John Woodward

John Woodward, an English geologist and fossil collector, was born May 1, 1665. Woodward was an early believer in the organic origin of fossils (first proposed by Steno and Hooke around 1668), but he was initially at a loss to explain how fossils became embedded in the earth’s crust, if they were the remains of living animals on the surface. And then he got his Big Idea. What if, during the Great Flood of Noah, God had miraculously suspended gravity (by which Woodward meant not Newtonian gravity, but the force of cohesion that holds things together)? As the earth’s rocks dissolved into thick pudding, all the drowned animals and planets would sink down until their density was equaled by that of the surrounding muck. When gravity returned, the rocks would cohere again, with the animals remains now imprisoned as fossils within. It was actually a clever idea, except for the density part, which would suggest that the top layers of rock should contain all the jellyfish and the bottom layers all the turtles…

William Bradford

William Bradford, an American explorer and painter, was born Apr. 30, 1823. He is known primarily for his paintings of the Far North, and for a book that is a milestone in the history of photography. Bradford travelled to the Arctic on the 1860 voyage led by Isaac Israel Hayes, in search of the supposed North Polar Sea. After his return, Bradford began to paint Arctic landscapes, often involving whalers and sealers, of which we see a sample above. “Caught in the Ice Floes,” painted around 1867, is in the New Bedford Whaling Museum in Massachusetts. “An Incident of Whaling,” of unknown date, is in the Metropolitan Museum of Art, as is “An Arctic Summer,” 1871…

William Cavendish

William Cavendish, the 7th Duke of Devonshire, was born Apr. 27, 1808. The Cavendish family was one of the most distinguished (in a peer kind of way) in British history. Before the 7th Duke, there was only one Cavendish who took an interest in science, and that was Henry, and he wasn’t in the ducal line of succession, being the eldest son of the third son of the second Duke. But Henry, although he would never become Duke, was a brilliant scientist, discovering hydrogen, and performing the famous Cavendish experiment to measure the mass of the earth. The 6th Duke, also a William, was not himself a scientist, but he hired Joseph Paxton to supervise the gardens at Chatsworth House, the Cavendish family estate in Derbyshire…

Charles Richter

Charles Richter, an American seismologist, was born Apr. 26, 1900. It was in 1935 that Richter, working with Beno Gutenberg at the Seismo Lab at Cal Tech, developed a scale to express the energy of local earthquakes from measurements of seismograph records. The scale was the brainchild of both men, and Richter maintained for the rest of his life that it ought to be called the Richter-Gutenberg or Gutenberg-Richter scale, but Gutenberg wanted nothing to do with the press or the public and was quite happy being anonymous, so the Richter scale it became and remains. The Richter scale is a logarithmic scale, meaning that a magnitude increase of one, from magnitude 3 to magnitude 4, indicates a ten-fold increase in the energy released by the quake. Richter chose the scale carefully, so that the smallest possible quake would still be greater than zero, and the largest would be less than 10. This is not a scale limit–it is theoretically possible to have a magnitude 11 quake, but the earth does not cooperate, seldom producing quakes greater than magnitude 8.5. The Richter scale was introduced in a paper published in the Bulletin of the Seismological Society of America in 1935…

James Ferguson

James Ferguson, a Scottish astronomical mechanic and writer, was born Apr. 25, 1710. Ferguson was a remarkable talent, who worked as a shepherd and had no formal schooling, and yet who taught himself astronomy, mechanics, and the art of limning, or portrait drawing. He came to London in 1743, making mechanical devices and publishing the odd paper in the Philosophical Transactions of the Royal Society, while earning his means by drawing portraits. His breakthrough came with the publication of Astronomy explained upon Sir Isaac Newton’s Principles (1756), which was so popular it required a second edition a year later. Our Library has this second edition, and it is the source for four of the illustrations above. The frontispiece (first image) depicts an orrery that Ferguson designed and built, reportedly after he had seen another orrery, and without even looking at that orrery’s mechanism. He also invented a lunar eclipse machine of which he was very proud…