Scientist of the Day

Paolo Toscanelli

May 10, 2018

Paolo dal Pozzo Toscanelli, an Italian mathematician, humanist, and astronomer, died May 10, 1482, at the age of about 85. Toscanelli is a very wispy historical figure; he is like that magnet under the floor that affects the actions of everything in the room, but which no one can quite lay their hands on. The contemporary astronomer Regiomontanus likened Toscanelli to a second Archimedes, about as high a compliment as one mathematician in the 15th century could pay to another. Nicholas of Cusa, or Cusanus, the great German philosopher who served as a papal legate to Germany but spent many years in Italy, considered Toscanelli his best friend and most able mathematical accomplice, and when Cusanus and Regiomontanus almost came to blows over their conflicting ideas about the problem of squaring the circle, it was Toscanelli who acted as intermediary. Cusanus dedicated his book on quadrature to Toscanelli, and when Cusanus lay dying in the remote Perugian town of Todi in 1464, Toscanelli travelled the 120 miles from Florence to be at his bedside. Marsilio Ficino, the foremost Renaissance Platonist, also dedicated a book to Toscanelli, and the architects Filippo Brunelleschi and Leon Battista Alberti both considered Toscanelli a close friend and an extremely capable mathematician. That is pretty much the cream of Florentine humanist culture, all touting the virtues of the man they called Master Paul…

Lansdown Guilding

May 9, 2018

Lansdown Guilding, an English clergyman naturalist, was born May 9, 1797. Guilding was born in St. Vincent in the Caribbean, was educated at Oxford, and then returned to St. Vincent, where he took up a church rectorship and became a devoted supporter of the St. Vincent Botanic Garden. The garden, founded in 1765, was the oldest of what would become, by the early 19th century, an extensive network of British colonial botanic gardens, with Kew Gardens at its hub. The director at St. Vincent resigned in 1822 and was not replaced, and Guilding eased into the vacuum and apparently gained access to the papers of previous administrators. As a result, he wrote a book, which he published at his own expense: An Account of the Botanic Garden in the Island of St. Vincent, from its first establishment to the present time (1825). The work contains four hand-colored plates that give us an idea of how the garden looked in the early 19th century (third and fourth images), and the text includes lists of the plants grown at St. Vincent in the previous 50 years…

Henry Baker

May 8, 2018

Henry Baker, an English microscopist, was born May 8, 1698. In 1740, a French naturalist, Abraham Trembley , had discovered that hydra (tiny organisms found in pond water, also called polyps), have astonishing regenerative powers. Cut them in half, crosswise or lengthwise, and the remaining half grows back, good as new. Most naturalists would have found this unbelievable at the time, so Trembley cleverly sent samples of his little beasties to many of the scientific societies of Europe, so that others could try the experiments for themselves. Baker latched onto the specimens that were sent to the Royal Society in London; he received the first one in the spring of 1743, and by November, he had a 220-page book ready for the press, An Attempt towards a Natural History of the Polype, and it beat Trembley’s own book into print by a full year. Baker gave Trembley credit for the discovery in his own book, but he still made a tidy penny from the sale of his work. We see above the frontispiece, showing a magnified polyp (first image), the title page, and a two-page spread, in which he illustrates the stages of regeneration after a polyp is cut in half…

David Hume

May 7, 2018

David Hume, a Scottish philosopher, was born May 7, 1711. Hume’s A Treatise of Human Nature (1739-40) and An Enquiry Concerning Human Understanding (1748) are not explicitly about natural philosophy, but he had a great deal to say about our attempts to understand and explain the workings of the world. He greatly admired the work of Isaac Newton and Robert Boyle, especially the way they uncovered new phenomena and new laws of nature. But Hume had no use for their postulated entities, such as atoms or forces. Science, for Hume, should concern itself with gathering empirical information and establishing relationships between things. Discussing causes or invoking hypothetical entities was not only unwarranted, but impossible to justify. We can never know causes in nature with any degree of certainly; all we can do is notice that when A occurs, B usually follows. To say that A causes B is to state a conclusion we can never demonstrate…

Rubens Peale

May 4, 2018

Rubens Peale, an American painter and museum administrator, was born May 4, 1784. Rubens was the son of Charles Willson Peale, the noted portrait painter, naturalist, and founder of Philadelphia’s Peale Museum. His two older brothers, Raphaelle and Rembrandt, were accomplished artists, as was the much younger fourth brother, Titian, who was an explorer as well. Rubens was the odd duck in this famous filial foursome, and you can see why if you look at a portrait of Rubens by Rembrandt, painted in 1801. Take your eyes off the geranium for a moment and look at what is perched upon Rubens’ nose. Glasses were so cumbersome and awkward in the late 18th century that no one wore them unless they really could not see without them. It was Rubens’ poor eyesight that prevented him from following in his father’s and brothers’ footsteps as a portrait painter…

Bertha Benz

May 3, 2018

Bertha Benz, pioneer of the automotive road trip, was born May 3, 1849. Bertha was the wife and partner of Karl Benz, who built the first automobile powered by an internal combusion engine in 1885. This prototype is called the Benz Patent Motorwagen no. 1, and it still survives, in the Deutsches Museum in Munich (third image). Karl quickly built an improved model (1887), of which there survives a wonderful photo (fourth image)–that is Karl, holding the tiller. Notice the bicyclists, one with a penny-farthing, standing by the fence. Karl built a third version, no. 3 (1888), and he felt he now had something to market. But, of course, there was no market–someone would have to create one. That someone was Bertha…