portions of granite for carving. After an egg-shaped volume of rock was prepared for each head, the pointers went to work measuring for facial features.

Skilled blasters dynamited to within a few inches of a desired measurement. The closer the blasters got to the finished face, the more carefully Borglum studied the heads, making changes as necessary. The most drastic change was the relocation of the Jefferson head from Washington's right to his left side because of insufficient rock to complete the figure.

Blasting Tools
The Faces Emerge Finishing Touches

 

Finishing Touches

After blasting, the features were shaped by workers suspended by cables in swing seats called Bosun chairs. First they used pneumatic drills to honeycomb the granite with closely spaced holes to nearly the depth of the final surface. Excess rock was then chiseled off. A blacksmith sharpened hundreds of drill bits each day that dulled quickly on the rock.

Afterwards the men "bumped" away drill holes with pneumatic hammers to create a smooth, white surface. It was attention to detail that gave humanity to the sculptures: Up close, the pupils of the eyes are shallow recessions with projecting shafts of granite. From a distance, this unlikely shape makes the eyes sparkle and bring the Presidents to life.