« PreviousContinue »
years have made serious inroads upon the hard-earned funds of small and sorrowful investors. It is a common thing for stocks, based on properties of relatively small or even of no value, to be offered to the public as safe and profitable investments, and to be sold at enormous profit for the promoters at the expense of the sanguine investor who is allured. by the Midas touch of the "most honorable men" on the directorate. This method of getting other people's money is more respectable than asking them for it on a dark night at a pistol's point. It is also far safer, for it seems to be covered within the law. But does it not seem rather anomalous to send to jail a "bunco steerer" for selling a gilded brick to an unsophisticated rustic, while another who sells a fellow a finely engraved certificate, of exactly similar value, should be merely expected to give a small fraction of his gains to philanthropic purposes?
Neither business reaction, nor tight money, nor politics will explain the persistent stubbornness of the people in refusing to flock back to the stock market. They have seen the long list of receiverships with their unsavory revelations, re
duced dividends, and unexplained slumps MARCONI, in discussing the progress
in stocks of other companies, and naturally look askance at all stocks with which the names of the manipulating "Napoleons" of finance, however exalted and pious, are associated. They suspect that the gambling is going on with loaded dice, and will invest only when they have. a tip that the dice are loaded on their side. The whole business thus becomes immoral.
of wireless telegraphy, calls attention to its value in exploration. It will not be necessary in the future for arctic explorers to die from starvation because they are lost from civilization. By means of wireless telegraphy it will be very easy for an exploring party to keep in daily communication with their home people. Hereafter every arctic expedition, probably, will be equipped with a wireless telegraphic outfit. The explorer can tell his friends at just what point he stands. If he is in need of supplies he can direct how these shall be forwarded to him and of what they shall consist, and he can direct his rescuers how to reach him.
All that applies to the arctic explorer applies with equal truth to the explorer in the jungles in the interior of Africa and Australia. Had the wireless telegraph been invented in Dr. Livingstone's time, it would not have been necessary to send Henry M. Stanley to Lake Tanganyika to find him. He would have been able to wire for help when he first fell a victim to the jungle fever.
A greater man than Mr. Lawson once sang of the "damned lust for gold;" the "Story of Amalgamated" is the solo obligato of the financial chorus.
A New Cure for Intemperance
T THE OPTICIANS' CONVENTION held recently in Milwaukee, Wisconsin, Dr. Prentice of Chicago, in a paper read before the delegates, stated that in properly fitted eyeglasses lay a possible cure for alcoholism. This statement is based on observations to the ef
fect that the craving for alcoholic stimulants is caused mainly by a derangement of the intimate and delicate relations of the optic nerve to the system.
Of course it is only natural to smile at such an idea, and whisper softly "crank." In view of the fact, however, that medical specialists often put eyeglasses on their patients to cure headaches and nervous dyspepsia, it would seem well to reserve our decision. An editorial discussing Dr. Prentice's paper, says: "If we once concede that a failure of the eyes to 'focus' properly upon an object produces a nervous irritation which in turn produces an abnormal appetite, and that the patient acquires the habit of trying to satisfy this appetite with alcoholic stimulants, is it unreasonable to assume that a correction of the ocular difficulty would restore natural conditions?"
We look forward with much interest to the discussion of Dr. Prentice's paper in the scientific journals.
Wireless Telegraphy and Exploration
How to Make Electrotypes
By S. R. BOTTONE
HE ENTHUSIASTIC AMATEUR who has succeeded in
producing some of the beautifully artistic work of which the lathe is capable, or who has in his possession a coin or medallion from which he requires to take a duplicate, will be pleased, and agreeably surprised, by the charming results that can be obtained by reproducing these in copper, by electrodeposition. The process is at once simple and inexpensive, and, by a little modification, can be used to give reproductions either precisely similar to the original, or ones in which the reliefs and depressions are reversed. As the latter, in ornamental turned work, are very effective, we shall describe the method of obtaining these first.
