length, is from outside the husk at the bottom to the top of the firm part of the fangs or burs. The Court had instructed the Jury that the property in the teazles had passed but was yet in the plaintiff's hands ; and that if they found against the defendants, they would be bound to ascess damages to the amount of the difference between the market price or value at the time of the offer and refusal, and the price stipulated for in the contract. The jury had found these at 1505; but the parties, while the Jury were out, had agreed that upon the July's finding the measure and so the quantity delivered, the defendants should take them at a stipulated price. Judgment was accordingly entered for the plaintiffs for $2753 damages, and ninety-five dollars costs. The plaintiffs, with Bodman and Root who were also interested with them, have probably made a profit of between two and three thousund dollars upon this contract, including the profits on the eight hundred thousand first delivered.

From the American Gardener's Magazine.
NOTICE OF SOME OF THE EPIPHYTE, AND
PARASITIC PLANTS OF THE U. STATES,
WITH REMARKS ON THEIR PHYSIOLOGI-
CAL CHARACTERS. BY JOHN LEWIS

MASS. HORT. SOC.

volved in inextricable confusion; and then, as if in triumph at the mischief it has occa sioned, cover its leafless, voluble stems, with a mass of clustered flowers ?

The first growth of the Cuscuta exhibits an anomaly of a vascular plant with perRUSSELL, PROF. BOT. ETC., ΤΟ THE fect seeds, germinating without any cotyle don. A few other plants arranged under the exogenæ on account of their organizaAlthough the tropics are peculiarly rich tion, are, in common with this, in fact, acoin these curious vegetables, which luxu-tyledonous. The absence of cotyledons, riate in the dark and rapidly growing and has led to the theory of their presence in a decaying forests, yet even our more north-consolidated, and consequently unfolded or ern clime, can furnish a few no less interest undeveloped condition. ing to the lover of science, though far less Throughout the Western States, you will attractive to the artificial taste of the florist. find particularly upon the branches of the Several genera may be found in the New elm,the sempervirent mistletoe (Viscum verEngland States, which, independent of ticillatum), whose parasitic and epiphytic their parasitic character are remarkable for character, and supposed virtues so early atthe singularity of their form. In your tracted notice. summer ramble through the dense and connected with the superstitions of a barbaIt is one of the few plants damp woods, you may perchance meet rous age, and from its rare occurrence on with a curious cluster of brown, or yel- the oak, was estimated, when discovered in lowish, and extremely succulent, vegeta-that situation, as peculiarly sacred. But bles, covered with a pubescence, and in-like many other things that have nothing One of the particulars relative to the stead of leaves, invested, with minute but antiquity to recommend them, its fictiteazle business, which came out in the scales. Should your curiosity prompt you tious good qualities are overlooked, while course of the evidence, was that there were to stoop and examine the anomalous and its more prominent character of disfiguthree kinds of American teazles known in fungous-looking body, you will discover, ing he banches of its otherwise gracethis market, none of them quite equal to the gentle reader! the curious and beautiful ful and elegant supporter, are only noticeforeign teazles, and all differing from each native epiphytic Orobanche, whose minute other in value. The Connecticut or Weth-examination may repay your attention.— Farther south, in Florida, and on the sea ersfield teazles are the best native ones, This genus forms the type of the natural coast of Georgia and Carolina, we meet and are worth twenty-fiv cents more by the order of Orobanche of Jussieu and of with a species of the true and genuine epithousand than the Williamburgh teazles Lindley, and under this same order is its phyte, in the "Epidendrum conopesum." which are raised in Williamsburgh, Hart-cogenus Epiphagus of Nuttall; which be- This is the only representative in the U. field, and vicinity. These last, again, are ing a parasite on the roots of the beech States, of that curious genus. better than the Vermont teazles, which are (Fagus) has received from him its beauti- found growing on the trunks of the noble raised principally in the Valley of the White fully appropriate name One species, the||« Magnolia grandiflora," both by Nuttall River. One of the witnesses expressed "E americanus," is said to be found in and Elliott, and by the latter, observed also the opinion, that the short summers of the Maine, but not in this vicinity. on several species of oak. north, promoting rapid growth, was the cause of the burs growing coarser and looser.

able.

