472 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Deckmbkr, 



The t'xpeiinirnts of wjitch tlie present is a notice, were comniencetl by Mr. 

 Fairhairii in Jlareli, 1837, when ;i number of bars of CoeJtalon iron cast from 

 flie same moilcl, 5 feet long and 1 inch square, were placed horizontally on 

 props 4 feet fi inches asunder, and had dilVercnt weights, as 21. 3, 3i, and 4 

 ewt.. laid upon the middle of each : the last weight being within a few pounds 

 of the breatdng weight. The intention was to ascertain what cflcct would ari.se 

 from eacli of these weishis lyinf; constantly upon the b.irs. The results are, 

 1st. Tlic liars are still bearing the loads, aiid apparently may do so for many 

 ■years. 2nd. The deflections, which are frequently measured, the temperature 

 leing observed at the time, are constantly increasing, though in a decreasing 

 ratio, — a fact which shows that, though cast iron may be safely loaded far 

 beyond what has hitherlo been deemed prudent, still it is extremely probable 

 that the liars are advancing, by however slow degrees, to ultimate destruction. 



T]ie Baron Eugene die Me.'inil gm>e a description of a Snfety Lamp, itwented 

 hj him in 1834. 



He stated, that he had presented it to the French government in 1837. and 

 that it had been now adopted, after a favourable report upon it by M, C'h. 

 Combes. 



This lamp consists of a body of flint glass, defended I;y a dozen of iron 

 bars. The air is admilled by two conical tubes, inserted at the bottom, w hich 

 are capped with wu'c gauze, and enter by the side of tlie flame. The latter 

 rises into a chimney, which has a piece of metal phaced in the form of an 

 arch over its fop : the chimney, however, being quite open. The consequence 

 of this construction is. that a strong current is constantly pas.sing up the 

 chimney. M'ben carliuretled hydrogen passes in, the fact is discovered by 

 numerous small explosions, and the w hole glass w ork is throw n into vibrations 

 which emit a loud and shrill sound, which may be heard at a very consider- 

 able distance. 



Prof, (iraham stated, that the novelty in Baron dii MesniVs lamp was, the 

 circumstance of the chimney being quite open. He considered, that the Lamp 

 was left almost perfect liy that iibilosopher, and that all accidents proceeded 

 from carelessness. He alluded to the deleterious elT'ects of the afler-damp. 

 or carbonic acid left in the a'mnsphere of a mine after an explosion, which 

 is believed to occasion often greater loss of life among the miners than the 

 original explosion, and often prevented assistance being rendered in case of 

 accidents. In many casen, it w as certain (hat the oxygen of the air was not 

 oxhausled by I lie explosion, allhough. from the presence of five or ten per 

 cent, of carbonic acid, it was rendered irrespiralde. The atmosphere might, 

 therefore, be i-endered respirablo by withdrawing this carbonic acid, and he 

 suggested a method by which this might be elTected, He liad found that a 

 mixture of dry slaked lime and pounded Glaidier's salts, in equal proportions, 

 has a singular avidity for carbonic acid, and that air might be piiritied com- 

 pletely from that deleterious g.as. by inhaling it throirgh a cuthion of not 

 more than an inch in tliickne.ss. filled with (hat mixture, which co'jid be done 

 without difficulty. He suggested the use of an article of this kind by persons 

 who descended into a mine to afford assistance to tlie sufferers, after an 

 explosion ; indeed, wherever the safety-lamp was necessary, and the occur- 

 rence of an explosion possible, the possession of this lime-iilter would be an 

 additional source of security, 



Chi a small Voltaic Buttenj of e.xfraordinarij energy, iBy M'. R. Grove, Esq. 



In a Icller published in the Pliil. Mag. for February, I stated (said the 

 author) some reasons for hoping tliat by changes in the constitiietils of vol- 

 l.aic comljinalions of four elements, we might greatly increase their energy. 

