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stoves might be supplied with any kind of fuel, and, the damper being nearly closed, no attention would be required for twelve or twenty-four hours. The combustion being supported by the small quantity of hot air passing through the bars, and, as in the other cases, meeting the smoke at the bridge, thus giving a complete illustration of slow combustion. Mr. D. K. CLARK stated that it was important, in working out the problem of smoke-combustion, to keep steadily in view the principles on which it should be solved. He maintained that rapid, or, more properly, intense combustion, should be aimed at in general practice, in opposition to slow combustion; because the higher the temperature at which combustion was conducted, the more readily did the elements combine, and the less excess of air admitted to the furnace was necessary to the complete combustion of the fuel; in so far, the greater would be the economy. Moreover, the higher the rate of combustion, the less seriously did any irregularity of management on the part of the stoker affect the quality of combustion, as an excessive charge of fuel wonld be more speedily reduced to a manageable condition, for the prevention of smoke. It was fortunate that the comparative efficiency of the fuel was promoted by the same means by which smoke was to be prevented; a great excess of air being as injurious, in both respects, as a deficiency of air. He referred to the practice of locomotive boilers, with which he had had much experience, and he found that, whereas in stationary boilers combustion was usually conducted at a rate of from 101bs. to 201bs. of coal per square foot of fire-grate per hour, in locomotive boilers it was usually from 50lbs. to 100lbs. per foot per hour, or five times as much. Engine drivers would consider the low rate in stationary boilers mere trifling, and it was certain that the high rates of combustion achieved in locomotive practice, were as favourable for evaporative economy as the low rates employed in stationary practice. By judicious firing, from 81bs. to 10lbs., or even 11 lbs., of water could be evaporated per pound of coke; and, indeed, the evaporative economy was regulated rather by the proportions of the boiler than by the quality of the combustion. And, to show how this rapid combustion referred to facilitate the prevention of smoke, Mr. Clark referred to the simplicity and efficiency of the means employed by good engine drivers in burning coal. They placed the coal, in lumps, close to the back of the fire-box, just under the fire-door, and opened the fire-door a half inch or so, for the admission of air; and, occasionally also, particularly in approaching stations, and while standing there, they closed the ash-pan damper, and opened the fire-door more widely. The ashpan and damper under the fire-grate were very simple, but very important; and it was essential for their proper action that they should be well fitted together, and to the fire-box, so as to work air-tight, when required. By these simple means alone the drivers could consume a large proportion of coal with the coke, and in some cases coal entirely, without any material evolution of black smoke. He referred to some other incidental advantages of rapid combustion. In locomotives it was found that smaller boilers were required to do the same work when the combustion was more rapid; the grate, of course, being smaller, as the more intense heat was more rapidly absorbed, and less heating surface was necessary. He could not dwell too much on the importance of this result, for, in localities where space was valuable, much more compact boilers could be used, and equally powerful with those now used. The Cornish boiler, with its very large grate, and very slow combustion, was quoted as a conspicuous example of the necessity for very large boilers under such conditions. A locomotive boiler occupying a space not more than four feet, wide, and sixteen feet long, would develope 300 or 400 horse power; and the chimney was only five feet long, and twelve or fourteen inches diameter! There was nothing to prevent the proprietors of non-condensing engines blowing the waste steam into the
chimney, as in locomotives, and thus accelerating the draught. In condensing engines, some other appliance must be employed for this purpose. Mr. MANNING laid before the meeting a hollow fire-bar, a French invention, which had been put up at the Polytechnic, for ll. 16s., and which, by the introduction of heated air through the bars, would effect a saving in fuel, of 10, 15, or 20 per cent. The hollow fire-bar had been in use at one place fifteen months; it perfectly consumed its own smoke, and produced no clinkers. The CHAIRMAN said that on a recent visit he had made to the iron works in Styria, he found they used a fue. consisting of lignite, or brown coal; his attention was drawn to the fact that they used sloping bars, run across in the contrary direction to the usual plan, to support the fuel, which gave a better draft, very little smoke escaping from the chimney. He believed, by a simple arrangement of sloping bars, they might arrive at a close approximation to what they wanted. In the arrangement to which he alluded, the boiler was fixed in a small brick arch, under which was the furnace. The fuel was thrown in by a hopper, and slid down the bars, which were only a quarter of an inch apart, and the air was so admitted as to give a most perfect combustion. If the fuel were loose, it fell down, and there was a shaft by which