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CHAPTERS ON ANTIQUITIES.
COINS AND MEDALS.
Having been requested by the editor of The Student to resume my papers on the above subject, I have great pleasure in complying with his request. I shall therefore endeavour, in this short essay, to enlarge somewhat on two points connected with ancient medals ; — first, their usefulness; secondly, their durability.
Their usefulness will be easily stated, as no illustrations of history have been so much esteemed by the learned of all ages, as these small but lasting memorials of the past. We should know nothing of the features and titles of some of the greatest men of ancient times but from this source ; and it is no small pleasure to sit and read history with the medals and coins of a cotemporary period before you they seem to be living and acting over again the scenes in which they took a prominent part. But, apart from this source of delight, coins are of utility in fixing the dates of events, and thus corroborating the truths of the historian's pen, and vouching for the faithfulness of his chronicle. Their value and use have been of late more acknowledged, and will increase in proportion as knowledge increases ; thus the medal, like the lamp burning in the ancient tomb, throws its light around, and enables us to make out many a lost story, and discover many events and persons whose names would have been lost but for this medium. Let us not then despise, as puerile, the labours and studies of the antiquary, who does not merely collect these pieces of brass or gold as relics of another age, but views in them the irrefragable proofs of events now lost in the dust and ruins of the past, and interesting to the denizens of the world at the present period, who in their turn must quit the busy scenes in which they are engaged, and leave to others the task of relating their lives and histories. No; the man who feels correctly on this point, will rather value every memorial of the past, and treasure up with sacred care, these durable mementoes of antiquity, and with delight will lead the young and ardent mind to study them.
This leads me to the second part of my subject-their durability. This point will not require any lengthened argument, as it is so evident. What memorial has ever succeeded like these? The column and statue have crumbled to dust-the solemn temple has fallen to the ground, and its shrine been desecrated—the pyramid and the obelisk have been broken down or destroyed—while these undecaying, and almost eternal mementoes, have remained entire ; and thus in brief space has been conveyed down the stream of time, a record at once faithful, durable, and interesting; possessing in one short line or brief sentence, the history of a life or chronicle of the most important event of a life--some conquest-some building or circumstance in the history of an emperor or king, or transmitting, as in eternal brass, the features of the most celebrated heroes of antiquity; and, faithful to its charge of fame, bears each name and event along with it through various climes and remote ages. We will, therefore, value these little pieces of metal, and rejoice in their preservation, and cultivate a taste for collect
ing them; for be assured they are not to be despised, though small; not thrown away, though the rust of two thousand years be upon them; they are pleasant pictures — they delightfully illustrate history, are an innocent amusement to the enquiring mind, and will repay the attention bestowed upon them. I will here conclude, for the present, promising to resume the subject at greater length.
F. S. A.
REMARKS ON ILLUMINATION.*
IN 1842 a patent was taken out by Boccius for improvements in burners, which consisted principally in placing two concentric metal chimneys within the usual glass one, at about two inches above the top of the burner. These chimneys are supported by wires fastened on to the sides of the burner. The precise object of this arrangement it is difficult to discover ; he asserts that great increase of light is obtained, and that the top of the flame coming in contact with the bottom of the inner chimneys is cut off quite sharp, and its jagged and flickering edge thereby concealed. The latter object is effected, however, at the expense of casting a large shadow upon the ceiling, which causes a great loss of light. We think that the increased light obtained from his lamps, is owing, not to the chimneys, but to the very superior manner in which his burners are made, the holes being extremely small and close together: an idea of their size may be formed from the fact, that, in a burner of only one inch diameter, he puts from sixty to seventy holes, while in a common burner of the same size, there are only about fifteen. Another advantage in his burners is, that the part through which the holes are drilled is made of German silver, which is not so apt to corrode as the iron of which they are generally formed. The position of the glass chimney which he adopts, is decidedly bad, as he only brings the bottom of it to a level with the top of the burner, which exposes the flame very much to draughts. We have tried his burners without the inner chimneys, and placed about an inch or rather more up the glass one, and have no hesitation in saying that, used in this manner, they are the best that can be employed. . The fact that a decreased supply of air would be an advantage to ordinary gas burners, has at length been recognized, and within the last few months a patent has been taken out for an apparatus to admit gas and air in the precise proportion to produce the best light; at least, this is its intention ; how far it answers the purpose we shall shortly see. The apparatus consists of a disk of metal not quite large enough to fill the top of the chimney on which it is placed, and which it thus pretty nearly closes when in a horizontal position. This disk is connected by a lever with the supply cock, so that as the cock is opened it turns up edgeways, one-half going into the chimney, the other standing above it; thus the more gas that
* We omitted in our last to notice one great difference between oil and gas lamps, viz., the absence of any wick in the latter, which of itself constitutes a great source of solid matter in the flame of the former.
