Jan 112018

On this date in 1787 William Herschel discovered 2 moons of Uranus that were later named Titania and Oberon. I have covered Herschel (http://www.bookofdaystales.com/william-herschel/ ) and Uranus (http://www.bookofdaystales.com/uranus/ ) already in my posts. Now I would like to talk about the complex moon system of Uranus, and, especially, the way in which they got their names. Herschel was terrible at giving names to objects in the solar system and, in fact, did not name the moons of Uranus that he discovered (and, to make matters worse, he claimed to have observed 4 other moons that do not exist). Furthermore, he gave the name “George’s Star” to Uranus when he discovered it, because he wanted to toady up to George III. Astronomers in other countries were not amused.

Uranus has 27 known moons, all of which are named after characters from the works of William Shakespeare and Alexander Pope. Uranus’ moons are divided into three groups: 13 inner moons, 5 major moons, and 9 irregular moons. The inner moons are small dark bodies that share common properties and origins with Uranus’ rings. The 5 major moons are massive enough to have reached hydrostatic equilibrium, and 4 of them show signs of internally driven processes such as canyon formation and volcanism on their surfaces. The largest of these 5, Titania, is 1,578 km in diameter and the eighth-largest moon in the Solar System, and about one-twentieth the mass of Earth’s Moon. The orbits of the regular moons are nearly coplanar with Uranus’s equator, which is tilted 97.77° to its orbit. Uranus’ irregular moons have elliptical and strongly inclined (mostly retrograde) orbits at large distances from the planet.



Titania and Oberon were spotted by Herschel six years after he had discovered the planet itself. Later, Herschel thought he had discovered up to six moons and perhaps even a ring. For nearly 50 years, Herschel’s instrument was the only one with which the moons had been seen. In the 1840s, better instruments and a more favorable position of Uranus in the sky led to sporadic indications of satellites additional to Titania and Oberon. Eventually, the next two moons, Ariel and Umbriel, were discovered by William Lassell in 1851. The Roman numbering scheme of Uranus’ moons was in a state of flux for a considerable time, and publications hesitated between Herschel’s designations (where Titania and Oberon are Uranus II and IV) and William Lassell’s (where they are sometimes I and II). With the confirmation of Ariel and Umbriel, Lassell numbered the moons I to IV from Uranus outward, and this finally stuck. In 1852, Herschel’s son John Herschel gave the four then-known moons their names.

No other discoveries were made for almost another century. In 1948, Gerard Kuiper at the McDonald Observatory discovered the smallest and the last of the five large, spherical moons, Miranda. Decades later, the flyby of the Voyager 2 space probe in January 1986 led to the discovery of ten further inner moons. Another satellite, Perdita, was discovered in 1999 after studying old Voyager photographs.

Uranus was the last giant planet without any known irregular moons, but since 1997 nine distant irregular moons have been identified using ground-based telescopes. Two more small inner moons, Cupid and Mab, were discovered using the Hubble Space Telescope in 2003. As of 2016, the moon Margaret was the last Uranian moon discovered, and its characteristics were published in October 2003.

When the responsibility of naming the first four moons of Uranus was given to John Herschel, instead of assigning them names from Greek legend, he named them after magical spirits in English literature: the fairies Oberon and Titania from William Shakespeare’s A Midsummer Night’s Dream, and the sylphs Ariel and Umbriel from Alexander Pope’s The Rape of the Lock (Ariel is also a sprite in Shakespeare’s The Tempest). The reasoning was presumably that Uranus, as god of the sky and air, would be attended by spirits of the air. Subsequent names, rather than continuing the airy spirits theme (only Puck and Mab continued the trend), have focused on Herschel’s source material. In 1949, the fifth moon, Miranda, was named by its discoverer Gerard Kuiper after a thoroughly mortal character in Shakespeare’s The Tempest. The current IAU practice is to name moons after characters from Shakespeare’s plays and The Rape of the Lock (although at present only Ariel, Umbriel, and Belinda have names drawn from the latter; all the rest are from Shakespeare). At first, the outermost moons were all named after characters from one play, The Tempest; but with Margaret being named from Much Ado About Nothing that trend has ended. The moons’ names come from the following sources:

