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No. 68. Vol. II.] JOURNAL OF THE SOCIETY OF ARTS. [MARCH 10, 1854.
Journal of the Society of Arts.
FRIDAY, MARCH 10, 1854.
THIRTEENTH ORDINARY MEETING.
WEDNESDAY, MARCH 8, 1854.
The Thirteenth Ordinary Meeting of the One Hundredth Session, was held on Wednesday, the 8th instant, HENRY COLE, Esq., C.B., in the chair.
The following candidates were balloted for and duly elected :Cooke, John
temper," different chemical re-agents have been tried with variable success.
The clear liquor is now drawn off into the sugar pans. In these it is evaporated down to a state of thick syrup, and as soon as it has reached a proper degree of consistence, it is "skipped," that is removed off the fire into a shallow wooden vessel, termed a "cooler," where, as it gradually lowers in temperature, the greater portion becomes crystallized.
From the cooler, the mass of newly and partly-formed sugar, and that still uncrystallized is taken to the Curing-house," and put, or "potted," as it is termed, into hogsheads having perforated bottoms, to allow the molasses to drain off.
When the sugar is sufficiently "cured," that is, dried, fitted in,) the bottoms taken out; and the perforations the hogsheads are inverted, (the heading having been first plugged-the uncured portion of the sugar is then re moved, and its place supplied by some dry, and, after being well rammed, the bottoms of the hogsheads are again restored. The sugar is now ready for shipment.
| Parfitt, George John Curtis, William Joseph Pitman, Edward John T. Previous to the reading of the paper, the Secre- Such is the general routine of operations, where the tary called attention to some specimens of metallic sugar-making is carried on with open pans only, but when lace exhibited by Mr. Carey, of Nottingham. the Vacuum pans are employed the concentrated juice or This lace was produced by the ordinary Jacquard syrup, in place of being skipped into the coolers, is removed at an earlier stage of the boiling process to the lace machine, în 4 feet widths, and at about half vacuum pans, where it is finished. But in any case the the rate of ordinary cotton lace. It was con- boiling in open pans forms a necessary part of the manuceived that it would be found serviceable for efacture, and consequently they are not entirely superseded, costly rivals, the vacuum pans. as some persons have erroneously stated, by their more
great variety of purposes, but chiefly in upholstery. Possessing almost the flexibility of bobbin-net, and being in pattern equal to the best production of machine made cotton or silk lace, and to much of the Honiton lace also, it would be found valuable for window blinds and curtains, as well as for decoration generally; whilst, being of a metallic body, it could be made to resemble either gold or silver, and upon becoming tarnished by lengthened wear, it might be reburnished and rendered equal in lustre to what it was when new, | at a very moderate cost. The want of a metallic lace for striking electrotype patterns upon various articles of plate first suggested the making of these goods, and subsequently it has been adapted to many other objects.
The Paper read was :—
AN INVESTIGATION INTO THE RELATIVE
The manufacture of sugar from the juice of the cane not being very generally understood in this country, a few words on the modus operandi, as commonly conducted in the "Boiling house" of a sugar plantation, may not be out of place here by way of introduction.
The expressed juice, as it issues from the cane-mill is conveyed to a shallow vessel, made either of iron or copper, termed a "Clarifier or "Racker," in which it undergoes a partial clarification, preliminary to its concentration in the so-called" Pans." On many plantations however, these latter vessels are called "Coppers,” irrespective of the kind of metal of which they are made.
