290 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[August, 



wires, were seoiired by waterproof composition. The coiuluoting 

 wire from one pole of tlie battery passed first throna;li apowiler-barrcl 

 on dry ground; secondly, throngh one of those small charges smik in 

 tlic pond near Bronii)toii Barracks; thii'dly, through the other powder- 

 barrel on dry groimd ; and, fourthly, through the other small charge, 

 which was also sunk in the same pond ; after which it was leil back 

 to the other pole of the battery, the whole circuit being 1130 feet, but 

 the distance from the battery to the most distant barrel of powder 

 being, of course, rather less than half the abo\e. On the signal being 

 given to fire, each end of the conducting wire was lirought in contact 

 with a pole of the battery, so as to complete a circuit passing through 

 all those four masses of powder ; but only one of the small charges 

 was fired, instead of both, as was intended", which the officers present 

 at this experiment ascribed to the use of small bell-wires, as there 

 was not a suflScieney of the larger sort of wire to complete the whole 

 circuit without thein. After this explosion, some merriment was oc- 

 casioned by one of the powder-barrels being dragged into the pond 

 by accident; but being got out and opened immediately, the powder 

 vvas found uninjured, tlianks to the waterproof composition. The re- 

 maining charge was then coraiected with the other powder-barrel, and 

 the circuit which passed through both was completed, npon which an 

 immediate explosion of the second small charge took place. A great 

 nnmber of military and other spectators were assembled to witness 

 tliese explosions, each of which threw up the water to a much greater 

 height than any of the larger experimental charges had done in the 

 deep water of'the Medway. The circumstance of the powder in the 

 barrels being uninjured in these two experiments, though the voltaic 

 electricity passed through both of them in the first, and through one of 

 them in the second — for if it liad not done so, the circuit could not 

 have been perfect, and no explosion would have taken place — afibrds 

 by a parallel experiment a confirmation of Mr. Snow Harris's proceed- 

 ings at Plymouth in 1S23, to repeat which was all that Colonel Pasley 

 had in view at the time. He was on this occasion, as before, disap- 

 pointed in his simultaneous explosions, but he considers it of no use 

 to try any more experiments on this subject, till he shall be provided 

 with a greater quantity of large wire; and even for the common pur- 

 poses of lilasting rock, either on shore or mider water, with a length 

 of conducting wire not exceeding 80 or 100 feet, he would never use 

 copper wires of smaller diameter than one-eighth of an inch. It is to 

 be remarked, that in using the voltaic battery for practical purposes, 

 the principle conducting wires may serve for several Inuidred succes- 

 sive explosions, because in all those experiments the priming wires 

 wliich led into the charge were always short pieces, afterwards con- 

 nected with the former, and these priming wires, or a part of them 

 only, were destroyed, whilst the principal conducting wires were not 

 injured. Though the experiments at Chatham confirm tbe opinion of 

 the scientific inventor of this improved voltaic battery, that the same 

 number of cells possess greater power in a high than in a low tem- 

 perature, yet one great advantage of voltaic over common electricity 

 for practical purposes, is the superior Irardiness, if one may use the 

 expression, of the former. Whilst the connnon electrical machine can 

 do nothing, excepting in warm dry air, the voltaic battery may be said 

 to brave tlie elements, all Colonel Pasley's experiments having taken 

 place in the open air, and several of them when the battery was ex- 

 posed to violent rains, and, on one occasion, to a severe snow-storm. 

 In these experiments, it being necessary to carry the battery about, 

 which was done by a couple of bearers like those of a sedan-chair, 

 and to convey it on the river in boats, sometimes subject to motion, 

 the connecting screws, as originally fitted, proved liable to derange- 

 ment in those movements, wliich led Mr. Howe, with his usual in- 

 genuitv, to suggest an improvement on the mechanical fitments of the 

 battery, which renders the parts much more easily coimected for 

 action, but which, requiring a part of those fitments to be made of a 

 sort of brass instead of copper, Colonel Pasley would not adopt, until 

 he had made a reference to, and obtained an opinion from, Professor 

 Daniell, that this mixed metal, which was made of fifteen parts by 

 weight of copper and one of zinc, w ould not be objectionable ; and on 

 trial, having had a second batteiy of ten cylinders, also of the same 

 dimensions as the first, constructed at Chatham by the artificers of the 

 corps nntler his command, and fitted up in this manner, it was fomid 

 qidte equal in power to the first, which he received from London. 