The Rape of the Lock (Alexander Pope):

Ariel, Umbriel, Belinda

Plays by William Shakespeare:

A Midsummer Night’s Dream: Titania, Oberon, Puck

The Tempest: (Ariel), Miranda, Caliban, Sycorax, Prospero, Setebos, Stephano, Trinculo, Francisco, Ferdinand

King Lear: Cordelia

Hamlet: Ophelia

The Taming of the Shrew: Bianca

Troilus and Cressida: Cressida

Othello: Desdemona

Romeo and Juliet: Juliet, Mab

The Merchant of Venice: Portia

As You Like It: Rosalind

Much Ado About Nothing: Margaret

The Winter’s Tale: Perdita

Timon of Athens: Cupid

To quibble, just a tad, I’d have to say that Cupid is a bit of a cheat, or at least a cheat in calling the name one that is derived from Timon of Athens rather than from the ancient Roman pantheon. Obviously, the naming of the planets after Greek and Roman gods dates back to antiquity (in the West). Breaking the tradition with planetary satellites, comets, and whatnot seems fine. However, focusing on Shakespeare for the moons of Uranus does seem awfully ethnocentric. The naming of moons has been the responsibility of the International Astronomical Union’s committee for Planetary System Nomenclature since 1973. That committee is known today as the Working Group for Planetary System Nomenclature (WGPSN). Prior to its formation, the names of satellites had varying histories. The choice of names was often determined by a satellite’s discoverer. However, historically some satellites, such as Titania and Oberon were not given names for many years after their discovery. The longest is probably Titan, a moon of Saturn, discovered by Huygens in 1655, but not named until 1847, almost two centuries later.

The recipe of the day has to be fairy cakes, I think. My twisted mind thinks of them as being like delightful little moons, as well as evocative of Shakespeare’s characters. I’ll give you the basic recipe and then leave it to you to decorate them as you please. I’ve always liked them with little wings. There’s a small gallery of ideas at the end. They are about the easiest cakes to make that I know of. I used to assist my mum making them when I was little.

Fairy cakes


110g/4oz butter, softened at room temperature
110g/4oz caster sugar
2 eggs, lightly beaten
1 tsp vanilla extract
110g/4oz self-raising flour
1 or 2 tbsp milk


Preheat the oven to 180˚C/350˚F and line 2 x 12-hole cake tins with paper cases.

Cream the butter and sugar together in a bowl until pale. Beat in the eggs, a little at a time, and then stir in the vanilla extract.

Fold in the flour gently with a wooden spoon. Add the milk very slowly until the mixture is a soft dropping consistency, but not too wet. Spoon the mixture into the paper cases so that they are half full.

Bake in the oven for 8-10 minutes, or until the cakes are golden-brown on top and a toothpick inserted into one of the cakes comes out clean. Set the cake tins aside to cool for 10 minutes, then remove the individual cakes from the tins and cool them on a wire rack.

Decorate the cakes as you please with icing, whipped cream, sprinkles, or what-have-you.

Mar 132016


On this date in 1781 Sir William Herschel observed an object with his telescope which had previously been cataloged as a star, and determined that it moved. He believed at first that it was a comet, but after much debate reclassified it as a planet – what we now call Uranus. This was the first planet to be discovered since antiquity and Herschel became famous overnight. As a result of this discovery, George III appointed him Court Astronomer. He was elected as a Fellow of the Royal Society and grants were provided for the construction of new telescopes.

Though Uranus is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit. Nowadays, should a new planet in the solar system be discovered, as seems quite likely, we would probably be delighted, but take it in stride. It’s hard to put ourselves into the mindset of Georgian England and fathom what an amazing discovery this was. Herschel had expanded the known boundaries of the solar system for the first time in history.

