sally applied to duplex and lever watches, not, indeed' adjusted with the same care as in pocket chronometers, for the small difference of cost between one kind of escapement and another, compared with the value of the watch as a timekeeper when completed, renders this course at all times undesirable, but merely passed through the first stages of approximate adjustment, which could be done at comparatively little expense.

In chronometers, where the greatest attainable accuracy is required, the adjustments should be continued so long as any constant error is appreciable; and it would therefore be a delusion to suppose, if an article possesses a chronometer escapement and balance, it will of necessity be a good instrument. These are only the elements which afterwards require a long series of adjustments, for, however fine the mechanical workmanship may be throughout, it alone will prove of no avail. These adjustments, which may be called the mental workmanship of the chronometer, are not commenced until every part has been made, and the chronometer, so far as the eye can detect, finished. They occupy, on the average, twelve months in the finest chronometers, but numbers are manufactured and sold in which the adjustments have been run over within a month; it will not, therefore, appear surprising if, when a chronometer of the best mechanical workmanship is placed before a maker, he is unable to say, without a trial of six months, whether, as an instrument, it may be worth 301. or 60%. The first of these adjustments relates to the balance-spring, which should be so adjusted that the vibrations of the balance, whether long or short, should be performed in the same time, in order that when the chronometer becomes dirty, and the oil thick, the time may not be altered from the diminished power transmitted by the escapement, and the consequent diminution in the length of arc or distance which the balance vibrates. The second adjust-count of what is generally called the supplemental error. ment refers to the compensation for temperature-the only point in which any well established improvement has been made within the last half-century. The method of effecting this adjustment will be better understood after the balance has been described. The third adjustment, for positions, is not particularly required, except for pocket chronometers, as box chronometers are kept in nearly the same position, by being suspended in gimbols. With the pocket chronometer, however, the case is differen, as it must follow the positions of the wearer, for all of which it consequently requires to be adjusted. These may be resolved into five principal positions, one having the plane of the balance horizontal and four vertical, which can be adjusted, with a little aid from the balancespring, by four screws placed at the quarters on the diameter of the balance; these are screwed in or out, so as to alter their relative distance from the centre-as the chronometer, on being placed in the different positions, is found to lose or gain. It is by similar screws that the mean time or rate of all chronometers, whether box or pocket, is regulated, for this is not effected by a curb, as in the ordinary watch, which, from its acting on the balance-spring instead of on the balance, would entirely destroy the isochronous adjustment for change of arc. The regulation of chronometers is therefore, very judiciously, taken out of the power of the wearer.

The reason why a compensation for change of temperature is required, is that the balance-spring of chronometers, watches, &c., upon the invariable force of which the time depends, is subject, in common with all springs, to become weaker as the temperature is increased. This causes the chronometer to lose, and the error is further augmented by the expansion of the material composing the balance itself; the loss amounting altogether to about 380 seconds a day in a change of temperature from 32° to 100° Fahrenheit. It is to remove this error that the compensation-balance, invented during the last century, is employed. It consists of an arm having a concentric circle or rim, composed of two metals, firmly united together by melting one upon the other. These