it could be regulated. Mr. SIEMENs said he had but little to add to his observations on the previous evening. Mr. Clark had spoken in favour of rapid combustion; while Mr. Gilbertson, on the other hand, contended for slow combustion. He (Mr. Siemens), thought, that both views, though opposed to each other, could be reconciled with sound practice under different circumstances. Mr. Clark's observations had chiefly reference to the condition of the locomotive boiler, where it was important to obtain the greatest evaporation within a limited space, and where almost unlimited draft could be artificially produced by means of the blast-pipe. The draft of furnaces under land boilers, coppers, &c., depended, however, solely on the comparative lightness of the ascending column of the products of combustion, or on the amount of heat which they carried with them into the chimney. Considerations of economy here imposed slowness of draft. The available draft had, moreover, ordinarily to be diminished by means of the damper, in order to accommodate the generation of steam to the exceedingly variable demand. A good furnace ought, therefore, to effect perfect combustion at , quick and slow draft. It was, however, generally admitted, that perfect combustion could only be attained at high temperatures. Mr. Siemens found that the furnace with slanting bars, which he had previously described (and of which he made a diagram at the request of the chairman), fulfilled the required conditions. It should, however, be furnished with the simple means he had suggested of regulating the inclination of the bars. In reply to a question from the chairman, Mr. Siemens said he believed the idea of slanting bars originated with the great James Watt, and was mentioned in one of his patents. Mr. Hunt, of Stoke, near Birmingham, had patented some details of arrangement. The slanting grate, with horizontal steps like a staircase, which the chairman had seen abroad, was, he believed, the invention of Dr. Kufahl, of Berlin, and answered very well for burning “braunkole,” a fuel holding a medium position between coal and peat. Mr. LEE STEveNs forgot to mention, that a part of his plan was to use sloping bars, and that the combustion of the coal was increased in proportion to the heat of the parts of the furnace through which the air passed. Mr. CHANTER had worked a similar arrangement to that mentioned by the Chairman, on a locomotive engine, about 12 months ago, between Liverpool and Manchester, but found that it required a strong artificial draft. It worked admirably while the engine was in action, but as soon, as it was stopped, it poured forth large volumes of black smoke.
Mr. W. BRIDGES ADAMs remarked that all the mechanical processes had reference to one result, namely, distilling the volatile matter and passing it over incandescent fuel or other heated matter, and that it was a problem worth considering whether this could not be done better previous to putting the coal into the surnace; in short, manufacturing the fuel to its desirable chemical and mechanical condition before applying it to feed the fire. The objection made to this was, that coal was a much cheaper fuel than coke. But this went upon the assumption, first, that coke was the only kind of prepared fuel, and next, that in making the coke the vol. atile matters were to be wasted—a conclusion not finally settled, unless we supposed that coke-making had arrived at perfection. To ensure perfect combustion, it was requisite that oxygen be mixed in due proportion with the carbon, hydrogen, and other gases. To accomplish this mixing, it was essential that the fuel be provided with interspaces, or choking would ensue. The fuel would not digest. The oxygen was to the fuel in the furnace what the gastric juice was to the food in the stomach. If the food be granular, as fermented bread, the gastric juice would penetrate it, and the digestion would be rapid. If the food be a glutinous mass, like mashed potatoes, the gastric juice would only act on the exterior, and the digestion would be slow. As there were certain vegetables and fruits that we could eat raw, so there were certain natural fuels that we could burn raw, as dry wood, anthracite coal, cannel coal, lignite, etc. Their mechanical structure was such that the atmospheric air got free access to permeate the burning matter. But with bituminous coal the melting process shut out the access of the air, as mashed potatoes shut out the gastric juice, and indigestion or smoke ensued. So also, if the anthracite were too friable, it broke into small pieces, and choked or fell through the bars, and gave off the heat, so that the fire went out. Coke was coal artificially formed into the mechanical condition, best adapted for the action of the oxygen. ... Its irregular form insured permeation, and its solidity enabled it to give out a Y. mass of heat, while the absence of crystalline texture prevented its flying to pieces. It was a tough fuel, without being pliant or inclined to melt. The problem to solve was, how, without wasting the gases, as in the coking process, to put , the coal into the same mechanical condition as the coke. The screens on the Thames accomplished this by bringing the coal to the size of road metal—a condition advantageous to the fire when first lighted, but which, in bituminous coal, was quickly altered. There was an exact proportion of oxygen required to pass through a given quantity of goal to ensure combustion; less than this quantity would be inefficient; more would be mischievous; and it was