It has been

Perhaps not far distant, and in the same In the last number of the American's ramble, you will notice the remarkable, Gardner's Magazine, for April, it is incauand ivory Monotropa, in which nature tionsly stated, in speaking of this plant, that see ns to have forgotten her usual livery of it is interesting as the only parasitical green to invest one of her fairy and deli- plant yet discovered in the U. States."cate production in a vesture of entire, un- (p. 144, Vol. II.) It is true that it is the sullied purity. By a sort of desecration, only epiphyte connected with the numerous it has received, in common language, the congeners and co-species so common in othtrival name of that instrument, which afer and tropical climates. That we have fords an exhilarating solace to many a de-other parasitic epiphytes, has been already votee to the "fragrant weed." But how-shown.

It is not a little singular says the Mercury, that no satisfactory artificial substitute for the teazle has ever been invented, though many have been tried. It is used, as our readers are aware, for raising a regular nap upon cloth; its long barbs being drawn over the cloth repeatedly till they have combed out all the knots and made it perever apt its resemblance or name, it may An almost innumerable family of less fectly smooth. Should the barb of the tea-be a question, whether the simple taste perfectly organized vegetable forms, which zle, when in use, become fixed in a knot, or which dictates the admiration of the flow-are to a certain extent parasitic, is compoencounter sufficient resistance, it yields or er, would not have proved as beneficial to breaks without tearing or injuring the cloth the general happiness, as that more luxu-thus combining pliancy and stiffness to rious taste which invented both the name a degree which has not as yet been equalled and its origin. Another cogenus, and' you by any mechanical contrivance for the same have Hypopithys, of which "H. lanuginoobject. Both in England and in this coun-a" is by no means rare in the neighbortry, it is emphatically termed a "casualty hood of Boston, and is a distinct parasite, crop"-liable to a great variety of mischan-affixing its densely crowded stems to the ces, and of course exceedingly uncertain as roots of trees. to profit. We have been told that a large proportion of the teazle plants on the Connecticut river have perischd during the past winter if this is the case, the price will of course run up again.

The average price of teazles in England is stated in an English work, to have been for some years past about three dollars per thousand. They have varied, however, in that country, from two to ten dollars, and the extremes of fluctuation have been yet greater in this country.

sed of the Lichenes, Fungi, Hepaticæ, etc., but these deriving no necessary nutriment from the vegetables on which they are found, and growing also on the surface of rocks and of other bodies, are termed false parasites. None the less important are they, however, in the great economy of nature, which renders each minute particle of organized matter a great and necessary, agent in her operations. Yours,

JOHN LEWIS RUSSELL. South Hingham, April, 1836.

And have you not often observed the of the twining Cuscuta, climbing with an golden and glittering thread-like branches spiring habit, not unlike its more giganic, though not parasitic sister vegetables, up the slender stern of some delicate grass or plant herb; by the rapidity of its growth, and predatory disposition, draining the very vital energy from its supporter, till overclimb-dwelling house, the eyes the windows, the ing and overreaching, it still progresses on body, driven by a stream of water in a canose the chimney, and the machinery in the ward,over the topmost foilage and lays hold of nal, in the form of an immense bottle, empwhatever next presents itself, till all are in-tying into his mouth.-[Daily Times.

An Englishmen has just erected, on the river Theiss, in Hungary, a mill in the form of a colossal man--the head being the

From the Journal of the Franklin Institute. using charcoal as fuel, has succeeded.-|nized before it reaches the place of greatREPORT ON THE USE OF THE HOT AIR BLAST|| Mr. Combes states that at Lausen, (in Wir-est heat. If it were otherwise, the workIRON FURNACES AND FOUNDRIES. BY temburg) the blast is heated by pipes be- ing of the furnace would be very unsatisA. GUENYVEAU, ENGINEER AND PROFES-low the earth of a finery furnace, and has factory.

