威廉·赫歇尔William Herschel

威廉·赫歇尔的原名是弗里德里希Wilhelm Herschel，直到他来到英国居住后才使用赫歇尔这个名字。在本文中我们将一直使用赫歇尔这个名字。赫歇尔的父亲是Isaac Herschel（1707-1767），是园丁Abraham Herschel和伊娃·梅韦斯的儿子。艾萨克起初以园丁为生，但攒够钱后上了音乐课。在波茨坦获得双簧管手的工作后，他作为双簧管手加入了汉诺威步兵卫队。艾萨克与安娜·伊尔斯·莫里岑结婚，育有十个孩子：索菲亚Elizabeth Herschel（1733-1803）；海因里希·安东Jacob Herschel（1734-1792）；Johann Herschel（1737-1743）；弗里德里希·威廉（赫歇尔）赫歇尔（1738-1822，本传记的主人公）；安娜Christina Herschel（1741-1748）；约翰·亚历山大（亚历山大）赫歇尔（1745-1821）；玛丽亚·多蕾西娅赫歇尔（1748-1749）；卡罗琳·赫歇尔（1750-1848）；弗朗茨Johann Herschel（1752-1754）；以及约翰·迪特里希赫歇尔（1755-1827）。括号中的名字是他们现在为人所知的名字。快速浏览这些日期就会发现，十个孩子中只有六个活到了成年。

赫歇尔 家境贫寒，但艾萨克相信教育，通过向孩子们展示夜空的奇妙来激发他们的兴趣。他也喜欢与孩子们讨论哲学和数学话题。艾萨克为汉诺威步兵卫队工作可能薪水不高，但这确实意味着他的孩子们可以上卫队办的学校。这为所有孩子提供了基础教育，他们都充分利用了这一机会，除了安娜，她一生都是文盲。除了长女索菲亚·伊丽莎白外，所有孩子都表现出明显的音乐天赋。其中几个有音乐天赋的孩子在 赫歇尔 的职业生涯中扮演了重要角色，下面会提到。赫歇尔 在学校证明是一个有天赋的学生，到十五岁时已经学会了老师能教给他的一切。这时他加入汉诺威卫队当双簧管手，并用从中赚来的钱支付私人教师霍夫施拉格先生教他法语。他与哥哥雅各布分担费用，雅各布也从霍夫施拉格先生那里学法语。

奥地利王位继承战争于1740年开始，当时普鲁士的腓特烈二世入侵西里西亚。此后几年，整个欧洲都有战斗。1743年6月27日的代廷根战役中，英国、汉诺威和黑森联军击败了法国人。尽管艾萨克是一名音乐家，但他还是不得不忍受战斗的艰苦条件，这严重影响了他的健康。虽然到1748年整个欧洲的战斗已经结束，但各方仍然紧张。赫歇尔 在汉诺威步兵卫队的最初几年是平静的，但1756年汉诺威军队被派往英格兰，以增强英格兰军队，准备应对法国的入侵。赫歇尔 仍然是一名音乐家，随汉诺威军队被派去，他们驻扎在肯特郡的梅德斯通。法国的入侵从未发生，但 赫歇尔 抓住机会学习英语。他还获得了一本 弗瑞兹·约翰 洛克的著作 An essay concerning human understanding，他读了这本书，这部作品对他产生了显著影响。

回到汉诺威后，汉诺威人在1757年7月的哈斯滕贝克战役中遭到法国人攻击，并惨败。赫歇尔、他的兄弟雅各布和他的父亲艾萨克都是汉诺威军队中的音乐家，都遭到了炮火。艾萨克不想看到儿子们这样受苦，建议 赫歇尔 逃跑。由于从未宣誓入伍当兵，他认为这不算逃兵。赫歇尔 去了汉诺威，但没有护照，觉得有危险，又回到了军队。不久之后，赫歇尔 请求正式退伍。1758年，他决定返回英格兰，和雅各布一起去了汉堡，在那里乘船去英格兰。他们前往伦敦，虽然到达时没有钱，但他们很快利用音乐技能谋生。赫歇尔 成为音乐抄写员，而雅各布则授课，有时也演出。在伦敦待了两年后，雅各布返回汉诺威，而 赫歇尔 觉得伦敦音乐家之间的竞争太激烈，决定搬走。他接受了达勒姆民兵乐队队长的职位，并在1760-61年间住在北约克郡的里士满。