easy to imagine that a strong current might put a fire out instead offeeding it. But to feed the fire most efficiently, it was desirable that the fuel and air also should beheated, and the advantage would be precisely that obtoined by the hot-blast—an intenser heat. It was quite clear that a careful stoker or a machine were competent, 80 to apply the coal as to distil it into coke, and pass the Product over the red fuel and burn it; but this was only a 'luestion of factories and steam vessels, with a regulated "mount of work. In the steam vessels the machine was of most importance, for it would save the human lungs on much suffering. But making factories smokeless would not cure the great mass of kitchen chimneys, twelve of which, “Punch” said, were equivalent to a camphine P. The domestic smoke was the evil which would *in when the factories nuisance was abated; for who *uld go about from house to house to collect evidence *çainst all these separate nuisances. It was not ima§uary. During the summer season he was travelling along the coast towards Brighton. A dense cloud at the stance of fourteen miles made him ask the driver if that would rain. “No,” was his reply, “that be Brighton *e." As Brighton was not a place of factories, and the brewers used it was said, smoke consumers, it was
clear it was domestic smoke. The question therefore resolved itself into whether all private houses were to be furnished with smoke consuming apparatus, as with Cutler's stoves, to light the fire on the top of a mass of coal, and burn the smoke as it arose; or to induce coal owners to manufacture a fuel which would dispense with any extraordinary arrangement. It was probable that the mechanical admixture of bituminous coal with anthracite in small blocks, would produce a something analogous to cannel coal. It might be dear at first, but experience and competition would soon cheapen it; and, moreover, every portion of the fuel would be consumed, instead of large masses being piled up in waste. Some years ago it was a cussom to use what were called fireballs in open fires. They were balls of fireclay, about 4 inches in diameter, and pierced with several holes three-quarters of an inch diameter, in opposite directions. They thus formed hot air spaces of indestructible material, and appeared well calculated, if placed at the bottom of a furnace, to save the bars from destruction; but he was not aware that they were ever used in that way. They were worth the trial. In order to make the law of smoke consuming effective and selfacting, he did not see any mode so probable as the examination of the fuel. To keep watch over all the houses and factories of London, to be sure of catching offenders, ensured an endless source of disputes as to fact, making it almost an impossibility. To enact a law taxing smokemaking fuel mightseem a hardship, while people declared their willingness to burn it carefully with good stoking; but if it were proved that the carelessness of the general community defeated the object of the Smoke Act, there could be no remedy but to attack the root of the evil, and tax imperfect fuel, (a) Mr. PAYNE believed the proposal of Mr. Adams would be a beneficial arrangement but for the cost, as those who used coke in their machinery knew how expensive it was. It required 26 cwt. 2 q's, of coal to make one ton of coke, and it had to burn 48 hours. He maintained that the only perfect smoke-consuming furnace must have a rotatory movement and machine working. Jukes's surnace was the most perfect, and burnt to white heat under the shaft. All the gases were perfectly, evolved, and gave the flame a complete vitality, instead of the dulness produced by a coke fire. He did not say that Mr. Lee Stevens's invention did not possess merit, but it could by no means compete with Juckes's. There were also other furnaces of some merit, but nothing could equal the rotary furnace with machine working. Mr. SooHELL had turned his attention to the subject about two years since, and the first idea he formed of it was to draw the smoke by a shaft through the fire, not knowing that a patent had been previously taken out for a similar arrangement. He applied a fan and a sliding
(a) Since making the above remarks, I have had put into my hands a small work, by Mr.W. M. Buchanan, of Glasgow, with the very modest title of “Notes towards a Solution of the SmokeNuisance Question.”—(Joseph Griffin and Co., Baker-street Portman-square.) It is the work of a true mechanical ani chemical philosopher, and I trust this may be the means of making it widely known to all those desirous of really mastering the subject. Mr. Buchanan clearly shows that all modes of: distilling or coking coal in the furnaces are necessarily imperfectand that distilling the coal, beforehand—if the products of dise tillation were made available—would in no way increase the price of fuel. In fact, we might get light and fuel out of th: same material, just as both oil and tallow are produced from tho, cocoa-nut. , Still, as the fireside' requires a “living fire,e a picture-making fuel, with lambent flame and radiant heat, thi probable solution of that uestion will be the mechanical as wel as chemical preparation of the fuel. The time will come when we shall eschew raw fuel for our fires as we do raw food for our stomachs. It is some years since, in the pages of the “Westminster Review,” I arrived at this .. but can still see no way of ensuring the use of smokeless fuel, save that of a tax on the smoking, before it reaches and is lost in the coal cellar. B. ADAMs.