SOR IN THE ROYAL SCHOOL OF MINES. (Translated for this Journal, by Prof. A. D. Bache) Concluded from page 205.

its temperature raised to 390° Fah. With Experiment has proved the position just the cold air blast, they used 40 cubic feet taken, however liable to objection it may of charcoal to produce 200 lbs. of bar iron, seem on the score of the high heat which II. Application of the Hot Air Blast to and the weekly yield of the furnace was may be supposed, in every furnace, much Cupola Furnaces, to Smith's Forges, &c. 6,000 lbs. Now, with the hot air blast, above the tuyeres. It was found in the The hot air blast appears to have been ap- they consume 30 cubic feet of charcoal to Hartz, by trial in a furnace of twenty feet plied with great advantage, in England, in the two hundred pounds of iron, or in height, in which lead and copper ores furnaces for remelting pig iron. The about one part by weight of charcoal, to were smelted, that the wood used as fuel consumption of coke, per ton of iron, was one of malleable iron; the weekly yield is came within six or eight inches of the tuyreduced from 400 to 280 lbs., one ton of from 7,200 to 7,800 lbs. On several oc- eres, without having been carbonized. The metal passing per hour. The blast was casions the consumption of charcoal per experiment was made by having small heated by an apparatus placed at the trun- 200 lbs. of iron was as high as 36 cubic openings made at intervals in the stack, nel head. There are various advantages feet, which the workmen attributed to their through which the progress of the operaresulting from this application. The fu- using pig iron obtained by the hot air tion could be examined. In this case the sion of the metal takes place in about half blast, which they considered more difficult use of wood was abandoned, the furthe time required to melt it by the cold blast; to refine than that made with the cold blast. naces being worked, as before, with charit is thus less exposed to the injurious acThis last conjecture is opposed to the ex-coal. tion of the blast, and while twice the quan-perience at Konigsbronn, where they do tity of iron can be melted in a given time, not consider iron reduced by the hot air the quality of the material is better. It is blast as difficult to refine. The economy further stated that the quality of the iron is of fuel by this method of refining, has been improved by the melting, and that it is more rather more than one-sixth, and the loss in easily cast, owing to its greater fluidity. rendering the iron malleable is diminished. This successful result is obtained by using the hot air blast in melting the metal, while it is decarbonized by the aid of the cold This method of operating has been followed with success at the finery furnaces at Creusot and Decazeville.

At Vienne, France, there are two cupola furnaces supplied with hot air. The apparatus is at the trunnel head, and consists of two-bell-shaped vessels, through the interstice between which the draught is forced. This form of apparatus is decidedly bad, the alternate expansion and contraction of the parts renders it leaky in a very short The efficacy of the hot air blast is felt, however, even at this furnace.

time.

A further proof of the same position may be drawn from the fact that raw coal, although substituted for coke, with advantage, in some high furnaces, has not been used in cupolas.

It is then absolutely necessary that the wood, or coal, should be converted into charcoal, or coke, before reaching the reducing part of the furnace. When this does not occur, and this is proved to be sometimes the case, the working of the furnace is unsatisfactory. The nature of the I was present at some trials made upon coal will produce different effects in the a catalonia forge by an association of iron same kind of furnace. Thus at Alais a masters of the department of Ariege.-gradual deterioration in the working of the These were entirely unsuccessful. In the furnace resulted from the use of raw coal; last of them the consumption of coal at Creusot it was found necessary to mix was not greater than with the cold blast, but the iron was of very inferior quality. The hot air blast has been applied to the

In applying the heating apparatus at the
trunnel head of furnaces, for smelting lead,
copper, &c., care must be taken to pro-
tect the pipes from the sulphurous and me-
ta lic vapors, which, issuing from the fur-Smith's forge with success. The iron was
nace, would destroy them very rapidly.
brought more rapidly to a welding heat, and
The fan, or rotary, blowing machine is the loss by oxidation was less than with the
used in several establishments at Paris,
cold blast. There was no gain in the con-
Rouen, &c. for supplying cupola furnaces sumption of fuel. This method will pro-
with air. This though a simple means of bably be found useful in the working of
applying power, does not seem to be an
steel, but no experiments have yet been
economical one. Even when great velo-made of a decisive character.
city is given to the fans, the force of the On the Use of Raw Coal, or of Wood,
blast is inconsiderable, but by increasing in High Furnaces, &c.