从1760年开始的这段时期是 赫歇尔 创作交响曲的时期。他在拉尔夫·米尔班克爵士的住所哈尔纳比庄园创作了两首，并在那里演出。到1760年底，他已经完成了六首交响曲。他在包括爱丁堡和泰恩河畔纽卡斯尔在内的多个城市演出，但大约此时他开始学习语言和音乐理论。他通过音乐理论被引向数学，这可能看起来相当令人惊讶，但事实确实如此，他变得热衷于尽可能多地学习。1761年，他搬到桑德兰，被任命为查尔斯·阿维森的纽卡斯尔管弦乐团的首席小提琴和独奏家。他只演奏了一个演出季，然后在1762年2月被任命为利兹的音乐会总监。他继续担任这一职务直到1766年春天，为管弦乐团创作了六首交响曲和至少一首小提琴协奏曲。

在1762-66年期间，赫歇尔 于1764年回汉诺威短暂度假，在那里他七年来第一次见到了家人。他的妹妹 卡罗琳·赫歇尔 特别高兴见到 赫歇尔。然而，赫歇尔 对音乐的热情变得不那么明显，他越来越多地把业余时间花在学习数学上。1766年，他赢得了一场竞赛，成为哈利法克斯教区教堂的管风琴师。然而，几乎同时，他收到了邀请，成为巴斯米尔森街私人拥有的八角教堂的管风琴师。这是一个更有吸引力的提议，但 赫歇尔 觉得他必须对哈利法克斯公平，所以他在那里待了几个月，直到1766年12月才前往巴斯。哈利法克斯试图用更高的薪水留住他，但巴斯的吸引力太大了。

在巴斯，赫歇尔在博福特广场租了一处住所。他到达时，八角教堂的管风琴仍在建造中，因此他在1767年1月1日的首场音乐会上演奏了一首小提琴协奏曲、一首双簧管协奏曲和一首羽管键琴奏鸣曲，全部是他自己的作品。管风琴于1767年10月完工，当时他训练的合唱团演唱了⟦E1⟧，而赫歇尔演奏了他的一首管风琴协奏曲。他的弟弟雅各布当时已回到英格兰，也在这场音乐会上演出。赫歇尔的弟弟迪特里希让家人有些担忧，于是赫歇尔邀请他来巴斯，他在那里接受了一年的音乐教育。1770年6月1日，赫歇尔离开博福特广场的住所，搬到新国王街7号，与他在利兹时认识的布尔曼一家同住。此时他邀请弟弟亚历山大来巴斯与他同住。1772年，为了帮助卡罗琳·赫歇尔，他前往汉诺威，将她带回巴斯，让她接受歌唱训练。他不得不答应给母亲足够的钱雇一个仆人，母亲才允许卡罗琳·赫歇尔离开。回到巴斯后，赫歇尔给卡罗琳·赫歇尔上歌唱、羽管键琴和簿记课。她成了他的管家。

除了数学，赫歇尔开始对天文学产生兴趣，并购买了天文学书籍和星表。例如，他于1773年5月10日购买了詹姆斯·弗格森的Astronomy。他购买的其他书籍包括罗伯特·史密斯的两本书Opticks和Harmonics、爱默生的Trigonometry以及罗伯特·西姆松的Euclid。他仍然作为巴斯音乐生活中的重要人物谋生，担任教师、演奏者、作曲家和指挥。到1773年底，对天文学的热情已牢牢抓住了他，并占据了赫歇尔一家的生活。卡罗琳·赫歇尔写道[20]：-

……然后我痛心地看到几乎每个房间都变成了作坊。一位细木工在一间布置精美的客厅里制作镜筒和各式各样的支架；亚历克斯在一间卧室里安装了一台巨大的车床（秋天他从布里斯托尔带来的），用来车制模型、磨制镜片和车制目镜等。我则自娱自乐地用纸板制作镜筒，以配合从伦敦运来的镜片……