flange to about the middle of the shaft, one end of which was connected with the side of the shaft near the damper, and the other with the atmosphere, thus diminishing or increasing the quantity of air admitted. He first tried it with one boiler, opening the furnace at the foot to let out the carbonic acid gas, and he then tried it with two boilers connected with each other, stoking the fires alternately, the smoke from the one being passed through the other. This arrangement acted tolerably well, only it wasted the fuel. He still, however, thought it the best for brewers' coppers. He afterwards tried another plan, by making a communication between the door ..f the back of the bridge. When the door was closed he found this did not act exactly as he wished, and he put a square band round the bridge, perforated with holes. This was most effectual in curing the smoke, but it had this disadvantage—in a short time the holes got filled up and it would not work. Mr. E. A. CowPER wished to know whether Mr. Jukes's furnace was applicable to manufactories where high heats were required. Mr. FRASER believed that it was, for in one case within his own knowledge, the heat had been sufficient to vitrify the fire bricks at the sides of the furnace. Mr. WALENN thought that there was a class of furnaces to which all the inventions brought before them would be inore or less inapplicable, he meant chemical works. In Staffordshire, where other products as well as those of coal were thrown off, it was necessary to have some means of getting rid of them, and this was effected by dropping water like rain down the chimneys, thus sending down the carbonaceous and sulphurous particles into a pit prepared for them. He did not know how far this system might be applied to other manufactories or domestic fireplaces. He thought, however, if the coals could be used as if the stoves were turned upside down, and thus distilled through the rest of the fire, the smoke would be destroyed. Perhaps the most effectual method of consuming the smoke, would be by the introduction of hot air, which might be effected by the adoption of hollow fire-bars, in the ends of which should be introduced a small piece of gastube, as an air pipe, carried up on the side of the bridge. Mr. Powell wished to make only one remark. Mr. Juckes had been to their glass manufactory at Whitefriars, and admitted that his invention would be perfectly inefficient if applied to glass works. MR. Wilsos had made some experiments of late with large and small coal, and he found that by Hazeldine's rocking bar a saying of 12 per cent, in the fuel was effected, which he thought a sufficient economy to recommend the invention to notice. Mr. PETTITT having expressed his opinion in favour of high combustion, drew attention to a plan of continuous furnaces for glass works, smelting works, and the like, by which the waste gas of each passed through the next; so that, supposing there were twelve, the smoke of eleven would be consumed, that of the last only escaping into tho chimney, while 60 per cent. of coal would be saved. Mr. VARLEY wished to call attention to what had been eviously brought before the Society. Some years since e Rev. Mr. Rudge brought forward a plan which he learned from a common chimney sweep, by which there was a descending shaft leading into a chamber, from which there was an ascending flue. The result was, that all the carbon was deposited in the chamber, from which it was liberated by a door, and none of it went up the chimney, as was proved by the rev. gentleman having it swept two years after the plan was put in operation. Mr. EckstEIN observed that the smoke had been got rid of in Sir Henry Meux's brewery by the use of anthracite coal mixed with a very small portion of bituminous. Mr. R. Davison reviewed several systems which had been introduced, and expressed his opinion that there