 At that period I sought in vain for improvements, which a fair induction 

 convinced rne were altainable, but, being in the country, all my euperiments 

 were with copper as a negative metal. 1 was constantly unable to use con- 

 centrated nitric acid as an electrolyte, and its importance never occurred to 

 me until forced upon my nolice by an experiment, which I made at Paris for 

 a different object. This was an endeavour to prove the dissolution of guld in 

 nitro-muriatic acid to be an electrical phenomenon, or rather that this (as I 

 believe, willi .Sir Hum|ihrey Davy, eveiy other chemical phenomenon,) could 

 be resolved inio an cicctric'al one, bv operating upon mas.ses instead of mole- 

 cules. The experiment was the following:— The extremities of two strips of 

 gold leal were immersed. Ihe one in nitric, the other in muriatic acid, contact 

 between the two liquids being permitted, but mixture prevented, by an inter- 

 posed porous diaphragm. In this case the gold remained undissolved for an 

 indefinite period, but the circuit being completed by metallic contact, either 

 mediate or immediate, the strip of gold in the muriatic acid was instantly 

 dissolved. Thus, it seems, that the affinity of gold for chlorine is not able 

 alone to decompose muriatic acid ; but when it is aided by (hat of oxygen for 

 hydrogen, the decompusliii n s ertected. The phenomenon bears much .ana- 

 logy (o ordinary cases of double deeomposilion. The two gold strips in Ihe 

 experinvnt being conneced with a galvanometer, occasioned a considerable 

 deflexion ; and it now occurred to me, coupling this experiment with my pre- 

 vious observations, that these same liquids, with the subsdtution of zinc and 

 platinum for (he gold leaf, w ould produce a combination of surpassing energy. 

 My expeclalions were fully realized ; and on the 1 Ih of April, M.Becquerel 

 prespnied to the Insiitute a small battery of my construction, consisting of 

 seven liqueur glai,ses. conlaining the bowls of ctmmon lobacco-pipes, the 

 metals zinc and platinum, and the electrolytes concentrated nitric and dilute 

 muriatic acids. This little apparatus produced effii-cls of decomposilion equal 

 to the most powerful batleries of the old construction. I have since this 

 tried v.arious combinations upon (he same principle, and (hough some of the 

 rarer sulslances— surh 'or inslance, as chloric acid— have proikiced powerful 

 effects, I have found none superior, and few equal, to the preceding. I have 

 therefore, directed my attention to using these materials, and rendering the 

 apparatus more economical, although I soon found that it was not so expen- 

 sive as it at first appeared — the platinum remaining unaltered. Dilute nitric 

 acid diminishes the energy ; nitro-sulphuric acid acted as an electrolyte much 

 as nitric acid ; it is an excellent conductor, yielding oxygen at the anode, and 

 hydrogen at the caihode. Appl) ing (his to my battery, I found it to succeed 

 admirably, and hence a cons derable diminution of expence on the side of the 

 Kinc, and found salt and water nearly equal to dilute muriatic acid. It also 



removes the necessity of amalgamating the zinc ; but it sometimes, though 

 rarely, disaggregates the porous ware, from the crystallization of niirate of 

 soda ; and therefore, in large batteries, 1 should prefer muriatic acid diluted 

 with five times its volume of water. By using flaltened parallelopiped-shaped 

 vessels, tlie concentrated ,acid is much economized, and the metals approxi- 

 mateil. Now, according to Prof Ritchie, the power is inversely as the square 

 root of (he distance between the metals. The hastily constructed fjattery 

 which I have to present, consists of an outer case of wood, height 75 inches, 

 breadth 5, width 3, (it should be of glazed earthenware, similar to Fhe Wol- 

 laston troughs.) separated info four compar(men(s by glass divisions ; in 

 (hese compartments are placed four flat porous vessels, the interior dimen- 

 sions of which are 7, 2J, and 3-lOths of an inch, the thickness of the walls 

 g inch ; they contain each three measured ounces ; the metals, four pairs, 

 expose each a surface of 16 square inclies. and the battery gives, by decom- 

 position of aciduiated water. 3 cubic inches of mixed gases per minute ; char- 

 coal points burn brilliantly, and it heats (> inches of platinum wire of an inch 

 diameter ; its effect upon the magnet, when arranged as a single pair, is pro- 

 porfionally energetic ; it is constant for about an hour without any fresh 

 supply of acids. The porous vessels are idenlical in (heir constitution with 

 the common toliacco pipe. As far as my experiments go, its power, with 

 reference (o (he common constant baltt?ry, is cccteris paribus as six to one, Ijut 

 the relative proportions vary somewhat with the series. The cost of the 

 apparatus is 2/. 2s. During the operation of this battery, the nitric acid, by 

 losing successive portions of oxygen, assumes first a yellow, (hen a green, 

 (lien a blue colour, and lastly becomes perfectly aqueous ; hydrogen is now 

 evolved from the platina, tlieenergy lowers, and the action becomes incon- 

 stant. It is worthy of remark, an an argiunent for the secondary nature of 

 metallic precipitation by voltaic electricity, that the oxidated or dissolved 

 zinc remains entirely (or at least by far the greater portion) on the zinc side 

 of the diaphragm ; the hydrogen alone appears to be transferred ; and yet 

 the reversal of affinities which the theory of reduction by nascent hydrogen 

 supposes, is an enigma difficult of solution. I have invariably observed in 

 this batteiy, a current of endosmose from the zinc to the platinum, or with 

 the current of positive electricity. 