1773年9月，赫歇尔租用了一台由詹姆斯·格雷果里设计的小型格雷果里式望远镜。它的性能并不特别好，因此赫歇尔决定，与其制造透镜，不如尝试自己制造反射镜。他购买了一些设备来制造自己的反射镜，到1773年底他正在抛光它们。1774年，他们搬家，搬到靠近沃尔科特收费公路的一所房子。这所房子几乎在乡下，非常适合制造望远镜和进行观测，但离他仍然赖以谋生的巴斯音乐厅远得令人不便。音乐现在仅仅成了赚钱购买工具和设备的手段。1775年，卡罗琳·赫歇尔写道[19]：-

……我的时间被抄写乐谱和练习占得太多，此外还要在抛光时照看我的兄弟，为了让他活着，我甚至不得不把食物一点一点地放进他嘴里；——有一次，在完成一面7英尺反射镜时，他连续16个小时没有离开它。……每一个闲暇时刻都被急切地抓住，用来继续某项正在进行的工作，连换衣服的时间都没有，许多蕾丝褶边被熔化的沥青撕裂或溅污……

1777年9月29日，赫歇尔一家搬到新国王街19号，这里位于巴斯市中心，位置很好，但有一个花园，赫歇尔可以在那里用他的望远镜进行观测。1779年，他们再次搬家，这次搬到里弗斯街5号，这个区域靠近刚刚建成的皇家新月楼和马戏场。这次搬家的原因一定是这所房子靠近最近成立的巴斯文学与哲学学会，该学会从1780年1月开始每周五举行会议。然而，这所房子没有花园，赫歇尔不得不在他租用的新月楼后面的花园里架设望远镜。此时他遇到了几位重要人物，包括William Watson（1744-1824），后者邀请他加入巴斯文学与哲学学会。在接下来的三年里，他向该学会提交了31篇论文。这些论文涉及各种主题，包括电、光、热和形而上学。三篇天文学论文由William Watson转交给The Royal Society。此外，住在这所房子期间，内维尔·马斯基林拜访了他。

关于皇家学会发表的三篇天文学论文的摘录，见THIS LINK。

住在里弗斯街期间，他的音乐事业继续发展，并于1780年被任命为巴斯管弦乐团的指挥。1781年3月初，赫歇尔一家搬回新国王街19号。仅仅几天后，即3月13日，他发现了天王星，这是历史时期发现的第一颗行星。让我们简要解释一下当时的情况。赫歇尔一直在检查双星，即天空中看起来靠得很近的两颗恒星。他希望较暗的那颗要远得多，并且他能够以地球轨道的直径为基线，利用视差来确定相对距离。他正在观测双星双子座η（也称为Propus），它由一颗3.3等星和一颗6.5等星组成，相距1.5角秒。他注意到一个物体离这对星如此之近，几乎使它看起来像一个三合星系统，但这个第三个物体显示出圆面。三天后，他观察到它移动了，但他不确定它是行星还是彗星。他与几个人通信，包括内维尔·马斯基林，后者回复[20]：-

我必须感谢您告知您发现了当前这颗彗星，或行星，我不知道该称它什么。它既可能是一颗沿着近乎圆形的轨道绕太阳运行的规则行星，也可能是一颗沿着非常扁长的椭圆运行的彗星。我还没有看到任何彗发或彗尾。……

有趣的是，这封信的地址是“巴斯新月楼附近，音乐家赫歇尔先生。”赫歇尔将他的发现告知了皇家学会，他的论文于4月16日宣读。他于1781年11月获得科普利奖章，并于12月6日当选为皇家学会会士。1782年春，国王邀请他到伦敦，与他交谈了半小时。赫歇尔写信给留在巴斯的卡罗琳·赫歇尔[20]：-

我被引见给了最上层的社交圈。明天我在帕默斯顿勋爵家吃饭，后天与约瑟夫·班克斯爵士（Royal Society的主席）等人共餐，等等等等。在眼镜制造商和天文学家中间，现在谈论的只有他们所称的我的伟大发现。唉！这恰恰表明他们落后多远，连我所见到和所做的这等琐事都被称为伟大。只要让我再着手去做！我要制造望远镜，看到这样的东西……也就是说，我会努力这样做。