The operator will provide himself with two or three good "dry cells." A convenient size measures 6 in. by 2 in. He will also require a saturated solution of sulphate of copper (blue vitriol), which he can make by pouring one quart of boiling water on one pound of sulphate of copper, stirring frequently with a stick or glass rod until cold. The solution should be made up in a glazed earthen vessel. When quite cold, about one and a-half fluid ounces of oil of vitriol should be added to the blue fluid, in a fine stream, with constant stirring. The addition of the oil of vitriol will cause the solution to get hot. It must be allowed to cool, when it may be placed in a stoppered bottle, ready for use. Several discs of thin sheet copper (about 1-16 in. thick) of varying diameters, according to the size of the work to be reproduced, will also be needed; and to the edge of each of these (which are called "anodes") is to be attached a wire by drilling a little hole near the edge of the disc, and inserting therein one end of a 10-in. length of No. 16 copper wire, and
Reprinted by special arrangement, from The Engineering World, London, Eng.
burring it over the plate by hammering. This makes good contact, without soldering, which is to be avoided. The next requisite is a rather deep, flat-bottomed, circular, well-glazed, earthenware dish. A soup-plate will answer very well, unless the objects to be copied are very large, in which case one of the square white earthen dishes used by photographers wherein to wash their prints may be used. Two or three yards of No. 18 or No. 20 bare copper wire will also be required for the purpose of connecting up the wooden ornamental turned work to the negative pole of the dry cell.
Being provided with the above necessaries, the operator selects the turned work which he desires to reproduce in copper, and brushes over the worked surface with a paste made of good fine plumbago (black lead) and a little water.
The brush made use of must not be so hard as to mark or in any wise deface the delicate tracery of the original; but, on the other hand, it must be sufficiently firm to enable the operator to get up a brilliant, metallic-looking surface like that of a well-polished stove. For convenience of future reference we shall call this blackleaded surface the "front" of the mould (technically termed the "cathode"). The purpose of performing this operation is to render the wood, which would not otherwise conduct elecIt tricity, conductive on this surface. must be borne in mind that wherever the black lead has been applied, there will the copper be deposited. Hence to prevent waste of battery power, copper, and time, care must be taken not to carry the blackleading too far up the sides of the work. A little way up, it must reach, so as to enable good contact to be made with the wire, which will afterwards serve to connect the work to the negative pole of the dry cell. The best way to effect this is to take a strip of paper, and roll it tightly round the sides of the work, leaving about 1/4 in. bare all round near the front
of the mould. Holding this tightly in the left hand, it will be easy to blacklead and polish the edge as well as the front without encroaching too far up the sides. When this has been satisfactorily effected, the paper strip, which served as a guard, can be removed. Now, taking a piece of the No. 18 or No. 20 bare copper, and gripping one end in the vice, he will wind it two or three times round the blackleaded edge of the work, so as to grip it firmly and make good electrical contact with the black lead under it. The extremities of this wire are brought together and twisted tightly, so that the coils may not loosen. The wire should now be cut off at a distance of about 10
in. from the work, and bent upwards at right angles to the front of the mould. An anode is now selected, having a diameter as nearly as possible that of the front of the mould. (This wire, SO far as it will be immersed in the copper sulphate solution, must be painted over with a little Brunswick black, otherwise it will be eaten through by the solution.) The other end of this wire must then be clamped under the terminal affixed to the carbon (or positive) pole of the dry cell, and then bent twice at right angles in such a manner that the anode can lie flat at the bottom of the dish, which must be placed near the dry cell. The dish should now be filled to a height of about 1 to 1/4 in. from the bottom, with the copper sulphate solution prepared as directed. The work to be copied is now attached, by its slinging wire, to the zinc (or negative) pole of the dry cell, and the wire.
so bent that the front of the mould is immersed in the solution as far as the wire binding extends, or, say, for a depth of about 4 in. The work should lie perfectly horizontal, facing, but not touching, the anode, at a distance of about 3/4 in. to I in. from its surface. In immersing the mould, care must be taken to avoid air bubbles, and this can be done by letting down the front of the mould, somewhat tilted, so as to allow any air bubbles to escape; the wire can afterwards be straightened to cause it to lie horizontally. Great care must be taken that good metallic contact is made between the two wires and their respective dry-cell terminals; and also that no chance contact occurs, either between these two wires on the one hand, or between the mould and the anode on the other. After thus connecting up, the front of the mould should be allowed to remain in the solution for about fifteen minutes. It should then be examined in order to judge of the success of the work.