The cane juice, or as it is more frequently namedliquor-is heated in the clarifier to a little below the boiling point, and a small portion of crude lime, in the state of powder, is mixed intimately with it, by stirring. After simmering for a quarter of an hour or so, a separation takes place between the pure juice and the foreign bodies naturally and accidently combined with it. Although lime is the substance almost universally employed as a
The number and size of the pans (that is the ordinary pans), together with the mode of hanging or setting them, varies in different colonies, and even on different plantations in the same colony.
and their size, as a general rule, proportionate to the
The two first teaches-where two are adopted-aro ranged side by side, cach having its own separate furnace. The other pans are disposed in a line at right angles to the two first teaches, the flues of which meet in that of the second teach, or first of the series of the larger coppers. This is comparatively a modern arrangement, and known under the appellation of the "Demerara plan." The object of it is to keep up a continuous fire under the larger pans, thus, whilst one teach is being emptied, and the fire beneath is withdrawn, the fire under the other teach is maintained. The advantage of this must be obvious, and will be more apparent when viewed in connection with another improvement, which, I believe, originated in Demerara also, namely, the substitution of the "dipper," or "skipper," for discharging the teach at one operation, instead of taking it out by small portions at a time with the "ladle." The dipper is a copper vessel made to fit, as nearly as possible, the two first teaches, having a valve in the bottom opening upwards. As soon as the syrup is ready for "striking," the dipper is lowered by means of a traversing crane into the teach, the contents of which pass into the dipper, which is then raised by the crane, and delivered into the coolers. By this simple contrivance a great deal of time and labour is saved; the fire under the pans is kept up without interruption, and the syrup preserves a uniformity of consistence.
The invention patented by Mr. Purbrick, and published
under the title of "Purbrick and Yeates' Patent Sugar Pans," is the joint production of himself and a sugar planter of 30 years' practice, Mr. Purbrick having been actively employed as an engineer for upwards of 10 years in the West Indies.
The distinguishing feature of these vessels consists in the peculiarity of their shape, which is attained by sub stituting portions of a cylinder for that of a sphere to form their bottoms, the latter being the shape of the bottoms of the common pans. An unbroken metallic surface is thus presented to the action of the flame and heated airundulating longitudinally, and horizontal transversely.
The additional effective heating surface obtained by this modification is very considerable, and will be palpably evident on inspecting a plan of each description of pan, drawn to one scaie, and placed in juxta-position.
But, before going more fully into the relative advantages offered by the two systems in question, it may be as well to explain the figures.
Figure 1, exhibits a plan of a portion of a set of the Patent Pans, Figure 3, a transverse section of one of the large pans in its place; and Figure 2, a view of the two first teaches-one in section, with its corresponding furnace, and the other partly in section, and its furnace partly in elevation.
Figure 4, is a longitudinal section of a set of the Patent Pans, with stoke-hole, furnace, and flue, and a steamboiler at the extreme end of it.
Figures 5, 6, and 7 show the pans in ordinary use, and the construction of the arches between them, in plan and section. Fig. 3.
the capacity of the pans as they recede from the teach which has been the usual practice with the common pans In that case the dimensions would be enlarged longitudinally only, so as to preserve the side walls of the flue parallel throughout.
In figure 2, a part of the front wall of the furnace is broken away to show the manner in which the two first teaches are hung. The furnace-mouth and ash-pit of the furnace to the left are shown in elevation.
Figure 3 represents the second teach in section, as regards the brickwork, and in elevation, as regards the pan itself. A similar representation would apply to a transverse view of all the larger pans.
The details of figure 4 do not require a very minute description. The general arrangement of the pans, furnaces, flue, and steam-boiler, will speak for itself. This last appendage is merely brought into the drawing in order to illustrate the mode in which the waste heat, after leaving the pans, might be-and sometimes is-appropriated to great advantage.
The teaches and larger pans are shaded black, and figured, P 1, P 2, P 3. The two first are an outline or section in the direction of the flue of those vessels: the other is in elevation. The bottom of the flue is made to conform very nearly to the bottoms of the pans. By this means the flame and heated air are caused to impinge on the entire surface of the horizontal portion of the bottom, and an equable radiation of heat from the brickwork maintained to a considerable extent throughout the whole length of the flue. The letters A, A, denote the position of the ashpits underneath the pans, which are entered by an opening in the external wall, one of which is shewn under the last large pan. The adjoining opening (marked S) represents the flue leading from the steam-boiler to the chimney. According to the arrangement here shown, he steam-boiler must be regarded only as an auxiliary.