Uranus had been observed on many occasions before its recognition as a planet, but it was generally mistaken for a star. Possibly the earliest known observation was by Hipparchos, who in 128 BCE may have recorded it as a star for his star catalogue that was later incorporated into Ptolemy’s Almagest. The earliest definite sighting was in 1690 when John Flamsteed observed it at least six times, cataloging it as 34 Tauri. The French astronomer Pierre Lemonnier observed Uranus at least twelve times between 1750 and 1769.


Sir William Herschel observed Uranus on March 13, 1781 from the garden of his house at 19 New King Street in Bath, Somerset, (now the Herschel Museum of Astronomy), whilst engaged in observations on the parallax of fixed stars. Because of the accuracy of the telescope he was using (of his own design), he was able to detect the planet’s motion, which had previously gone unnoticed. He also noted that it increased in size when he increased the magnification of his telescope (which stars do not), thus indicating that it lay inside the solar system.

He recorded in his journal “In the quartile near ζ Tauri … either [a] Nebulous star or perhaps a comet”. On March 17, he noted, “I looked for the Comet or Nebulous Star and found that it is a Comet, for it has changed its place”. When he presented his discovery to the Royal Society, he continued to assert that he had found a comet, although he compared it to a planet:

The power I had on when I first saw the comet was 227. From experience I know that the diameters of the fixed stars are not proportionally magnified with higher powers, as planets are; therefore I now put the powers at 460 and 932, and found that the diameter of the comet increased in proportion to the power, as it ought to be, on the supposition of its not being a fixed star, while the diameters of the stars to which I compared it were not increased in the same ratio. Moreover, the comet being magnified much beyond what its light would admit of, appeared hazy and ill-defined with these great powers, while the stars preserved that lustre and distinctness which from many thousand observations I knew they would retain. The sequel has shown that my surmises were well-founded, this proving to be the Comet we have lately observed.

Herschel notified the Astronomer Royal, Nevil Maskelyne, of his discovery and received this reply from him on April 23: “I don’t know what to call it. It is as likely to be a regular planet moving in an orbit nearly circular to the sun as a Comet moving in a very eccentric ellipsis. I have not yet seen any coma or tail to it”.


Although Herschel continued to describe his new object as a comet, other astronomers had already begun to suspect otherwise. Finnish-Swedish astronomer Anders Johan Lexell, working in Russia, was the first to compute the orbit of the new object and its nearly circular orbit led him to a conclusion that it was a planet rather than a comet. Berlin astronomer Johann Elert Bode described Herschel’s discovery as “a moving star that can be deemed a hitherto unknown planet-like object circulating beyond the orbit of Saturn”. Bode concluded that its near-circular orbit was more like a planet than a comet.

The object was soon universally accepted as a new planet. By 1783, Herschel acknowledged this to Royal Society president Joseph Banks: “By the observation of the most eminent Astronomers in Europe it appears that the new star, which I had the honour of pointing out to them in March 1781, is a Primary Planet of our Solar System.” In recognition of his achievement, King George III gave Herschel an annual stipend of £200 on condition that he move to Windsor so that the Royal Family could look through his telescopes.


Uranus is named after the ancient Greek deity of the sky Uranus (Οὐρανός), the father of Cronus (Saturn) and grandfather of Zeus (Jupiter), which in Latin became “Ūranus”. It is the only planet whose name is derived from a figure of Greek mythology. The adjective of Uranus is “Uranian”. The pronunciation of the name Uranus preferred among astronomers is /ˈjʊərənəs/, with stress on the first syllable as in Latin Ūranus, in contrast to /jʊˈreɪnəs/, with stress on the second syllable and a long a, though both are considered acceptable. The first pronunciation avoids crude jokes concerning “your anus” !! It does, however, leave open the possibility of “urine us.”