metals are selected of different expansibilities, such as brass and steel, the metal expanding the most being placed on the outside. The rim is divided on each side the arm, and weights are placed on opposite portions, and as the metals on an increase of temperature cannot expand in a direct line, on account of being connected, the expansion of one over the other causes the rim to bend and the weights placed upon it to be carried in towards the centre of the balance, the effect of which is to make the chronometer go faster. The metals are united in order to obtain sufficient motion, as their simple expansion would be altogether inadequate to carry the weights a sufficient distance. The balance is adjusted by repeatedly trying the chronometer in different temperatures, and moving the weights backwards and forwards along the rim until the exact point has been found where one error will neutralise the other. So long as the errors are large, moderate intervals of trials will enable them to be seen, and an alteration to be made in the adjustment, but the nearer the compensation approaches to perfection the longer must be the trials in each temperature, before sufficient data are collected for making the alteration, while the chances are proportionably greater that it will be altered too much. Of course it occasionally happens that the adjustment is effected in a shorter time, but, from the liability of new chronometers to change their rate, and other causes, it is not advisable that the final adjustments should be completed within a much shorter period than twelve months. It will now be seen why the finest chronometers generally occupy so much longer time than others of inferior merit. In speaking of the finest chronometers, those having the ordinary balance cannot now be included, as their errors, when most perfectly adjusted, are still sufficiently large to be seen without very long trials, on acThis cannot be corrected by the ordinary means, as the balance-spring loses its elastic force at an accumulating rate, over the effect produced by the compound lamina of the balance, and consequently the chronometer can only be adjusted to keep the same rate at two points on the thermometer, between which it will gain. If, for instance, it is adjusted at 35° and 80° Fahrenheit, which are probably the best points that can be selected for the ordinary balance, on account of the error being divided and distributed pretty equally throughout; then, taking its rate at mean temperature for comparison, the chronometer will be found to lose, whether the temperature be either increased or diminished, the loss increasing as the extremes become greater. For special purposes, however, chronometers are sometimes compensated at one extreme, of heat or cold, and mean temperature. This proportionably reduces the error in the interval between mean temperature and the extreme for which it is adjusted, but doubles it at the opposite extreme; this me. thod is very objectionable for general use. The following appear to be the conditions which a perfect compensation for the secondary error should fulfil. 1. It should gradually accumulate in effect from one extreme of temperature to the other, in the proportion required by the change of elastic force in the balance-spring. 2. The secondary compensation should be susceptible of adjustment by rule alone; for if this could only be effected by actual trial, as in the primary compensation, the extra time required would preclude the probability of its coming into general use. 3. After it has once been adjusted, the compensation should remain permanent and not be liable to derangement. 4. The secondary compensation should not interfere in the slightest degree with the action of the primary compensation; for as the motion of the lamina in a large box chronometer only amounts to 1-250th of an inch to produce a difference in the rate of 380 seconds a day, in a change of temperature from 32° to 100° Fahrenheit, any such interference would eventually prove fatal to the chronometer's good performance.

(To be continued.)

can be more simple than this process. It boasts of no "art" it is based on no mysterious theory; but it appeals to common sense. When it is determined to bring any waste lands into the market, or, in other words, to form a new territory or colony, a land-office is established on the spot, the whole area is surveyed, allotted, and made ready for sale, at the upset price of 5s. 3d. an acre. Every sale is registered, and a Government title is granted to the original purchaser. After all expenses are paid, including a liberal provision for any natives that may have occupied the country, a profit remains to the Revenue of about 4s. 4d. per acre. A department of the landoffice settles all disputes that may arise in regard to boundaries or other matters. Congress passes an Act whereby administrative institutions, on a representative basis, are provided for the management of local affairs in the new settlement; and then its further progress towards the full dignity of an independent confederate State depends on itself. All this is perfectly consistent with the principles of English common law, on which the laws of the United States are mainly based. The Colonial Administration of the mother country is quite inconsistent therewith; for, instead of providing for local administration, on the pure representative system of our forefathers, it makes the colonists dependent on mere officials, and the disgraceful state of Melbourne is an illustration of the result. I have proposed a return to the "old ways," and there is abundant evidence to show that but few civilized nations are, or can be, really unfit for the simple exercise of municipal privileges and local administration. Existing circumstances suggest a course for the preliminary establishment of the settlement, which is at once simple, economical, and effective. Captain Stokes, R.N., who discovered the fine territory on the South coast of the sGulf, is prepared to return there in H. M. surveying pteamer Acheron, which is now idle at Sydney, to comolete the coast survey. The addition of a few sappers or ethers, as assistant-surveyors, a secretary, &c., would nable him to undertake the duty of starting the settlement; and the enlargement of the establishment should depend on the accession of revenue from land sales.