is turned on, the more the top of the chimney is opened, and the more air admitted. This would do very well if gas were supplied every where at an equal pressure; but as the pressure is different in almost every situation, in some places it is necessary to open the supply cock entirely to obtain a very small flame, while in others a very large one is produced by opening it a very little ; consequently, in the first case we should have the chimney entirely open, and so a large quantity of air admitted to a very small quantity of gas; while in the second, the chimney would be nearly stopped, while a large quantity of gas would be admitted into it, the consequence of which would be that the flame would smoke very much.
We ought, however, to state, that the burners which are sold with this apparatus are remarkably good, and may be employed with great advantage without the regulator. They are made, not by drilling holes through a piece of metal, as in a common burner, but the whole top of the burner is turned out so as to form a slit about one-eighth of an inch wide ; a ring of metal is then turned to fit this slit accurately, and the outer edge of it is finely milled, so that when it is put in its place in the slit, the milling forms a series of very fine holes. The advantages of this are two; first, that a mill can be made much finer than any hole can be drilled; secondly, that it is much more easily cleaned, all that is requisite, if they become dirty or corroded, being to take out the ring and well brush its milled edge.
Another invention, in which the fact that gas lamps have ordinarily too much air in proportion to their carbon, is that of Mr. Low; the defect being remedied, not by decreasing the supply of air, but by increasing that of carbon. This is done by passing the gas through a vessel filled with naptha, the vapour of which coming over with the gas, increases greatly its quantity of carbon.
We come now to the consideration of the most perfect lamp (theoretically speaking) which has ever been invented; we mean the ventilating lamp of Mr. Faraday, a patent for which was taken out by his brother in 1843. It may not be uninteresting briefly to relate a few of the circumstances which led to the invention, and which were detailed by the inventor in an admirable lecture delivered at the Royal Institution.
It seems that he was applied to by the authorities at the Trinity House to remedy some very great defects in their lighthouses, the first being the inconvenience experienced by the men who have to attend to the lamps, in consequence of the large quantity of foul air given out from them into the small room which constitutes the lantern of the lighthouse ; the second, the condensation on the windows of a large quantity of water (also produced by the lamps), which, in cold weather, becomes frozen, and renders the lights inside much less visible than they ought to be.
He found, on examination, that any attempts to get rid of the foul air by simply making a way for it to escape at the top of the lantern, would be useless, as the only thing which gives it an upward tendency is the circumstance of its being hot and rarified, so that before it can reach the top of the lantern it becomes cooled, and descends into the room. In order, then, to carry off the vapour, he placed a tube immediately over the lamp, rather smaller than the chimney, the top of which it just enters, the other end of the tube is carried out at the top of the lighthouse. This tube, being made of metal, soon becomes heated, and so serves to keep the foul air hot antil
it escapes out of the top of the tube. To prevent the wind blowing down this tube, and extinguishing the lamp, which in the high situations usually occupied by lighthouses it would be apt to do after it comes into the open air, it is formed into the shape shown at fig. 1, where it will be seen that any air blowing in at the top encountering the mpward current of foul air, will be driven out at the funnelshaped holes in the lower part of the tube, instead of going down to the lamp. Here, then, is very perfect ventilation, but a very ugly appearance: to do away with this, so as to render the invention applicable to lamps for drawingrooms, &c. was the next object, and, after a variety of experiments, Mr. Faraday was led to the form shown in fig. 2, in which & represents the supply pipe for gas, b the cock, c an ordinary argand burner, f the tube for carrying off the products of combustion, g a gallery formed on this tube to carry the chimneys d and e, there being an opening through the gallery into the tube f, opposite the space between the glasses d and e; the top of the glass e is covered with a plate of mica, in frame, to prevent any of the products of combustion passing out in that direction.