关于他发现天王星以及赫歇尔的其他发现的更多信息，见THIS LINK。

国王提出每年200英镑的养老金，条件是他搬到温莎附近居住，赫歇尔于1782年5月19日在巴斯圣玛格丽特教堂做了他最后一次职业音乐演出。关于赫歇尔作为音乐家的一些评论，请参见THIS LINK。

1782年8月，他与卡罗琳·赫歇尔一起离开了巴斯，最初住在达切特附近一处相当简陋的房产中。1785至1786年间，他们曾在老温莎的克莱厅住过几个月，随后搬到了斯劳一栋名为天文台屋的房子。接受国王每年200英镑的津贴意味着赫歇尔的收入大约只有他作为音乐家时的一半。他通过制造和出售望远镜来补贴收入。然而，1788年，他与富有的Mary Pitt结婚，即他的朋友约翰 哈利·皮特的遗孀，他的经济忧虑随之结束。赫歇尔搬到厄普顿建立家庭住所，而卡罗琳·赫歇尔则留在斯劳。赫歇尔与玛丽的儿子约翰·赫歇尔于1792年3月出生。经本杰明·富兰克林推荐，他于1787年2月18日当选为美国哲学学会会员。

尽管赫歇尔最著名的是发现天王星，但许多人认为他最伟大的成就是1800年发现红外辐射。关于这一发现的描述，请参见THIS LINK。

1802年，赫歇尔访问巴黎，在那里他会见了拉朗德、皮埃尔·梅尚、让·巴蒂斯特·约瑟夫·德朗布尔、皮埃尔·西蒙·拉普拉斯和查尔斯·梅西耶，并进行了讨论。在这次访问期间，他会见了当时担任第一执政的拿破仑·波拿巴。赫歇尔回答了拿破仑的几个问题，后来写道拿破仑的：-

……总体神态有点像故意装作知道的比他实际知道的多。

1807年春天，赫歇尔患了重病。从那时起，他的健康状况不佳，无法像多年来那样进行大量观测。他继续撰写论文，由皇家学会发表。

Royal Astronomical Society成立于1820年1月。约翰·赫歇尔在日记中写道：-

1820年2月29日，星期二。——在贝德福德广场安顿下来并在那里用餐。我的父母来吃晚饭。晚上，参加了天文学会的会议，会上我的父亲被选为副主席。

1820年3月3日，星期五。——与我的父母一起回到斯劳，途中拜访了我的叔叔B。

1820年4月，Astronomical Society理事会邀请赫歇尔担任首任主席，声明他无需承担任何实际工作。赫歇尔拒绝了，但在次年接受，成为皇家天文学会的首任主席。亨利·托马斯·科尔布鲁克主持会议，赫歇尔曾表示他不会发挥积极作用。1822年他去世后，科尔布鲁克成为天文学会的第二任主席。

关于赫歇尔和卡罗琳·赫歇尔的更多信息，请参见我们在THIS LINK上的文章A visit to the Herschel Museum。

关于赫歇尔的一些天文学发现的信息，请参见THIS LINK。

月球和火星上的环形山以赫歇尔命名。

William Herschel's original name was Friedrich Wilhelm Herschel and only after he came to live in England did he use the name William Herschel. We will use the name William Herschel throughout this article. William's father was Isaac Herschel (1707-1767), the son of the gardener Abraham Herschel and Eva Meves. Isaac began earning his living as a gardener but after he saved up enough money he took music lessons. After taking a job as an oboist in Potsdam, he joined the Hanoverian Foot Guards as an oboist. Isaac married Anna Isle Moritzen and they had ten children: Sophia Elizabeth Herschel (1733-1803); Heinrich Anton Jacob Herschel (1734-1792); Johann Herschel (1737-1743); Friedrich Wilhelm (William) Herschel (1738-1822, the subject of this biography); Anna Christina Herschel (1741-1748); Johann Alexander (Alexander) Herschel (1745-1821); Maria Dorethea Herschel (1748-1749); Carolina Lucretia (Caroline) Herschel (1750-1848); Franz Johann Herschel (1752-1754); and Johann Dietrich Herschel (1755-1827). The bracketed names are those by which they are now known. A quick look at these dates will show that only six of the ten children survived to adulthood.