If no other be used, then the connection between it and the pans must be effected in a different way. A furnace and fire-bars will, in that case, be required for the purpose of getting up the steam before the fire is put to the pans, and to assist in case of a deficiency from that source. But where the megass (the fuel employed to boil the cane-juice) is abundant, dry, and in good condition, and the steam-boiler of proper form and dimensions, sufficient steam will be generated by the waste heat from the flue of the sugar-pans to work a steam-engine proportional to the requirements of the plantation. This is not a matter of conjecture, as the patentee of the invention under consideration has demonstrated it on a large scale with the common pans, and the same object is secured in a superior degree with the patent vessels, inasmuch as they admit of greater compactness, whereby the steam-boiler is brought into closer promixity to their furnaces.
Figures 5, 6, and 7 relate exclusively to the common pans. Figure 5 is a plan of two of the larger ones; the vessels themselves shaded black, and surrounded by either tiles or sheet-lead. This appendage, incident and indispensable to the common pans, is a cosity and troublesome affair. Its object is twofold,-to form a
watertight and smooth covering to the brickwork beneath, order to show the position of the jambs of the arches and also to afford additional stowage for the cane-liquor between the pans, and the manner in which the flues are whilst boiling. A portion of this covering is represented carried round them. as taken off, and a part of the brickwork renioved, in
Figure 6 shows the pans in elevation, and the brickwork in section. That of the flue is taken along the line A, A, on the plan, and is supposed to be constructed on the improved plan of hanging the pans, namely, by giving to the bottom of the flue the shape of the pans themselves, or nearly so; consequently it will present along its central line an undulating appearance as here shown. The parts lettered B, B. B, are the crowns of the arches between the pans, and C, C, the ash pits.
Figure 7 exhibits a combination of sectional views. The foremost taken in the line D, D, and the more distant one taken along the line E, E, a portion of the pan being visible through the opening in the arch, and the remainder being represented by the dotted lines.
The more important advantages to which the patent pans lay claim, aie threefold :
1st. A large increase in the amount of effective surface for heating liquids.
2nd. A more favourable condition as regards the disposition or appropriation of that surface.
3rd. Considerable economy in the setting or hanging of the pans.
Now, the first of these positions admits of easy proof, as it will be found by calculating the relative area of the surface exposed to the action of the fire by the two descriptions of pans, occupying the like space, and of equal capacity, that the proportion will be nearly as 8 to 5 in favour of the patent vessels.
The second position we have laid down does not admit of the like mathematical demonstration, but a glance at the mere form given to the patent pana, especially when viewed in the transverse section, will, it is conceived, convince any competent judge in such matters of the soundness of the principle upon which it is based, and justify the superiority to which it lays claim. The horizontal is admitted, on all hands, to be the most favourable condition which can be presented to the action of the fire for heating liquids. And this, it will be seen, obtains to a much larger extent in the patent pans than in the common ones, even those o the most approved shape.
The saving both in labour and materials in the setting of the patent pans will be self-evident, on a bare inspection of the figures. It will be seen that the most difficult and expensive portions of the brickwork required! to hang the common pans are altogether dispensed with. No arches between the pans, no circular wails to form the flues around them, both of which must be constructed chiefly of fire-bricks and fire-clay, and by skilled workmen. Nothing more is required to hang the patent pans than two straight parallel upright walls of common brick and mortar, with the exception of the first teaches, which, from their proximity to the furnace, must be set with fire-proof materials. Then there is another considerable saving, by doing away with the "tiling and leading," which forms a very prominent feature, not only in the first hanging of the pans, but periodically, and frequently many times repeated during the sugar making season, in the item of plumbers' work. Taking this and the item of brickwork together, it may be fairly stated, that at least 50%. will be saved in the first hanging alone.
What the amount may be in the shape of repairs, and renewals of plumbers' and bricklayers' work, it is difficult to estimate, but every practical sugar planter knows that it figures but too conspicuously in the estates accounts.