Whatever course H. M. Government may adopt, there is no difficulty in finding population to occupy the new territory. Those who are best fitted to encounter the first difficulties of settlement are near at hand, in the persons of the squatters and old colonists of New South Wales, who are well aware of the profits which accrue to those who get possession of the best localities. I must not enlarge on this point. but it is considered quite unnecessary to entice emigrants from home; for those whose connections with Eastern trade and tropical pursuits, or expectations of profit, or enterprising dispositions, fit them for the work, will easily find the way to the settlement whenever it is started. In the meantime, it will give me pleasure to meet any persons of that stamp. A note addressed to me by an eminent colonial authority, supplies all that need be said on the important subject of labour,-"From what I observed during a residence of some weeks in the Indian Archipelago, I should say, that really intelligent and active operatives, of all classes, might be procured from China to an unlimited extent, and almost without cost." This observation is fully confirmed by abundant evidence, and the influence of such a prolific source of labour on the production of staples, may hereafter wield no mean influence over the foreign markets on which our manufacturers now depend. The position of the new settlement, with regard to Sydney, Melbourne, and Adelaide, gives it superior ad vantages. The principal imported articles of consumption in Australia are tea, sugar, and tobacco. These are derived from Manilla, Java, China, &c. Those places are not only much nearer to the new port, but the voyage is also much safer. Prices will consequently rule in favour of the northern port, and a wide range of the interior will bring its produce there, from whence supplies can be drawn at the cheapest rate. Its postal communication

with Europe and Asia can also be effected with superior despatch by means of the Overland Mail, which now reaches Batavia in 46 days from England.

I have now only to wait for the decision of H. M. Government. I am, Sir, your obedient servant,

TRELAWNY SAUNDERS, F.R.G.S.

GOLD CRUSHING AND WASHING. SIR,-Having read in the last number of your Journal a paper, by Mr. C. Stansbury relating to gold crushing nd washing, and the discussion which took place at the meeting of the Society, I beg leave to make one or two remarks upon the same. And first I may perhaps be allowed to correct a slight error into which Mr. Stansbury has fallen respecting the gold of Mexico. He says it is there "always found associated with silver." It would have been better to have said "it has hitherto generally been so found;" the fact being that gold occurs in its free state in various parts of Mexico, in Sonora, in El Doctor, near Tasco, and recently it is said to have been discovered on the river Mescala. It exists in large quartz veins in several places, but which are so arid and bare of water that it would be alınost impossible to work to advantage.

I now come to the more important part of Mr. Stansbury's paper-that which relates to Berdan's new Amalgamator, the chemical novelty in which consists, it is said, in the heating of the mercury, which has never been attempted on a large scale before. I turned to Aiken's Chemical Dictionary, article Gold, and there I found a description of the method used in Hungary for separating the gold from quartz. After describing the stamping and pulverizing, the writer goes on to say, "The mixture of pulverized gold ore and mercury is rubbed together for some time by means of a wooden pestle, to expedite the incorporation of the mercury and the gold, and is afterwards heated in a proper vessel, to about the temperature of boiling water, for three or four days; finally, the mixture is washed," &c. But besides this evidence that the application of heat is no novelty, it is well known in the establishments for the amalgamation of silver ores, that the application of artificial heat has been used and tried in various ways, over and over again; in some cases it has been useful, in others thrown aside. That it assists the amalgamation of the gold with the quicksilver is not disputed; but it is no novelty.

Without touching upon the question of the merits of Mr. Berdan's grinding and amalgamating machine, I must be permitted to say that the separator attached to it for saving the stray amalgam from the residues, by passing these through a body of quicksilver, is not new. The merit of proposing, in this country, the adoption of that principle aided by centrifugal force, is, I think, due to an American gentleman, who brought it here about the end of 1851, at which time it was little noticed. It, however, occurred to me that it would answer very well to pass the residues from the silver reduction works through a column of mercury, provided a sufficient fall could be obtained; and in a letter, dated January 15, 1852, to the Superintendent of the Fabrica of the Bella Raquel Company, in Spain (of which Company I am the Secretary), I suggested a trial. It seems that it was difficult to obtain a sufficient fall, and, to obviate this difficulty, Mr. Edward Rowse, the engineer, invented a very ingenious apparatus, which answered perfectly, and is certainly superior to Mr. Berdan's. By this time the reduction of gold ores attracted great attraction; and in the spring of 1852, Mr. Richard Taylor, being then on a visit to Spain, and seeing the success which had attended Mr. Rowse's machine, applied, as it had been, not only to the residues but to the whole of the slimes from the barrels, determined upon having a trial made in England on gold stuff. The result of this determination was the invention, by Mr. T. B. Jordan, the Superintendent of the

Colonial Gold Company's Works, at Rotherhithe, of a machine in which the original idea of simply passing the stuff, with a column of water, through the mercury is reverted to, but with additions and applications which render it one of the most economical and beautiful machines for separating gold yet invented, and for which, so far as I am aware, no patent right can or will be claimed.