If the binding wire shows that it has received a rosy-pink deposit, beginning to extend to the edge and creeping round to the front of the mould, all is going well-the current is of the right strength; and if the mould be carefully replaced in the solution, the terminal contacts being maintained tight and good, it will be found that after ten or twelve hours' immersion the entire surface of the mould will have received a delicate coating of copper. To get a layer 1-16 in. thick it may be needful to continue the operation for three or even four days, or even to replace the dry cell by a fresh one, according to the size of the mould. But if, on examination, it is found that the surface of the binding wire and of the front of the mould are coated with a ruddy brownish mud, tending to fall to the bottom of the dish, and especially if bubbles of gas form on and round about the mould, it is a sign that the current is too strong. In this case it will be necessary to remove the anode farther away from the front of the work, or even to insert a "resistance" in the shape of a foot or two of No. 36 iron wire between the anode and the carbon terminal of the dry cell. When it is considered
that the copper deposited has attained. sufficient thickness, the mould should be removed from the sulphate of copper solution, the wire detached from the dry cell, and the mould washed for some time in a stream of running water; after which it should be slung up by its wire to dry thoroughly in in a warm place. When the work is quite dry, the binding wire is untwisted, and the wire carefully unwound from round the edge of the work. If the copper deposit is very thick at these points it will be advisable to file it down cautiously all round, so as to avoid breaking away any of the copper deposited on the front. Having thus filed away any copper that may have extended round the edges of the work, the front of the mould should be held for a few seconds before a clear fire so as to warm the copper coating. This will cause it to expand slightly, after which, by cautiously pushing with the fingers from the back of the mould, the copper coating or "electrotype" can easily be detached. It may then be washed and brushed up with a soft nail-brush and soap and water, dried and mounted on velvet; or it may be "bronzed" with blacklead, or lacquered, if it is desired to preserve the beautiful surface it presents when first detached from the mould. The work or mould, if soiled with blacklead, may be cleaned with a soft tooth-brush moistened with benzine. It may be necessary after this to brush up with soap and water, using a fresh, clean brush.
When it is desired to produce a facsimile of the article to be copied, a trifling
modification must be made in the manipulation. This consists essentially in preparing, first, a wax mould or from the original, from which mould the copper electrotype is produced. To this end, take a strip of paper long enough to make four or five turns round the sides of the object to be copied. This must be bound round the edge so as to extend up above the face of the work to a height of nearly half an inch, and tied tightly round the sides. The whole should now be laid on a flat table, face upwards. Sufficient good beeswax to cover the face of the work to a depth of about 3% in. is now melted in a perfectly clean pipkin or ladle. The surface of the work and the inside of the paper binder are now heavily breathed upon, so as to prevent the wax adhering, when the melted wax is immediately poured in to a depth, as we have said, of about 3% in. The mould should now be allowed to stand for an hour or two to set and harden thoroughly. oughly. The paper binder is then removed, the wax mould pulled off, three or four turns of No. 20 wire bound round the edge, and the surface and edge of the mould carefully blackleaded with a very soft camel-hair brush. It will not be advisable to wet the blacklead; but, using fine powder, breathing on the mould will suffice to render the surface sufficiently adhesive to take a good polish. The blackleaded mould is now to be treated
precisely as recommended for the reversed facsimile. In the accompanying diagram are shown sectionally the proper position and connections of dry cell, wire. to anode, depositing dish, mould, and wire from mould to negative pole of cell.