January 24, 1895] 



NA TURE 



297 



needle (75^'), is 74^28'. Hence the agreement is quite 

 satisfactory. We can prob.ibly say that the magnetic 

 dip in r,ondon in 17200 was 74 5 ± 05 . 



The invention of this new method of determining dip, 

 led to still more important results. In making the dip 

 observations with the long needle in 1720, for the pur- 

 pose of his second chart, he at the same lime observed 

 the time of one horizontal vibration of the same needle, 

 with the express purpose of determining the distribution 

 of the force. These vibration-times are tabulated on his 

 second chart." From them the distribution of relative 

 intensity can be determined. These observations of 

 Whision's are undoubtedly the earliest relative terrestrial 

 ma(;netic force observations ever tnade. It is usually 

 believed that the earliest relative intensity observations 

 are the defective ones of .Mallet (1769), or the more 

 successful ones, but lost in shipwreck, of Lamanon (17S5- 

 87). The abs >lute value of these Whistonian intensity 

 observations can, of course, not be checked ; however, the 

 relative value admits of some control. Thus the writer 

 in his paper has reduced the observations, taking the 

 value of the horizontal force at London as unity, and, 

 with the aid of the reduced values, has roughly sketched 

 the isodynamics (the broken lines in the figure) 

 as prevailing over southern England in 1720. It will 

 be seen that these lines of equal magnetic hori- 

 zontal force have the same general trend as the 

 isoclinics, as, indeed, they roughly should. Again, taking 

 two stations (London and Sallfleet), which are prac- 

 tically in the same meridian and are distant from 

 each other 2' in latitude, through which, consequently, 

 the same isodynamic would not be likely to pass, it is 

 found that the difference of the vibration-times — 6o| and 

 66 -seconds respectively, is in the right sense, i.e., since 

 the force varies inversely as the squares of the vibration- 

 times, the more northerly station, Saltfleet, gives the 

 smaller horizontal force, as it should. To be sure these 

 early intensity observations are affected with a large 

 probable error ; they may, however, not deserve to be 

 assigned to utter oblivion. 



Upon the presentation of the writer's paper before the 

 Washington Philosophical Society, Prof. Abbe became 

 interested in the matter, and kindly called the author's 

 attention to a later book'- of Whiston's, a copy of which 

 was likewise found in the Royal Library of Berlin. 

 Whiston, in this book, gives an account of dip-observa- 

 tions made in various portions of the earth, with the aid 

 of most liberal means furnished by King George and 

 others, for the purpose of testing his magnetic method of 

 determining geographical position. He sent "four 

 several Dipping-Needles to Sea,'' and "with proper In- 

 structions to the Masters of the Vessels" to observe the 

 dip with both methods ''direct and indirect)," to discover 

 the State of Magnetism in the several parts of the 

 Globe." Thus Captain James Jolly set out in July, 1722, 

 for Archangel with one of Whiston's dipping-needles. 

 Owing to a defect of the instrument he could observe 

 only horizontal vibrations. Whiston says (p. 84), " he 

 made me twenty-eight very good Horizontal Observations 

 from the Latitude of 65 quite to Archangel." ... "In 



!■ The only thing that Whiston says with respect to the method employed, 

 is the f -llowins Passage on page 112, viz : "The Difference of this. S7r,-«^r/: 

 of the Magnetick Power, from its Direction, is most visible in my Second .Map 

 hereto prelix'd. Where I have all ating set do%vn the * Seconds* wherein my 

 Needle pcrform'd a single h-jrizontal Vibration, at about 123 Degrees from 

 the M.ignetick Meridian, in most Places, whose Squares, when Allowance has 

 ')ccn made for the different Obliquity of the several Directions as to our 

 Horizon, will give us the different Strength of that Magnelick Power at those 

 several Places ; .s does the angle of dip give us the different Direction of 

 the same power there. Now, at first .Sight, the former there appears to be 

 irregular, and the latter regular : as is the Case also of our Tcrella " Why 

 Whiston should have observed the vibration time iso' from the magnetic 

 merriiian, instead of across the magnetic meridian, the writer has not been 

 able to ascertain. Whiston does not appear to have made any further use 

 of his observations. 



