[13] See Things not generally Known, p. 88.
[14] Some time before the first announcement of the discovery of sun-painting, the following extract from Sir John Herschel’s Treatise on Light, in the Encyclopædia Metropolitana, appeared in a popular work entitled Parlour Magic: “Strain a piece of paper or linen upon a wooden frame, and sponge it over with a solution of nitrate of silver in water; place it behind a painting upon glass, or a stained window-pane, and the light, traversing the painting or figures, will produce a copy of it upon the prepared paper or linen; those parts in which the rays were least intercepted being the shadows of the picture.”
[15] In his book on Colours, Mr. Doyle informs us that divers, if not all, essential oils, as also spirits of wine, when shaken, “have a good store of bubbles, which appear adorned with various and lively colours.” He mentions also that bubbles of soap and turpentine exhibit the same colours, which “vary according to the incidence of the sight and the position of the eye;” and he had seen a glass-blower blow bubbles of glass which burst, and displayed “the varying colours of the rainbow, which were exceedingly vivid.”
[16] The original idea is even attributed to Copernicus. M. Blundevile, in his Treatise on Cosmography, 1594, has the following passage, perhaps the most distinct recognition of authority in our language: “How prooue (prove) you that there is but one world? By the authoritie of Aristotle, who saieth that if there were any other world out of this, then the earth of that world would mooue (move) towards the centre of this world,” &c.
Sir Isaac Newton, in a conversation with Conduitt, said he took “all the planets to be composed of the same matter with the earth, viz. earth, water, and stone, but variously concocted.”
[17] Sir William Herschel ascertained that our solar system is advancing towards the constellation Hercules, or more accurately to a point in space whose right ascension is 245° 52′ 30″, and north polar distance 40° 22′; and that the quantity of this motion is such, that to an astronomer placed in Sirius, our sun would appear to describe an arc of little more than a second every year.—North-British Review, No. 3.
[18] See M. Arago’s researches upon this interesting subject, in Things not generally Known, p. 4.
[19] This eloquent advocacy of the doctrine of “More Worlds than One” (referred to at p. 51) is from the author’s valuable Outlines of Astronomy.
[20] Professor Challis, of the Cambridge Observatory, directing the Northumberland telescope of that institution to the place assigned by Mr. Adams’s calculations and its vicinity on the 4th and 12th of August 1846, saw the planet on both those days, and noted its place (among those of other stars) for re-observation. He, however, postponed the comparison of the places observed, and not possessing Dr. Bremiker’s chart (which would at once have indicated the presence of an unmapped star), remained in ignorance of the planet’s existence as a visible object till the announcement of such by Dr. Galle.
[21] For several interesting details of Comets, see “Destruction of the World by a Comet,” in Popular Errors Explained and Illustrated, new edit. pp. 165–168.