Every man is entitled to be fairly rewarded for his ingenuity; but when there is a disposition to overrate any particular invention, it is right to put the public on their guard. I am, Sir, your obedient Servant,

JOHN PHILLIPS. 6, Queen-street-place, Upper Thames-street, Nov. 29, 1853.

DECIMAL COINAGE.

SIR,-Some years ago my attention was drawn to the extraordinary properties contained in the rape seed oil, for softening and restoring flexibility to manufactured leather goods, in fact producing the like effect on the skins of animals generally. On introducing it to my friends, its use was suggested for lubrication. On a first trial upon a pair of marine engines, which had been making eighteen revolutions per minute with olive oil, the speed was increased to nineteen revolutions; but on a subsequent trial with another sample, the speed was reduced below SIR-Being engaged in paying the workmen in this sixteen revolutions, showing a great want of uniformity estabishment, involving a considerable number of pay-in the quality of the material. This circumstance led to ments in shillings and pence, weekly, I feel some degree of interest in this subject. I cannot view the introduction of such a small division of the pound into 1000 parts without some alarm, as such, as far as I can learn at present, is the plan recommended by the commissioners engaged in investigating the subject. At present the fractional part of a penny is seldom found in the books of the manufacturer and merchant; but when the mil is introduced as the unit of the decimal part of a pound, I fear it will enter into every transaction, however small or large such transaction may be: and its effect will be rather to increase than decrease the labour, of all parties engaged in paying and receiving money in coin, and accountants, with whom, principally, will be the labour of practically carrying out the change.

Permit me to lay before you the following plan for your consideration, trusting that it will meet with that attention you are accustomed to give to questions affecting materially the well being of society in general. I would, therefore, suggest that the half-sovereign should be the unit, and consequently the shilling would be the tenth part of it, as at present, and a trifling change made in the penny, by an addition to its value of one-fifth, making it the tenth of the shilling. By such an arrangement, we should have, as at present, an unit of the gold coin, an unit of the silver coin, and an unit of the copper coin, which is of considerable advantage in counting money. We should also reduce the places of decimals to two instead of three figures, and, therefore, lessen the labour of calculations. Any amount, say, 1l. 19s. 4d. would be written thus, 3.94, or three units (substituting any name that might be agreed upon), nine shillings and four

pence.

The sub-division of the penny I would still represent by,,, leaving it to parties to drop them without em barrasing their accounts. Under some such an arrangement as this the present coinage need not be disturbed; but, after a certain day, the pennies now in circulation should become the tenth of a shilling, and the change is complete.

The present copper coinage should be gradually withdrawn, and new coins substituted of the proper size. This alteration would involve a loss to the Government of about one-fifth of the amount of the value of the copper now in circulation, but would spread over the time the process of withdrawal would be carried on. This loss would, I presume, be more than compensated by the increased payment by postage and receipt stamps, and which the country would gladly pay for the increased accommodation thus secured. The only objection I see to this plan is, that the sovereign is associated with all our ideas of the value of commodities, &c. But it may still be retained in all Government securities and bankers' notes without inconvenience; all that would be necessary for entry in books or calculation, would be, to double the number of the pounds to reduce them to the new coinage.

some research on the subject, and having now spent seven years in the cultivation and treatment of the products of this article, a few particulars relative to the history and great value (as a British product) of the British rape plant may not be uninteresting.

As my remarks will refer more particularly to the oil, it will be necessary, to a proper appreciation of the subject, to give a few details relative to the properties of oils generally.

