SCIENCE. 



First, let the fact be stated, that during' the total phase 

 of the eclipse which lasted but 162 seconds, two exper- 

 ienced observers, with telescopes in everyway well adapted 

 for the work, state with positiveness that each saw two 

 objects not down on any star chart, and, that they were 

 not there when the sun had sufficiently withdrawn to 

 allow the locality to be re-observed. On the other hand, 

 three observers who searched west of the sun, one in a 

 cloudy sky, and two of the others poorly equipped, and, 

 devoting but a few seconds to the search, saw nothing, 

 not even 6 Cancri, a star of the fifth magnitude, near 

 where one of Watson's and both of my objects were 

 seen. The weakness of this negative testimony will be 

 apparent from a few extracts from their reports. 



Mr. Wheeler (telescope 5 inch, power 100) says, he 

 observed the second and third contacts (beginning and 

 end of totality), also the Corona on both sides of the sun, 

 saw with the naked eye Venus, Mercury and Regulus, 

 observed carefully the several prominences, etc., and then 

 says, " An unsatisfactory attempt was made to sweep 

 for Vulcan. The time given to it was limited, as I was 

 expected to observe all the contacts, and time was con- 

 sumed in recording the second, and again in bringing the 

 telescope into position for observing the third contact." 

 Now when it is considered that he undoubtedly occupied 

 several seconds in looking at the grand sight with the 

 naked eye, and, that the power used was altogether 

 too high, and of course, the field very small, the 

 time devoted to the search for Vulcan could have 

 been but a few seconds. Is it therefore surprising that 

 Mr. Wheeler saw nothing of the objects seen by me ? 

 Only those familiar with the use of telescopes know how 

 perplexingly difficult it is to bring a well-known object in 

 the field of a telescope, using a power of 100. 



Mr. Bowman (telescope 3 inch, power 30) says he 

 searched north and west ot the sun (my objects, also 

 Watson's, were southwest), and that some time was lost 

 (during totality) in exchanging the diagonal tube for the 

 straight one, swept to the westward 5 or 6° in the 

 declination of the sun, and then returning, shifted the 

 declination just far enough north to clear the Corona and 

 swept to the westward again, then returned to the R. A. 

 of the sun and shifted to the proper declination just in 

 time to observe the third contact. When it is consid- 

 ered how much precious time was lost in observing and 

 recording in his note-book the time of second contact, 

 changing tubes, and probably observing the eclipse for 

 several seconds with his naked eye, which he could 

 hardly refrain from doing, is it at all wonderful that Mr. 

 Bowman saw nothing of my objects or Watson's either? 



Prof. Todd (telescope 4 inch, power 20) says, " I 

 searched 15° each side of the sun, but the sky was cloudy, so 

 much so that I was unable to see Delta Cancri," (a 4th 

 mag. star). He does not say how much time he spent 

 searching west of the sun. It certainly could have been but 

 a moment, and, in the region where my objects were, but a 

 few seconds. He, too, observed the second contact, also 

 the Corona, saw Mercury, Venus, Mars, and Procyon. 

 Again I ask is it at all surprising that Prof. Todd saw 

 nothing of the objects seen by me ? 



Prof. Pritchett (telescope y/ z inch, power 90) says he 

 first observed the grand scene with a naked eye, then 

 swept along the ecliptic several degrees each side of the 

 sun, observed all the phenomena of the eclipse, the sec- 

 ond contact, Corona, the prominences, and the question 

 arises how many seconds he searched with a very small 

 field west of the sun for the "Ghost of Vulcan," as he 

 facetiously calls it. Still again I ask is it at all wonder- 

 ful that Prof. Pritchett saw nothing of the objects seen 

 by me ? Would it not, in fact, have been very surprising 

 had he seen them at all ? 



Your correspondent has given in his diagram the out- 

 lines of the regions swept over by the above observers, 

 saying : " The place of one of Watson's stars was cov- 

 ered by Wheeler, Bowman and Pritchett, and the place of 



Swift's two stars was examined by Bowman and Wheeler, 

 and that one of the stars appears in the corner of 

 Pritchett's sweep." Now all this is calculated to convey 

 a wrong impression, for it is not likely that either of 

 them knew within from i° to 3" the exact boundaries 

 of their hastily-made sweeps ; neither do I pretend to be 

 exact about the .location of the stars I saw, although I 

 made three estimates of their deviation and distance from 

 the sun, by sighting along the outside of the telescope 

 tube. 



They are wrongly placed in the diagram. They were 

 nearer where Theta is, and probably somewhat west of it, 

 which would place it outside of the sweeps of all the ob- 

 servers. I should strongly suspect that one of them 

 was 6, wert it not that Watson, who says he saw that 

 star, says nothing about another equally bright some 7' 

 from it, both ranging with the sun's centre. 



Neither in his published statements, or letters to me, 

 does he allude to this vital point. It was as impossible for 

 him to have seen one and not the other, as for one to see 

 Epsilon 4 Lyras, without, at the same time, seeing Ep- 

 silon 5. 



Again, he says, as far as relative position is concerned, 

 my objects resemble closely d- Cancri. and B. A. C. 2810, 

 on the east side of the sun. I hope he does not mean to 

 be understood as inferring that it was on the east, instead 

 of the west, of the sun I was searching. 



Finally, he says, the existence of an intra-mercurial 

 planet is not yet admitted by the majority of astronomers. 

 This may be true, but I hope their opinion is based on 

 stronger evidence than that adduced by "W. C. W." 



Lewis Swift. 



Rochester, N. Y., April n, 1881. 



CORRESPONDENCE. 



[ The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous communi- 

 cations.] 



DISCREPANCIES IN RECENT SCIENCE. 

 To the Editor of Science : — 



The article on " Discrepancies in Recent Science " in 

 a late number of this journal demands some attention, not 

 because the Nebula Theory is seriously threatened by it, 

 but because it properly calls attentions to some physical 

 inferences that have been drawn from other phenomena 

 and applied to the Nebula Theory, especially in the domain 

 of heat. It is assumed by the writers quoted in that 

 article, that luminousness implies high temperature and 

 also that the rarity of the gaseous material of the nebula 

 is the immediate result of the high temperature of 'the 

 constituent atoms. Neither of these assumptions is 

 correct. The trouble comes chiefly from the writer's fail- 

 ure to make the proper distinction between energy and 

 heat, and I apprehend, also, in the failure to see clearlv 

 what the nature of heat is. Most of the books treat of 

 this in a very loose way, and most of the statements on the 

 subject by Mr. Charles Morris are wrong. How far wrong 

 may be seen by comparing his statements with the follow- 

 ing quotation from " The Mechanical Theory of Heat," by 

 Clausius, Chap. 1st, Sec. X, p. 24: "All heat existing in 

 a body is appreciable by the touch and by the thermome- 

 ter ; the heat which disappears under the above changes 

 of condition {fusion and zaporization) exist no louder 

 as heat, but has been converted into work, and the heat 

 which makes its appearance under the opposite changes 

 {solidification and condensation) does not come from any 

 concealed source, but is newly produced by work done on 

 the body." We have all along been familiar with the 

 conception of heat as a mode of motion, but not with the 

 character of the motion except as " a brisk agitation ot 

 the molecules " or " a rapid vibration of the atoms ;" but 

 there are two kinds of vibratory motions possible to 

 atoms, one of the character of pendulous motion or a 



