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may be more than its cohesion can overcome: it (which the rope will carry. Thus, if the rope has will therefore break. Consequently, if we pull at six inches circumference, six times six is thirty-six, this twisted skein, we shall not separate it by draw- the fifth of which is seven tuns and one fisih. ing one parcel out from among the rest, but the It is usual in the manufacture of large ropes, eswhole fibres will break; and if the distribution of pecially in those for nautical purposes, to saturate the fibres has been very equable, the skein will be them with tar. This is often done in the state of nearly of the same strength in every part. If there twine or yarn, as being the bes mode by which the is any part where many ends of fibres meet, the hemp can be uniformly penetrated. The yarn is skein will break in that part.

made to wind off from one reel, and, having passed We know very well that we can twist á skein of through a vessel of liquid hot tar, is wound on anothfibres so very hard that it will break with any at- er reel; the superfluous tar is taken off by passing tempt to twist it harder. In this state all the fibres through a hole surrounded with oakum: or it is are already strained to the utmost of their strength. sometimes tarred in skeins, which are drawn by a Such a skein of fibres can have no strength. What capstan through a tar-kettle, and a hole formed by we have said of this extreme case is true in a cer- two plates of metal held together by a lever loaded tain extent of every degree of twist that we give with a weight. There is this peculiarity to be nothe fibres. Whatever force is actually exerted by a ticed-tarred cordage is weaker when new than twisted fibre, in order that it may sufficiently com- white, and the difference increases by the keeping. press the rest lo hinder them from being drawn out, From some very accurate experiments, made more must be considered as a weight hanging on that than half a century ago, it was found that on newlyfibre, and must be deduced from its absolute strength made cordage the white was one eighth stronger of cohesion, before we can estimate the strength of than that which was tarred; that, at the expiration the skein. The strength of the skein is the remain- of three months, the difference in favour of the new der of the absolute strength of the fibres, after we was almost one fourth ; and, in abont three years have deducted the force employed in twisting them and a half, the difference was as twenty-nine to together.

eighteen. From these, and other experiments, it From this view of the matter may be deduced a was ascertained-1. That white cordage in continfundamental principle in rope-making, that all twist- ual service is one third more durable than that which ing, beyond what is necessary for preventing the is subjected to the operation of tarring. 2. That it fibres from being drawn out without breaking, dimin- retains its strength much longer while kept in wareishes the strength of the cordage, and should be house. 3. That it resists the ordinary injuries of avoided when in our power. It is of importance to the weather one fourth longer. It may then be asked, keep this in mind.

• Why is tar ever used by the rope-maker ?" BeIi is necessary then to twist the fibres of hemp cause white cordage when exposed to be alternately together, in order to make a rope ; but we should very wet and dry is weaker than that which is tarmake a very bad rope if we contented ourselves with red, and to this cables and ground-tackie are contintwisting together a bunch of hemp sufficiently large ually subjected. It has also been pretty well ascerto withstand the strains to which the rope is to be tained that cordage which is only superficially tarexposed. As soon as we let it go out of our hands, red is constantly stronger than that which is tarred it would untwist itself, and be again a loose bundle throughout. of hemp. It is necessary therefore to contrive the Mr. Hancock has discovered a process for covertwist in such a manner that the tendency to untwist ing, ropes with elastick gum (caoutchouck) in a li. in one part may act against the same tendency in quid state, for the purpose of protecting the vegetaanother and balance it.

ble materials that compose them from the destructive Without going deeply into a process which would effects of damp, by which they are so rapidly brought excite but little interest in the general reader, it may into a state of decay. be enough to state that fibres of hemp are twisted The hempen materials are to be soaked in a soluinto yarns, that they may make a line of any length, tion of caouichouck procured from a tree common to and adhere among each other with a force equal to South America and some parts of the East Indies, their own cohesion. The yarns are made into cords and is the same with Indian-rubber. As it flows of permanent twist by laying them; and, that we from the tree it is about the consistence and much may have a rope of any degree of strength, many the appearance of cream. It is to be used exactly yarns are united in one strand, for the same reason in the same way as tar is commonly used, except ihat many fibres were united in one yarn; and in the that it is not to be heated. course of this

process it is in our power to give the Several coats of this body may be laid over the rope a solidity and hardness which would make it external surface of the cords, one succeeding the less penetrable by water, which would speedily other, before the preceding coat has become perfectdestroy it. Some of these purposes are inconsistently dry. -After this the ropes are to be placed in a with others : and the skill of a rope-maker lies in drying-room, moderately heated, until the gummy making the best compensation, so that the rope may, material on the outside of the ropes has become on the whole, be the best in point of strength, pli- perfectly free from stickiness. The patentee states ancy, and duration, that the quantity of hemp in it that ropes for ships' cables to tackling when thus can produce. The following rule for judging of the prepared are equally pliable to those coated with tar; weight such a rope will bear is not far from the and as the material cannot crack by drying, so as to truth. It supposes them rather too strong; but it is expose the internal fibres to the action of the air or so easily remembered that it may be of use. Mul- damp, ropeś so prepared will last much longer than tiply the circumference in inches by itself, and take by the ordinary treatment, being less liable either the fifth part of the product; it will express the tuus to external or internal injury.