The Herschel family were poor but Isaac believed in education and enthused his children by showing them the wonders of the night sky. He also loved to discuss philosophical and mathematical subjects with his children. Isaac's work for the Hanoverian foot guards may not have been well paid but it did mean that his children could attend a school run by the Guards. This provided a basic education for all the children and they all took full advantage of it except Anna who remained illiterate all her life. All the children except for the eldest Sophia Elizabeth showed marked musical talents. Several of these musically talented children play an important role in William's career and are mentioned below. William proved a talented pupil at the school and by the age of fifteen had learnt all that the master could teach him. At this time he joined the Hanoverian Guards as an oboe player and used the money he earned from this to pay for a private tutor, Mr Hofschlager, to teach him French. He shared the costs with his older brother Jacob who also learnt French from Mr Hofschlager.

The War of Austrian Succession began in 1740 when Frederick II of Prussia invaded Silesia. For several years after this there was fighting across Europe. The Battle of Dettingen on 27 June 1743 saw the British, Hanoverians and Hessians defeat the French. Although Isaac was a musician nevertheless he had to endure the difficult conditions of battle which seriously affected his health. Although all fighting across Europe had ended by 1748, there was still tensions on all sides. William's first years in the Hanoverian Foot Guards were peaceful but in 1756 Hanoverian forces were sent to England to augment the English forces to prepare for an invasion by the French. William, still a musician, was sent with the Hanoverian forces and they were stationed in Maidstone, Kent. The invasion by the French never happened but William took the opportunity to learn English. He also acquired a copy of John Locke's book An essay concerning human understanding which he read and the work influenced him markedly.

Back in Hanover, the Hanoverians were attacked by the French at the Battle of Hastenbeck in July 1757 and were heavily defeated. William, his brother Jacob and his father Isaac, were all musicians in the Hanoverian army and came under fire. Isaac, who did not want to see his sons suffer in this way, advised William to run off. Having never been sworn in as a soldier, he believed that this did not amount to desertion. William went to Hanover but, having no passport, thought he was in danger and returned to the army. A little while later William requested an official discharge. In 1758 he decided that he would return to England and, with Jacob, went to Hamburg where they took a ship to England. They made their way to London and, although they had no money when they arrived, they soon used their musical skills to earn a living. William became a music copyist while Jacob gave lessons and sometimes performed. After two years spent in London, Jacob returned to Hanover while William, feeling that the competition between musicians in London was too great, decided to move away. He accepted a position as head of the Durham Militia Band and lived in Richmond, North Yorkshire during 1760-61.

This period beginning in 1760 was one when William composed symphonies. He composed two while at Halnaby Hall, the home of Sir Ralph Milbanke, where he also performed. By the end of 1760 had completed six symphonies. He performed in a number of cities including Edinburgh and Newcastle-upon-Tyne but around this time he began to study languages and the theory of music. It might be seen as rather surprising that he was led to mathematics through the theory of music but this is indeed what happened and he became keen to study as much as he could. He moved to Sunderland in 1761 when he was appointed as first violin and soloist for the Newcastle orchestra of Charles Avison. He only played for one season before, in February 1762, being appointed as Director of Concerts in Leeds. He continued in this role until the Spring 1766, writing six symphonies for orchestra and at least one violin concerto.

During this 1762-66 period, William took a short holiday back in Hanover in 1764 where he saw members of his family for the first time in seven years. His sister Caroline was particularly pleased to see William. However, William's passion for music was becoming less pronounced and he spent more and more of his spare time studying mathematics. In 1766 he won a competition to become organist at the parish church in Halifax. However, at almost the same time he received an invitation to become the organist at the privately owned Octagon Chapel on Milsom Street in Bath. This was a much more attractive offer but William felt that he had to be fair to Halifax so he remained there for a few months, only leaving for Bath in December of 1766. Halifax made an effort to keep him with an offer of a higher salary but the attraction of Bath was too great.