Consensus on the name was not reached until almost 70 years after the planet’s discovery. During the original discussions following discovery, Maskelyne asked Herschel to “do the astronomical world the faver to give a name to your planet, which is entirely your own, which we are so much obliged to you for the discovery of.” In response to Maskelyne’s request, Herschel decided to name the object Georgium Sidus (George’s Star), or the “Georgian Planet” in honor of his new patron, King George III. He explained this decision in a letter to Joseph Banks:

In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third’.


Herschel’s proposed name was not popular outside Britain, and alternatives were soon proposed. Astronomer Jérôme Lalande proposed that it be named Herschel in honor of its discoverer. Swedish astronomer Erik Prosperin proposed the name Neptune, which was supported by other astronomers who liked the idea to commemorate the victories of the British Royal Naval fleet in the course of the American Revolutionary War by calling the new planet even Neptune George III or Neptune Great Britain.

In a March 1782 treatise, Bode proposed Uranus. Bode argued that the name should follow ancient mythology so as not to stand out as different from the other planets, and that Uranus was an appropriate name, being the father of the first generation of the Titans. He also noted the elegance of the name in that just as Saturn was the father of Jupiter, the new planet should be named after the father of Saturn. In 1789, Bode’s Royal Academy colleague Martin Klaproth named his newly discovered element uranium in support of Bode’s choice. Ultimately, Bode’s suggestion became the most widely used, and became universal in 1850 when HM Nautical Almanac Office, the final holdout, switched from using Georgium Sidus to Uranus.

Uranus is called by a variety of names in other languages. In Chinese, Japanese, Korean, and Vietnamese, its name is literally translated as the “sky king star” (天王星). In Thai, its official name is Dao Yurenat (ดาวยูเรนัส), as in English. Its other name in Thai is Dao Maritayu (ดาวมฤตยู, Star of Mṛtyu), after the Sanskrit word for “death”, Mrtyu (मृत्यु). In Mongolian, its name is Tengeriin Van (Тэнгэрийн ван), translated as “King of the Sky”, reflecting its namesake god’s role as the ruler of the heavens.

Observation of Uranus has taken leaps forward in recent decades courtesy of images from the Hubble telescope and Voyager. Its ring and moon system is complex, not to mention its multilayered and deep atmosphere. Well worth your further inquiry.


I’ve been interested for some time in the cooking of Georgian England, which has perked the interest of contemporary amateurs. This site has a wealth of information about reconstructing old recipes from the eclectic MS collection known as The Cookbook of Unknown Ladies https://lostcookbook.wordpress.com/category/cookbook-recipes/18th-century-recipes/page/9/ . The recipes are difficult to interpret with any degree of historical accuracy because they are generally terse, and assume knowledge of the cooking skills of the day, without elaboration on them. Furthermore, the quantities are usually huge as for a large Georgian household, and need to be cut down. I note two important distinctions between Georgian and modern cooking. First, the distinction between main course dishes and desserts is blurry by modern standards. Sweeteners and fruits are common in meat dishes, and you’ll find vegetables such as carrots and spinach in desserts. This fact is not entirely anomalous given that we routinely eat carrot cake and sweet potato pie for dessert, and don’t especially mind ham with pineapple or pumpkin with marshmallows for a main course. Second, relatedly, Georgian cooks used a number of spices and flavorings for main dishes that are more conventionally used in desserts in the modern kitchen, such as nutmeg, cinnamon, allspice, or cloves. Their taste palate was also a bit more varied, frequently employing mace, rosewater, orange flower water, and the like, which are rarities in modern recipes.

There may be a hint of the Georgian cook in me. I use powdered mace (when I can find it), cloves, and allspice all the time when I want a rich gravy. Courtesy of my mentor Robert Carrier, I never make steak and kidney pie without a trace of cloves in the gravy. Try it – it’s a great addition. Don’t overdo it, though.

Here’s a recipe called “White Pease Soop” from the Unknown Ladies. First, we must be clear what “white pease” means. “Pease” is Middle English for “peas” which has survived (barely) in “pease pudding.” Note that this is a recipe for soup and not pudding, and the recipe specifically cautions about making it too thick. You’ll need to find white peas if you can. They’re now usually sold in Indian markets as safed vatana. Yellow splits will work as a substitute, although they have a different flavor.