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[Chinese Rope-Making.) In China they twist together long filaments of many authors far preferable, not being a compound bamboo ; and this material for ropes is preferred to of two languages, a fault but too frequently observahemp.

ble in the terminology of all works on natural his.. The above engraving is designed to represent the tory. Until within about the last half century, Chinese manner of making ropes. It bears considera- nearly every author on this branch of nature has ble resemblance to our own method. Their cables and written exclusively on the arrangement of shells, other large ropes, however, the Chinese spin verti- detached from the animals inhabiting and constructcally. The workmen are mounted on a high scaf- ing them ; this, with very little exception, continued fold, and the rope descends, as fast as it is made, down to the period when the immortal Linnæus, and is immersed in a liquor which renders it more who may be styled the father of systems, among strong and elastick.

others, formed one of Conchology, but, like his predecessors, it was based entirely on the form of the shell, and his genera composed from the characters it présented. This was done with considerable

judgment, and many of his descriptions are extremeCONCHOLOGY.

ly accurate, so far as regards external configuration, Under this title, or that of TESTACEOLOGY, nat- but in theory, this system is wholly artificial, and uralists have hitherto comprehended a systematick consequently bad. It is true he seems to have felt arrangement of shells, whether marine, fluviatile, or it so to a certain extent, since he has made some terrestrial : it is the science by means of which that reference to the analogous animal which he imabranch of natural history is distributed into genera gined to have belonged to the shell ; these he placed and species. The title conchology, has, however, among his Zoophytes, but he still took no other been somewhat misapplied, having been used in a guide than the form of the shell, and made but fem less extended sense than its etymological meaning inquiries with respect to the supposed inhabitant implies ; since conchylion does not express a shll The impulse given throughout Europe by his sysonly, but the molluscous animals, whose body is al. tem, and that of several other eminent naturalists, together protracted—merely partially covered with led to an extended view of the subject; their atten. a shell, or possessing portions of shelly matter, con- tion became drawn to the anatomical investigation cealed under its skin, or in its folds, to defend cer- of the animals themselves; and the subject presenttain organs most liable to external injury from their ed an interest never before experienced ; accounts exposed situation. Such of our earlier naturalists were published of the result of these inquiries, as merely studied an arrangement of shells, detached gradually producing a different method of viewing from their parent architect, (as was, in fact, the case the classification of molluscous animals; and Pallas with nearly all of them,) have in many cases, and may be considered the head of this new school, as, should in every one, have designated their systems in fact, it was from his Miscellanea Zoologica that by the term Testaceology, which is more appropriate, the first germe of improvement was derived in the as not admitting any perversion of the meaning they arrangement of shells, since grown into its present Attached to it, and clearly expressing its derivation form, though as yet, in many respects, only in its inand object—Testa, the Latin word for a shell; and fancy. Logos, a Greek word, meaning a discourse or trea- To persons who are collecting shells and forming tise on the subject to which that word is added cabinets of them only as beautiful objects of creawhen descriptive of a science, The Greek writers tion, the system of Linnæus may answer as well on natural history also used the term Ostracology, as any other, since they feel no interest in the sciwhich has the same meaning, and is considered by entifick arrangement of the species, or those won

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neous conclusions entertained by book-naturalists | tries where vegetation is too luxuriant to be trained and book-makers, among which are some (and those, by art to the use of mankind, covering immense too, professing to instruct the rising generation) who tracts of land with impenetrable gloom, not only have recently published a poetical description of snails, but other species of terrestrial molluscs, certain shells sailing together in little fleets-one achatina, bulinas, &c., are found, some of a very valve expanded to catch the passing breeze that large size, proportioned to the magnitude of the wasts them o'er the unruffled bosom of the vasty duties they have to perform, and in these situations deep-of others that may be supposed to pass their their voracity is said to be most extraordinaryleisure moments in playing at leap-frog with each stripping the loftiest trees of their verdure in an inother. But these, like all other tales conjured up credibly short space of time. Shall we then grudge by the magick wand of fancy, are more entertaining it a slender portion of our superfluous luxury, withthan true, and must be condemned in works whose out ascertaining, by actual examination and rational object should be to clothe facts in the simplest garb, reflection, that this little creature was not merely divesting them of the tinselled ornaments of fiction, ordained to devour our choicest fruit, but that it has which, though they may dazzle for a time, shortly also a duty to perform by consuming, in a far greater sink before the light of truth, and are rejected as proportion, other things in the vegetable world that worthless., Another serious evil arises from these would, without them, prevent the full completion of pretty nursery tales, that of casting a doubt upon the very object for which we ignorantly destroy a every other assertion, however well founded in principal agent. The well-established fact, that the truth.