In Bath William rented a home in Beaufort Square. The organ at the Octagon Chapel was still being constructed when he arrived so for his first concert on 1 January 1767 he performed a violin concerto, an oboe concerto and a harpsichord sonata, all of his own composition. The organ was completed by October 1767 when the choir he had trained performed the Messiah while William performed one of his organ concertos. His brother Jacob, who was at this time back in England, also performed at this concert. William's younger brother Dietrich was causing the family some anxiety so William invited him to Bath where he spent a year receiving a musical education. On 1 June 1770 William left the house in Beaufort Square and went to live at 7 New King Street, a house which he shared with the Bulman family whom he had known from his time in Leeds. At this time he invited his brother Alexander to join him in Bath. In 1772, wishing to help Caroline, he travelled to Hanover and brought her back to Bath with him so that she could become a trained singer. He had to agree to pay his mother enough to employ a servant before she would allow Caroline to leave. Back in Bath William gave Caroline lessons in singing, playing the harpsichord and in bookkeeping. She became his housekeeper.

In addition to mathematics, William started to become interested in astronomy and purchased astronomy books and tables. For example he purchased James Ferguson's Astronomy on 10 May 1773. Other books he had purchased included two of Robert Smith's books, Opticks and Harmonics, Emerson's Trigonometry, and Robert Simson's Euclid. He still earned his living as a major figure in the musical life of Bath, as a teacher, performer, composer and director. By the end of 1773 the passion for astronomy had firmly gripped him and had taken over the lives of the Herschels. Caroline wrote [20]:-

... then it was to my sorrow I saw almost every room turned into a workshop. A cabinet maker making a tube and stands of all description in a handsome furnished drawing room; Alex putting up a huge turning machine (which in the autumn he brought from Bristol) in a bedroom for turning patterns, grinding lenses and turning eye-pieces etc. I was to amuse myself with making the tube of pasteboard against the lenses arrived from London ...

In September William hired a small Gregorian telescope of the style designed by James Gregory. Its performance was not particularly good so that William decided that, rather than make lenses, he would try making his own mirrors. He purchased some equipment to make his own mirrors and by the end of 1773 he was polishing them. In 1774 they moved home, going to a house close to the Walcot turnpike. This house was almost in the country and ideal for making telescopes and for observing but inconveniently far away from the concert halls of Bath where he was still making his living. Music had now become simply the means of making money to buy tools and equipment. In 1775 Caroline wrote [19]:-

... my time was so much taken up with copying Music and practising besides attendance on my Brother when polishing, that by way of keeping him alive I was even obliged to feed him by putting the vitals by bits into his mouth; - this was once the case when at the finishing of a 7 foot mirror he had not left his hands from it for 16 hours together. ... every leisure moment was eagerly snatched at for resuming some work that was in progress, without taking time for changing dress, and many a lace ruffle was torn or bespattered by molten pitch ...

On 29 September 1777 the Herschels moved to 19 New King Street well situated in the centre of Bath, yet with a garden where William could observe with his telescopes. In 1779 they moved again, this time to 5 Rivers Street, an area near where the Royal Crescent and the Circus had just been built. The reason for this move must have been the fact that the house was close to the Bath Literary and Philosophical Society which had been recently founded and began weekly Friday meetings from January 1780. However, the house had no garden and William had to set up his telescopes in a garden behind the Crescent which he hired. He met several important people at this time including William Watson (1744-1824) who invited him to join the Bath Literary and Philosophical Society. He submitted 31 papers to it over the next three years. These were on a variety of subjects including electricity, light, heat, and metaphysics. Three astronomy papers were communicated by William Watson to The Royal Society. Also while in the house, he was visited by Nevil Maskelyne.

For extracts from the three astronomy papers published by the Royal Society, see THIS LINK.