the opening of the blast pipe, the quantity In order to produce a high temperature
of air thrown in may be rendered very in a furnace, it is obviously necessary that
great. In one case at Rouen, by increas- the fuel should be consumed rapidly, and
ing the diameter of the tuyeres from 30 to should not give off when heated, any
54 lines, the daily yield of the furnace was vapors or incombustible gases, to carry off
nearly doubled, and an economy of fuel heat. The air thrown in by the draught
(coke) of 20 per cent. resulted, the cold contains four-fifths of its weight of nitro-
blast being used in both cases. At La gen, which becoming heated causes a waste
Voulte the fan makes from 800 to 1000 re- of fuel; if in addition to this vaporizable
volutions per minute, and the pressure at matters are present in the fuel, the loss of
the tuyere is only four-tenths of an inch of heat is greatly increased. Charcoal, coke,
Three and a half to four inches &c. make such hot fires because their vo-
is the ordinary pressure with other blowing latile parts have been driven off by previous
machines. If the air were to be heated, beating.
this machine would be hardly applicable, as
the friction in the tubes of the heating appa-
ratus would tend materially to diminish the
draught.

mercury.

Unsuccessful attempts have been made both in England and France, to apply the hot air blast to bloomery furnaces.The causes of failure are, however, not

the raw coal and coke in nearly equal proportions; in Scotland the hot air blast is required to enable them to use raw coal, while in Wales and at Decazeville they use raw coal with the cold air blast. The effect of the hot air blast is doubtless to facilitate the carbonization of the raw fuel.To use wood for the smelting of iron, even in high furnaces, it has been found necesary to dry it before charging with it.

Th's

is true both in the Russian furnaces, andat Plons, in the latter of which the hot air blast is used, and the wood is mixed with charcoal. It should be observed further,

that resinous woods, easily charred, have been the only ones hitherto tried.

This reasoning shows also why the more or less perfect roasting of an ore, the more or less moist state of the materials of the charge, the more or less complete carbonization of the wood or coal, produce such important effects, even in the largest furnaces. It is plain that the temperature just above the point when the ore is reduced is low, since coal, or wood, is not charred, and that to this we must look for the reason why it is sc difficult to use these combustibles in the raw state.

66

M. Lampadius, of Freyburg, in his essay, on the use of combustibles in their crude state," has shown how necessary it is to heat the wood, or turf, to a point near to that in which it begins to carbonize, before using it as fuel. He remarks that the cost of transporting wood or turf being, of

In high furnaces wood has been used to
advantage, even in the smelting of iron,
while it has failed in law ones. In the former
the fuel descends slowly, and after having its
temperature gradually raised, reaches the
part of the furnace in which the blast is
most operative. At this place the highest
heat is to be found, and here the principal
chemical changes take place. Thus in
fact the fuel is gradually dried and carbo-vol. XII. 1931.

*Erdmann's Journal of Chem. and Technology,

---

course, much greater than the freight upon || contain more oxygen in a given bulk, and
the charcoal from them, will prevent their experience showed, in conformity with this
use in many cases. Thus if it be sup- view of the matter, that blast furnaces
posed that there is a gain of twenty-five per worked better in winter than in summer,
cent in the quantity of charcoal, by using and better at night than during the day.
wood not carbonized, as was the case in the The expansion of air by heat causing, un-
Russian furnaces, the balance would at der a given pressure, less oxygen to be
Freyburg, be against the use of the raw thrown into the furnace, will produce a di-
material, on account of the cost of trans-minished consumption of fuel, and yield of
portation. M. Lampadius conclude that metal. In wind furnaces, in reverberating
when the material is at hand, or the cost of furnaces, and generally in all where an or-
transportation low, uncarbonized wood may dinary draught is used, an increased tem-
be used to advantage, in high furnaces, for perature in the air diminishes the draught.
s.nelting iron, if it has been duly dried; a it can only be increased by raising the
result due to the heat given out in the com- temperature of the air in the furnace, by
bustion of the gases driven off from the the use of a more freely burning fuel, by
wood, and to their reducing power.
additional attention in firing, &c. The
same difficulty occurs in the blast furnace,
if the power of the blowing machine can-
not be increased.

