1846.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



15^ 



of the air pump rests of thick plate glass, but that on exhausting the bell- 

 jar, the pressure of the atmosphere had shivered the plate glass into pieces, 

 Mr. Tod, in this paper, suggested a plan by which the necessary strength 

 might be obtained, while, at the same time, all parts of the interior would 

 be as visible as when the plate glass disc was used. Mr. Tod suggested that, 

 by taking two semi-elliptical bell-jars, the one of which should be per- 

 forated at the bottom, and fixed in a brass or other collar attached to the 

 pump, and the other made to fit upon its ground lip, there would then be a 

 double bell-jar formed of great strength, able to resist the atmospheric 

 pressure equally from above and from below ; and that the galvanic wires 

 could be introduced into the interior of the jar through perforations in the 

 collar at the bottom and properly insulated. 



3. A Communication from Australia on a new arrangement of the Screw- 

 Propeller. By Mr. Ja.mes P.iterson, engineer. Melbourne, Port-Philip, 

 Australia. In this new arrangement of the screw propeller, the screw is 

 made to traverse in an angle of 30 deg., by means of a Hook's joint, and is 

 thus intended to serve the purpose not only of a propeller but of the rudder. 

 It is not fixed, as usual, in the dead wood, but at the outside of the steru 

 post, just where the ordinary rudder is placed. 



April 13.— Sir G. S. JIackenzie, Bart., F.R.S.E,, President, in the Chair. 



The following communications were made: 



1. Verbal observations on the use of the Fibres of Plants, and jiar- 

 ticu'larly on the use of the Plantain Fibre : illustrated by Drawings and 

 Specimens. By Professor Balfour, F.R.S.E. — Dr. Balfour made some 

 general observations on the plants which furnish fibre for the purposes of 

 manufacture. He noticed the dillerence iu the tenacity of the woody fibre 

 of various species of plants, such as flax and hemp, and illustrated by 

 drawings of the form and nature of the fibre, as contrasted with the other 

 tissues,''and its distribution in the stems of herbaceous plants. Fibres, 

 from various plants belonging to the nettle and mallow tribe, from screw 

 pines, pine apple leaves, and palms ; also New Zealand flax, Pita (lax, 

 African or Bowstring hemp, Bengal hemp, Coir, kc, were brought under 

 consideration. Dr. Balfour then alluded to various trees, the bark of 

 which furnished cordage, and such as the lime or linden tree, the lace-bark 

 tree, and the East Indian sack tree or chandul (a species of Antiaris), 

 which grows iu the deep ravines of Kandalla, and iu the jungle near 

 Coorg. He then proceeded to notice various species of plants belonging 

 to the banana and plantain tribe, as Musa textilis, jiaradisaica, sapicntum, 

 and rosacea, from which fibres have been prepared, the mode of prepara- 

 tion, the quantity yielded, and the nature of Ibe fibre. Specimens of plan- 

 tain fibres, in various states, were exhibited. In some of the specimens 

 not fully prepared, the microscope showed, in addition to woody fibres, 

 spiral and dotted vessels, which are by no means so tenacious as ligneous 

 tissue. The fibres, although tliey bear a considerable weight, are not well 

 fitted for the ordinary purposes of manufacture : they break easily wheu 

 a knot is made on them. The communication was illustrated by fresh 

 specimens of the leaves of many of the plants, from the Botanic Garden, 

 and by a large drawing of the plantain. 



2. Description and Drawing of a Cabinet Lock and Key of a new con- 

 struction. By Paul S. Samuells, SI.D. There are three plates in this 

 lock, a bark, a front, and a centre plate. A square hole is formed in each, 

 but it is only the middle one which can be moved by the key ; so that un- 

 less the key go down to the proper depth and no farther, the bolt cannot be 

 shifted. There is also a back spring behind the bolt, ou which two pins 

 or studs are fixed, the one of which enters a hole in the bolt, which pre- 

 vents it shifting until the spring be depressed by the key. The other pin 

 or stud enters the pipe of the key ; so that unless it exactly fits the length 

 of that pipe, the key will not depress it far enough to relieve the bolt, or if 

 too long, the key vvill not get into its place, but be caught by the outer 

 square. Another advantage of this lock is, that on withdrawing the key, 

 the bolt is necessarily locked. 



3. Description,' with Diagrams, of a Uydrn-Pneumatic Railway. By 

 Mr. George Clark, Edinburgh. The weight of water is made use of to 

 compress the air, which is forced into the tube laid betwixt the tvi'o sets of 

 rails. He then contrives an apparatus for opening the continuous valves 

 of the tube, and for conveying the compressed air from it to the boiler 

 of the locomotive, from which it is admitted to the pistous of the cylinders, 

 as the steam is used, in the common method. 



4. Description of a Model of an improved method of Hanging Windows, 

 zvhereby, at small expense, windows in common use can be so altered, that 

 the Sashes can be taken out and cleaned, painted, or glazed, from the interior 

 of the room. By Mr. John Steven, Edinburgh. This simple method can 

 be applied to all windows as now constructed at a very trifling expense, 

 probably under five shillings for each window. The sashes can be taken 

 out with ease and in about two minutes. There is nothing liable to get 

 out of repair; and it possesses other advantages, such as allowing the 

 upper sash to come down to the very bottom, the steps covering the pocket 

 holes being removed to the inside frame. As a separate improvement, Mr. 

 Steven recommends that in new windows the sashes should be made with 

 a slight taper, so as to fit closely when shut, but to move freely wheu pulled 

 up or down. 