White Pease Soope

Take a pottle of good white pease & 5 qrts of water. Let yr pease be put in the water, cold, & let them boil till the are soft but dont break them at all. Then pour the broth from them very cleer & cut some salery small & som lettice & some spearmint & the ends of 2 o 3 leeks & some spinage & beets & some parsley. Cut all these very small & stew them in half a pnd of butter in a sauce pan, very soft. Then put them in yr pease broth & a qrt of strong gravy & a good deal of pounded mace & a little pepper. Give these a boil or 2 together, stirring them well & have some small rashers of bacon & bread fryed & laid in the bottom of your dish. Pour yr soope over them. You must take care yr pease be very clear. You must let it stew a very little while for it will be apt to grow too thick.

This recipe is not hard to follow, you just need to adjust the quantities down a good bit (a pottle (of peas) is half a gallon). Begin by soaking the peas overnight, then simmering them in double their quantity of fresh water until they are soft. Chop a mix of celery, lettuce, spearmint, leeks, spinach, beets and parsley (I’d go with equal amounts of each), and sauté in a heavy skillet in a generous amount of butter until soft. Combine the vegetables and peas in a saucepan with some good beef stock, and season generously with mace and black pepper. Do not allow the peas to break up, or thicken the soup. Fry some rashers of bacon until the fat is rendered, and fry bread slices in the fat. Transfer the fried bread and bacon to soup plates, and pour the soup over them.

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Nov 152013


Today is the birthday (1738) of Sir Frederick William Herschel, KH, FRS (German: Friedrich Wilhelm Herschel), German-born British astronomer, technical expert, and minor composer. He was born in Hanover and followed his father into the Military Band of Hanover, before emigrating to Britain at age 19. He became famous for his discovery of the planet Uranus, along with two of its major moons (Titania and Oberon), and also discovered two moons of Saturn. In addition, he was the first person to discover the existence of infrared radiation.  He was also a musician and composed a number of symphonies, organ pieces, and other works.  Being rather derivative and lackluster, these works have largely been forgotten except by enthusiasts.

Herschel was born in Hanover, Electorate of Hanover, one of ten children of Anna Ilse (née Moritzen) and Isaac Herschel. His family were Protestant Christians, probably descended on his father’s side from converted Moravian Jews. His father was an oboist in the Hanover Military Band. In 1755 the Hanoverian Guards regiment, in whose band Wilhelm and his brother Jakob were engaged as oboists, was ordered to England. At the time the crowns of Great Britain and Hanover were united under George II. As the threat of war with France loomed, the Hanoverian Guard was recalled from England to defend Hanover. After the Hanoverian guard was defeated at the Battle of Hastenbeck, Herschel’s father Isaak sent his two sons to seek refuge in England in late 1757. Although his older brother Jakob had received his dismissal from the Hanoverian Guard, Wilhelm was accused of desertion (for which he was pardoned by George III in 1782). Wilhelm, nineteen years old at this time, was a quick student of the English language. In England he went by the English rendition of his name, Frederick William Herschel.

Herschel moved to Sunderland in 1761 when Charles Avison immediately engaged him as first violin and soloist for his Newcastle orchestra, where he played for one season and wrote his symphony no. 8 in C minor. He was head of the Durham Militia band 1760–61 and visited the home of Sir Ralph Milbanke at Halnaby Hall in 1760, where he wrote two symphonies, as well as giving performances himself.

After Newcastle he moved to Leeds and Halifax where he was the first organist at St John the Baptist church (now Halifax Minster). He became organist of the Octagon Chapel, Bath, a fashionable chapel in the well-known spa, and also became Director of Public Concerts. He was appointed as the organist in 1766 and gave his introductory concert on 1 January 1767. When he arrived the organ was still being built so he wrote pieces including a violin concerto, an oboe concerto, and a harpsichord sonata to fill the gap until the organ was ready.