eggs of these animals have been absolutely baked, An instance may here be adduced of the ease during six months, under the scorching rays of a with which some of the interesting operations of tropical sun, without destroying the germ of life, nature can be witnessed in the portion of creation proves, could no other facts be adduced, that nature now under our consideration, and amply repay us has vested in these creatures certain important uses for the trouble. It is afforded by the humble, per- and powers far beyond our short-sighted views; and secuted, but most beautiful of our native molluscs, it must lead a philosophical mind to conclude, that the snail, (Helix nemoralis,) the little creature we in this instance, as well as in many others equally barbarously crush beneath our feet, considering it a remarkable, we stubbornly close our eyes to the common enemy to horticulture. When we examine good that is forced upon us. We think we hear it its wonderful formation, its tenacity of life, its re- said, that in advocating the cause of snails, we have productive powers, an instructive lesson may be fur- never had the mortification of seeing our ripe and nished to the conchological student, most satisfac- delicately painted peaches disfigured by their hungry torily explaining the growth of the vast proportion propensities. Be that as it may, we have also obof similarly constructed shells in other genera, and served, that they, like ourselves, when no such treat enabling him to understand by actual observation, presented itself, were content with humbler fare, and and the evidence of his own reason, some of na- as industriously as voraciously consumed other obture's steps in this branch of her works; he may jects, to us useless, or noxious as food, never desert easily watch the various changes that take place ing the purpose of their existence, though that end from the slight viscous covering with which the an- is not yet fully revealed to us. As an article of imal's body, in the first instance, is coated, or, as it food, they are entitled to our consideration ; for, were, merely glazed, till that substance becomes a though they form no part of our gastronomick deliconsistent firm shell, finally fashioned into a painted cacies, they nevertheless were considered such by palace adapted to the forni and use of its inhabitant. the Roman gourmand; and even down to the presIt needs no logick to prove, that wherever creatures ent day, snails form an important article of nourish. are endowed with a long endurance of life and great ment and commerce in Germany, France, Spain, reproductive powers, great purposes are assigned to Italy, Turkey, and the Levant. This digression them. The contemned snail does not, therefore, leads to a conclusion, constantly to be drawn by merit the ill treatment it constantly experiences from every reflective mind, that from the colossus of biman; and if we for a moment reflect upon its good valves (the Tridacna gigantea) whose inhabitant services, and overlook its bad ones, we are bound would satiate the “sharp-set appetites of a hundred to confess the former greatly outweigh the latter. men,” down to the shell less than a grain of sand, It is viewed as a destructive marauder in our trim each is endowed with similar mechanical powers gardens; but we forget that we have invited its in- and bodily faculties, adapted to its sphere of action roads by placing, within a comparatively limited in the place it is destined to occupy, the one and the space, a choice selection of dainty food even to the other playing an equally important part in this crumpampered appetite of man, but altogether irresistible bling theatre of mortality, and forming so many conto a snail.

In the open fields, or the widely ex- necting links of the chain that binds together the panded forest, this little creature performs useful invisible operations of nature under the directing purposes in conformity to the ends of its creation; wisdom of omnipotence. one of the most important of which is that of assisting in consuming the exuberant productions of nature, which, without its operations, would encumber the surface of the globe, check the progress of fu

AMERICAN COMMERCE. ture vegetation, and interrupt that perpetual harmony

HAMBURGH. of system, which has wisely ordained that the extinction of life shall nci be felt, bụt its devastations HAMBURGH is one of the most considerable of tho become supplied by succeeding çenerations, each of free cities of Germany; it is situated about eighty their kind, whether vegetable or animal. In coun- miles from the mouth of the Elbe, upon the northern

bank of the river, which is navigable for large ves-val of the old fortification was commenced in 1 sels as far as this port. The circuit of the city is and the great French works have also been about twenty-two thousand feet. In the northern demolished. part is a lake, formed by the small river Alster, The established religion in this city is the which runs through the city into the Elbe, and turns theran, but complete toleration prevails. The several mills. An arm of the Elbe enters the city ners of the inhabitans resemble those of the from the east, and is there divided into a number of mercantile cilies of Germany or Holland; pul canals, which take various lirections, till they unite, worship is regularly attended, industry is gene and join the Alster in the southern part of the city, diffused, and good morals prevail. Foreigners where they form a deep harbour for ships, which long been freely admitted to reside in the town; communicates with the main branch of the river; the troubles of the French revolution brought and there is a large space enclosed by strong piles, individuals of different nations and characters, a where ships may lie in safety; which is called whom were allowed to remain as long as the Rummelhaven.

