Academy’s Darwin Bust Copied In High-Tech Project for NAS

In honor of the bicentennial of Charles Darwin’s birth, the Academy’s bust of its legendary member is being replicated for display in the Great Hall of the National Academy of Sciences in Washington.

The replica is being produced using a state-of-the-art digital scanning and computer-controlled milling process. The original bronze, one of very few known to exist of Darwin, was commissioned by NYAS in 1909 for the centennial of his birth and the 50th anniversary of the publication of Darwin’s On the Origin of Species.

Working from a photograph, sculptor William Couper produced a remarkable likeness of the scientist in his later years. After admiring the sculpture on a recent visit to the Academy, NAS President Ralph Cicerone became interested in having a duplicate made for his organization.

Not long ago, such a venture would have put the original at risk of damage during transportation to and from a studio and during the casting of a new mold. But today’s technology leaves the original touched only by light. Direct Dimensions, a company enlisted to make a digital model of the bust, used a portable coordinate-measuring machine consisting of a laser scanner attached to an articulated measuring arm to collect the three-dimensional data. Technicians moved a structured laser line along the surface of the sculpture while a camera sensor mounted in the laser scanner captured the data. The cloud of data points was transferred to a soft ware program that translated it into a digital polygonal model.

The whole process took only five hours and the bust never left its home in the NYAS lobby at 7 World Trade Center. To begin the journey back to bronze, the restoration preservation company John Milner Associates next made a foam base using a computer-controlled milling machine driven by the digital information. An artist then applied a very thin clay coating to smooth out the tool marks. This “clay-up” was sent to the foundry, for the creation of a silicon mold. The rest of the process follows an age-old casting technique, from which a new Darwin will be born.