His sister Caroline went to England in 1772 and lived with him there in New King Street. His brothers Dietrich, Alexander and Jakob also appeared as musicians in Bath. In 1780, Herschel was appointed director of the Bath orchestra, with his sister often appearing as soprano soloist.

Herschel’s music led him to an interest in mathematics, not an uncommon connexion in the Enlightenment era, and then he became interested in optics and lenses. His interest in astronomy developed after he made the acquaintance of the English Astronomer Royal, Nevil Maskelyne. He started building his own reflecting telescopes and would spend up to 16 hours a day grinding and polishing the speculum metal primary mirrors.  He “began to look at the planets and the stars” in May 1773 and on 1 March 1774 began an astronomical journal by noting his observations of Saturn’s rings and the Great Orion Nebula (M 42).


Herschel’s early observational work soon focused on the search for pairs of stars that were very close together visually. Astronomers of the era expected that changes over time in the apparent separation and relative location of these stars would provide evidence for both the proper motion of stars and, by means of parallax shifts in their separation, for the distance of stars from the Earth (a method first suggested by Galileo). From the back garden of his house in New King Street, Bath, and using a 6.2-inch aperture (160 mm), 7-foot focal length (2.1 m) (f/13) Newtonian telescope “with a most capital speculum” of his own manufacture, in October 1779, Herschel began a systematic search for such stars among “every star in the Heavens,” with new discoveries listed through 1792. He soon discovered many more binary and multiple stars than expected, and compiled them with careful measurements of their relative positions in two catalogues presented to the Royal Society in London in 1782 (269 double or multiple systems) and 1784 (434 systems). A third catalogue of discoveries made after 1783 was published in 1821 (145 systems).

In 1797 Herschel measured many of the systems again, and discovered changes in their relative positions that could not be attributed to the parallax caused by the Earth’s orbit. He waited until 1802 (in Catalogue of 500 new Nebulae, nebulous Stars, planetary Nebulae, and Clusters of Stars; with Remarks on the Construction of the Heavens) to announce the hypothesis that the two stars might be “binary sidereal systems” orbiting under mutual gravitational attraction, a hypothesis he confirmed in 1803 in his Account of the Changes that have happened, during the last Twenty-five Years, in the relative Situation of Double-stars; with an Investigation of the Cause to which they are owing. In all, Herschel discovered over 800 confirmed double or multiple star systems, almost all of them physical rather than virtual pairs. His theoretical and observational work provided the foundation for modern binary star astronomy; new catalogues adding to his work were not published until after 1820 by Friedrich Wilhelm Struve, James South and John Herschel.


In March 1781, during his search for double stars, Herschel noticed an object appearing as a nonstellar disk. Herschel originally thought it was a comet or a star. He made many more observations of it, and afterwards Russian Academician Anders Lexell computed the orbit and found it to be probably planetary. Herschel determined in agreement that it must be a planet beyond the orbit of Saturn. He called the new planet the ‘Georgian star’ (Georgium sidus) after King George III, which also brought him favor; the name did not stick. In France, where reference to the British king was to be avoided if possible, the planet was known as ‘Herschel’ until the name ‘Uranus’ was universally adopted. The same year, Herschel was awarded the Copley Medal and elected a Fellow of the Royal Society. In 1782, he was appointed “The King’s Astronomer” (not to be confused with the Astronomer Royal). He and his sister subsequently moved to Datchet (then in Buckinghamshire but now in Berkshire) on 1 August 1782. He continued his work as a telescope maker and achieved an international reputation for their manufacture, profitably selling over 60 completed reflectors to British and Continental astronomers.