and there is no doubt a point at which this effect begins, and another beyond which it would hardly be sensible. Observation con firms th s explanation. Bars of iron are readily raised to a welding heat in a smith's forge, supplied with hot air, in half the time required by the cold blast, and as the same quantity of coal is consumed per day in both cases, the greater effect in the former can only result from an increased intensity of combustion.* In the most successful trials the air was heated to 370° and the dia meter of the blast pipe not being changed, the quantity thrown in was actually diminished, and yet there was an increased consumption of fuel. It is then the temperature of the air, and not its density, which determines the intensity of the fire. slightly heated, why should a further increase of temperature, even in a diminished pressure and density, produce so great advantages? The explanation is that the temperature of the air has a most important effect on the intensity of combustion, In the furnace, then, the fuel is burned to the greatest advantage; but, further, the heat thus produced is rendered most effective.There can be no doubt that, in order to the regular working of the furnace, the different layers of the charge must descend regularly and horizontally. By the hot air process, the fuel is more completely converted into carbonic acid, than in the old process; An artificial heating of the blast should more fuel is consumed in a given place, the produce the same effects as that just allu- temperature of which is, therefore, higher ded to, and it is by no means surprising that than in the former case; and this place of the efficacy of the hot blast has been doubt-intense heat is more extended. As coned. It remains to be seen whence this ef-sequences, a greater mass of orc is reficacy results. duced in a given time by the same weight of fuel, and inore refractory ores can be reduced.

The cause just assigned seems to me insufficient to explain the very great economy so.ne.imes resulting from the use of the raw material; I consider the effect mainly It so happens that at the very time the due to the mode of carbonization, by which air is warmest, springs are lowest, and the a much larger per centage of the carboni- condensation of steam most difficult, two zed fuel results than by the ordinary meth-facts which will explain why the workods. The volatile parts of the fuel are ing of furnaces, both as to quantity and driven off by the heated and incombustible quality, is better in winter than in summer. gases passing through it, and there is no If the weight of air thrown into the furnace waste, by combustion. Being carbonized had been made the same in summer as in slowly, uniformly and without sensible winter, by increasing the power of the waste, the greatest useful effect must re-blowing machine, and the area of the blast sult, and it is easily understood why a given pipes, it is probable that the working would weight of dry wood, or coal, may when not have been worse, in the former season thus circumstanced, yield a fourth, or even than in the latter. a half more charcoal, or coke, than it would by the ordinary method, and thus may be competent to reduce a fourth, or half more

ore.

It must be admitted however, that this explanation does not account sa isfactorily for the very great advantage found in the use of raw coal, in the high furnaces of Scotlan1, with the hot blast, and at Decazeville with the cold bast. At Decazeville, coal inore thin replaces an equal weight of coke. Thus one part by weight of cose was used for the fision of 1.131 of mixed ore and flax, and now one part of coal is used to 1.675 of ore and flux. This coal would yield but .33 ("ths) of its weight of coke, and melt therefore but .43 of mixed ore and flux. The causes assigned by M. Lampadius, are therefore proba bly correct, being necessary in addition to that just examined, to explain the various

effects.

M. Dufrenoy* has, in his explanation of the advantages of the hot air blast, shown the difference between the quantities of heat introd iced into the furnace with the hot and cold blasts, and in an assumed case has determined this difference to amount to about one-sixteenth of the heat evolved by the combustion of the fuel. Since less air is thrown into the furnace in using the hot blast, there is of course, on that account, less cooling effect to contend against than in the other case.

M. Clement Desormes concluded by calculating from data in an assumed case, that the temperature within the furnace is increased between 270° and 360° Fah. by the heated air blast; an increase which he nsiders ade piat: to explain all the ob

served effects.

propose therefore to classify the oberved effects, and to point out their relative degrees of importance, and their connexon with each other and with established physical principles.

It is plain that if cold materials are in- These theories are far froin settling entroduced within a furnace, they tend to low-thely, the question in an economical point er its te.np-ratore, while their own is raised. of view. They suppose indeed, that the If then the fuel and the blast be heated be- consumption of fuel in heating the air may fore they act chemically, to a temperature be equal to that saved in the reduction of nearly equal to that of the part of the fur- he ore, which is by no means the case. nace at which the combination takes place, I this heated portion will be increased in extent, its temperature will be higher than it would be under other circumstances, and the amount of heat, the efore, available in melting the ore, &c. will be greater. In The effect of heating air being to dismelting furnaces the fuel and ore are al-ninish its density, and the consequences of ways thus heated. This is not the case, this being decidedly bad when the air is but however, with the blast. In fact it has hitherto been considered an advantage to have the air as cold as possible, that it might

The charges descend more slowly, probably, because it requires more time to consume a large quantity of combustible in a given place, than to burn it through a considerable extent of the furnace. The air being completely deprived of its oxygen in the lower part of the furnace, cannot consume any of the combustible higher up. The charges have all moisture, or gaseous matter, completely driven off by he hot gasses passing through them, and a rive, duly heated, at the place where the most intense heating effects are produced. This diminished rate of descent is entirely consistent with an increased yield of metal, since the amount of ore in each charge is

increased.

