I827.J Varieties. 



existed in the length he had assigned to it ; 

 so far, however, from apprizing them of his 

 unintentional mistake, the circumstance was 

 kept a profound secret, and we now learn 

 from a paper, inserted in the last number of 

 the Quarterly Journal of Science, that ever 

 since Capt. Sahine's visit to America, the 

 philosophers of that country, relying upon 

 his statement, have been occupied in ad- 

 justing their measures by his incorrect stand- 

 ard : when we assert, which we do fearlessly, 

 that he has known for a year and a halt' that 

 the measure which he gave was incorrect, 

 and that he has failed to communicate the 

 fact, the circumstance needs no comment. 

 From this recipiendary of the Copley medal, 

 let us now turn to the royal medals. A year 

 or two since, his Majesty graciously be- 

 stowed upon the Royal Society two annual 

 gold medals, of the value of fifty guineas 

 each, to be awarded as honorary premiums, 

 under the direction of the " President and 

 Council of the Royal Society, in such a man- 

 ner as shall, by the excitement of competi- 

 tion among men of science, seem best cal- 

 culated to promote the object for which the 

 Royal Society was instituted" (extract from 

 Mr. Peel's letter) ; desiring, at the same time, 

 to be informed of the conditions upon which 

 the Society intended to award them. The 

 resolution adopted on the occasion, by the 

 council, communicated to, and approved 

 of by, his Majesty, was, that they should be 

 given for the most useful " discoveries, or 

 series of investigations, completed and made" 

 known to the Royal Society, in the year 

 preceding the day of their award." In con- 

 travention of this, their own resolution, the 

 council adjudged the royal medals for 1826 

 to Mr. Dalton, for his chemical theory of de- 

 finite proportions, published nearly twenty 

 years ago ; and to Mr, Ivory, for his mathe- 

 matical papers, inserted in the philosophical 

 transactions some three or four years since. 



We have not as yet heard that Mr. Peel 

 has signified his Majesty's approbation of 

 these incongruous resolutions, the glaring in- 

 consistency of which has, it is reported, led 

 to some warm discussions in the society ; but 

 we hope that its pecuniary affairs are admi- 

 nistered with more integrity than those upon 

 which its scientific character depend, and 

 we recommend to all our readers a perusal 

 of Dr. Brewster's remarks, contained in the 

 last number of his Journal, on the signal im- 

 propriety of plundering the present genera- 

 tion of their honours, to bestow them on the 

 race that is past. 



Hybernation of the Black Ant. On the 

 18th January, a large elm tree, to all appear- 

 ance sound, was cut down, on the estate of 

 Mr. Baden Powell, of Lackington Green, 

 near Tunbridge Wells. On examining the 

 lower part of the trunk, close to the root, a 

 large excavation was discovered, rendering 

 the base of the tree quite hollow; this cavity 

 was filled with a large nest, somewhat re- 

 sembling a wasp's nest, but of looser mate- 

 rials, being composed of cells, or separate 



547 



excavations, the sides of which were tough 

 and pliable, and of a brownish colour, smell- 

 ing strongly of the sap of the tree, and filled 

 with innumerable large black ants, and 

 their eggs quite alive, that is, not torpid. The 

 tree had evidently been excavated by them, 

 and would, in all probability, have ere long 

 failed in its accustomed foliage, the cavity 

 being very large ; it appeared, indeed, to 

 have measured above a loot in height, and 

 the same in diameter, tapering towards the 

 upper part. I am not aware that the nidus 

 of this species of ant has ever been described, 

 and, should any of your correspondents wish 

 it, Phave not any doubt but a drawing might 

 be obtained, as the nest is preserved. 

 T. Forster, Phil. Mag. 



Steam Boilers. In the Philosophical Ma- 

 gazine for February, there is a very valuable 

 communication from Mr. J. Taylor, who is 

 led to inquire, with much modest caution, 

 whether or not the bursting of steam-boilers 

 may not be occasioned by a vacuum, form- 

 ed in the furnace, by the formation and ex- 

 plosion of gas, leaving the boiler to support, 

 suddenly, the increased expansive force of the 

 steam. Mr. Perkins, in a very able paper, 

 inserted in Newton's Journal of the Arts, for 

 April, has advanced a different theory, of 

 which the following is an abstract. Steam, 

 he says, is often so generated as to indicate 

 very high degrees of temperature without a 

 corresponding increase of power, so as evi- 

 dently to prove that temperature alone can- 

 not be relied on as a measure of the elastic 

 power of steam. Having ascertained this 

 curious fact, he imagined, that if heated 

 water were suddenly injected into the super- 

 heated steam, the effect would instantly bo 

 the formation of highly elastic steam, the 

 strength of which would depend upon the 

 temperature and quantity of the supercharged 

 steam, and of the water injected. This theory 

 was verified by experiment, and it soon oc- 

 curred to him that to this might be traced 

 the cause of the tremendous explosions that 

 suddenly take place in low as well as high 

 pressure boilers. There are many instances 

 where, immediately before one of these ter- 

 rific explosions had taken place, the engines 

 laboured, shewing evidently a decrease of 

 power in the engine. To illustrate the theory 

 of sudden explosions, let us suppose the feed- 

 pipe, or pump, to be choked ; in this case the 

 water would soon sink below some parts of the 

 boiler, which should be constantly covered by 

 it, thus causing them to become heated to a 

 much higher temperature than the water: 

 the steam being now in contact with the 

 heated metal, readily takes up the heat, and 

 becomes supercharged with it ; since caloric 

 will not descend in water, it cannot be taken 

 up by the water which is below it. The 

 steam thus supercharged will heat the upper 

 surface of the boiler, in some cases red hot, 

 and will ignite coals or any other combus- 

 tible matter which may be in contact with 

 it. If the water, which is kept below the 

 supercharged steam by the pressure of it, 



4 A 2 