would be little need of machinery if a proper system of stoking and admisssion of the atmospheric air were attended to. Mr. CHANTER stated that he had put up a reciprocating fire bar in an extensive manufactory 14 years ago, and it was still in good working order. He had put up learly 400 of these bars within the last two years, at sugar refineries and other places, and they had been found very efficient. He had lately put up one 8 feet 6 inches in length, at Hoare's brewery, and he believed he should be shortly enabled, with the assistance of his friend Mr. Mackenzie, to add a self-feeder. Mr. Jackson had a plan, which, if not equal to that of Mr. Juckes, had worked very satisfactorily, and was much less expensive. He divided the furnace into two parts, by a partition from the bridge to close to the door. To either division there was a damper. He stoked one part by itself, when, the damper being closed, the smoke was sent over to the other part and consumed. He then closed the door, and when the smoke was consumed, and the coal in active combustion, he applied the same process to the next division, the smoke being thus effeetually destroyed. The CHAIRMAN said he believed a similar plan was published in 1841. Mr. CHANTER might observe it was in operation at Messrs. Fairbairn and Son, Mr. Mordant's, and other places. Mr. DAvison here read an extract from a lecture of Mr. Fairbairn, to show that, if the stoking was properly attended to, no machinery would be required to assist in the consumption of smoke. After a few observations, in which it was stated that Mr. Juckes', and Messrs. Bristow and Attwood's patents were in successful operation at Messrs. Ponsford and White's, Mr. CHANTER said he was convinced, if the manufacturers would give their stokers a little extra pay not to make smoke, and fine them when they did, there would be no necessity for smoke preventors or smoke consumers. Mr. HockING had always found it to his advantage to employ educated stokers, and pay them accordingly. In Cornwall they had never thought of preventing smoke, but they had thought a great deal about saving fuel. Mr. AUSTIN wished to call attention to an analysis which he had made from “The Builder,” relative to the results of five different experiments on the working of two forty-horse power boilers. The consumption of coal in each experiment was 26 tons. In the first, 49 hours were occupied in its combustion; in the second, 54; and in the third, 64. In the first experiment, 107 feet of water were evaporated in the hour; in the second, 117; and in the third, 128; the quantity increasing with the increased consumption of coal. The weight of coal consumed per horse-power per hour, was, in the first experiment, 15lbs.; in the second, 13% ; and in the third, 114; and the refuse in ashes respectively 30 cwt., 283 cwt. and 26 cwt. The first experiment was tried by the exclusion of as much air as possible, the second by its admission, and the third by the admission of air and thick fires; and the cost of fuel to the 100 feet of water evaporated was, in the first experiment, 3s.6d.; in the second, 2s. 11d. ; and in the third, 2s. 2d.; showing the advantages of the slow over quick combustion. In the fourth and fifth experiments the same quantity of coal was used, but a large portion of it was slack, the average cost being 4s. 9d. against 7s, in the previous experiments; and in these instances, instead of a cost of 3s. 6d., 2s. 11d., and 2s. 2d. per 100 feet of water *. they came out at 2s. and is. 10}d. respectively. He believed it was generally a false economy in not using coals mixed with slack, as, though it produced more ashes, in many districts they were valuable as breeze, to mix with liquid manure. Mr. TAYLost alluded to the evidence given before the committee of the House of Commons, in 1820, as he was sure it would be well worth perusal.