This oil may be considered one of the three primary fixed oils, viz., Flax or Linseed, the Olive, and the Rape; all other oils being mere modifications of one or other of these. Flax oil possesses the peculiar property, when exposed to the atmosphere, of absorbing its oxygen, and forming a substance capable of great duration; rape and olive, on the contrary, possess no affinity for that gas, and are termed non-drying oils. These three oils, being vegetable products, possess those properties only in proportion to the state of cultivation of the plant. The ancients, from the earliest period, understood this, and obtained from the vegetable kingdom these three oils in a state of perfection and purity that we have but an imperfect knowledge of. This is apparent in the construction of their lamps, which principally take the form of the berry of the olive, the seed of the rape, and the almond.

The ancient Greeks and Romans were extensive manufacturers of lamps in terra cotta, principally after the rape pattern. They are nearly all ornamented with devices of various kinds. On some are found the rape plant; others bear the shape of the rape pod, with a number of lights corresponding with the number of seeds in the pod. This, I think, is conclusive that rape was the oil consumed in them. It would also appear that this oil was employed for producing heat, on precisely the same principle as gas is being employed at the present day. The formation of some of the lamps, with their numerous burners, indicate it; and the number of vases and other terra cotta vessels also present the way in which they were employed. In the British Museum there are two vases (Nos. 2595 and 2557) of this kind. The first is a flower vase, the body of which is intended to contain a lamp, the sides being perforated to admit the heat of the lamp to act upon the projecting tubes, which are presumed to contain the essential oils of the flowers placed in the small vases at the end of the tubes. The action of the heat liberates the gases of the oils, and produces a powerful odour. The second vase is formed to admit three lamps, with one or two burners each, and perforated to admit air for combustion, so that any amount of heat could be employed. It might be used for domestic or other purposes.

It must be observed that asbestos was employed in those lamps as a means of combustion, and, with a pure oil, would produce a brilliant light and a powerful heat. The Romans were also exporters of those lamps, and introduced them into Britain; and, it is not improbable, introduced the rape plant also. Be this as it may, the

Wandsworth, Nov. 26, 1853.

WM. BROTHERTON.

rape has flourished in the three kingdoms for several cen- rent. It must also be borne in mind that there is a turies, and, with the flax, supplied these countries with rapidly-increasing demand for this article for the purposes the principle portion of the oil required. About the mid-before-named. The soil in most parts of Great Britain dle of the last century an increased demand sprung up, and Ireland is as well adapted to the growth of rape as from the introduction of the woollen trade and its subse- any on the continent, and there is no reason why we quent machinery. At its close, the cultivation had become may not yet become exporters, instead of importers of oils. so extensive, and such large returns had been made to the The English farmer has no prejudice against this species farmer, that the country took alarm. One celebrated of produce; on the contrary, he is ready to enter into it, gentleman stated to the House of Commons that, if imme- but he is no speculator. The distance manifested between diate steps were not taken to stay the growth of oil, he the agricultural and manufacturing interests have been land would become so impoverished that wheat would be unfortunately such, that, however desirous the one might ultimately lost to the country; and such was the popular be to produce and the other to consume, neither have feeling that no one would let a farm to grow rape. Con- stepped out of their ordinary path, while the foreigner sequently in a few years oil-growing ceased throughout has all the time been reaping a rich harvest. the country; hence the facilities given to the whale fishI am, Sir, your obedient servant, ery, and the importation of olive and other oils and seeds; the demand still increasing, until, in the past year (1852), the value of oils imported exceeded seven millions sterling. In the course of time these sources failed to meet REPORT ON NEW ZEALAND FLAX. the still-increasing demand, when, about sixteen years ago, a house in London introduced the rape under the desig- CONTRIBUTED BY WM. CHARLEY, SEYMOUR HILL, BELFAST. nation of "patent refined" for burning in lamps. This gave My first step, after receiving the request of your s fresh impetus for the importation of rape seed, which secretary, directing my attention to the communication has, and continues to be, brought from India and other forwarded by the Council of the New Zealand Society, on eastern countries in vast quantities. A large proportion | the subject of the "Phormium tenax," was to call public of it possesses a mere resemblance, but without the pro- attention to the question, by publishing the letter of Mr. perties of the rape. The late King of the French gave Roberts, extracted from your Journal, and my reply in the great encouragement to the culture of this plant, and local papers. In the few introductory remarks forwarded to erected mills for the extraction of its oil, and we are now the Editors, I pointed out the liberal offer made by the New importing largely from France, Belgium, Holland, and Zealand Society for the improved machinery required; some parts of Germany. The quantity brought from those and I have no doubt, when the large sample of Flax, so countries during the first nine months of the present year, long promised, arrives, and is distributed, some of our was 2,500,000 gallons, or what would be the produce of clever mechanics may be induced to try their hands and about 37,000 acres of land, if grown in England, Ireland, heads at the invention of machinery for the purpose or Scotland. The importation of the seed during the same specified by Mr. Roberts. Having thus submitted the period from other parts was 51,576 quarters, or the pro- matter to public notice, I proceeded to gain as much duce, if home grown, of 11,000 acres. The largest pro-information as possible about the plant. I found the portion of this oil is of very inferior quality, and the seed particularly so.