'- " The Calculation of Solar I-'clipses without Parallaxes .... with an 

 Account of some late Observations made with Dipping-Necdies. in order to 

 discover the Ixjngitude and I.atitude at Sea." (London, 1724.) 



NO. 13 I 7, VOL. 51] 



this Space the Needle altered its \'elocity very greatly, 

 as I expected it would : And 5 Vibrations which at first 

 were perform'd in about 280', beyond the North Cape, 

 came to 250 ; till towards .\rchangel it gradually returned 

 toabout 177"." Thefirst figure, 280", is probably a misprint, 

 andshouldbe 180". These ob.^er-i'ations are thefirst to sho-jo 

 the truth of the law that horizontal intensity decreases 

 in approaching the magnetic pole. Humboldt has 

 credited Lamanon (1785-S7) with the discovery of this 

 law ; it was not, however, firmly established until Hum- 

 boldt's observations of 1798-1803. Furthermore, Captain 

 Othniel Beal set out about the same time as Captain Jolly 

 for Boston. From thence he sailed to Barbados, and 

 thence to Charlestown, South Carolina. At all these 

 places and at sea he made dip observations with both 

 methods. A dip of 68' 22' is given for Bo-ton, and of 

 44^' for Barbados, on p. 92. These two dips precede by 

 ft/ty-eight years any dip tliat has hitherto become known 

 in the United States. The vibration-times are unfortun- 

 ately not given. A third dip instrument was sent with 

 Captain Tempest to Antigua and St. Christopher's, a 

 fourth sent with Captain Michel to Hamburg. The results 

 with the last two instruments had not yet been all received 

 at the writing of the book. Whiston does not give the 

 actual observations, but says, on p. 90, "The original 

 Journals are all in the Hands of my great Friend and 

 patron, .Samuel Molyneux, Esq., Secretary to his Royal 

 Highness the Prince of Wales, and Fellow of the Royal 

 Society : which Journals, when I have compleated the 

 rest of the Observations I hope to procure, I intend to 

 publish entire, for the more full Satisfaction of the 

 curious." It seems that Whiston never published these 

 records. It is hoped that the present article will induce 

 some one to look them up. They may possibly be a 

 valuable find. 



In conclusion, let us sum up Whiston's achieve- 

 ments. 



(i) Whiston drew the first isoclinics (1719-20). 



(2) He invented the vibration method of determining 

 the dip. 



(3) He made the first relative terrestrial magnetic 

 intensity observations (1720). 



(4) The first intensity observations (1722), revealing 

 the law of decrease of horizontal terrestrial magnetic 

 force with approach towards magnetic pole, were made 

 under his instructions. L. A. Bauer. 



THE TEACHING UNIVERSITY FOR LONDON. 



"TOURING the last week very satisfactory progress 

 ^-^ has been made towards the reorganisation of the 

 University of London as a teaching asw"ellas an examin- 

 ing body. In the first place. King's College has been 

 brought into line with the other teaching institutions of the 

 metropolis by expressing a general assent to the recom- 

 mendations of the Gresham Commission, coupled with 

 the proviso that any Statutory Commission appointed to 

 give effect to the Gresham Commissioners' recommenda- 

 tions should have power to make such modifications in 

 the scheme as may seem to them expedient after consulta- 

 tion wiih the bodies affected — a proviso already insisted 

 on by every teaching institution that has expressed its 

 general approval of the scheme. 



The adhesion of King's College to the views of the 

 other teaching institutions mentioned in the Report of 

 the Gresham Commission, was made known on the eve 

 of the reception by Lord Rosebery of the deputation of 

 delegates from the London colleges, and made it pos- 

 sible for these to present their case with the strength 

 derived from complete accord. 



On Tuesday last, Lord Rosebery received two deputa- 

 tions — one in the morning in favour of the Gresham 

 scheme, in which representatives of the Senate, the 