" As every engineer officer who is acquainted with the common mode 

 of firing military mines by a piece of portfire or slow match, comiected 

 with a powder-hose, leading to one or more charges, knows that some 

 delay, \isually of at least one minute, always occurs between the lighting 

 of the portfire and the explosion; and, further, that it is quite out of 

 the question to expect several mines to go olf simultaneously by this 

 system, for no two equal lengths of portfire, or equal lengtlis of pow- 

 der-hose, were ever known to burn exactly alike, — it is evident that 



the voltaic battery, which communicates ignition to one or more 

 changes instantaneously, offers the only possible means of firing de- 

 fensive mines at the moment of time when they are required; that is, 

 when the enemy's troops, in advancing to the assault of works thus 

 protected, are seen to be upon the very spot of ground under the sur- 

 face of which those mines have been prepared. At that critical mo- 

 ment, the tap of one piece of copper wire npon another opens the 

 earth under their feet, and launches them into tlie air; and though 

 mines are perhaps more terrible in imagination, than destructive in 

 reality, yet the instantaneous action of the voltaic battery, which gives 

 no warning and brooks no delay, may, on such an occasion, be the 

 means of repelling an attack, against which the same number of mines, 

 fired by the connnon mode, might prove unavailing; because an 

 enemy's colunni, marching to the assault, might either have jjassed 

 beyond, or not yet have reached, the position of such mines at the 

 period of explosion. For large subaqueous explosions, to be directed 

 against wrecks sunk in deep water, and in a rapid tideway, the supe- 

 riority of the voltaic battery over all former expedients is no less 

 striking; so nuich so, that Colonel Pasley has always declared, since 

 his late successful experiments with it, that if he had been possessed of 

 such a battery, and known how to use it, last sinnmer in the Thames, 

 a gjeat deal of trouble, time, and expense would have been saved." 



NELSON MEMORDU.. 

 We have been induced at the request of several architects and artists 

 to publish the descripticms of the various models and designs exhibited 

 at the St. James's Bazaar, there being no document in which they are 

 collectively described. Wehavenotbeenable to obtain the whole of them, 

 but if those architects or artists whose descriptions we have omitted, 

 will furnish us with them, they shall appear in the next journal. 



MoDKi. No. 2, Thomas Hopper.— ^The custom of mankind has Iiecu to ele- 

 vate those characters who have distingnishcd themselves, Ijy investing llicm 

 with power and titles, and to transmit those names to posterity who have 

 been ])re-eminently exalted, hy erecting temples to their memory. — Such was 

 the practice of the great nations, whose example other nations have endea- 

 voured to imitate. The Jews had a divine command to erect a temple for 

 the Ark of the Covenant, and Christian nations have dedicated churches to 

 honour the memory of men of eminent piety. Even Trajan's pillar was part 

 of a temple. 



Believing that the highest honoiu- which can be bestowed in commemora- 

 tion of great actions by a nation, is the dedication of a temple to immortalize 

 the character of the hero : and as no difference of opinion exists, as to the 

 inunense sui)eriority of Lord Nelson, over the nudtitude of naval lieroes 

 whose names adorn the Uritish history, he, al)Ove all men, has desened the 

 noblest tribute that a nation can bestow. — Such lieing the conviction of my 

 mind, I have endeavoured to design a naval temple, commemorative of Nelson , 

 and founded on the princijiles of ancient art. I have adopted a circular open 

 temple for many consi<ler.itions, Ijut above all, because I tliink it Ijcst a<laptetl 

 to the site, and calculated to improve the grouping of the other Ijuildings in 

 Trafalgar-square. 



The upper part of the temple and the steps only are cxhibiteil : the crypt 

 and bJisso relievos want of time compelled me lo omit, as w efl as the painting 

 of the dome. — The crypt I propose to surround the granite pedestal « Ijich 

 supports tlie statue, on which Nelson's motto should beinscrd)ed : thecohiimis 

 111 llic crypt lo lui\e the names of the ships and the commanders deliTieated 

 on tliem, anil the niches to contain the statues of the ci mmanclcrs who feff 

 in tfie battles ; and also paintings of Nelson's ariuiis personal encounters. — 

 The pedestals \\bich divide the steps are intended to contain the entrances to 

 the crypt, anil tlic statues of the three seconds in command. — The divisions 

 on the frieze to contain, in sculpture, the history of a naval fight : the arclii- 

 trave withm to contain a procession of naval triumph, and also a lamentation 

 for the loss of the hero in tlic moment of victory. The dome to be painted 

 with three stars as an allegory, descriptive of ihe three great flatties, in all 

 of whicli Nelson had Iriumphed. The centre to be lighted from the crown, 

 in imitation of a star, with Nelson's last glorious command, tlie light from 

 wliicli Mould descend f\dl upon the statue. — The capitals of the columns are 

 ci mposed of oak, thistle, and shamrock : and all the niolibngs and architec- 

 tural ornaments are taken from parts of naval architecture, as the ornaments 

 of the Ercctheium were taken from Ihe nautilus. — The design is formed to ad- 

 mit of a great fountain to play on the anniversaries of Nelson's birth, — and 

 the three battles : and at night the tthole building could be Illuminated. 



This is all that would be required in the dedication of the temple of Nelson. 



P. S. Tlie flag ships of the naval crown aie intended to represent the navy ; 

 the coiiimanders to represent the officers of the service ; the sailors who sup- 

 port Nelson's statue, to rejiresent the foremost men ; and the naval crown, 

 which surmoiuits the building, is intended as the emblem of power and 

 authority, and of the immortality of Nelson. 



Model, No. 3, T. Butler. — In the model which I oflfer to the consideration 

 of the coimiiittee, 1 have laboured to embody those jioints of character upon 

 which is founded the naval greatness of England, and which in my luniible 

 opinion, (in wliatever way they may be expressed) ought not to be forgotten, 

 in association with a monument consecrated to the memory of a hero, whose 