Mr. Joseph GLYNN said that in the course of the dis
cussion the injection of steam into the furnace had been suggested as a means of preventing smoke. Now, it had long been known that no beneficial effect could be produced by the use of steam, unless it were applied by means of a “blast-pipe,” to accelerate the current upward through the chimney, and consequently to quicken the age of air through the fire grate. The same idea was i. before the Parliamentary Committee of 1843, who examined and disposed of it then. The fire grate with bars sloping from the furnace mouth, and inclined at a considerable angle, was used by Mr. Watt for the first steam-engines he erected in London, at the Albion mills. An engraving of the boilers and furnaces was given in Dr. Robinson's “Mechanical Philosophy.” Watt also used a “feed mouth,” in which the coal was ignited and partially coked, the heated vapours flaming as they passed over the clear fire. The fuel was then pushed gradually forward to supply the consumption of the furnace, and the clinkers, by the act of stoking, discharged into the ashpit. Mr. Watt afterwards had the walls or fire-bridges behind the grates of his furnaces built hollow, with apertures at the top, to admit the air which entered from the ash-pit after passing over the hot ashes and clinkers. Thus it was evident that he understood, and to a considerable extent practised, much that was now brought before the public as new. The ChairMAN said that, from all that had come before them, excellent as many of the inventions were, there was nothing to excel good stoking. There was no question that a better education in their business would be of adYantage to stokers. He hoped the various inventors would favour the Council with a list of the places at which their respective inventions were in operation, when they should be examined and tested by a Committee of the Society, who would make a report of the results of their inquiry in the course of the session.
SIXTH ORDINARY MEETING.
WEDNESDAY, DECEMBER 21, 1853. THE Sixth Ordinary Meeting of the One Hun
firedth Session was held on Wednesday, the 21st ||8
instant, HARRY CHESTER, Esq., in the Chair.
carries general orders to search for and report on new deposits of it. It is questionable whether the gift of guano, which has been so profitable to the credit of the Peruvian state, might not prove a fatal gift, were there a certainty of the supply being permanent; and, as the case stands, we cannot say whether the jealousies of rival customers for this singular article of national wealth may not increase as the guano islands diminish, and bring fresh trouble on the already distracted republics of the Pacific. Guano, it is generally understood, was introduced to the notice of Europeans by Von Humboldt, in 1804. It was brought to England as an object of merchandise in 1839. It had been used in Peru for six hundred years and upwards, and the island depositaries had been for ages under the management of the state. Its early history is too well known, through the lectures and essays of Professors Johnston, Way, and others, to need repetition. The only points of the evidence of the earlier witnesses on this subject to which we need now refer, is that, even in those days, the flocks of birds, being disturbed by the operations of the traders, had begun to desert the islands, and that the annual new deposits were regularly swept off for the home consumption of Peru. These points will be referred to presently. With reference to the early price: in 1841, Mr. Johnston, to whose papers every person interested in the question naturally refers, gave the price of guano as 25l. per ton in this country, and not more than 2l. 5s. to 37.10s. on the spot ; and having iven an analysis, and calculated the price at which the same amount of fertilising matter might be added to the soil from the manufactories of this country (say 91. 10s.), he deduced that the British farmer should not be called upon to pay more than 201. for his ton of Peruvian guano, and should certainly refuse to do so. Mr. Philip Pusey, then president of the Royal Agricultural Society, in a paper on the subject in the journal of that body also gives the same opinion, and without doubt the very rapid adjustment of the price to the sum of 91. 5s. per ton may be taken as a prudent acknowledgment by the Peruvian agents of the very forcible nature of the Professor's argument. Of the excrementitious matter voided by the sea-birds, a very large proportion is decomposed before the guano of commerce is extracted from its beds, and more still before its arrival in this country. More than four-fifths of the weight of the original droppings of the fowl pass away in the slow process of decay, and a very large proportion of value escapes in the decomposition of the urea of the recent excrement into the salts of ammonia of the imported manure. This accounts for theihigh price set on the recent or white guano on the coasts of Peru at present, and naturally also draws attention to the consideration of the time occupied in the formation of such deposits. The expressive words of Professor Johnston on this point may be here introduced: “We are astonished; even geologists who are familiar with extended periods of time, and are accustomed to contemplate immense results produced by the prolonged action of apparently insignificant causes, even geologists are struck with the occurrence on the existing surface of the globe, of such vast accumulations of excrementitious matter; yet how are our ideas still further magnified, both in regard to the number of birds necessary to deposit them, and to the lapse of time during which they must have been gathering, when we learn that what now remains is not, either in bulk or weight, more than oneeighth or a tenth part of that which originally fell from the living sea fowl.” Proof of the rapid depreciation of guano in keeping may be found in the analyses of the dung of birds by M. de Coindet and Sir Humphry Davy. Coindet found in recent excrement. Of pure ammonia. - Of ammonia, in the form of its equivalent of uric acid . . . 35.20
8-61 per cent.