But the economy does not stop here. The interruptions to which the boiling-house operations, and many others, are subject, consequent on the falling in of the arches between the pans, the melting of the lead, &c., &c., constitutes a serious loss. In addition to that sustained on the score of labour, we must take into the account the waste of unmanufactured cane juice and of unground canes, which for the purpose of converting into sugar, each soon becomes alike useless. And this sometimes take place to the extent of a hogshead of sugar.
The sources of waste and annoyance will be obviated by the adoption of the patent pans. But in the event of any stoppage by accident to the pans, their removal and replacement can be effected with so much ease and dispatch as scarcely to affect the regular progress of the boiling-house work. The junctions of the pans may be either by rivets or screw-bolts, and their separation is the work of a few minutes; and, being constructed of wroughtiron, they can be more readily and efficiently repaired.
Another point remains to be noticed, and it is one of no mean importance in connection with the patent pansand that is, their superior evaporating qualities, by which the duration of the boiling process is very much reduced; and thus ensuring a better quality of sugar as well as an increased quantity. The deterioration which takes place in the quality of the sugar, and the large increase of molasses produced by a sluggish evaporation, the loss of time and waste of fuel are facts well known to, and their value only to be duly appreciated by, the practical sugar maker.
The CHAIRMAN said, that it seemed to him that the alterations suggested rested upon the question of cheap construction, as he did not gather that the sugar was better made by the proposed pans than by the old ones. He should, however, be glad to hear the opinion of some of the gentlemen present, technically acquainted with the subject, as to the practical value of these pans.
Mr. DALE (of Thames-street,) remarked that there was scarcely sufficient novelty in the plan to provoke much discussion, as the only improvement consisted in the pans being oblong in place of being round. No doubt a great saving of brickwork was effected; but he thought there was not sufficient improvement to induce the planters to introduce the new system in place of the one which had been so long established.
Mr. PURBRICK explained that the old round pans required a large surface of lead or tiles in the fixing. He did away with that, and also with a large mass of brick work between and surrounding the pans. His plan simply required two straight walls of brickwork, on which the pans were laid, and as they were made to but against each other there was a continuous metallic surface exposed to the fire from one end to the other,-whereas in the common pans there was a mass of brickwork between the pans, which
was excessively liable to get out of order, besides taking off a great deal of the heat. The setting of the pans would therefore not only be less costly in the first instance, but there would be less outlay required for repairs. Under the old plan the arches were continually falling down; he had known them to fall two or three times during a crop.
the heat was not wasted. They wanted the heat completely under the evaporating pan, and it had been very truly remarked that the heat would flow up between the pans rather than underneath them; and it would be difficult to attain uniformity in the heating without the use of steam. It was also necessary always to have the pans filled with liquor or they would become charred at the top, as the heat would be between them and not at the bottom.
Mr. SIEMENS remarked that the new plan was simple in construction, and judicious in the arrangement of the pans, which were placed one after the other, so as to obMr. AUSTIN said, although not versed in the theory, tain a more extended surface within the same compass. he had a practical acquaintance with the subject, having That appeared to be the chief merit claimed by the pa- for 6 or 7 years had the management of a property in the tentse, and there seemed to be very little doubt upon it West Indies. It appeared to him that in discussing a but the other question-that of obtaining a superior question of this nature, they must treat it as a matter of quality of sugar-was not adverted to in the paper. Ile art and its claims to utility. It had been shown to be thought perhaps the new pans were less calculated to not quite so original as the patentee might have imamaintain the syrup in a liquid state and crystallize it gined; but practically the invention seemed likely to be than the old ones, for this reason,-the cane-juice was of value. In the West Indies, up to the present day, not a perfect liquor, but syrup-like, and if the fire im- the "teaches" were fixed exactly like those placed before pinged on any part of the surface with energy, the liquid him, the round pans with leaden or tile tops-and he would be heated to a degree which would prevent its saw at a glance the advantages attending the new plans. crystallizing afterwards. It appeared to him that in the There would be far less consumption of fuel, which was a new pan the flame would impinge upon parts of the surmost