206 



THE CIVIL ENGIKEER AND ARCHITECTS JOURNAL. 



LJUNK, 



SOCIETY OF ARTS, LONDON. 



April \'. — Mr. Antoixe Claldet read a paper " On //if Pro;ierties of 

 the Diamond for Culling Glass, with descriptions of machines invented hy 

 him, in which the Diamond is made to perform perfectly wltat by manual 

 la'four hnd before been very imperfectly done." 



The author commenced liis paper by a very interesting dpscription of 

 the nature of tlie diamond, of llie form of its natural cr>stal» and of tiie 

 mode in wliich it cuts glass, — quoting a paper on the subject by the late 

 I)r. U'ollaston, in the ' Philosopliicul Transactions' for 181G, as well as 

 by a history of the use of glass in u'in>l()ws from the earliest times, when 

 it was used only in ecclesiastical bujldinj:s of great splendour, flown to its 

 present universal application. He has also, in order the more thoroughly 

 to make apparent the advantage of the use of the diamond, described mi- 

 nutely the very tedious and imperfect methods by which, before its intro- 

 duction, glass was cut and shaped. The property in question was lirst 

 found out about the time of Francis I. of Fi'ance, the well known anecdote 

 of svhom is quoted ; and the different tools used from that time to the pre- 

 sent for its manual application are detailed and commented on, many of 

 them being exhibited by the author. 1 he first of these was a mere handle, 

 having the diamond firmly inserted into the lower end. I3ut the handle 

 being round, and the diamond, from the form of its crystal, requiring one 

 unvarying direction to be preserved in order to produce a cut, this was 

 found so imperfect that a step was taken by making the end of the handle 

 Wat, to preserve the parallelism against the rule. This, from the shape of 

 the bottom in which the stone was set, was called the *' plough diamond.** 

 In 1814, .Shaw, of London, made a great improvement, and brought the 

 instrument to the shape in which it is still used, by making the metallic 

 setting of the diamond moveable on a ferrule at the bottom of the handle, 

 thus putting it out of the power of any deviation of the hand from the pro- 

 per position to art'ect the direction of the stone. This, perfect as it may 

 seem, is still dilficult to use, and requires long practice for expert per- 

 formance. The two tests by which the workmdu knows when his tool is 

 " making a cut" are, the sound and the feel. A modification of the last- 

 named tool, by the brother of its inventor, was formerly used for those 

 who have but little practice; but it was very little used, and the one 

 shown to the meeting by Mr. Cliiudet was curious, from being, perhap-, 

 the only one now in existence. A contrivance for cutting circular plates 

 was shown in action. 



The cause of the invention of the machines, the description of which was 

 the principal olijent of the paper, was the increased use of glass shades for 

 covering ornaments, the cutting of which, so tliiit they should stand per- 

 fectly firm and with an even base, was a most ••. iJious and imperfect ope- 

 ration when done by baud. The manufacture of these shd'les, which, 

 under the name of " cylinders de verre," had long been carried on in 

 France, was first undertaken in England, at the instance of Mr. Claudet, 

 by Blr. Lucas Chance of Birmingham, who, in the true spirit of enlight- 

 ened enterprise, notwithstanding the vexatious pressure of the excise laws, 

 DOW repealed, embarked largely in the umuufaclure, getting workmen 

 from France, for making both shades aud the sheet glass, which had there 

 beeu for some time made from cylinders. It was now, however, f.)Uijd 

 that some method of cutting the botloin of the shades and cylinders must 

 be adopied surer and less expensive than the manual method, and Mr. 

 Claudet was driven hy this necessiiy to invent his machine. 



The principle of the machine, expressed in the fewest words, is this: 

 The shade is firmly fixed between an internal support and a transverse bar 

 above it, in a perfectly upright position, above a horizontal, level, and 

 tinooth table, ils bolloin beiug a few inches aliove llie table. Upon the 

 table travels a small hut heavily. weighted base mjviog on castors, having 

 springing from it two upright pillars, one holding llie diamond, and the 

 other forming a support opposite to it. The pillar holding the diamond is 

 Used, but the oilier is moveable, being by a spring kept close to it. The 

 lieight of the whole is such that wheu ou the table, the diamond is about 

 an inch above the bottom of the shade. The diamond being introduced 

 inside the shade as it hangs suspended, the p essure of the spring is suf- 

 ficient to cause it to cut, and it has only lo be moved round the shade, the 

 horizontality of the table causing the out to be perfectly level. This 

 machine was exhibited, and the botioms of shades cut by it, before the 

 meeting. The shape of the shade, whether oval, round, or square, is un- 

 important in the use of this niachiue, but Mr. Claudet h ;3 contrived 

 another for the cutting of round shades only, in which the shade is laid 

 horizoulall.v, — an elegant system of adjustments being provided, by which 

 shades of any diameter can be cut by the workman with Utile risk of 

 error. This machine was also shown in action. 



May 1. — G. MoFFATT, Esq., M.P., in the Chair. 



" Abstract of a Paper on the Causes ami Preventives of Mildew in Paper 

 and Parchments ; with an account of E\periments made on the saturation 

 of growiufj H'oud with Antiseptic Chemical Solutions."* 13} Alfred Gvde, 

 il.K.C.S.E. 