From the intense action referred to above,

results a greater fluidity in the slag, a diminution in the quantity of flux, the possi

*Anthracite coal merely requires its temperature to be sufficiently raised to make it keep up the combustion by the beat which it gives out. Iron wire, to burn in oxygen, requires its temperatures to be first raised, and may be burned in chlorine if first fired by the combustion of copper wire. Iron filings, finely divided, burn in the air, and in the experiments of Mr. Tyler, a fire was made in a smith's forge, from iron turnings, by raising the temperature with fine turn ings. At last the whole burning mass v 1 *Annales des Mines, vol. IV. This Journal, page iron, and a welding heat was produced upo a bar thrust into it.-[Trans.]

119, vol XV.

ble use of more refractory ores, or an in-of tenacity is common to copper, iron,
creased proportion of others in the charges, platinum, and the alloys of copper and
and the production of gray pig iron, by zinc.
proportions in the charge in a furnace,
which, before, would yield only white, or
mottled, castings.

tain furnaces using charcoal as a fuel.

EFFECTS OF DRAWING, ROLLING, AN-
NEALING, &c., OF THE METALS.

In a paper on the ductility and malleability of certain metals, and on the variations of density which they undergo by different operations, M. Baudrimont developes the following interesting facts.

Brass wire approaches to iron in strength, while copper is inferior to it. Brass may be used instead of iron, where the lat er would oxidate too rapidly.

The diameters of the

sound and good as the day on which it was first put down. The same year I reared up, in the end of a neglected and notoriously damp barn, a lot of newly felled larch poles; and I placed another lot of larch poles against the wall on the outside of the same barn. These are now good and well seasoned: those within became tainted the first year, with what is called dry rot, and were used for fire-wood.

In conclusion, it may be remarked tha some changes may probably be made with The iron wires are given at strengths advantage in the forms of furnaces using from 79,000 lbs. to the square inch to the hot air blast. It is difficult to point 127,600 lbs. The brass wires, from 78 to them out, and their determination will re 187,000 lbs. to square inch. Copper, from If, then, you admit a free circulation of quire repeated trials, and with the precise 38 to 44,000 lbs. air to the timber which is used in a house ores and combustibles intended to be used least and greatest wires were, iron, .014||(no difficult matter) and abstain from paintin a particular case. I would suggest, inch, and .205 inch; brass, .070 and 267 ing that timber till it be perfectly seasoned, however, especially where forged iron is nch; copper, .019 and .285 inch. you will never suffer from what is called to be made, enlarging the furnace at and The finer wires bear greater weights, in dry rot. And if the naval architect, by above the boshes, diminishing, at the same proportion to their areas, than the coarser means of air-holes in the gunwale of a time, the height of the whole furnace.-ones, because the particles of the former vessel (which might might be closed in This later change is understood to have are compacted through the whole crosbad weather), could adinit a free circulaalready been made with advantage, in cer-section, while those of the latter, for a cer- ion of air to the timbers; and if, he could, tain depth only, are thus forced together.-also, abstain, from painting, or doing with [Ann. de Chim. et de Phys.] Turpentine, &c., the outer parts of the ves A short Remark or two on what is com· sel, till the wood had become sufficiently monly called Dry Rot, by Chas. Water-seasoned, he would not have to complain of dry rot. ton, Esq. I am of opinion, that if a vesDry rot is a misnomer. This diseasesel were to make three or four voyages be in timber ought to be designated a decom-fore it is painted, or done with turpentine, &c., its outer wood would suffer much less position of wood by its own internal juices, from the influence of the weather, than it which have become vitiated for want of a usually suffers from its own internal juices, which cannot get vent, on account of arti ficial applications to the pores. But still he timber would be subject to the depredation of the insect. To prevent this effec tually, Mr. Kayan's process must absolutely be adopted; and it must also be adopted 'o secure wood from what is called the dry But should you have painted the piece rot, in places where a free circulation of air of wood which you placed in an upright po- cannot be introduced. I consider Mr. Kysition, it will not last long; because, thean's process perfectly unexceptionable. paint having stopped up i's pore: the incar- The long arrows which the Indians use in cerated juices have become vitiated, and Guiana are very subject to be eaten by the have caused the wood to rot. Nine times worm. In 1812, I applied the solution of in ten, wood is painted too soon. The up-corrosive sublimate to a large quantity of right unpainted posts, in the houses of our hese arrows. At this hour they are perancestors, though exposed to the heats of fectly sound, and show no appearance of summer, and the blasts of winter, have that the worm has ever tried to feed upon lasted for centuries; because the pores o. hem. the wood were not closed by any external) application of tar or paint; and thus the juices had an opportunity of drying up gradually.