From 1782 to 1802, and most intensively from 1783 to 1790, Herschel conducted systematic surveys in search of “deep sky” or nonstellar objects with two 20-foot focal length (610 cm), 12-inch aperture (30 cm) and 18.7-inch aperture (47 cm) telescopes (in combination with his favoured 6-inch aperture instrument). Excluding duplicated and “lost” entries, Herschel ultimately discovered over 2400 objects defined by him as nebulae. (At that time, nebula was the generic term for any visually extended or diffuse astronomical object, including galaxies beyond the Milky Way, until galaxies were confirmed as extragalactic systems by Edwin Hubble in 1924.)

Herschel published his discoveries as three catalogues: Catalogue of One Thousand New Nebulae and Clusters of Stars (1786), Catalogue of a Second Thousand New Nebulae and Clusters of Stars (1789) and the previously cited Catalogue of 500 New Nebulae … (1802). He arranged his discoveries under eight “classes”: (I) bright nebulae, (II) faint nebulae, (III) very faint nebulae, (IV) planetary nebulae, (V) very large nebulae, (VI) very compressed and rich clusters of stars, (VII) compressed clusters of small and large [faint and bright] stars, and (VIII) coarsely scattered clusters of stars. Herschel’s discoveries were supplemented by those of Caroline Herschel (11 objects) and his son John Herschel (1754 objects) and published by him as General Catalogue of Nebulae and Clusters in 1864. This catalogue was later edited by John Dreyer, supplemented with discoveries by many other 19th century astronomers, and published in 1888 as the New General Catalogue (abbreviated NGC) of 7840 deep sky objects. The NGC numbering is still the most commonly used identifying label for these celestial landmarks.


In 1783 he gave Caroline a telescope, and she began to make astronomical discoveries in her own right, particularly comets. She discovered or observed eight comets, eleven nebulae and, at her brother’s suggestion, updated and corrected Flamsteed’s work detailing the position of stars. This was published as the British Catalogue of Stars. She was honored by the Royal Astronomical Society for this work. Caroline also continued to serve as his assistant, often taking notes while he observed at the telescope.

In June 1785, owing to damp conditions, he and Caroline moved to Clay Hall in Old Windsor. In 1786, the Herschels moved to a new residence on Windsor Road in Slough. He lived the rest of his life in this residence, which came to be known as Observatory House. It is no longer standing. On 7 May 1788, he married the widow Mary Pitt (née Baldwin) at St Laurence’s Church, Upton in Slough. His sister Caroline then moved to separate lodgings, but continued to work as his assistant.

During the course of his career, he constructed more than four hundred telescopes. The largest and most famous of these was a reflecting telescope with a 49 1?2-inch-diameter (1.26 m) primary mirror and a 40-foot (12 m) focal length. Because of the poor reflectivity of the speculum mirrors of that day, Herschel eliminated the small diagonal mirror of a standard newtonian reflector from his design and tilted his primary mirror so he could view the formed image directly. This design has come to be called the Herschelian telescope. On 28 August 1789, his first night of observation using this instrument, he discovered a new moon of Saturn. A second moon followed within the first month of observation. The “40-foot telescope” proved very cumbersome, and most of his observations were done with a smaller 18.5-inch (47 cm) 20-foot-focal-length (6.1 m) reflector. Herschel discovered that unfilled telescope apertures can be used to obtain high angular resolution, something which became the essential basis for interferometric imaging in astronomy (in particular Aperture Masking Interferometry and hypertelescopes).

In his later career, Herschel discovered two moons of Saturn, Mimas and Enceladus; as well as two moons of Uranus, Titania and Oberon. He did not give these moons their names; they were named by his son John in 1847 and 1852, respectively, after his death.



In 2007 evidence was cited by Dr. Stuart Eves that Herschel might have discovered rings around Uranus. Herschel measured the axial tilt of Mars and discovered that the martian ice caps, first observed by Giovanni Domenico Cassini (1666) and Christiaan Huygens (1672), changed size with the planet’s seasons.

From studying the proper motion of stars, he was the first to realize that the solar system is moving through space, and he determined the approximate direction of that movement. He also studied the structure of the Milky Way and concluded that it was in the shape of a disk.

