250 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[June, 



the agency of a bolt, which is placed vertically, immediately over the GO 

 minutes, or about two inches bacli, sufficiently long to reach a spring of hard 

 brass vfhich is about half an inch wide, and which passes transversely over 

 the frame-work of the clocli, and is fixed securely to the backboard of the 

 clock-case. Now the mode in which tlie spring unites its action with the 

 rest of the apparatus is by sUght cross-bars, wliich extend to the extremities 

 of the sides of the frame, so that the ends are immediately over the ham- 

 mers, with which they are connected by silk threads. Therefore, by pres- 

 sing down the bolt before named, the hammers are allowed to fall into ac- 

 tion, and do their duty simultaneously with the teeth of the wheel upon the 

 pallets. While the little hammers are in action, the teeth of the wheel are 

 no longer heard. The Astronomer Royal has examined the plan, and says 

 that it answers completely for its proposed ]nirpose ; and that it appears 

 likely to be very useful. Moreover, that the rate of the clock will not neces- 

 sarily be disturbed during the time of its connexion — though that will greatly 

 depend on certain conditions. 



ENERGIATYPE. A NEW PHOTOGRAPHIC PROCESS. 



Mr. Hunt of Falmouth, has communicated to the Jthenietim the follow- 

 ing notice. While pursuing some investigations, with a view to deter- 

 mine the influence of the solar rays upon precipitation, I have been led to 

 the discovery of a new photographic agent wliich can be employed in the 

 preparation of paper, with a facility winch no other sensitive process pos- 

 sesses. Being desirous of aflbrding all the information I possibly can to those 

 who are anxious to avail themselves of the advantages offered by Photogra- 

 phy, I solicit a little space in your columns for the purpose of publishing the 

 particulars of this new process. All the Photographic processes with which 

 we are at present acquainted, sufficiently sensitive for the fixation of the 

 images of the camera obscura, require the most careful and precise manipu- 

 lation ; consequently, those who not accustomed to the niceties of experi- 

 mental pursuits are frequently annoyed by failures. The following statement 

 will at once show the exceeding simplicity of the new discovery. 

 Good letter-paper is first washed over with the following solution — 

 A saturated solution of succinic acid . 2 drachms. 

 Mucilage of gum arabic . . . 4 „ 



Water ij „ 



When the paper is dry, it is washed over once with an argentine solution, 

 consisting of one drachm of nitrate of silver to one ounce of distilled water. 

 The paper is allowed to dry in the dark, and it is fit for use ; it can be pre- 

 served in a portfolio, and at any time employed in the camera. This paper 

 is a pure white, and it retains its colour, which is a great advantage. At 

 present,, I find it necessary to expose this prepared paper in the camera 

 obscura for periods, varying with the quantity of sunshine, from two to eight 

 minutes, although from some results which I have obtained, I am satisfied 

 that by a nice adjustment of the proportions of tlie materials, a much shorter 

 exposure will suffice . When the paper is removed from the camera, no trace 

 of a picture is visible. We have then to mix together one drachm of a satu- 

 rated solution of sulphate of iron, and two or three drachms of the mucilaffe 

 of gum arahic. A wide flat brush saturated with this solution is now swept 

 over the face of the paper rapidly and evenly. In a few seconds, the dor- 

 mant images are seen to develope themselves, and with great rapidity a 

 pleasing negatii'e photographic picture is produced. The iron solution is to 

 be washed oft' as soon as the best effect appears, this being done with a soft 

 sponge and clean water. The drawing is then soaked for a short time in 

 water, and may be permanently fixed, by being washed over with ammonia — 

 or perhaps better, with a solution of the hyposulphate of soda, care being 

 taken that the salt is afterwards well washed out of the paper. From the 

 pictures thus produced, any number of others correct in position, and in light 

 and shadow, may be produced, by using the same succinated papers in the 

 ordinary way ; from five to ten minutes in sunshine producing the desired 

 effect. 



The advantages which this process possesses over every other, must be, I 

 think, appa.ent. The papers are prepared in the most simple manner, and 

 may be kept ready by the tourist until required for use ; tliey require no pre- 

 paration previously to their being being placed in the camera, and they can 

 be preserved until a convenient opportunity otters for bringing out the pic- 

 ture, which is done in the most simple manner, with a material which can be 

 anywhere procured. 



Anxious to give the public the advantage of this process during the beau- 

 tiful weather of the present season, I have not waited to perfect the mani- 

 pulatory details which are necessary for the production of portraits. It is 

 sufficient, however, to say, that experiment has satisfied me of its applica- 

 bility for this purpose. 



Prismatic examination has proved that the rays effecting this chemical 

 change are those which I have elsewhere shown to he perfectly independent 

 of solar light or heat. I therefore propose to distinguish this process by a 

 name which has a general rather than a particular application. Regarding 

 all photographic phenomena as due to the principle Energia, I would never- 

 theless wish to distinguish this very interesting process as the Enehgiatype. 

 I incloie you a fevr specimens of the results already obtained. The ex- 



ceeding sensibility of the Energiatype is best shown hy an attempt to copy 

 engravings or leaves by it. The three specimens I inclose were produced by 

 an exposure of considerably less than one second. 



