520 



Philosoj)hicaI, Chemical, and Scieniiftc Miscellanies. [May, 



is in contemplation to build an iron sus- 

 pension bridge across the Neva at St. 

 Petersluirg. A project suggested in con- 

 sequence of tlie difficulty or injpossibility 

 of erecting one of wood or stone. Tlie 

 bottom of the river is about forty-two feet 

 beneath the ordinary level of the waters, 

 and inundations increase this by eighteen 

 or twenty feet. The proposed bridge is to 

 have an arch of 1022 feet span. It is to be 

 composed of three distinct bridges : one 

 on each side nine feet wide for carts, &.-C. ; 

 a middle one, with a road twenty-one feet 

 wide for carriages, and two pathwaj-s of 

 five feet each for foot passengers. The 

 suspension chains are to have a total sec- 

 tion of iOO square inclies. 



Preservaiion of Wood from Fire. — Pro- 

 fessor Fuchs, a Bavarian chemist, has dis- 

 covered that if ten parts of potash or soda, 

 fifteen parts of siliceous sand, and one part 

 of charcoal be melted together, their mass 

 dissolved in water, and eitlier alone or 

 mixed with sultry matteis applied to wood, 

 it will preserve it from fire completely. — 

 Edin. P/iil. Jonrn. 



Jmprnvpd method of hardeninf} Steel Tools. 

 — In Gill's Technical Repositorj", itis stated 

 that the qualities of cutting and boring in- 

 struments, such as the graver, the scythe, 

 the points of small drills, and square 

 broaches or boring-bits, may be improved 

 by the condensing jirocess of hammer 

 hardening their edges in the cold ; and also 

 in those of greater d(!licacy, the pen-knife, 

 for example, by burnishing their edges. 



Rosa. — From a recent enumeration, and 

 recent discoveries, it appears that the total 

 number of known species of the genus rosa 

 amounts to 240. 



Mode followed hy the Serpent-Eater, 

 (Falco SerpentariM) for destroying Ser- 

 pents.— Profe^^OT .Tameson has inserted in 

 the last number of liis journal the following 

 extract of a letter to him from Mr. Tliomas 

 Smitli. " Museum, Cape Town: — I may 



mention a curious circumstance of wiiich I 

 was informed a few days ago by a gentle- 

 man, upon \\-li()se veracity I can place the 

 utmost dependence, and which is a fact, in 

 as far as I know, not generally known. It 

 relates to the mode which the Falco Ser- 

 pentarius of Linnaeus follows in destroying 

 snakes. Some time ago, when the said 

 gentleman was out riding, he observed a 

 bird of the above-mentioned si)ccies, while 

 on the wing, make two or three circles, at 

 a little distance from the spot on which he 

 then was, and after that suddenly descend 

 to the ground. On observing the l>ird, lie 

 found it engaged in examining and watch- 

 ing some object near the spot where it 

 stood, which it continued to do for some 

 minutes. After tliat it moved with con- 

 siderable apparent caution to a little dis- 

 tiince from the spot where it had alighted, 

 and then extended one of its wings, which 

 it kept in continual motion. Soon after 

 this artifice, the gentleman remarked a 

 large snake raise its head to a considerable 

 distance from the ground, wliich seemed to 

 be wliat the bird was longing for, at the 

 moment that took place he instantly struck 

 a blow with the extremity of the wing, by 

 which he laid his prey flat, on the ground. 

 The bird, however, did not yet appear con- 

 fident of victory, but kept eyeing his 

 enemy for a few seconds, when he found 

 him again in action, a circumstance that 

 led exactly to a repetition of the means 

 already detailed. The result of tlie second 

 blow apjieared, however, to inspire more 

 confidence ; for almost the moment it was 

 inflicted, the bird marched up to the snake, 

 and commenced kicking it with his feet; 

 after which he seized it with his bill, and 

 rose almost perpendicularly to a very con- 

 siderable height, when he let go the reptile, 

 which fell with such violence upon the 

 ground, as seemingly to satisfy him that 

 he might now indulge himself with the well- 

 earned meal in perfect safety." 



TROCEEDINGS OF LEARNED SOCIETIES. 



DOMESTIC. 

 IIOYAL SOCIETY. 



Feb. 23d. A paper was read entitled 

 " An account of a new reflecting curve 

 with its ap]>lication to the construction of 

 a telescope having only one reflector," hy 

 Abram Robertson, d.d., f.rs., Savelian 

 professor of astronomy, Oxford. 



Also a paper " On the constitution of the 

 atmosphere," by J. Dalton, Esq., f. r. s. 



March 2d. — Two papers by Sir E. 

 Home, Bart., v. i.it.s., were read "On 

 the coagulation of blood by heated iron." 



March 9th. — A paper was reail " On oil 



of wine" by 3Mr. H. Herrell : communi- 

 cated by AV. T. Brande, Esq. Sec. r. s. 



A paper was also read, " On the mathe- 

 matical principles of suspension bridges," 

 by Davies Gilbert, Esq., M.i>., v.r.R.s. 



Tlie reading v.'as commenced of a paper, 

 " On a new method of determining the 

 parallax of the fixed stars," by J. F. W. 

 Hersehel, E^^q., Sec. R.s. 



March ICth.-The reading of Mr. Kers- 

 chel's paper was concluded. And a paper 

 was read, " On the expression of the parts 

 of machineiy by signs," hy C.Babbage, Esq. 

 r R.s. The society then adjourneil till 

 theGth April. 



