August 30th in stamps Mary Shelley, Christopher Polhem, Jacobus Henricus van 't Hoff

Here are some events that happened on August 30th. It could be an event or a person that died or was born on that day

1751 Died: Christopher Polhem, Swedish physicist and engineer (b. 1661)

Christopher Polhammar (18 December 1661 – 30 August 1751) better known as Christopher Polhem, which he took after his ennoblement in 1716, was a Swedish scientist, inventor and industrialist. He made significant contributions to the economic and industrial development of Sweden, particularly mining. He was ennobled by King Charles XII of Sweden for his contributions to Swedish technological development.

Notable accomplishments

• Founded Stjärnsunds manufakturverk in södra Dalarna during 1700.
• Reinvented the Cardan joint under the name of "Polhem knot" (Swedish: Polhemknut) independently of Gerolamo Cardano, the pioneer inventor.
• Organized machinery into a "mechanical alphabet" and provided examples of such. Of 80 models carved in wood, 32 are still in the collections of the National Museum of Science and Technology (Swedish:Tekniska Museet) in Stockholm. Another 13 models of the "mechanical alphabet" are to be found in the Falun Mining Museum, Sweden.

Swedish stamps depicting Christopher Polhem

1797 Born: Mary Shelley, English novelist and playwright (d. 1851)

Mary Wollstonecraft Shelley (30 August 1797 – 1 February 1851) was an English novelist who wrote the Gothic novel Frankenstein; or, The Modern Prometheus (1818). She also edited and promoted the works of her husband, the Romantic poet and philosopher Percy Bysshe Shelley. Her father was the political philosopher William Godwin and her mother was the philosopher and feminist Mary Wollstonecraft.

Shelley's mother died less than a month after giving birth to her. She was raised by her father who provided her with a rich if informal education, encouraging her to adhere to his own anarchist political theories. When she was four, her father married a neighbour with whom Shelley came to have a troubled relationship. 

In 1814, Shelley began a romance with one of her father's political followers, Percy Bysshe Shelley, who was already married. Together with her stepsister, Claire Clairmont, she and Percy left for France and travelled through Europe. Upon their return to England, Shelley was pregnant with Percy's child. Over the next two years, she and Percy faced ostracism, constant debt and the death of their prematurely born daughter. They married in late 1816, after the suicide of Percy Shelley's first wife, Harriet.

In 1816, the couple famously spent a summer with Lord Byron, John William Polidori and Claire Clairmont near Geneva, Switzerland, where Shelley conceived the idea for her novel Frankenstein. The Shelleys left Britain in 1818 for Italy, where their second and third children died before Shelley gave birth to her last and only surviving child, Percy Florence Shelley. In 1822, her husband drowned when his sailing boat sank during a storm near Viareggio. A year later, Shelley returned to England and from then on devoted herself to the upbringing of her son and a career as a professional author. The last decade of her life was dogged by illness, most likely caused by the brain tumour which killed her at age 53.

Until the 1970s, Shelley was known mainly for her efforts to publish her husband's works and for her novel Frankenstein, which remains widely read and has inspired many theatrical and film adaptations. Recent scholarship has yielded a more comprehensive view of Shelley's achievements. Scholars have shown increasing interest in her literary output, particularly in her novels, which include the historical novels Valperga (1823) and Perkin Warbeck (1830), the apocalyptic novel The Last Man (1826) and her final two novels, Lodore (1835) and Falkner (1837). Studies of her lesser-known works, such as the travel book Rambles in Germany and Italy (1844) and the biographical articles for Dionysius Lardner's Cabinet Cyclopaedia (1829–1846), support the growing view that Shelley remained a political radical throughout her life. Shelley's works often argue that cooperation and sympathy, particularly as practised by women in the family, were the ways to reform civil society. This view was a direct challenge to the individualistic Romantic ethos promoted by Percy Shelley and the Enlightenment political theories articulated by her father, William Godwin.

Stamps and cover from Jersey and Great Britain depicting Shelley's Frankenstein

1852 Born: Jacobus Henricus van 't Hoff, Dutch chemist and academic, Nobel Prize laureate (d. 1911)

Jacobus Henricus "Henry" van 't Hoff Jr. (30 August 1852 – 1 March 1911) was a Dutch physical chemist. A highly influential theoretical chemist of his time, Van 't Hoff was the first winner of the Nobel Prize in Chemistry. His pioneering work helped found the modern theory of chemical affinity, chemical equilibrium, chemical kinetics, and chemical thermodynamics. In his 1874 pamphlet Van 't Hoff formulated the theory of the tetrahedral carbon atom and laid the foundations of stereochemistry. In 1875, he predicted the correct structures of allenes and cumulenes as well as their axial chirality. He is also widely considered one of the founders of physical chemistry as the discipline is known today.

Van 't Hoff earned his earliest reputation in the field of organic chemistry. In 1874, he accounted for the phenomenon of optical activity by assuming that the chemical bonds between carbon atoms and their neighbors were directed towards the corners of a regular tetrahedron. This three-dimensional structure accounted for the isomers found in nature. He shares credit for this with the French chemist Joseph Le Bel, who independently came up with the same idea.

Three months before his doctoral degree was awarded, Van 't Hoff published this theory, which today is regarded as the foundation of stereochemistry, first in a Dutch pamphlet in the fall of 1874, and then in the following May in a small French book entitled La chimie dans l'espace. A German translation appeared in 1877, at a time when the only job Van 't Hoff could find was at the Veterinary School in Utrecht. In these early years his theory was largely ignored by the scientific community, and was sharply criticized by one prominent chemist.

In 1884, Van 't Hoff published his research on chemical kinetics, titled Études de Dynamique chimique ("Studies in Chemical Dynamics"), in which he described a new method for determining the order of a reaction using graphics and applied the laws of thermodynamics to chemical equilibria. He also introduced the modern concept of chemical affinity. In 1886, he showed a similarity between the behaviour of dilute solutions and gases. In 1887, he and German chemist Wilhelm Ostwald founded an influential scientific magazine named Zeitschrift für physikalische Chemie ("Journal of Physical Chemistry"). He worked on Svante Arrhenius's theory of the dissociation of electrolytes and in 1889 provided physical justification for the Arrhenius equation. In 1896, he became a professor at the Prussian Academy of Sciences in Berlin. His studies of the salt deposits at Stassfurt were an important contribution to Prussia's chemical industry.

Van 't Hoff became a lecturer in chemistry and physics at the Veterinary College in Utrecht. He then worked as a professor of chemistry, mineralogy, and geology at the University of Amsterdam for almost 18 years before eventually becoming the chairman of the chemistry department. In 1896, Van 't Hoff moved to Germany, where he finished his career at the University of Berlin in 1911. In 1901, he received the first Nobel Prize in Chemistry for his work with solutions. His work showed that very dilute solutions follow mathematical laws that closely resemble the laws describing the behavior of gases.

Stamps from Grenada and the Netherlands depicting Jacobus Henricus van 't Hoff