4X6 



NA TURE 



[March 3, 1892 



another beach will have a constant supply, and for no obvious 

 reason. 



The causes which affect the movement of sand and silt are so 

 numerous, and their resultant effects so well balanced, that if 

 one of the former be increased or diminished the combined 

 result may be completely reversed. I have just come across an 

 interesting instance. For more than twenty years I kept a 

 6-ton boat in the tidal harbour here, where, when at her moor- 

 ings, she took the ground in all weathers twice a day without 

 any damage whatever. Since the erection of the new harbour 

 arm, the silt has been cleared out of the harbour, leaving a hard 

 bottom, and the coxswain of the lifeboat informs me that a 

 boat moored in my old berth sprung a leak in a few days and 

 had to be removed. The mode of accumulation of sand on the 

 Torre Abbey beach is also changed in character. I cannot 

 but think that it is a pity experiments are viewed with dis- 

 favour. The Torquay inlet and harbour works were eminently 

 adapted for reproduction in an experimental tank. The then 

 local surveyor, who had practically planned the new works, was 

 anxious to carry the experiments out. We had begun to con- 

 sider the details of the tank, when my intended colleague told 

 me that superior authority " did not favour " the idea, and it was 

 useless to proceed further. 



I am now informed by practical seafaring men that the pre- 

 sent plan must ultimately be amended, and clearly at considerable 

 cost. Whether this be so or not, the question could have been 

 decided in a tank in a few minutes, at the cost of, say, ;^I5. 

 The experimental tank for waves playing upon beaches was the 

 suggestion of the late Mr. W. Froude, C.E., F.R.S. ; so it is no 

 mere fad of an unprofessional outsider. 



Southwood, Torquay, February 19. A. R. Hunt. 



Torpid Cuckoo. 



In the last volume of Nature (vol. xliv. p. 223) an account 

 is given by "E. W. P." of a cuckoo which was brought up in 

 a house, and which disappeared one day in November, and was 

 found in the following March on a shelf in the back kitchen, 

 "still alive, and asleep, with all its feathers off, and clothed 

 only in down, the feathers lying in a heap round the body." 



It is rather interesting to note that Aristotle, who firmly be- 

 lieved that some birds hybernate, seems to have come across 

 cases of birds in a similar condition. In his " History of 

 Animals" (Book viii., chap, xviii.), he says, "Many kinds of 

 birds also conceal themselves, and they do not all, as some 

 suppose, migrate to warmer climates ; but those which are near 

 the places of which they are permanent inhabitants, as the kite 

 and swallow, migrate thither ; but those that are farther off 

 from such places do not migrate, but conceal themselves ; and 

 many swallows have been seen in hollow places almost stripped 

 of feathers ; ... for the stork, blackbird, turtledove, and 

 lark hide themselves, and by general agreement the turtledove 

 most of all, for no one is ever said to have seen one during the 

 winter. At the commencement of hybernation it is very fat, 

 and during that season it loses its feathers, though they remain 

 thick for a long while." I have adopted the translation in 

 Bohn's edition. The italics are mine. 



A. HoLTE Macpherson. 



51 Gloucester Place, Hyde Park, W., February 22. 



A Swan's Secret. 



Now that the breeding-season for birds is coming near, it 

 would be interesting to note if the following sight I saw last 

 spring is common to swans. A pair of swans built on an 

 island on the River Wey, which runs through our grounds, and I 

 stood on the bank opposite their nesl, and watched for a view 

 of the cygnets, which were just hatched out. The male bird 

 presently picked up an empty half egg-shell lying beside the 

 nest, and carefdlly carried it to the edge of the water, some 

 20 feet from where the nest was built, and proceeded to 

 fill it with mud, and then pushed it into the river, where it 

 sank to the bottom. He then fetched the only other remaining 

 piece of shell, and did the same. On returning to his nest the 

 last time, he placed a few sticks across the small track he had 

 made, as if to conceal his actions. Evidently this process had 

 been done to each piece of shell, as no other pieces were to be 

 seen, although five cygnets were hatched out. 



