214 



NATURE 



{Jan. 14, 1875 



editor of Gassendi's works*), and afterwards at M. 

 Theveiiot's.f A few foreign visitors to Paris were pre- 

 sent at these meetings. . . . It is possible that tliese 

 Paris assemblies have given birth to several Academies 

 in the rest of Europe. However, it is certain that the 

 English gentlemen who created the Royal Society had 

 travelled in France, and had visited at Montmort's and 

 Thevenot's. 



" When they were again in England they held meetings 

 at Oxford, and kept on practising the exercises to which 

 they had been accustomed in France. The rule of 

 Cromwell was beneficial to these meetings. These 

 English gentlemen, secretly attached to their legitimate 

 lord, and unwilling to take any part in public affairs, 

 were very glad to find an occupation which would give 

 them an opportunity of living far from London without 

 being suspected by the Protector. The Society remained 

 in this state up to the time when Charles II., having re- 

 sumed the kingly office, brought it to London, con- 

 firmed it by his regal power, and gave it privileges. So 

 Charles II. rewarded the sciences which had lent an easy 

 pretext for keeping the faith towards him." 



The narrative explains that the creation of the Royal 

 Society was an example given to Louis XIV. for esta- 

 blishing his Academy of Sciences. 



THE TRANSIT OF VENUS 



SINCE our last notice of the Transit observations, a 

 letter, dated Mauritius, Dec. 10, has been received 

 by the Astronomer Royal from Lord Lindsay, containing 

 a detailed account of the results he obtained. Besides, a 

 brief statement of the observations of Mr. Meldrum, the 

 Director of the Government Observatory, Mauritius, 

 has appeared in the Times, with news from other ob- 

 servers, which, with its comments upon them, we repro- 

 duce in a condensed form. 



Mr. Meldrum, with a perfect telescope of six inches 

 aperture, by Cooke, of York, has been fortunate enough 

 to obtain an observation of the ingress, although both 

 Lord Lindsay and the German party were prevented from 

 doing this by the cloudy state of the sky. But, although 

 Mr. Meldrum obtained the two interior contacts, clouds 

 and haze were at intcn'als passing over the sun, which, 

 in fact, was obscured during the greater part of the 

 transit. At times, beautiful definitions of the planet were 

 noted, especially soon after the first interior contact. 

 Then there was a long period of obscuration, after which, 

 most fortunately, the sun shone out for the second interior 

 contact. Only the first exterior contact was lost, the sun 

 not appearing at all until 6h. i6m. A few minutes before 

 the last exterior contact the sun was again obscured, and 

 when the clouds passed away the transit was over. 



Lord Lindsay states that his expedition has been in a 

 great measure successful. The morning of the 9th was 

 cloudy before sunrise, and for a short time afterwards. 

 The first external and first internal contacts were missed 

 from this cause ; the sun was not seen until ih. 2m. after 

 the first external contact, when it came out for a few 

 minutes, when photographs and measures were obtained. 

 It was not till 8 A.M. (local mean time) that it became 

 fairly fine, and remained so with small periods of cloud 

 obscuration until the eijd of the transit. Lord Lindsay 

 took 271 plates, out of which number, perhaps, 110 will 

 be of value. One of his photographs shows the second 

 internal contact beautifully. 



With the heliometer, Mr. Gill obtained five complete 

 determinations of greatest and least distance of the centres 



* Montmort for years entertained Gassendi in his house. He 

 ^e.-a\.^&lfibliophtle , and all the books from his hbrary now realise 

 value. He was a member of the Academic Fran(;aise, 



+ Thevenot had travelled much, and was in constant correspondence with 

 many tr.-ivcllers He had been appointed librarian to tlie King, and lived 



the house where the library was kept, in what is now the Rue Vivienne, 

 within a little distance of its present site. 