REDCLIFFE CHURCH. 



It will be seen by public advertisement, that the vestry of the parish of St . 

 Mary Redcli9"e again appeal to the public on behalf of the beautiful fabric of 

 which they are the present custodians. They do not feel justified in entering 

 upon so great an undertaking as the substantial repair of the church, until 

 they have obtained a sum sufficient to insure the satisfactory execution of that 

 portion of the work absolutely essential to the stability of the building ; and 

 this sum they have fixed at ^7,000. The amount already raised we under- 

 stand to be about £5,000, and latterly subscriptions have come in but slowly. 

 We believe the public are not fully aware of the nature of the demand made 

 upon them. They do not know that this magnificent fabric is crumbling 

 away with a rapidity that must soon reduce it to ruin, if steps are not speedily 

 taken to check the progress of decay, and support its declining masses. We 

 can speak from observation, having carefully inspected the building; and we 

 are sorry to say that the architects Messrs. Britton and llosking, whose re- 

 port has been published, have not exaggerated tlie dangerous condition in 

 which it stands. Tlie rotten state of the external stone-work is an evil only 

 of second magnitude, yet one not to be fully appreciated without close in- 

 spection. The Crockets, Finials, Ball-flowers and other ornamental works 

 are crumbling away ; but, however, much we might regret their loss, as the 

 stability of the fabric is little dependent upon them, there would be no im- 

 perative necessity for repairs on that account j though it should be known 

 that these do not wear away by imperceptible degrees, but are constantly 

 falling in fragments of considerable size. Almost the whole of the exterior 

 surface of the stone-work consists of a loose crust of soot and sand, the dis- 

 integration of the stone having taken place to a depth of from one to three 

 or four inches. But an evil of a much more formidable nature exists in the 

 declension of the walls themselves from the perpendicular, in their unstable 

 foundations, and the thrust constantly exerted by the roof to push them out- 

 wards. The parts where this is most observable are the Choir, with its South 

 Aisle, and the South Transept. The walls of the Choir (or what is called 

 its clerestory) are supported on the piers and arches that separate it from its 

 aisles, and its heavy groined roof has, of course, a tendency to thrust them 

 outwards ; to this thrust of the roof the architect had applied the usual couu- 

 teracting forces, pinnacles placed over those parts of the wall against which 

 the ribs of the groining converge, to give the outward thrust a more down- 

 ward tendency, and flying buttresses supporting the clerestory wall from that 

 of the aisle, which in its turn was strengthened by strong buttresses, in stages. 

 We doubt whether sufficient support was originally given to the clerestory ; 

 but probably little injury would have resulted, if the stability of the outer 

 walls and buttresses had not materially sutfered from the reprehensible prac- 

 tice of digging graves close to their bases. This practice has destroyed the 

 resisting power the walls would derive from foundations firmly set in the 

 earth ; and the outward pressure of the flying buttresses, wliich convey the 

 thrust of the roof from the walls of the clerestory to that of the aisle, has 

 thrown the wall of the aisle, likewise, and its buttresses, out of the perpen- 

 dicular. The clerestory, as we have already explained, was originally sup- 

 ported from the wall of the aisle ; but as this can now scarcely support itself, 

 it may be supposed it has become incapable of affording sufficient support to 

 the other. Some bungler has been employed to remedy this evil, and has 

 endeavoured to uphold the outer wall by connecting it by iron bars with the 

 inner one ; thus each has now the office assigned it of supporting the other, 

 which, as they both lean in the same direction, and not towards each other, 

 it is impossible for them to do. The transept is in a similarly unstable state, 

 but in that both the walls have an inclination to the westward. The muUions 

 and tracery of most of the windows are so much decayed that it is with diffi- 

 culty they have been held together. 



On going up the tower and upon the roof of the church, the manner in 

 which the masonry is crumbling away becomes more apparent than from 

 below. We observed one mass of stone, weighing fifty or sixty pounds, 

 which had fallen very lately from the pinnacle at the South West corner of 

 the Church, upon the Leads of the South Aisle ; it was part of a Finial, and 

 the Iron Bar in its centre, which had been used to connect it with the rest 

 of the stonework, had made, in its fall, a hole through the leads of the size 

 of a hens' egg. Within the parapet at the top of the tower was a still larger 

 fragment, which had likewise fallen within the last few weeks. A member of 

 the vestry, who obligingly accompanied us in our examination of the build- 

 ing, stated that it had fallen since he was last up the tower, which was not 

 long since. In another place we observed a split down the centre of a pin- 

 nacle, a large portion of which can scarcely fail to be detached by the first 

 frost occuring after rain, and it will fall on the west side of the tower towards 

 the street. 



It will be seen from what we have said that the question of the Restora- 

 tion of Redchffe Church, is not merely one of what would be well in an a;s- 

 thetieal point of view, but it is a question of whether the building is to stand 

 or fall. And this being understood, we cannot entertain any doubt as to tlie 

 jiberality with which the dwellers in the weat will come forward to support 



