so 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[January, 



exterior surface of these valves. By tlie proposed construction, tlie steam is 

 brought to the ports by a method tiiat places the valve in an equilibrium of 

 pressure, on the principle of action anil reaction being equal and in opposite 

 directions. The usual friction of the slide is expected to^be thereby almost 

 entirely removed. 



ROYAL INSTITUTE OF BRITISH ARCHITECTS. 

 Dec. 4.— T. Bellamy, V.P., in the Chair. 



A paper " On the Ivfitiity of Geometric Design as regards Tracery," 

 was read by Mr. R. H. Billiugs. 



The object of ihis paper was to show that design, as regards Gothic 

 tracery, is a fit- Id as yet almost untouched ; from diagrams of the most 

 simple characti-r, and composed of purely geometric curves, an infinity of 

 beautiful tracery may be produced. By varying the diagrams which serve 

 as the ioundalion of the tracery to be produced, an endh'ss variety of 

 designs may be obtained. This IMr. Billiugs illustrated by means of one 

 of the most simple forms of diagram ; consisting of a circle, wilhin 

 winch were four others touching the circumference, and whose diameters 

 were oue-lhird iliatof the larger one. Nunierous drawings of tiie designs 

 produced from lliis simple form were exhibit-id ; as well as engravinss of 

 upwards of one hundred others, all obtained from the same skeleton form, 

 — and which are a porlion of a work by which Mr. Billings is about to 

 make known to the profession at large the results of his studies ou ibis 

 subject. 



Dee. IS. — .'Vmongstihe donations announced was a IMS. volume from a 

 Dutch architect, containing notices of 100 Dutch architects, from the 

 middle ages to the present time — A discussion took place on the merits 

 and defects of sea sand in the formation of mortar. Mr. Burn expressed 

 an opinion that au analysis then on the table buie out his own feeliug, that 

 ilownsea sand «as not the cause of damp in houses. — Mr. W. W. Hocock 

 staled that in two houses in the Isle oi \Viglit near the sea, 'ouilt simulta- 

 neously ,ou sea sand, covering a stone foundation, salme to taste, one 

 finished with pit sand was perfectly dry, while that in which the ceilings 

 were worked out with sand from the seashore gave water out to the ex- 

 tent of dropping. He added that a chemist supplied a powerful wash, 

 boding hot, which removed the evil. — Dr. Dickinson mentioned that sul- 

 phuric acid in an earthen vase placed in a damp room would soon absorb 

 the vapour. — Mr. C. H. Smith suggested alum might have been employed. 

 Mr. Donaldsiiu observed that sea sand could ouly be used when well 

 washed by the rain. 



A communication was read from Messrs. J. and T. Smith, of Darnick, 

 on the use of Whiustone rubble in construction of bridges, with details of 

 one lately built over the Tweed at Ashiestiel, price l,200i., 131 ft. 6 in. 

 span, 10 feel wide in the middle. 



Messrs. Fox and Barrett's patent floor was explained (see Journal, vol. 

 xi., p. 359), and a plan of Northwoods was exhibited. 



At the meeting held Nov. 20th last, the following Royal Medals, toge- 

 llier with the Premiums in Books, awarded during the last Session, were 

 presented by the President, as follows:- — 



The Kojal Gold Aledal of the Institute, to Charles Robert Cockerell, 

 Esq., R.A., Professor of Arihilecture in the Royal Academy of Arts, 

 London, Member of the Institute of France, &c. ; in testimony of his dis- 

 tinguished merits as an Architect. 



The Soaiie iMedalliun, to Mr. James IMaclaben, of Edinburgh; for a 

 Design for a Building to contain Public Baths. 



The Silver Medal of the lustiiule, to Mr. Henry Bayiv Garling, As- 

 sociate ; for the best Es^ay on the application of Sculpture and Sculp- 

 tured Ornament to Archilecture, 



A Copy of Sir W. C'hamber.-i' Treatise on the Decorative Part of Civil 

 Architecture, to Mr Thos. Hill, Student ; for a Design for a Garden 

 Pavilion, &c. 



A Copy of Gwilt's Encyclopaidia of Architecture, to IMr. Bright 

 Smith, Student ; fur (he best Series of Sketches from Sulijecls given 

 monthly by the Council during the Session. 



ROYAL SOCIETY. 



Dec. 7, 1848.— Ihe Earl of RossE, President, in the Chair. 



Dr. Faraday delivered the Dakerian lecture, " On the Crystalline Polarity 

 of Bismuth and other bodies, and on its Relation to the Mayuetic Form of 

 Force." 



The author states that in preparing small cylinders of bismuth by cast- 

 ing them ill glass lubes, he had often been embarrassed by the anomalous 

 magnetic results which they gave, and that having determined to investi- 

 gate the mailer closely, it ended in a reference of the elfecls to the crys- 

 talline condition of the bismulli, which maybe thus briefly slated. If 

 bismuth be crystalized in the ordinary way, and then crystal, or a group 

 of symnuuic crystals, be selected and suspended in the magnetic lield 

 between horiziiiital pules, it immediately either points in a given direction 

 or vibrates alioui that position, as a small magnetic needle would do, and 

 if disturbed from this position it returns to it. On resuspending the crys- 



tal so that the horizontal line which is transverse to the magnetic axis shall 

 become the vertical line, the crystal then points with its maximum degree 

 of force. If it be again resuspended so that the line parallel to the niag- 

 netic axis be rendered vertical, llie crystal loses all directive force. This 

 line of direction therefore, which tends to place itself parallel to the mag- 

 netic axis, the author calls the ntayne-crystallic a.vis of the crystal. It is 

 perpendicular, or nearly so, lo the briglitest and most perfect of the four 

 cleavage planes oftlie crjstal. It is the same for all crystals of bismuth. 

