June 9, 1881] 



NATURE 



129 



office of the Post Office telegraphs. In connection with 

 this system, I would express the hope that the proposal 

 to establish an hourly signal at the Start Point will be 

 borne in mind. 



" Last autumn a telegraphic determination of the longi- 

 tude of Leiden was made with great care by M. M. 

 Bakhuyzen. The interchange of signals between Green- 

 wich and I eiden occupied nearly tour months. I may 

 here remark that the American extension of longitude 

 carried out under Commander Green, U.S.N., to which 

 reference was made in the last report, will be most useful 

 for the transit of Venus in 1S82. Cannot a British officer 

 be found to complete the operations for Australia and 

 New Zealand } 1 lament that this has not been done. 

 Mr. Gill has undertaken the necessary work for the 

 Cape." 



The following important general remarks conclude the 

 report : — 



"The present meeting may afford a fitting oppor- 

 tunity for the expression of my views on the general 

 objects of the Observatory, and on the duties which they 

 impose on ail who are actively concerned in its conduct. 

 Assuming as beyond dispute that these ought to be carried 

 out in a spirit liberal in itself and honourable to the 

 nation, I proceed to state my opinion on the line of 

 action which they suggest. 



'"The object prescribed to the Observatory is the pro- 

 motion of ''Astronomy and Navigation." And, since the 

 abolition of the Board of Longitude, the second of these 

 objects (which historically gave rise to the introduction of 

 the first) presses upon the directors of the Observatory 

 much more strongly than before. Consideritig then the 

 claims of astronomy as b aring on navigation and our 

 responsibilities in reference to them, we find that those 

 responsibilities are b) no means narrow. Whatever the 

 rest of the scientific world may do or may not do, we are 

 responsible for determinations of the fundamental ele- 

 ■ments of sidereal, solar, and especially lunar astronomy, 

 with the highest accura;y that modern skill can secure. 

 The same apparatus of instruments and of mathematical 

 treatment which fix the places of fundamental stars will 

 apply to those of other stars ; the same which apply to 

 the sun will apply to planets and comets (not unconnected 

 with solar theory, by virtue of perturbation) and even to 

 satellites. And we could hardly consider ourselves as 

 discharging our duty to the more educated portion of the 

 nation, or as maintaining our proper position in the world, 

 if we did not include in our operations these latter off- 

 shoots of the first-mentioned objects. 



" But new astronomical subjects have arisen of which no 

 one dreamed when our constitution was first fixed. The 

 first of these was the measures of double stars But this, 

 though important as ever, has almost disappeared from 

 our view when occupied with solar and spectroscopic 

 physi "S. I yield to no one in the interest which I take 

 in these subjects, and in the admiration with which I 

 regard the positive conclusions and the problematic 

 suggestions which are founded on them But I still point 

 out that these are not parts of our original system, and 

 their connection with the Greenwich Cibservatory is at 

 any time liable to question. 



" I now advert to the general subject of navigation. And 

 first I remark that magnetisn, in its ordinary and nautical 

 form, is indisputably a proper subject for the Observatory. 

 But within the present century there have arisen : — the 

 accurate examination of maj,'netic irregularities, the par- 

 tial redu.nion of daily irregularities to practical laws (still 

 wanting theoretical explanation), and the establishment 

 of the simultaneous co-existence of occasional disturb- 

 ances covering the whole surface of the earth. Connected 

 with these is the observation of magnetic currents through 

 the terrestrial soil, registered at Greenwich for many years 

 past, and now attracting attention on the Continent. 

 Perhaps no branch of physics bears the same prospective 



importance as these. Yet I conceive that their continued 

 study in this Observatory requires special authorisation. 



" The original views in making astronomy contributory 

 to navigation were limited to observations of the moon. 

 But in the latter part of the last century the possibihty of 

 making chronometers subservient to the determination of 

 longitude (a subject to which the late Board of Longi- 

 tude gave good attention, and to which the Government 

 has always offered liberal rewards) was proved, and in 

 the present century the improvement has been very great. 

 This has been effected by our Hydrographical Office 

 (mainly through the action of the Observatory), partly by 

 specific rewards, partly by careful attention to the 

 accuracy of every chronometer purchased. And the 

 practical value of the chronometric system has been very 

 greatly increased by taking advantage of the galvanic 

 distribution of time currents, and by the galvanic exhibi- 

 tion of ball-drops and other signals. There can be no 

 doubt that all the agencies involved in this system are 

 well employed, and that they are a legitimate part of the 

 Observatory duty as originally contemplated. 



"Still I remark that the Observatory operations bearing 

 on chronometric navigation are not carried out to the 

 extent which I could desire. It is known to all persons 

 familiar with chronometers that rates of the chronometers, 

 obtained while the ships are actually in voyage, would 

 possess remarkable value. We possess the power of giving 

 facility for obtaining these to a large part of our mercan- 

 tile navy, by exhibiting a time-signal at every hour, at 

 Deal (where the necessary apparatus already exists) and 

 on the Start Point. I have several times brought this 

 proposal, as regards the Start, before the Government, 

 but unsuccessfully. But I should have done wrong if I 

 had omitted, in this general survey of the duties of the 

 Observatory, to state my continued conviction that this 

 is a proper and very desirable addition to the other points 

 of assistance which we can give to navigation. 



"Next — closely connected however with the subject of 

 navigation — is the knowledge of the longitudes of distant 

 ports, as referred to the Greenwich Clbservator)'. And I 

 approach this subject with grief. We have entirely aban- 

 doned the longitudes of the Atlantic, which have been 

 cleared away, before our eyes, by the scientific enterprise 

 of another nation. The Pa:ific, bearing those vast and 

 important colonies, almost entirely British, is equally 

 neglected ; though so much is ready that the mission 

 of a single officer would c[uickly establish all. The same 

 aspiring nation which has mastered the Atlantic is now 

 bent (as I understand) on adding to its scientific dominion 

 the Pacific. I think this is not honourable to our nation. 



"There remains another subject, which occupies no small 

 part of the force of the Observatory, and which I am 

 unable to connect with either of the two great divisions 

 to which I have alluded — the subject of meteorology. It 

 is exceedingly popular in the country, perhaps because it 

 requires little of expense or of science. It is also pursued 

 at many foreign observatories, where vast numbers of 

 observations are produced without attempt at classifica- 

 tion or reduction. We at least are not amenable to this 

 accusation, and may appeal to our reduction of more 

 than twenty years' collected obsei"vations as giving matter 

 of permment interest to the more scientific meteorologist, 

 and even to the geologist. Still I call attention to the 

 fact that this is a subject which, though introduced 

 mainly by myself, I regard as foreign to the original 

 'Astronomy and Navigation' of the Observatory. 



" There is still a matter for consideration, not in our 

 obser\-ations, but in the mechanism by which they are 

 made available to the world — I mean our printing. I 

 have repeatedly expressed my opinion that the extent of 

 our printing is far too great : not in the full exhibition of 

 reductions, but in the minute details of individual obser- 

 vations. There are printed every year more than 7000 

 transits or circle readings, each consisting of 6 or 7 indi- 