Total 43.81 per cent.
Davy found that the soluble matter of the dung of pigeons (which it will be remembered were formerly protected here by statute) decreased from 23 per cent. in the recent excrement to 16 per cent. in that of six months' old, and to 8 per cent. after fermentation.
It would appear that, until the opening of the trade in guano, the Peruvians had confined themselves mostly to the use of the new deposits, and had used up annually, or nearly so, the supply provided for them, because we have not received from Peru any guano as rich as new deposit would be, nor indeed as is imported from Bolivia and other entrepots of very minor capabilities; and the earlier imports, as being nearer the surface of the solidified deposits, were inferior to that which arrives at the present time. It is more than likely that solid masses, nearly in a virgin state, not having been cut into by the Peruvians, were attacked with pick and spade to load the earlier ships. As the work went on, the diggers arrived at harder strata, enriched at the cost of those above by the filtration of ages, and so consolidated as to require in some places the operation of blasting.
Notwithstanding the conflict of opinions on this subject, it is generally believed that the zenith of supply from Peru is past. We are aware that there is an increasing demand, and yet there is so marked a falling off in the import, that the following notice on the subject appeared in the columns of the Times of August 25, 1853:—
“Imports AND Consumption of GUANo. “A calculation has been made by the importers that the consumption of Peruvian guano in Great Britain is now from 190,000 to 200,000 tons a-year, and the increase is said to be from 15 to 20 per cent. annually. , Scotland consumes largely, but Ireland very little. At present the unrestricted system of adulteration operates greatly to its disadvantage. The imports into the United Kingdom
during the last five years have been as follows:–
1848............ 71,415 tons 1851............243,014 tons 1849... . 83,438 ,, 1852............ 129,889 , 1850...... 116,926 ,, f
“The countries from which it was imported, and the quantities brought from each, last year, were as undernoted, 36,247 tons of which were re-exported:—
Peru............ 86,293 tons Buenos Ayres. 932 tons Chili............ 11,191 , , China........... 790 , Patagonia...... 7,282 , Australia ..... 727 ,, South Africa. 7,273 ,, 705 , Bolivia......... 6,213 ,, 650 , W. C. Africa. 4,192 ,, Eight other places 703 , Uruguay....... 1,575 ,
E. C. Africa... 1,363 , 129,889 in
“The stocks of Peruvian in this country are now stated to be almost nil, and of the inferior sorts altogether not more than 10,000 tons, one moiety of which is housed in the port of Liverpool—say 5,000 tons—value 40,000l. The imports of last year appear to have been in value 1,180,000l. The imports of the present year, so far, are a mere bagatelle.” So it appears that in five years nearly 650,000 tons of Guano have been brought almost round the world for the stimulation of the soils of this country. This may have been the result of six times the quantity of excrementious matter or not. Let us take it as it is at rather more than half a million, and we may well imagine, considering that the agriculture of Peru and Chili (the only rainless depositaries), has, for all recorded times, to a great extent availed itself of the fresh-made guano, which does not form annually a stratum half an inch deep, we may well imagine that the store or reserve of ages has been severely trenched un)0Il. *W. see the amazing falling off in the imports from Peru, in the face of an increasing demand. We have seen the entire exhaustion of the Ichaboe islands in 1845, 1846, and 1847—a short space of three years—and we may therefore well turn attention to new sources of supply of this concentration of fertilising matter, before considering of home-made aids or substitutes. Of the 129,000 tons imported in 1852, 97,484 were from Peru and Chili, and 6,213 from Bolivia, or, together, 103,697. The Bolivian guano is of excellent quality; it is, in fact, collected as it falls; there is not, therefore, the shadow of a probability of its being a material stop-gap should the Peruvian supplies run short. But for the other depots little can be said. In the previously named places, no rain falls, but in most of the sources of the 26,000 tons unaccounted for, the virtue of the guano has been washed out by intense and long-continued tropical rains. Out of many analyses of guanos, one or two may be presented
to carry out the argument. We may avail our