lick tranquillity was not disturbed : hence the Canals intersect the lower part of the city in all ous and sometimes contradictory accounts of directions, and almost all the warehouses are built morality of the place. The favourite taste of upon their banks. In this part of the city, and also inhabitants, in point of amusement, is musick ; in that which lies on the east of the Alster, the previous to 1807, the era of commercial misfort streets are, for the most part, narrow and crooked.to Hamburgh, the higher class of merchants 1 Many, however, of those in the western or New not only with hospitality, but with a certain deg Town, are broader and straighter. The church of of luxury. Hamburgh has long been distinguis St. Michael, with its tower, four hundred and fifty- as a commercial city of the first importance. six feet in height, built by Sonnin, and intended for transactions consist partly in agency, but more astronomical observations and for experiments in the purchase and sale of goods on account of natural philosophy, was finished in 1786. This merchants. They buy the commodities of Amer building, and some of the private houses, are re- Great Britain, France, Spain, Portugal, Holla markable for their architecture. The exteriours of Belgium, the West Indies, &c., and supply w the exchange and the council-house are also hand- these all the countries lying along the Elbe, dif somely ornamented. Among the most remarkable ent districts on the Rhine and Lower Maine, and buildings are the bank, the admiralty buildings, the part of the Prussian and Austrian dominions. TI orphan asylum, the new general hospital, the thea- also buy up the products of these countries, tres, the exchange, the city and commercial libraries, which linen and thread are the chief. These a Röding's museum, &c. The gymnasium and the cles are brought in great quantities from Bohen Johanneum are excellent institutions for education. Moravia, Lower Saxony, and Westphalia, and The building for the school of navigation, opened in inhabitants of these retired quarters have discover 1826, is provided with an observatory, and a botan- that to make sales through the medium of Hambur ick garden is also annexed to it.

is less hazardous than direct intercourse with In institutions for the relief of the destitute, for countries where their commodities finally arri the sick, and for the education of poor children, The trade in timber is also of great importance, Hamburgh is inferiour to no city in Germany. Most pecially during a maritime war, Hamburgh being of these are under the direction of private individu- chief medium between the Baltick and the south als, and they are principally supported by voluntary Europe. The other articles of trade are very vario contributions. The constitution of Hamburgh is comprising flax, hemp, potash, tar, tobacco, wa aristocratick. The government consists of four bur-honey, hides, wool, woollen yarn, smoked and s gomasters and twenty-four councillors. To the sen- meat, mineral products, iron wares, in short all t1 ate are attached four syndics and four secretaries. products of the northeast of Germany, and a gre Calvinists are excluded from the government of part of those of the centre and south. This trad Hamburgh, as Lutherans are from that of Bremen. like that in foreign goods, is carried on, partly The ordinary publick business, both internal and commission, partly for account of the Hamburg external, is transacted by the senate alone; matters merchants. of more importance are regulated in connexion with

with), The territory of Hamburgh, which contains or the citizens possessed of a certain property. These hundred and sixteen square miles, is bounded by are divided into five parishes, each of which sends that of Holstein on the north and west ; the city thirty-six members to the assembly or general col- Altona, in the territory of Holstein, is not two mile lege. From these are chosen the members of the distant from the gates of Hamburgh. Toward th council of sixty, and again from these fifteen elders. east the Hamburgh territory borders on Lauenburg Each of these colleges has peculiar privileges. The and on the south it is separated by the Elbe fror senate and the elders alone receive salaries. Justice the territories of Hanover. Some of the islands i is administered by several courts. But the court of the Elbe belong also, either wholly or in part, t appeal of the free cities of the Germanick confeder- Hamburgh, together with the village of Moorbur acy is the superiour tribunal. The publick revenues on the left bank. Besides this, it has a jurisdictio were formerly considerable, without the taxes being over the bailiwick of Ritzebüttel, which contains the oppressive; but the heavy debts incurred by the important town of Cuxhaven, at the mouth of th city, of late years, have greatly increased the taxes. Elbe. Hamburgh, in common with Lubeck, als The citizens are provided with arms, and accustom- has jurisdiction over the bailiwick of Bergedorf

, wit

] ed to military exercises, so as to form a body of in- the small town of the same name, over the Vierlands fantry, caralry, and artillery, in regular uniform, and a few places in Lauenburgh. The city owe amounting to about ten thousand men. The remo- its foundation to the emperor Charlemagne, who, is

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