Now, it is manifest that the only way in which any vapour can escape from this lamp, is in the direction shown by the arrows, viz. out of the top of the inner glass, down between the two chimneys, and so through the tube f, into the outward air: this direction, however, it cannot take, unless a draught is first established in the tube f, which is done by holding a lamp under the bend of the tube f, at h, so as to heat the air it contains, and cause it to rush up the ascending part of the tube ; after the draught is once established, the supply of hot air from the lamp is sufficient to keep it up, unless it has to go a very long way, when it is better, if possible, to carry it into a chimney, the draught of which will very much assist that of the lamp. In the drawing here given, the supply pipe and the exit tube are made at a short distance apart, in order that they may be better seen, but they may of course be placed quite close together, so that the one enters and the other leaves the room through the same hole, all appearance of the exit pipe being thus avoided.
The great inconvenience in these lamps is, that, should the person employed to light them neglect to warm the bend of the tube f, the chimney will be sure to be broken, by the flame being driven against it. Their advantages are obvious, namely, the getting rid of all the products of combustion, and also burning the gas with a greatly diminished supply of air, which renders their employment very economical, and their light more agreeable.
One fact was elicited during the progress of the invention of these lamps, viz. that those large glass bells, with a tube coming out of the top, hung at some distance above gas lamps, for the purpose of carrying off their vapours, are of no use, as they so cool them, that they descend again into the room.
We now take our leave of this subject, trusting that the principles we have endeavoured to lay down may be of some assistance to those who wish to combine a good light with economy, and an absence of as much deleterious vapour as possible.
MARCELLUS; OR, "THE OLD COBBLER OF THE COTTAGE.
(Concluded from page 99.) He turned the louis-d'ors over and over, shook them in the palm of his hand, and then carefully folded them up again in the paper. He felt no inclination to sleep, but looked, first at the road which the traveller had taken, and next at his cottage. Bertha, in her turn, was at the window, looking round for her husband. He called to her, and made signs that she should come to him. What are you doing there ? cried she.
MARCELLUS. A noble find, Berthal look at this paper.
BERTHA. Double-one, two, three, four; why then there are eight louisand what a little room they go into! and is this cross gold or copper?
MARCELLUS. I believe it is gold, and the chain also.
BERTHA. My God, my God, what a treasure! it is as if an angel had placed it here for us. It is your prayer that has obtained this find. God has sent food to the ravens. Now, we are rich for the present, and for a long time to come! Here, Marcellus, with one of these pieces we will both have clothes, and good warm ones too; with another, we will lay in some wheat ; with the third some furniture and utensils; and with the fourth there is not enough for a cow? No; we must not be too ambitious ; we will keep the fourth, and the cross, for accidents. If we should fall ill, for example.—You laugh, Marcellus, now; and truly I think so too, if we had only
MARCELLUS, interrupting her with vivacity. Good Bertha, I laugh at the manner in which you dispose of what does not belong to us.
BERTHA. What! what do you say? have you not found it? do you even know who has lost it? neither gold nor money have marks, but belong to those who find them.
MARCELLUS. But, Bertha, I do know to whom they belong.
MARCELLUS. They belong to a traveller who rested himself at this place not a quarter of an hour ago. I saw him from our window. He opened a wallet, and spread out a piece of cloth ; and it was then that this packet fell upon the grass.
BERTHA. He must have a great many of these louis, since he pays so little attention to them, and could lose them in such a manner : to him, the loss is a trifle ; and to us, the find is our all.
MARCELLUS. You are right, Bertha, it is our all, for it is able to save or lose our souls. We have but a few years to live, and shall we burden our consciences with the weight of these eight louis? Do you believe that they would do us any good? you deceive yourself; we shall be a hundred