While living in Rivers Street his musical career had continued to progress and he was appointed as director of the Bath orchestra in 1780. At the beginning of March 1781 the Herschels moved back to 19 New King Street. Only a few days later, on 13 March, he discovered the planet Uranus, the first planet to be discovered in historic times. Let us explain briefly the circumstances. William had been examining double stars, that is two stars appearing close together in the sky. His hope was that the fainter one was much further away and he would be able to determine the relative distances using parallax with the diameter of the Earth's orbit as the base line. He was observing the double star Eta Geminorum (also known as Propus) which consists of a 3.3 magnitude star and a 6.5 magnitude star 1.5" apart. He noticed an object so close to the pair as to almost make it look like a triple system, but this third object showed a disk. Three days later he observed that it had moved but he was unsure whether it was a planet of a comet. He corresponded with several people including Maskelyne who replied [20]:-

I am to acknowledge my obligation to you for the communication of your discovery of the present comet, or planet, I don't know which to call it. It is as likely to be a regular planet moving in an orbit nearly circular round the sun as a comet moving in a very eccentric ellipse. I have not yet seen any coma or tail. ...

Interestingly this letter is addressed to "Mr William Herschel, Musician, near the Crescent, Bath." William communicated his discovery to the Royal Society and his paper was read on 16 April. He received the Copley Medal in November 1781 and was elected to the Royal Society on 6 December. In the spring of 1782 he was invited to London by the King who talked with him for half an hour. William wrote to Caroline, who remained in Bath [20]:-

I am introduced to the best company. Tomorrow I dine at Lord Palmerston's, and the next day with Sir Joseph Banks (President of the Royal Society), etc, etc. Among opticians and astronomers nothing now is talked but of what they call my Great discoveries. Alas! this shows how far they are behind, when such trifles as I have seen and done are called great. Let me but get at it again! I will make telescopes, and see such things ... that is, I will endeavour to do so.

For more information about his discovery of Uranus and other discoveries by William Herschel, see THIS LINK.

Offered a pension of £200 a year by the King on condition he came to live near Windsor, William made his last professional musical appearance on 19 May 1782 at St Margaret's Chapel, Bath. For some comments on William Herschel as a musician see THIS LINK.

Together with Caroline, he left Bath in August 1782 living first in a rather poor property near Datchet. For a few months in 1785-86 they lived at Clay Hall in Old Windsor before moving to a house, known as Observatory House, in Slough. Accepting the King's offer of £200 a year meant that William was earning around half of what he earned as a musician. He supplemented his income by making and selling telescopes. However, in 1788 his financial worries ended when he married the rich Mary Pitt, the widow of his friend John Pitt. William moved to make a family home at Upton while Caroline remained at Slough. William and Mary's son John Frederick William Herschel was born in March 1792. On the recommendation of Benjamin Franklin, he had been elected to the American Philosophical Society on 18 February 1787.

Although William is best known for his discovery of Uranus, many consider his greatest achievement was the discovery of infrared radiation in 1800. For a description of this discovery see THIS LINK.

In 1802 William visited Paris where he met and had discussions with Jérôme Lalande, Pierre Méchain, Jean-Baptiste-Joseph Delambre, Pierre-Simon Laplace and Charles Messier. During this visit he met with Napoleon Bonaparte who at the time was First Consul. William answered a few of Napoleon's questions and later wrote that Napoleon's:-

... general air was something like affecting to know more than he did know.

In the spring of 1807 William had a serious illness. From that time on his health was poor and he could not do as much in the way of observing as he had been doing for many years. He continued to write papers which were published by the Royal Society.

The Royal Astronomical Society was founded in January 1820. John Herschel wrote in his diary:-

Tuesday, February 29, 1820. - Took up quarters at Bedford Place and dined there. My Father and Mother came to dinner. Evening, attended the meeting of the Astronomical Society, at which my Father was voted Vice-President.

Friday, March 3, 1820. - Returned to Slough with my Father and Mother, calling on my uncle B on the way.

In April 1820 the Council of the Astronomical Society asked William to become their first President, stating that he would not be required to give any active service. William refused but accepted in the following year becoming the Royal Astronomical Society's first President. Henry Thomas Colebrooke took the chair at meetings, William having said he would not play an active role. After his death in 1822, Colebrooke became the Astronomical Society's second President.

For additional information on William and Caroline Herschel, see our article A visit to the Herschel Museum at THIS LINK.

For information about some of William Herschel's astronomical discoveries, see THIS LINK.

Craters on the Moon and on Mars have been named after William Herschel.