of the sun and Venus, besides nine measures of cusps and 

 two separate determinations of the diameter of Venus 

 near the end of the transit. Dr. Copeland obtained, with 

 the six-inch equatorial and Airy double-image micrometer, 

 fifteen measures of least distance of Venus from the sun's 

 limb, and ten measures of cusps. Dr. Copeland also 

 observed the last internal and external contacts with this 

 instrument. The last internal contact was observed with 

 the four-inch equatorial and the polarising eye-piece by 

 Mr. Gill. He also observed the last external contact with 

 the heliometer. Both Dr. Copeland and Mr. Gill agree 

 that the contacts of Venus and the sun are remarkably 

 similar to those seen in the model. They also agree that 

 any phenomena which could be classed under the head 

 " black drop " took place and disappeared within a period 

 of five seconds. All the photographic exposures are auto- 

 matically registered on the chronograph by a method 

 which gives the actual duration of the exposure. The 

 heliometer observations were also registered there. Dr. 

 Copeland observed by eye and ear ; all other observa- 

 tions (photographic and heliometric) also observed by 

 eye and ear as a check on the chronograph. The German 

 expedition under Dr. Low got the third and fourth con- 

 tacts, with three complete sets of heliometric measures. 



With regard to the operations of the party sent out by 

 the Government of Holland to Reunion, the further infor- 

 mation shows that there, as at Mauritius, the ingress was 

 missed altogether, in consequence of the bad weather. 

 The second interior contact at egress was observed both 

 by Dr. Oudemans and Dr. Soeters, not the least trace of 

 the black drop being observed. Only nineteen plates could 

 be exposed, and of these only two or three are considered 

 of value. The observations with the heliometer were more 

 successful. The party, instead of measuring the distance 

 of the planet from the sun's edge along a radius, had cal- 

 culated beforehand, for each ten minutes, the direction of 

 the most favourable chord for determining the relative 

 parallax of Venus ; two sets of eight measures of this kind 

 were recorded. 



Some observations made at Colombo by Mr. George 

 Wall, and communicated to the Ccyloii Times, are of 

 great interest, as here is again recorded an exact repro- 

 duction of the appearance observed by Chappe d'Auteroche 

 in 1769. On this the Times remarks that it is clear that 

 science will lose much from an incomplete discussion of 

 all the observations made in 1761 and 1769. On this 

 subject we also draw attention to the following letter 

 which we have received from Mr. E. W. Pringle, dated 

 Manantoddi, Wynaad, Dec. 13 : — 



" I make no apology for sending you a slioit account of the late 

 transit as seen by me in Wynaad, especially as I feel some sur- 

 prise at the difference between the expected and actual phe- 

 nomena. 



" Owing to non-receipt of instruments from England, I had to 

 fall back on a small 2^ refractor by Cooke, of York, the defi- 

 nition of which is superb, even with a power of 53 — that used 

 on the occasion. 



"My station was "on a hill nine miles from Manantoddi, about 

 800' above that place and 3,600' above sea-level. 



" The morning of the gth was simply perfect ; not a breath of 

 air, and not a cloud, with the exception of a wisp or two of 

 cirrus that the sun soon shook off. 



" The plateau beneath was wrapped in the fleecy mantle that 

 proved so disastrous to the eclipse observers of 1S71, but this I 

 could afford to despise from my more lofty station. 



"I missed first external contact, and watched anxiously for the 

 internal contact. When the planet was about half immersed, the 

 entire disc became visible, for the portion external to the solar 

 surface was surrounded by a fine silvery ring like a minute corona. 

 This obseivation was verified by my brotlier, and the pheno- 

 menon was again visible at emersion. 



" As first internal contact approached I looked carefully for the 

 ' black drop,' but, to my astonishment, the horns of the sun 

 grew nearer and nearer, and at last seemed to fade into the last 

 portion ot the before-mentioned silvery ring, without my seeing 

 the smallest vestige of the far-famed ' drop, ' or any apparent 