 Whether this magne-crjsiallic axis is parallel or transverse to the magnetic 

 axis, tne bismuth is in both cases repelled fioiu a single or the stronger pole ; 

 its diamagnetic relations being in no way affected. If the crystal be broken 

 up, or if it be fused and resolidified, and the metal then subjected to the 

 action of the magnet, the diamagnetic phenomena remain, but Ihe mague- 

 crystallic results disappear, because ot the confused and opposing crys- 

 talline condition of the various parts. If an ingot of bisniuili be broken 

 up and fragmentary plates selected which are crystallised uniformly 

 throughout, these also point; the magne-crystallic axis being, as before, 

 perpendicular to the chief plane of cleavage, and the external form, in 

 this respect, of no consequence. The ert'i'cl lakes place when the crys'al 

 is surrounded by masses of bismuth, or when it is iiiiuierscd in water or 

 solution of sulphate of iron, and with as much force apparently as if 

 nothing intervened. The position of the crystal in the magnetic field is 

 affected by the approximation of extra magnets or of soft iron ; but the 

 author does not believe that this results from any attractive or repulsive 

 force exerted on the bismuth, bul ouly from Ihe disturbance of the lines 

 of fore or resultants of niaguctic action, by which they acquire as it were 

 new forms; and, as the law of action which he gives is, thai the line or 

 a.ris of magne-crystallic force tends to place itself parallel, or as a tangent, 

 to the magnetic curve or line of magnetic force, passing through the place 

 where the crystal is situated, so the crystal changes Us position with any 

 change of direction in these lines, .\fler noticing the magne-crystallic 

 condition of various bodies, the author enters upon a consideration of the 

 nature of the magne-crystallic force. In the first place he examines 

 closely whether a crystal of bismuth has exactly the same amount of re- 

 pulsion, diamagnetic or otherwise, when presenting its inagoe-crystallic 

 a^is parallel uv transverse to the lines of magnetic force acting on it. For 

 this purpose the crystal was suspended either from a torsion balance, or 

 as a peudulum thirty feet in length, but whatever the position of the 

 magne-cryslallic axis, the amount of repulsion was the same. In other 

 experiments, a vertical axis v^as constructed of cocoon silk, and the body 

 to be examined was attached at right angles to it as radius ; a prismatic 

 crystal of sulphate of iron, for instance, whose length was four times its 

 breadth, was fixed on the axis Willi iis lengili as radius and its magoe- 

 cryslallic axis horizoutal, and therefore as tangent ; then, « hen this crystal 

 was al rest under the torsion force of the axis, an electio-magnetic pole 

 with a conical terniinalion was so placed that the axial line of magnetic 

 force should be, when exerled, oblique to both the length and the magne- 

 crystallic axis of the crystal, and the consequence was, that, when the 

 electric current circulated round the magnet, the crystal actually reeerfed 

 from the magnet under the influeuce of the force, which tended to place 

 the magne-ciyslallic axis and the magnetic axis parallel. Kuiploying a 

 crystal or plate of bismuth, that body could be made to approach the mag- 

 netic pole under the influence of the magiieciystallic force ; and this force 

 is so strong as to counteract either the tendency of the magnetic body to 

 approach or of the diamagnetic body to retreat, when it is exerted in the 

 contrary direction. Hence the author concludes that it is neither attraction 

 nor repulsion which causes the set or determines the final position of a 

 magne-crystallic body. He next considers it as a force dependent upon 

 the crystalline condition of the body, imd therefore associated with the 

 original molecular forces of the matter. He shows expeninentally, that, 

 as Ihe magnet can move a crystal, so also a crystal can move a magnet. 

 Also that heal takes away this power just before the crystal fuses, and 

 that cooling restores it in its original direction. He next considers whe- 

 ther Ihe ellVcis are due to a force altogether original and inherent in the 

 crystal, or whether that which appears in it is not partly induced by the 

 magnetic and electric forces; and he concludes, that llie force mani- 

 fested in the magnetic field, which appears by external aciiiMis and causes 

 Ihe motion of the mass, is chiefly, and alniosi entirely induced in a manner 

 subject indeed lo the crystalline force and additive to il ; but at the same 

 time exalting the force and the effects to a degree which they could not 

 have approached wilhout the induction. To this part of the force he 

 applies the word magneto crystallic, in coulradislinctiun lo magne-crystallic, 

 which is employed to express the condition, quality, or power which 

 belongs essentially to the crystal. The aullior then remarks upon the ex- 

 traordinary character of the power, which he cannot refer to polarity, and 

 giies expre.-siou lo certain considerations and views which will be best 

 learned from Ihe paper itself. After this, he resumes the consideration of 

 Plucker's results '^ upon the repulsion of the optic a.ies of crystals" 

 already rilLrred lo, and arrives al the conclusion that his results and those 

 now described have one common origin and cause. He then considers 

 Plucker's re.->ults in relation to those \^ bicli he formerly obtained with 

 heavy optical glass and many other bodies, lu couclusiou he remarks, 

 " how rapidly the knowledge of molecular furces grows upon us, and how 

 strikingly every invesligatiuii tends to develope more and more their im- 

 portance and llieir extreme atlraclion as an object of study. A few years 

 ago magnetism was lo us an occult power ali'ecliog only a few bodies ; now 

 it is found to influence all bodies, and to possess the most intimate relations 

 wilh electricity, heat, chemical action, light, crystallisation, and, through 