objection hitherto urged against the fibre was its extreme brittleness, owing, it was supposed, to the large amount of The uses to which this rape oil is applicable are numerous silica in its composition; that this brittleness had been and important. For artificial light very large quantities are successfully overcome, by the application of a process consumed; the English and Irish lighthouses alone consum-invented some years ago, by a person named Burns; but ing about 150,000 gallons per annum. Railway and ship- that this process, though successful in its operation, was so ping companies are also extensive consumers. For manufac- expensive as to suit only in the laboratory. This Mr. turing purposes it will supersede the olive as soon as a Burns asked my informant, Mr. Herdman (an eminent better quality is obtained. But the most important of all Belfast spinner), the modest sum of, I believe, 20,000l. for the properties of this oil is its adaptation for the lubrica-the use of his invention, and showed, on paper, a beautiful tion of machinery, and the possibility of its becoming to theory of profits resulting therefrom, amounting to mechanism what the synovia of nature is to the joints 14,000l. a year! Mr. Herdman was not sanguine of the animate creation. To obtain this facility and eco-enough to accept this proposal, and the matter fell to the nomy in motion is a thing greatly to be desired by all who ground. By the kindness of the latter gentleman, I am are interested in it and its progress. There are, I believe, enabled to forward you, in different stages, three samples other valuable properties in this oil which were highly of the Phormium tenax-two in a partially prepared appreciated by the ancients, to which I shall not further state, and one in yarn. The half of the rough Flax has allude, only stating that, as they possessed it, it was with-been treated by Mr. Burns, exhibiting the extraordinary out colour, taste, or smell.

change effected by his process; the other half of the same stem being kept unaltered, to show the contrast. This process is of course a secret, but the result is believed to have been effected by the application of some powerful acid on the silica or silicates of the non-fibrous portion of the dried plant.

The cultivation of the rape plant is best understood in some parts of Holland and Belgium, where it is grown to considerable perfection. It is sewn about September, and reaped in the June following. In many cases the seed is sold to the crusher with a stipulation to return the cake, which is given to the cattle, and if a portion of the oil is A peculiar quality of the Phormium tenax fibre is, given occasionally, it improves their condition and adds that it hackles out to almost inconceivable fineness; the to their weight materially. The straw is bruised and divisibility of the fibre appears very great, and the sample converted into manure, when the whole is returned to the thread of yarn sent herewith will show how fine the first land again, charged with gases that produce most abun-experiment in spinning at once reached to. The proposal dant crops of wheat. It is also a fact admitted by all the parties I have consulted in those countries most famed for the best knowledge on the subject, that although it is subject to a troublesome fly in two stages of its growth, yet it is the most profitable and inexhaustive crop grown by them. From these remarks it will readily be per ceived, that the quality not only of this but other oils may be greatly improved by a more careful study of their cultivation; and the necessity for giving encouragement to their production at home and in the colonies will be appa

of Burns occurred so long back as the year 1836 or 1837. Mr. Herdman thinks that Burns is alive, and in Manchester, but does not know his address. (a) Previous to my interview with Mr. Herdman, I had a communication with Mr. McAdam, the able secretary of the Royal Flax Society at Belfast, and he, as well as Mr. Herdman, have

(a) Dr. Robinson, of the Observatory, Armagh, was, I understand, the first person to recognise the talents of Mr. James Burns, who was a resident in that town at one time.