5. On a Machine for Beating Carpets, Wringing and Drying Clothes, 

 l(c. By Mr. John Baillie, Edinburgh. This consists of a broad wheel 

 with four arms, on each of which leather is stretched — and on being turned 

 round by a handle, these leaves strike on the carpet, while the broad lea- 



ther fan drives away the dust. The wheel is then reversed, which beats 

 the under side of the carpet, which is brought in successive parts under the 

 beaters. By having a hook attached to the axle of the wheel, heavy- 

 clothes, such as blankets, may be easily wrung ; and the wind of the fans 

 speedily dries them wheu suspended within its influence. 



SOCIETY OF ARTS, LONDON. 

 March 25. -G. Moore, Esq., V.P., in the Chair. 



The first paper read was, by the Rev. Dr. Thompson, " On the Earth- 

 quakes of Peru and Chili." The paper also described the peculiarities of 

 the mountains of North and South America, and concluded with an ac- 

 count of the most celebrated earthquakes that have occurred in America. 



The second communication was, " On an Improred Safety Lamp for 

 Miners." By Dr. Clannv. The improvement consists in preventing cur- 

 rents of air coming in contact with the flame ; a glass, or other transparent 

 substance, being substituted for the wire gauze at the lower part of the 

 lamp. It is also less liable to be blown out than the Davy lamp. 

 April S.—W. F. Cooke, Esq., V.P., in the Chair. 



Ths following communications were made by Dr. Green, " On a Neio 

 Portable Stand for Telescopes with an Equatorial Movement, but witliout a 

 Polar Axis." The subject of the improvement was introduced with au 

 account of the telescope from the time of its discovery, and the improve- 

 ments which have been made upon it up to the present time. He next 

 alluded to the stand ordinarily used, and pointed out the peculiarities of 

 the Herschelian, achromatic, and other stands, and the objections to them, 

 arising either from their unsteadiness, unportabilily, or other causes; he 

 then proceeded to point out the improvements which he had ell'ected, by- 

 describing his own stand. The true principle upon which every stand 

 ought to be constructed (observed Dr. Green) is to have the heaviest end 

 of the telescope supported on a solid foundation, and the moving power 

 should be placed as far as possible from the centre of motion. To ellect 

 both these conversions has been my aim in the stand which I now submit. 

 As a triangular support is found to be the most steady, it has been adopted 

 in this case, and pervades almost every part of the stand. The object-end 

 of the tube containing the great mirror rests upon a circular disc, having a 

 diameter about one-half larger than that of the tube. It is supported by 

 three feet, which are not more than three-quarters of an inch high, so that 

 it may be said to rest solidly on the earth. To admit of easy rotation, a 

 second disc of the same diameter rests on the surface of the one described, 

 and moves on three friction wheels round a pivot passed through the centre 

 of each. Near the periphery of this upper circular disc, upon the opposite 

 sides of it, are fixed, vertically, two flat pieces of brass, about half the dia- 

 meter of the tube iu height; upon these the telescope rests by means of 

 two horizontal arms projecting from the sides. The object is to form a 

 universal joint, and prevent the telescope rotating on its own axis. The 

 upper end of the tube rests upon a pair of shears a little inclined towards 

 the tube, thus the entire fabric is one large triangle, possessing the greatest 

 steadiness. The shears are attached at their lower end to a horizontal 

 bar, which slides in a groove. The bar is worked by means of a universal 

 joint and rack and pinion, and by which the slow motion in azimuth is 

 given. The shears are so constructed as tu admit of being lengthened or 

 sliortened. The fine movement in altitude for finding a star is provided by 

 a slide on the outside of the under part of the tube, to which slide the 

 shears are attached. The slide is moved by a rack and pinion. The 

 equatorial movement is the link of connexion between the head of the 



shears and the slide for the fine altitude movement, and is thusetfected : 



the two legs forming the shears are hinged together at the top by a circular 

 joint, in the centre of which is inserted a piece of brass, which carries the 

 equatorial movement slide, and is worked by a toothed-wheel and pinion. 

 The equatorial slides are attached to the altitude slide by a universal Joint. 

 By placing the lower end with the discs it rests upon,ona tripod, this frame 

 may be made to suit the Newtonian telescope for viewing terrestrial ob- 

 jects. 



2. " Ok a Process for the Preservation of Animal and Vegetable Sub- 

 stances with their forms and colours unimpaired." By Dr. J. Silvestri. — 

 A number of specimens of preserved animal and other substances were ex- 

 hibited. 



3. " Specimens of a new process of dulling the surface of electrotypes." 

 By Mr. Colchester, and also specimens of a new method of brjnzing, by 

 Mr. Loope, were also exhibited. 



April 13. — T. M'ebster, Esq., V.P., in the Chair. 

 The first communication was on " Mr. Rand's inventions for the Manu- 

 facture of Flexible Metal Vessels for preserving paint and otlw.r matters." 

 By W. Carpmael. Mr. Carpmael slated that Mr. Rand, who is an artist, 

 had, from the inconvenience and waste of colour which takes place when 

 it is put up in the bladders ordinarily used, been led to endeavour to find 

 a substitute, and the use of metallic vessels suggested itself. After ex- 

 periments he succeeded in forming them of so thin a body of metal that 

 they are capable of being collapsed so as to shut out all air. The tubes 

 are made of block tin the 150th part of an inch in thickness, and have at 

 their upper end a nozzle and screw cap, and are closed at the bottom by 

 being folded over once or twice with a pair of pincers so as to exclude all 

 air. .A.S the colour or other matter which they contain is pressed out, the 

 tubes are collapsed and thus the upper part of the tube always remains 

 full. Each tube has to go through the following process of manufacture. 



