March 7, 1878] 



NA TURE 



361 



but on the Clettophoi-a;, a family well known to all students of 

 pelagic animals. Anton Dohrn 



Naples, Febraary 28 



Faraday's " Experimental Researches" 



If yonr readers will compare Mr. Quaritch's letter in last 

 week's Nature with his advertisement of the two preceding 

 weeks, they will see that it bears its condemnation on its own 

 face. No words of mine can make it plainer than his do, that 

 a reprint of an obsolete and valuable book was offered to the 

 public as something not stated to be a reprint. Had that adver- 

 tisement stated that the work was a "facsimile reprint," there 

 could have been no ground either for complaint or for an indig- 

 nation for which no apology is needed. 



University College, Bristol SiLVANUs P. Thompson 



Mimicry in Birds 



On the evening of the 24th inst. my attention was attracted by 

 an interesting example of mimicry in the case of the starling. 

 The first thing which attracted my att'intion was hearing the cry 

 of a blackbird in distress, and on looking round, the only bird 

 to be seen was a solitary starling, which, when I first observed 

 it, was uttering its own note ; but almost immediately thereafter 

 it began to whistle loudly in imitation of the blackbird. After 

 this, for the space of about half an hour, it kept up a constant 

 succession of notes in mimicry of the chaffinch and sparrow, 

 always, however, using its own note for the space of about half 

 a minute between each change. I may add that it did not seem 

 to have'any particular order in which it repeated the various 

 notes. 



A gentleman In this neighbourhood tells me that last year he 

 observed a similar occurrence in his garden ; but this, so far as 

 I can learn, is the only other instance of similar mimicry in this 

 quarter. Perhaps some of your readers may be able to inform 

 me if it it is of common occurrence elsewhere. 



Edinburgh, February 26 J. Stuart Thomson 



Great Waterfalls 



Seeing Mr. Guillemard's inquiry (vol. xvii. p. 221), I refer 

 him for accounts of the Falls of Tequendama, which I visited in 

 1851, to " Viajes Cientificos alos Andes Ecuatoriales, &c.," por 

 M. Boussingault, traducidas por T. Acosta ; Paris, 1849, and 

 "New Granada : Twenty Months in the Andes," by Prof. 

 Isaac F. Hotton. (New York : Harperjand Brothers, 1857.) 



New York, Febniary Thos. Bland 



SEVERAL NEW APPLICATIONS OF SCIENCE 

 INTRODUCED INTO WAR 



ON Saturday last, the Speaker of the House of 

 Commons and a large following of members, 

 visited the Portsmouth Dockyards, mainly for the purpose 

 of witnessing some torpedo warfare ; the Iiijlexiblc was also 

 inspected. Near the starboard side of the ship, one of the 

 sheds had been converted into a temporary lecture-room, 

 and provided with numerous diagrams, a model of the 

 ship, and a full-sized skeleton model of the 80-ton gun, 

 26 feet long, 6 feet broad at the breach, and having a 

 cahbre of 16 inches, with four of which it is intended to 

 arm the turrets of the Inflexible. The diagrams were 

 drawn on a scale of one-fourth of an inch, half an inch, 

 and 6 inches (half-size) to the foot, and were designed with 

 the object of enabling the visitors to draw a comparison 

 between the structures of the Dreadnought and the In- 

 flexible, and the respective thicknesses and disposition of 

 their armour. As soon as the party had assembled 

 around the drawings, Mr. W. B. Robinson, the Chief 

 Constructor of the yard, stepped forward and delivered a 

 brief illustrative lecture on the main points and differences 

 of the two ships. He pointed out that while the length 

 of the Inflexible — 320 feet — was exactly the same as the 

 Dreadnought, its beam — 75 feet— was il feet 2 inches 

 broader ; that its volume of displacement was greater, its 



armour heavier, its turrets thicker, and its armament 

 more formidable. While, however, the Dreadnought was 

 armoured along the water-line, the citadel of the other 

 ship, which was placed upon an armoured deck below, was 

 the only protected portion of the Inflexible above the 

 water. The arrangements of the turrets was also different ; 

 for whereas those of the smaller ship were placed along 

 the middle line, the turrets of the larger were echeloned io 

 starboard and port in order that all the four guns might 

 be trained upon an enemy cither direct ahead or direct 

 astern. The weather deck between the turrets had also 

 been raised, so that the guns could be loaded from below 

 without the necessity of depressing their muzzles. She 

 was supplied with steam and hand pumps, and with 

 Friedland's injectors, which would enable her to discharge 

 5,300 tons of water an hour. She had 133 water-tight com- 

 partments, and water would be admitted into the double 

 iDOttom to reduce the rolling of the ship. Her torpedoes 

 would be discharged from submerged ports in the bows 

 instead of from above the water in the side, as in the 

 Thunderer. The ventilating arrangements will be of the 

 most perfect kind ; for, as Air. Robinson remarked, while 

 in the other ships the fresh air is pumped into all parts, 

 no means are adopted for assisting the vitiated atmo- 

 sphere out of the ship. In the Inflexible, however, the 

 ventilation comprises both supply and exhaust arrange- 

 ments. The air is brought down into an air chamber, or 

 cave of ^olus, in the central part of the citadel, and is 

 driven thence by steam fans through large pipes, which 

 pass under the armour deck and up into the structures 

 above, and by means of branch pipes fitted with cocks 

 every compartment in the ship can receive an abundant 

 supply. By these cocks an officer can regulate his air 

 supply in much the same way that a householder on 

 shore can regulate his water supply. The vitiated air is 

 sucked up through pipes with perforated ends into the 

 funnels, and thence through the citadel into the open air. 

 The Inflexible will be brig-rigged, but her masts will be 

 unshipped before going into action. Her engines are of 

 8,000-horse power, and she is expected to attain a speed 

 of 14 knots. 



Runs of the 1 6-inch Whitehead torpedo were next made. 

 One was fired from a steam pinnace as in actual warfare, 

 its course, which wa,s in a straight line for about 200 yards, 

 being distinctly traceable by the exhaust air-bubbles 

 which it threw up. The other was discharged from the 

 surface of the water for the purpose of showing how 

 readily it sank automatically to the required depth. The 

 next novelty submitted was the steam pinnace, which, 

 without having a single man on board, can do everything 

 but stoke and keep its own fires alight. Its engines are 

 worked and its movements are controlled wholly by elec- 

 tricity, the cable which supplies it with its mysterious 

 power being unwound from winches as the pinnace sails 

 on its mission, "And drags at each remove a lengthen- 

 ing chain." Its principal use is to drop and explode 

 countermines in the neighbourhood of an enemy's mines, 

 and by destroying them clear a harbour for the approach 

 of the fleet. It performed its work to the amazement of 

 the beholders on Saturday. The countermines were re- 

 presented by a couple of barrels containing small charges 

 of gun-cotton, and with these slung over the sides it took 

 its departure from the boat containing the battery and 

 dropped the casks at a distance of about 200 yards, 

 igniting at the same time the fuses which blew the barrels 

 into match-wood, and returned obediently, like a '' thing 

 of life," to the controlling hand after having accomplished 

 its duty. Near at hand in the basin the torpedo nettings 

 for protecting ships against the locomotive torpedo were 

 exhibited on the sides of the Actceon, while the prow of 

 the Bloodhound, gunboat, was armed with the trawl with 

 which it is proposed to pick up sunken mines. The notes 

 of the bugle were next heard as a summons to quarters 

 and for the Thunderer to be cleared for action. In an 



