Trnnxifion Stiidux 49 



ruuiiiiip; eiust and wewt on a carria^t- wliicii runs oiiHt and west «»n rniln under 

 the map. Let uh Huppose the top of the rtxls to i-eHt on the templates; then 

 it" the tein{)hites he adjusted hy shiftinj^ east and west, so that the rodH 

 all rest on tlie points of the templates corresponding to the same instant 

 of time, their tops will mark the cor»teniponineous value of the chosen 

 variate at that time; and, if the stations Ih; fairly numerous, will indicate a 

 sort of surfiice of the variate. Let now the carriage l)e ir • •■! dong, and 

 the surface will change with the time, and the eye will r. how the 



fall in one area is accompanied hy a rise in another. For example we should 

 actually see a cyclone or anticyclone })assing along. 



As a matter of fact Galton linked up his vertiod rods with his templates 

 by a system of levers, and this might be neetlful for one or two stations 

 aosolutely in the sjime latitude, hut the cheapest construction would be 

 fairly light rods endinj' with knife-edges to rest on the corresponding tem- 

 plates. He proposed also to convert the up and down motion of the wind 

 curves into the angular motion of an arrow turning round a vertical axis at 

 the station on tlie map. Galton's drawing of his apparatus is dated April 6, 

 1867, Sorrento, Italy, and his description of it April 1 1, 1867'. Mrs Galton's 

 diary says that they travelled to Italy at the end of January 1867. "staid 

 chiefly in Rome and Naples and the neigh L>ourhood of Venice, then by S. 

 Tyrol to St Moritz, where the cure did wonders for me, but did not suit 

 Frank." Then the Galtons went to Heidelberg and Bavaria, reaching England 

 in October, where after a n)und of visits they .settled in London by the 

 end of November. Such were the conditions under which Galton had largely 

 to do his work ! One is forced to believe that he walke<l and thought, and 

 his jiocket notebooks suggest that he jotted down his diagrams and rougli 

 calculations at odd moments. 



D. OTHER MECHANISMS 



We have already referred to 'Galton's Toys,' models made up of strings, 

 pieces of wood, lenses, or often of card and bits of gla.ss only, which it is 

 now practically impossible to interpret. But these 'Toys' are not all, there 

 are constantly diagrams and schemes for instruments or the improvement of 

 instruments among Galton's papere. I take almost at raiulom a bundle with 

 papei-s dating from 1858 to early in the 'seventies; this contains intm- nJin 

 the following packets : 



(a) One entitled "Examination of Sextants." It appears that at Galtons 

 suggestion in 1858 the General Committee of the British Association passed 

 the following resolution : 



"That the consideration of tlie Kew Coniniittee hv re<iue8t<Hl to the l)est ni' iioving 



the (iitSculty which is now experienced hy officers proceeding ou Government I. , ■^. and 



by other scientific travellers in procuring instrumenta for determination of j: il 



positions, of the most approved portable construction, and properly verifieit That i. -i-^t 



of geographical science would be materially advanced by similar measunM being taken by the 

 Kew Committee in respect to such instruments to those which have proved so beneficial in the 

 case of magneticid and meteorologiciil instruments.'' 



' Balfour Stewart's letter is dated Kew Observatory, May 1, \^fu. 

 run J 



