246 



NA JURE 



{Jan. 14, I ! 



towards morning moderated, and brilliant flashes of lightning 

 were seen to the eastward." Charles West 



Lloyd's, London, E.C., Januaiy II 



The Admiralty Manual on Terrestrial Magnetism 

 In a recent number of Nature yon mention that the new 

 edition of the Admiralty Manual on Terrestrial Magnetism is 

 being edited by me. It gives me great pleasure to be able to 

 inform those interested in this work that I have obtained the 

 advice and assistance of Capt. Creak and Mr. Whipple as to 

 the changes required in the description of the ship- and land- 

 obseivations respectively. From the guidance of such able 

 specialists 1 feel that the work will Iiave a value that it could 

 never have had from my unaided exertions. 



Geo. Fras. Fitzgerald 

 Trinity College, Dublin, January 6 



Anchor Frosts 



On the night of Friday, January S, there was an anchor frost 

 in the Cherwell such as has not been known for twenty years, 

 according to people who have lived at a mill on the river 

 (Clifton Mill, near Aynho Station) for that period. In a mild 

 form the phenomenon is fairly frequent there. The most 

 marked effects are seen in comparatively still water. 



Thus, in the mill-pond, where the current is stopped by the 

 mill during the night, the whole stream becomes semi-viscous. 

 Roots beneath the water, the brickwork at the sides of the mill- 

 pond, &c. , are seen to be coated with ice beneath the water as 

 far down as can be seen, and between this ice and the surface 

 ice-crystals form, not in a sheet or block, but interlaced loosely, 

 like snow crystals in a drift. The mass thus formed blocks the 

 channel, and it is said that water coming upon it from above 

 will rise in level and flow over it, as over a solid obstruction. 

 This I have not seen myself. 



When the mill is started, at first the water will hardly fiow 

 past the wheel ; but at length the crystals are forced to the sur- 

 face, where they remain in floating masses, under which the 

 water flows as usual. 



The surface is not covered with a sheet of ice in these frosts. 



In a broad, shallow ditch at right angles to the river, where 

 the water is comparatively still, similar effects could be seen : 

 the pebbles at the bottom coated with ice and the water filled 

 with loose crystals. One consequence of the bottom ice forming 

 on this occasion was that the floodgates were frozen down on 

 the Friday evening, so that they could not be drawn up as 

 usual, and the river overflowed during the night. In the 

 morning, when they were at last raised, the water would hardly 

 flow through, as already mentioned in the case of the water- 

 wheel. T. Hands 



Clifton Mill, near Aynho Station 



Curious Phenomenon in Cephalonia 

 I beg leave to forward to yuu an extract from a letter which I 

 have recently received from a friend a id former pupil who is at pre- 

 sent an officer on board one of Her Majesty's ships in the Mediter- 

 ranean. I have never seen any reference to the phenomenon 

 which he describes. If you can insert the extract, perhaps it 

 may evoke further information with regard to it. I would not 

 forward the statement unless I had every confidence in the 

 writer, so that I do not think he would be likely to be easily 

 deceived or mistaken in his observations. He is a gentleman 

 who t03k an excellent position in the Cambridge Mathematical 

 Tripos. E. Ledger 



Barham, January 7 



" By the way, at Cephalonia there is a very remarkable phe- 

 nomenon. The sea runs into the land in a strong stream, 

 turning a water-wheel on the way, and disappears iu the earth 

 about a hundred yards from the entrance. Can you explain 

 this ? I believe no one has yet done so. No part of the island 

 is below the level of the sea, nor is there any .salt lake or spring 

 in the island. I imagine this water must be converted into 

 steam, which comes out either at Naples or Stromboli." 



SIR F. J. O. EVANS 

 r^APTAIN SIR FREDERICK J. O. EVANS, R.N., 

 ^^ K.C.B , F.R.S., late Hydrographer of the Admiralty, 

 died at his residence, 21, Dawson Place, on December 20, 

 1885, in his seventy-first year. 



This eminently scientific officer entered the Royal 

 Navy in the year 1828, and served in H.M. ships Rose 

 and W'hincltester, on the North American station, until 

 1S33, when he was transferred to H.M. surveying-vessel 

 Tliiinder, Commander Richard Owen, and was employed 

 until 1836 in surveying operations in various parts of the 

 West Indies. 



It was in this ship, and under the guidance of her able 

 Captain, that he imbibed those scientific tastes which 

 formed his character later in life, and laid the foundation 

 of a career of usefulness, uninterrupted to its close, and 

 which has perhaps rarely found a parallel in the naval 

 profession. 



Mr. Evans subsequently served in the Cakdonia, the 

 flag-ship in the Mediterranean, the Asia, the Rapid, the 

 Rolla, the Dido, and Wolverene, of which two latter ships 

 he was acting master. He was confirmed in that rank in 

 1841, and was then appointed to H.M.S. Fly, Capt. F. P. 

 Blackwood, fitting for special exploring and surveying 

 service in Australia and New Guinea, where he was con- 

 tinuously employed until 1846. He took a very leading 

 part in the examination of the Coral Sea, the Barrier 

 Reefs of Australia, Torres Strait, and the neighbouring 

 shores of New Guinea, regions then comparatively un- 

 known. After a short period of surveying service on the 

 home coasts, Evans was appointed to the Aelieroii, under 

 the late Admiral Stokes, and was engaged until 1851 in 

 exploring and surveying the coasts of the then young 

 colony of New Zealand ; in both these important enter- 

 prises he took a very conspicuous part, and gained for 

 himself the reputation of a skilftil and scientific surveying 

 ofiicer, second to none in the profession. 



During the Russian W"ar Evans was employed in the 

 Baltic on special reconnoitring service, and was attached to 

 various ships of the fleet, ta'.ing an active part in the 

 operations against Bomarsund and among the Aland Isles, 

 for which he was mentioned in gazetted despatches. 



It may be truly said that for many years of his life 

 Evans was a zealous contributor to magnetic science. 

 He had already begun to make observations of the three 

 magnetic elements whilst employed on hydrographic 

 work in H.M. ships Fly and Acheron in the Australian 

 Colonies and New Zealand, between the years 1842-1S51 ; 

 but it was not until 1S55, when he became Superintendent 

 of the Compass Department of the Royal Navy that he 

 was able to devote himself entirely to the magnetism of 

 iron ships, a subject which was then growing yearly 

 in importance, from the increasing amount of iron 

 used in fitting as well as construction even before iron 

 plating had brought about an actual crisis. 



Sagaciously fore:eeing the important part the science of 

 magnetism was destined to play in the Navy, then being 

 revolutionised by tlie change from wood to iron, he 

 devoted his whole energies to the study of the subject 

 until he had made himself completely master of it. 



In 1865 Capt. Evans was appointed Chief Assistant to 

 the Hydrographer, retaining his position as head of the 

 magnetic department ; this post he continued to hold until 

 the early part of 1874, when a vacancy occurring in the 

 Hydrographership of the Admiralty he was selected to 

 fill it, and continued to do so with equal ability and con- 

 scientiousness until within a little more than a year of his 

 death. 



From the time of his first appointment in 1855 as Chief 

 of the Admiralty Coinpass Department until his death 

 Capt. Evans (in happy co-operation during a great part 

 of the time with that great mathematical genius Archibald 

 Smith) devoted himself heart and soul to the solution of 

 what was really a question of life and death to the British 

 Navy, and indeed to seafaring people all over the world. 

 The question was whether it was possible so to deal with 

 the disturbing element of iron, then entering largely into 

 the construction of ships of all kinds, as to prevent the 

 time-honoured compass from becoming a useless toy, or 