He also coined the word “asteroid,” meaning star-like (from the Greek asteroeides, aster “star” + -eidos “form, shape”), in 1802 (shortly after Olbers discovered the second minor planet, 2 Pallas, in late March), to describe the star-like appearance of the small moons of the giant planets and of the minor planets; the planets all show discs, by comparison. By the 1850s ‘asteroid’ became a standard term for describing certain minor planets.

On 11 February 1800, Herschel was testing filters for the sun so he could observe sun spots. When using a red filter he found there was a lot of heat produced. Herschel discovered infrared radiation in sunlight by passing it through a prism and holding a thermometer just beyond the red end of the visible spectrum. This thermometer was meant to be a control to measure the ambient air temperature in the room. He was shocked when it showed a higher temperature than the visible spectrum. Further experimentation led to Herschel’s conclusion that there must be an invisible form of light beyond the visible spectrum.

On 25 August 1822, Herschel died at Observatory House, Windsor Road, Slough, and is buried at nearby St Laurence’s Church, Upton (now in Slough).  Slough is the butt of many derisive jokes because in the post-war era it became known for its industrial estate that was, at the time, distinctly not idyllic, rural England.  But Herschel is very much respected in the town and there are several memorials to him and his discoveries. In 2011 a new bus station was built in the town center, the design of which was inspired by Herschel’s infrared experiment.  My father was a member of the Slough freemason’s lodge, named Herschel lodge.


Written in 1747, Hannah Glasse’s (1708–1770) The Art of Cookery made Plain and Easy represents one of the most important references for culinary practice in England during the latter half of the 18th century and the beginning of the 19th. In the introduction she writes:

A Frenchman in his own country will dress a fine dinner of twenty dishes, and all genteel and pretty, for the expence he will put an English lord to for dressing one dish. But then there is the little petty profit.  I have heard of a cook that used six pounds of butter to fry twelve eggs; when every body knows (that understands cooking) that half a pound is full enough, or more than need be used: but then it would not be French. So much is the blind folly of this age that they would rather be imposed on by a French booby, than give encouragement to a good English cook!

Here is a delightful recipe from the book:

A ragoo of eggs

BOIL twelve eggs hard, take off the shells, and with a little knife very carefully cut the white a cross long-ways, so that the white may be in two halves, and the yolk whole. Be very careful neither to break the whites, nor yolks, take a quarter of a pint of pickled mushrooms chopped very fine, half an ounce of truffles and morels, boiled in three or four spoonfuls of water, save the water, and chop the truffles and morels very small, boil a little parsley, chop it fine, mix them together with the truffle-water you saved, grate a little nutmeg in, a little beaten mace, put it into a sauce-pan with three spoonfuls of water, a gill of red wine, one spoonful of catchup, a piece of butter, as big as a large walnut, rolled in flour, stir all together and let it boil. In the mean time get ready your eggs, lay the yolks and whites in order in your dish, the hollow parts of the whites uppermost, that they may be filled; take some crumbs of bread, and fry them brown and crisp, as you do for larks, with which fill up the whites of the eggs as high as they will lye, then pour in your sauce all over, and garnish with fry’d crumbs of bread. This is a very genteel pretty dish, if it be well done.


I took a shot at this recipe using what I had on hand, and the photo shows the result. Truffles and morels are in short supply in my pantry right now, so I made do with some rich brown fresh mushrooms.  By “catchup” Glasse means a rich and spicy mushroom sauce in vinegar which you can still find in gourmet stores or online (or make yourself). I used a Chinese mushroom sauce.  I am not sure how to fry breadcrumbs “as you do for larks” so I just browned them in a dry skillet.  Cutting the eggs was a challenge in that I could not keep the yolks whole – they fell in half even though I was careful cutting the whites.  A sauce of mushrooms and nutmeg does go well with eggs, and the breadcrumbs add a toasted note and a slight crunch. I ate them cold and hot – delicious both ways.