an autobiography-第75章
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hat when my friend William Lassell saw it； he said 〃it made his mouth water。〃 It was about this time （1840） that I had the great happiness of becoming acquainted with Mr。 Lassell；* ＇footnote。。。 Mr。 Lassell was a man of superb powers。 Like many others who have done so much for astronomy； he started as an amateur。 He was first apprenticed to a merchant at Liverpool。 He then began business as a brewer。 Eventually he devoted himself to astronomy and astronomical mechanics。 When in his twenty…first year he began constructing reflecting telescopes for himself。 He proceeded to make a Newtonian of nine inches aperture； which he erected in an observatory at his residence near Liverpool； happily named 〃Starfield。〃 With this instrument he worked diligently； and detected the sixth star in the trapezium of Orion。 In 1844 he conceived the bold idea of constructing a reflector of two feet aperture； and twenty feet focal length； to be mounted equatorially。 Sir John Herschel； in mentioning Mr。 Lassell's work； did me the honour of saying 〃that in Mr Nasmyth he was fortunate to find a mechanist capable of executing in the highest perfection all his conceptions； and prepared by his own love of astronomy and practical acquaintance with astronomical observations； and with the construction of specula； to give them their full effect。〃 With this fine instrument Mr。 Lassell discovered the satellite of Neptune。 He also discovered the eighth satellite of Saturn； of extreme minuteness； as well as two additional satellites of Uranus。 But perhaps his best work was done at Malta with a much larger telescope； four feet in aperture； and thirty…seven feet focus； erected there in 1861。 He remained at Malta for three years； and published a catalogue of 600 new nebulae； which will be found in the Memoirs of the Royal Astronomical Society。 One of his curious sayings was； 〃I have had a great deal to do with opticians； some of themlike Cooke of Yorkare really opticians； but the greater number of them are merely shopticians！〃 。。。＇ and profiting by his devotion to astronomical pursuits and his profound knowledge of the subject。 He had acquired much technical skill in the construction of reflecting telescopes； and the companionship between us was thus rendered very agreeable。 There was an intimate exchange of opinions on the subject； and my friendship with him continued during forty successive years。 I was perhaps a little ahead of him in certain respects。 I had more practical knowledge of casting； for I had begun when a boy in my bedroom at Edinburgh。 In course of time I contrived many practical 〃dodges〃 （if I may use such a word）； and could nimbly vault over difficulties of a special kind which had hitherto formed a barrier in the way of amateur speculum makers when fighting their way to a home…made telescope。 I may mention that I know of no mechanical pursuit in connection with science； that offers such an opportunity for practising the technical arts； as that of constructing from first to last a complete Newtonian or Gregorian Reflecting Telescope。 Such an enterprise brings before the amateur a succession of the most interesting and instructive mechanical arts； and obliges the experimenter to exercise the faculty of delicate manipulation。 If I were asked what course of practice was the best to instil a true taste for refined mechanical work； I should say； set to and make for yourself from first to last a reflecting telescope with a metallic speculum。 Buy nothing but the raw material； and work your way to the possession of a telescope by means of your own individual labour and skill。 If you do your work with the care； intelligence； and patience that is necessary； you will find a glorious reward in the enhanced enjoyment of a night with the heavensall the result of your own ingenuity and handiwork。 It will prove a source of abundant pleasure and of infinite enjoyment for the rest of your life。
I well remember the visit I received from my dear friend Warren de la Rue in the year 1840。 I was executing some work for him with respect to a new process which he had contrived for the production of white lead。 I was then busy with the casting of my thirteen…inch speculum。 He watched my proceedings with earnest interest and most careful attention。 He told me many years after； that it was the sight of my special process of casting a sound speculum that in a manner caused him to turn his thoughts to practical astronomy； a subject in which he has exhibited such noble devotion as well as masterly skill。 Soon after his visit I had the honour of casting for him a thirteen…inch speculum； which he afterwards ground and polished by a method of his own。 He mounted it in an equatorial instrument of such surpassing excellence as enabled him； aided by his devotion and pure love of the subject； to record a series of observations and results which will hand his name down to posterity as one of the most faithful and patient of astronomical observers。
＇Image＇ Fireside； Patricroft。 After a drawing by James Nasmyth
But to return to my own little work at Patricroft。 I mounted my ten…inch home…made reflecting telescope； and began my survey of the heavens。 Need I say with what exquisite delight the harmony of their splendour filled me。 I began as a learner； and my learning grew with experience。 There were the prominent stars； the planets； the Milky Way with thousands of far…off sunsto be seen。 My observations were at first merely general； by degrees they became particular。 I was not satisfied with enjoying these sights myself； I made my friends and neighbours sharers in my pleasure； and some of them enjoyed the wonders of the heavens as much as I did。
In my early use of the telescope I had fitted the speculum into a light square tube of deal to which the eye…piece was attached； so as to have all the essential parts of the telescope combined together in the most simple and portable form。 I had often to remove it from place to place in my small garden at the side of the Bridgewater Canal； in order to get it clear of the trees and branches which intercepted some object in the heavens which I wished to see。 How eager and enthusiastic I was in those days！ Sometimes I got out of bed in the clear small hours of the morning； and went down to the garden in my night…shirt。 I would take the telescope in my arms and plant it in some suitable spot； where I might get a peep at some special planet or star then above the horizon。
It became bruited about that a ghost was seen at Patricroft！ A barge was silently gliding along the canal near midnight； when the boatman suddenly saw a figure in white。 〃It moved among the trees with a coffin in its arms！〃 The apparition was so sudden and strange that he immediately concluded that it was a ghost。 The weird sight was reported at the stations along the canal； and also at Wolverhampton； which was the boatman's headquarters。 He told the people at Patricroft on his return journey what he had seen； and great was the excitement produced。 The place was haunted： there was no doubt about it！ After all； the rumour was founded on fact； for the ghost was merely myself in my night…shirt； and the coffin was my telescope； which I was quietly shifting from one place to another in order to get a clearer sight of the heavens at midnight。
My ambition expanded。 I now resolved to construct a reflecting telescope of considerably greater power than that which I possessed。 I made one of twenty inches diameter； and mounted it on a very simple plan； thus removing many of the inconveniences and even personal risks that attend the use of such instruments。 （For illustration of the plan of mounting a large telescope； see p。 338） It had been necessary to mount steps or ladders to get at the eyepiece； especially when the objects to be observed were at a high elevation above the horizon。 I now prepared to do some special work with this instrument。 In 1842 I began my systematic researches upon the Moon。 I carefully and minutely scrutinised the marvellous details of its surface； a pursuit which I continued for many years； and still continue with ardour until this day。 My method was as follows：
I availed myself of every favourable opportunity for ca