important consideration; for, in many parts of face in such a way as to make the heat given off, espe- the country, they were so short of fuel that they were cially in those portions, too great. He thought the obliged to use the squeezed cane, which was dried in the system of evaporating by fire an objectionable one. There was a difficulty even in getting a sufficient the Continent the sugar was prepared from the more costly supply of that fuel, and therefore any plan which admitted beet-root, almost to the exclusion of cane juice, and there of a smaller amount of fuel would prove a useful invensuch a thing as a furnace for boiling the liquor was not tion. A gentleman had suggested that steam should be known, steam heat being invariably used. The object of applied to the manufacture of sugar as a heating Haworth's vacuum pan was no other than evaporating at agent. He did not know how that might be, a lower temperature; but it was not necessary to have but he knew in many parts of the West Indies the costly apparatus of the vacuum pan in order to effect there was a difficulty in getting water for the ordinary purthat. In British Cayenne two sugar planters seemed to poses of life much less for the supply of a steam boiler. Alhave moved one step in advance by combining an open though on a few of the richer estates there were steam mills evaporating pan placed over a very mild and diffused for crushing the cane and expressing the liquor, yet in the fire, with a paddle-wheel dipping into the liquid, majority of cases windmills were employed for that purand exposing it through its rotation to the action pose. The steam for the boiling of the sugar itself would of the dry trade-winds. There appeared to be a involve intricate and expensive machinery, which undecided improvement in the new pans, but he sub-fortunately too many of the estates would not be able to mitted that in using paus of any kind fire ought not to be employed directly, but through the medium of steam, as the latter would not heat a degree beyond its own temperature. Besides, there was another convenience,―a series of pans could be heated, and it would allow of one pan boing discharged whilst the steam was applied to another series, so that great advantage thereby accrued in a large establishment from the use of steam. He called attention to this apparent defect in the old process in general, and which appeared to be equally applica
ble to the new pans.
Mr. PONTIFEX remarked, that the pans in use in Java were oblong, and were joined together without the intervention of brickwork; the only difference between them and those described by Mr. Purbrick was that, in some instances, the bottoms were convex instead of concave. The vacuum pans were very little used until the liquor was much evaporated. Therefore the common pans might be used until it arrived at the point beyond which the liquor would be injured, viz:-212 degrees, the common heat of steam-then the vacuum pan was employed for finishing the sugar.
Mr. PURBRICK agreed with Mr. Siemens, that the use of steam as a heating agent was preferable to the application of fire direct; but his object was to induce the planters to adopt a less expensive mode than steam; for if an apparatus cost only 107. more than that now in use it would not be adopted. He, therefore, wished to introduce a plan which, at the same cost, would accomplish the object cheaper and better-better, because if the liquor was a long time simmering they would not get good sugar. By this plan, he got one-third more surface in the same amount of space as the common pans occupied, by means of which he obtained increased evaporation. Mr. MARTINEAU said, the heating surface was increased, but he doubted whether in evaporating a great deal of
incur. He thought there were practical advantages to be derived from the new plan; in fact he remembered, in keeping the accounts of the estate to which he had tended, that there was a constant expenditure in rebuilding the brickwork during the crop season, by which the operations were very seriously delayed. This would be avoided by the flue passing continuously under the teaches," and would cause the manufacture of the sugar to be carried on with much greater economy than under the old system.
Mr. SIEMENS Considered the arguments as to the scarcity of water and fuel to be in favour of evaporating by steam. If the whole of the heating power was put under the boiler, and as much power taken out of the steam as was necessary, and then the steam turned under the evaporating pans, it would be the most economical way of obtaining heat from fuel; and on the other hand the whole of the water would be returned to the boiler, so that, strictly speaking, no additional water would be used. That was a point which had been ovoriooked.
Mr. REEVES, as practically acquainted with the powers of evaporation for chemical purposes, gave the preference to the round pans, as in his experience they had answered better than those of any other form.
A vote of thanks having been passed to Mr. Purbrick for the paper which had been read,
The Secretary announced that at the meeting of Wednesday next, the 15th inst., a paper would be read "On Machines for Dressing Flour, with a description of a New Machine for that purpose," by Mr. T. Egan.