At a temperature rather above a cherry red, iron wire remained three months, surrounded by charcoal, without cementation taking place. A white heat, in five minutes, gave the properties of cast iron to a square bar of malleable iron, of four-tenths

of an inch on a side.

Wires of copper, and of alloys of cop; per and zinc, are increased in diameter, and diminished in density, by annealing. The operation of rolling condenses the metals more than that of wire drawing. The density of iron and copper is greater, if the metals are heated before being passed through the rollers. The reverse is the case with alloys of copper and zinc. The density of the metals is greatest when drawn into very fine wires.

Wires may be increased in length in two ways, by a diminution in the area of the cross section, or by increasing the distances between their particles.

When

wires are lengthened in the manner la named, they return to their former length by annealing.

Hydrogen has an action on copper and silver, at high temperatures, which permanently separates their particles. On alloys of copper and zinc, and even of silver and copper, it has no such action.

free circulation of air.

If you rear a piece of timber, newly cu down, in an upright position in the open air, it will last for ages. Put another piece of the same tree into a ship, or into a house, where there is no access to the fresh air, and ere long it will be decomposed.

In 1827, on making some alterations in a passage, I put down and painted a new linth, made of the best, and apparently, well-seasoned foreign deal. The stone wall was faced with wood and laths; and he plaster was so well worked to the plinth, that it might be said to have been tir-tight. In about four months, a yellow fungus was perceived to ooze out between the bottom of the plinth and the flags; and on taking up the plinth, both it and the

Wires of different metals, which, after passing through the same hole in the wire drawing plate, have different diameters, ac-laths, and the ends of the upright pieces of quire equal diameters by annealing.

I

I have penned down these transient remarks by way of preface to others, which may possibly write, at some future time, on decay in living trees.-[Loudon's Archiect. Mag.]

Now Spirit Lamp -A new and convenient spirit lamp, with an eolipyle having a vertical jet, is described by M. Pelletan, the invention of M. Breuzin, of Paris.The entire apparatus is placed on a neat ripod stand, arranged for holding the vessel to be heated. The wick of the lamp is hollow, and is raised or depressed by a screw and rack. Above the lamp is an colipyle of cylindrical shape, through the middle of which the flame of the lamp wood to which the laths had been nailed, passes. The vessel to be heated being were found in as complete a state of de placed above the eolipyle, retains the full efcomposition as though they had been buried fect of the flame of the lamp. The jet in a hot-bed. Part of these materials ex- pipe from the eolipyle passes downwards, hib ted the appearance of what is usually and by a bend is introduced into the axis of called dry rot; and part was still moist, the cylindrical wick of the lamp. The alWires exposed to a high heat, lose a with fungus on it, sending forth a very cohol flame is thus entirely vertical, and part of their tenacity. They require to disagreeable odour. A new plinth was im- the apparatus is much more convenient be annealed in wire drawing, not to render mediately put down; and holes, 1 inches than the common eolipyle where the jet is them more tenacious, but to allow the par-in diameter, at every yard, were bored horizontal. By using vessels properly articles to resume the positions from which through it. This admitted a free circula-ranged to economise heat, a pint of water they may again be displaced. The lossion of air; and to this day the wood is as may be boiled in five minutes, and at a cost

The diameter of a wire increases, very slowly, by time, after passing through the wire drawing plate. Wires which have been bent, and then straightened, re-acquire

a curvature.

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