Jessie Godwin- Austen. 



Shalford House, Guildford, February 22. 



NO. II 66, VOL. 45] 



A Simple Heat Engine. 



Mr. Frederick Smith described in Nature of January 2S 

 (p. 294) a simple heating machine, which he constructed with a 

 nickel disk, so that when heated before a magnet it began to 

 revolve. A similar heating machine was shown by Prof. Dr. T. 

 Stefan, Vice-President of ihe Imperial and Royal Academy in 

 Vienna, in the course of a lecture to his students, among whom I 

 \yas, in the year 1885. A memoir on it appeared in the publica- 

 tions of the above-named Society. The machine was thus con- 

 structed : nickel plates were fixed on a wheel, like that of a 

 water-mill, and a magnet was placed before it. By heating a 

 nickel plate before the magnet, it was repulsed by the magnet, and 

 a succeeding plate was attracted, so that the wheel commenced 

 to rotate. 



So much I thought it necessary to communicate about the 

 priority of such a heating machine. 



Konstantin Karamate. 



Buccari next Fiume, Austria, Nautical School, 

 February 18. 



New Extinct Rail. 



{Telegram.'] 



I have just obtained from the Chatham Islands a nearly 

 perfect sub-fossil skull of an extinct Ocydromine rail, closely 

 resembling the Mauritian Aphanapteryx, five and quarter inches^ 

 long, beak arched, slender, very pointed, for which I propose 

 the specific name Hawkinsi. Henry O. Forbes. 



Canterbury Museum. 



ON A RECENT DISCOVERY OF THE REMAINS 



OF EXTINCT BIRDS IN NE W ZEALAND. 

 A DEPOSIT of moa bones, larger than has been found 

 -^"^ . for many years, has just been discovered near the 

 town of Oamaru, in the province of Otago, in the South 

 Island of this colony. Their presence was indicated by 

 the disinterring of a bone during the ploughing of a 

 field, by the proprietor of which the circumstance was 

 communicated to Dr. H. de Lautour, of Oamaru. This 

 gentleman, who is well known through his papers on the 

 diatomaceous deposits discovered by him in his district,, 

 at once inspected the spot. Finding that the deposit was 

 large, he first secured, through the kindness of the pro- 

 prietor, the inviolability of the ground, and then tele- 

 graphed the information to the Canterbury Museum. I 

 lost no time in proceeding to Oamaru with one of my 

 assistants, and superintended the diggingout of the bones 

 in a systematic manner. The site of the deposit was at 

 Enfield, some ten miles to the north-west of the town, on 

 ground elevated several hundred feet above the level of the 

 sea, in a shallow bayleted hollow, into which the unbroken 

 surface of the expansive slope gently descending from the 

 Kurow hills to the open vale of the Waireka (a stream 

 that rises further to the west) has sunk here for some 7 to 8 

 feet below the general level, and which, proceeding with 

 a gentle gradient valleywards, becomes a ditch-like con- 

 duit for a tributary of the Waireka. In the centre of this 

 depression, which does not exceed 10 to 12 yards in width, 

 the ground was of a dark brown colour, damp and peaty. 

 On removing the upper layer of soil for a depth of 3 to 4 

 inches round where the bones had first been brought to 

 the surface, and whereon was strewn abundance of small 

 crop-stones, a bed of very solid peat was reached, and 

 firmly embedded in it were seen the extremities of 

 numerous Dinornis bones, most of them in excellent pre- 

 servation, though dyed almost black. Further digging 

 showed that certainly many of the skeletons were com- 

 plete, and had been but slightly, if at all, disturbed since 

 the birds had decayed. Owing, however, to the close 

 manner in which they were packed together, and espe- 

 cially in which the limbs were intertwined, it was rarely 

 possible to extricate the bones in the order of their rela- 

 tions, or to identify with certainty the various bones of 

 the same skeleton, each bone having to be extracted as 