Gallery of Inventors.
Portrait received since the last announcement
FREDERICK AUGUSTUS WINSOR.
INSTITUTE BOOK ORDERS.
PUBLIC LIBRARIES ACT.
The following Circular and Queries have just been issued to the Town Clerks of all boroughs included in the Act 13 and 14 Vict. Cap. LXV. It is requested that Members and others will aid the Council in obtaining the returns requested, and otherwise in promoting this enquiry. Society of Arts, Manufactures, and Commerce, Adelphi, London, March 2, 1854.
SIR, It is well known that many difficulties exist
The following statement shows the amount of the in the working of the 18 and 14 Vict. c. LXV. called by
its short title the "Public Libraries Act, which, in a very great degree diminish the value of its provisions. The Council of the Society of Arts are about to take steps for procuring an amendment of the Act, so as to Red. Price. render it more efficient for the purposes it has in view; and they are anxious to collect the experience of those who have a practical knowledge of the subject.
£ s. d. 12 0 9 10 13
I am therefore desired to lay before you the accompa 0 14 4 nying questions, and to beg the favour of your reply. Should there be any points not covered by the questions, on which you can give information or make 5 10 1 suggestions, the Council will be much gratified at receiving them.
4 11 11
0 14 1
Holmfirth, Mechanics' Institution 11 Lancaster, Church of England Instruction Society
Leiston, Mechanics' Institute
London, Bank of England Library and Literary Institution Macclesfield, Useful Knowledge Society
11 12 6
21 2 0
Masham, Mechanics' Institution Northallerton, Institute Northamptonshire, Religions and Useful Knowledge Society Pershore, Mechanics' Institution Romford, Literary and Mechanics' Institution
Royston, Mechanics' Institute Sevenoaks, Literary Institution Shaftesbury, Literary Institution Tiverton, Literary and Scientific Institution
Welshpool, Reading Society Woburn, Literary, Scientific, and Mechanics' Institution
4 10 6
2 15 3 22 0 5
3 12 91
I am, sir, your obedient servant,
P. LE NEVE FOSTER, Secretary.
QUESTIONS PROPOSED MARCH 2, 1854. 1. Is the "Public Libraries Act" in operation in your town?
2. Was it adopted with or without opposition? What is the number of Burgesses entitled to vote in your Borough? How many polled in favour of, and how many against adopting the provisions of the Act?
3. Has any building been provided and opened, or when will it open; what are the conditions of admittance, and what are the numbers frequenting it?
4. Have any unsuccessful attempts been made to adopt the provisions of the Act?
5. Do the provisions of the Act unnecessarily impede its adoption, and if so, how?
6. Is the prohibition against the re-proposal of the Act within two years desirable? Is the amount of rate sufficient?
7. Ought the purposes of the rate to be limited to the provision of the Building and other objects specified in the Act, or extended to the purchase of specimens, books, &c.
8. Should a maximum rate be fixed by the Act, or should the amount of the rate be left to the option of the rate-payers?
9. Would a central metropolitan Museum by means of correspondence and interchange of specimens conduce to the prosperity of local Museums? Would it be desirable that arrangements should be made by which the duplicates and superfluous specimens in the British Museum, Museum of Department of Science and Art, Kew Museum, &c., should be distributed to Provincial Museums?
10. Would it be desirable to have collections of works of Art and illustrative series of now discoveries and inventions systematically circulated through provincial Museums, and whether by arrangements with the central Museums in London, or otherwise?
11. Is there any public Library or Local Museum in your town? If not, has any attempt been made to establish one? Are there any facilities for obtaining loans of books? Are there any circulating libraries, and if so, what classes make use of them? What is the general feeling in your town with respect to the establishment of a public Library, Museum, or Reading-room?
PAPER FROM WOOD.-A patent for the manufacture of paper from wood-fibre has been taken out by Messrs. Watt and Burgess. It is said to be equal to any writing-paper now selling at 7d. per pound. The cost of production is stated to be somewhat under £25 a ton-more then £12 less than the price of ragpaper now in use.