The radonale of (he action of this combination, according to the chemical 

 theory of galvanism, appears to be as follows; — In the common zinc and 

 copper combination, the resulting power is as the affinity of the anion of the 

 electrolyte for zinc, minus its affinity fur copper ; in the common constant 

 battery it is as the affinity of (he anion for zinc, plus that of oxygen for 

 hydrogen, minus that of hydrogen for copper. In the combination in ques- 

 tion, (he resulting power is as the affinity of the anion for zinc, plus that of 

 oxygen for hydrogen, minus that of oxygen for azote. Nitric acid being 

 much more readily decomposed (ban sulphate of copper, resisiance is lessened 

 and (he power increased ; and no hydrogen being evolved from the negative 

 metal, there is no precipitation upon it, aiul consequently no counter-action. 

 I need scarcely add a word as to the importance of improvements of this 

 description in the voltaic battery. This valuable instrument of chemical 

 research is thus made nortable, and, by increased power in diminished space, 

 its adaptation to meciianical, especially to locomotive purposes, becomes 

 more feasible, 



Mr. Spencer then exhibited a cylindrical battery, so as to include great 

 intensily in small space. Prof Graham considered Mr. Grove's battery an 

 im))ortant improvement, and could only account for its power from the cir- 

 cumstance, as in Daniell's battery, of the removal of liydrogen. 



Prof, llliewell comniiuiicated some tide observations, forwarded to him hy ihe 

 liiissian Admiral Liitke. 



These observations supplied— first, the tide hours of various places on the 

 coasts of Lapland, the White .Sea, and the Frozen Sea, and the co.asts of 

 Nova Zemlia, These observations enable us to follow the progress of the 

 tide mean further than had hitherfo been done. Mr. UTiewoll's map of 

 Cotidal Lines, (the second approximadon con(aincd in (he PJtil. Trans, 1836,) 

 follows (lie tide only as far as the North Cape of Norway, e.as(ward of Nova 

 Zemlia. Prof. WTiewell stafed. (hat he was informed 1jy Admiral Liitke, 

 that in (he Frozen ,Sea, cast of Nova Zemlia, there is little or no perceptible 

 tide. The observations comniunieated by Admiral Liitke, offijred various 

 o(her results, and especially the existence of (he diurnal inequality in the 

 seas explored by Russian navigators, as on the coast of Kamscatka, and the 

 west coast of North America. 



Prof. WheiccU made some observations on Capt. Fitzroy^s vieivs of the tides. 



In the account of the voyage of H.M.S. Adventure and Beagle, just pub- 

 lished, there is an article in the Appendix, containing remarks on the tides. 

 Captain Fitzroy obsen'cs, that facts have led him to doubt several of the 

 assertions made in Mr. Whewell's memoir, published in (he Pliil. Trans. 

 1833, and cndtled " Essay towards a First Approximation to a Map of Cotidal 

 Lines." — (Appendix, p. 279.) Prof AVhewell stated, that he conceived that 

 doubts, such as Captain Fitzroy 's, are reasonable, fill Ihe assertions are fully 

 substantiated by facts. Capt. Fitzroy has further offered an hypothesis of 

 the nature of (he (idal mo(ion of (be waters of w ide oceans, different from 

 the hypolhesis of a progressive wave, which is ihe basis of Prof. Whewell's 

 researches. Capt. Fitzroy conceives, that in the Atlantic and the Pacific, 

 (he waters oscillate laterally between the eastern and weslern shores of these 

 oceans, and thus produce the tides. This supi>osi(ion would explain such 

 fac(s as these, (hat the tide takes place along the whole west coast of South 

 America at the same time ; and (he supposidon might be so modified as to 

 account for the absence of tides in the central part of Ihe ocean, Prof.M'he- 

 well stated, that he was not at all disposed to deny, that such a mode of 

 oscillation of the waters of Ihe ocean is possible. Whether such a mo(ion 

 be consisient with the forces exerted by (be sun and moon, is a problem o 

 hydrodynamics hitherto unsolved, and probably very difficult. No demon- 

 strative reason, however, has yet been published, to show that such a motion 

 of the ocean waters may not approach more nearly to their actual motion, 

 than the equilibrium tlicory, as usually applied, does. When ihe actual 

 phenomena of the tides of the Atlantic and Pacific have beetj fully explored, 



