July 17: Mary Leakey discovers Paranthropus boisei, seatbelt inventor Nils Bohlin born, nebulae astrophotographer Isaac Roberts dies

Paranthropus boisei discovered

On 17 July 1959, Mary Leakey discovered an ancient hominid skull in Olduvai Gorge in present-day Tanzania, where Leakey and her husband Dr Louis Leakey had dedicated nearly three decades of their lives to careful exploration.

The young male skull is an almost complete cranium and had a brain size estimated to have been about 530cm³. Louis Leakey briefly considered this to have been a human ancestor, but the claim was dropped when Homo habilis was found soon afterwards. It was originally placed into its own genus as Zinjanthropus boisei, but is now relegated to Paranthropus along with other robust australopithecines. The P. boisei skull has been accurately dated to 1.8 million years BC.

Nils Bohlin

Swedish engineer Nils Bohlin was born 17 July 1920. Bohlin invented the familiar three-point lap and shoulder seatbelt which is considered one of the most important innovations in automobile safety. Bohlin left the aircraft industry, where he worked on jet ejector seats and restraints, and joined AB Volvo in 1958 as safety engineer, where he invented and patented this seat belt. In August 1959 Volvo was the first vehicle manufacturer to introduce the three-point seat belt in its cars, and made the design freely available to other car manufacturers to save more lives.

 

Isaac Roberts

We remember Welsh astronomer Isaac Roberts, who died 17 July 1904 at age 75. Roberts was a pioneer in the photography of nebulae. In 1885 he had built an observatory with a 20-inch (50.8cm) reflector. Using this instrument, Roberts made considerable progress in the newly developing science of astrophotography. He photographed numerous celestial objects, including the Orion Nebula on 15 January, 1886 (90-minute exposure) and Pleiades. Undoubtedly his finest work was a photograph showing the spiral structure of the Great Nebula in Andromeda, M31, on 29 December, 1888. In addition to his contribution to astro-photography, Roberts also devised a machine used to engrave stellar positions on copper plates, known as the Stellar Pantograver. He was also a geologist of some considerable note.