Owing to the imperfections formerly existing in the microscope, little was 

 known of tlie real nature of the cla^s of plants called _/"«n//i until wiiliin the 

 la&t few years; but since the improvernents in that iu&hnment, the Mii-ject of 

 the development, growth, and otliues ot the fungi has received much aiteii- 



* This Paper was rewarded in lS4d vvitli tlic Society'* Gjtd l&.s Sledal. 



tion. They compose, with the alga; and lichens, the class of Thalhgcru 

 (I.indley), the algai existing in water, the other two in air only. A fungus 

 is a cidlular flowerless plant, fructifying solely hy spores, by which it is 

 prftpjgated, and the methods of attaciinient of which are singularly various 

 and beautiful. The fungi difTer from the lichens and alga; in deriving their 

 nourishment from the substances on which they grow, instead of from the 

 media in which they live. They contain a larger quantity of nitrogen in their 

 constitution than vegetables in general do, and the substance called " fun- 

 gine" has a near resemblanre to animal matter. Their spores are incon- 

 ceivably numerous and minute, and are diffused very widely, developing 

 themselves wherever they find orgiinic matter in a fit state. The principal 

 conditions required for their growth are moisture, heat, and the presence of 

 oxygen and of electricity. No decomposition or development of fungi takes 

 place in dry organic n;atter ; a fact illustrated by the high state of preser. 

 vation in which timher iias been found after the lapse of centuries, as well 

 as by the condition of mummy cases, bandages, &c., kept dry in the hot 

 climate of Egypt. Oecay will not take place in a temperature below that of 

 the freezing point of water, nor witlMiut oxygen, hy excluding which — as 

 contained in the air — meat and vegetables may be kept fresh and sweet for 

 many years. 



The piocess which takes place when moist vegetable su' stances are ex- 

 posrd to <ixygen is one of slow combustion, and has been called hy Liehig 

 " Ercmacausis," the oxygen uniting with the wood and liberating a volume 

 equal to itself of carbonic acid; another portion combining with the hydro- 

 gen of the wond to form water. Decomposition takes place on contact with 

 a 'ir dy already undergoing tlie same change, in the same manner that yeast 

 causes fermeiMation. Animal matter enters into combination with oxygett 

 in precisely the same way with vegetable matter ; but as, in addition to 

 carbon and hydrogen, it contains nitrogen, the products of the Eremacausis 

 are more numerous — carbonate and nitrate of ammonia, carbnretted and 

 sulphuretted hydrogen, and water : and these ammoniacal salts greatly 

 favour the growth of fungi. Now, paper consists essentially of woody fibre 

 forming its substance, with animal matter, as size, on its surface. 



The first microscopic symptom of decay in paper is irregularity of surface, 

 with slight change of colour, indicating the commencement of the processes 

 just noticed; during which, in addition to carbonic acid, certain organic 

 acids are formed — as creniic and ulmic acid, which, if the paper have been 

 stained by a cidouring matter, will form spots of red on the surface. Spots 

 of the same kind are similarly formed on leather coloured during its manu- 

 fatture. Provided that fungi have not taken root, the colour can be re- 

 stored by ammonia or any alkali. The same process of decay goes on in 

 parchment as in paper; only with more rapidity, from the presence of nitro- 

 gen in its composition. When this decay has begun to take place, fungi are 

 produced — the most common species being Penicillum glaucuni ; they insi- 

 nuate themselves between the fibre, causing a freer admission of air, and 

 consequently hastening the decay. 



The substances most successfully used as preventives of decay, are the 

 salts of mercury, co|)per, and zinc. Bichloride of mercury (corrosive subli- 

 mate) is the material employed in the kyanisation of timher, tlie probable 

 mode of action being its cuMibination with the albumen of the wood, to form 

 an insolu'jle compound insus^-eptihle of spontaneous decomposition, and 

 therefore iiicapabie of exciting fermentaiion. The antiseptic power of cor- 

 rosive suhliiuaie may be easily tested hy mixing a little of it with llour 

 paste; the decay of, and ajipearance of fungi on which are quite prevented 

 iiy it. Next to corrosive sublimate in antiseptic value stand the sails of 

 copper and zinc. Chloride of zinc has been patented hy Sir \V. Lturnett for 

 the preservation of woo.l, sail-cloili, &c., and appears to succeed admirably. 

 For use in the preservation of paper, the sulphate of zinc is better thaa 

 the chloride, which is to a certain extent deliquescent. 



A scries of experiments were made by the author in the summer of 1810 

 on the use of metallic and other solutions for the preservation of wood. A 

 df ep saw-cut was m;ide all round the circumference of the growing trees 

 near their base, into which the solutions were introduced by forming a basin 

 ol clay beneath the cut; thus the solution took the place of the ascending 

 sap, and in periods of time, varying from one to three days, was found to have 

 impregnated even the topmost leaves of trees fifty feet high. The trees 

 were chiifiy beech and larch. After impregnation they were felled, and 

 spHciinens about five leet long by two inches square cut out, and packed in 

 decaying sawdust in a warm damp cellar, where they were left for seven 

 years. The details of the expemueiit are given in a table, by which the 

 following general results are made to appear : — The wood saturated with 

 sulphate of copper, in the proportion of one pound to one gallon of water, 

 or with acetate of copper, one pound to one pint of vinegar and one gallon 

 of water, were found in perfect preservation, clean, dry, and free from fnn- 

 gus; the remainder, which were saturated with nitrate of soda, prussiate of 

 potash, pyrolignite of iron, sulphate of iron, common salt, and creosote, 

 presented much decay, and a large growth of fungi. 



The results obtained from solutions of corrosive sublimate — one-eighteenth 

 of a pound to a gallon of water (Kyan's proportion) varied in an anomalous 

 manner. 



" Oh the Patent Safely Steering- Wheel of Captain Fayrer, R.N., and 

 Lieut. Kobinson, li.N." 



Serious accidents occur to the helmsmen in large vessels from the little 

 power which they have to resist the sudden shocks caused hy the sea 



