Chapter VIII: MISCELLANEOUS.--The Repair of the Burned Models after the Patent (1)

Office Fire of 1877. By GEORGE DUDLEY LAWSON. An interesting
description of the importance and difficulty of the work, and the
enterprise and care shown. Reconstructing complicated models from
miscellaneous fragments.
Verneuil, Winner of the Ascot Cup, 1 illustration.

Price 10 cents. To be had at this office and of all newsdealers.

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=PROGRESS OF IRON MAKING.=

The success of the Dank's puddling furnace fired with pulverized coal seems to be no longer a matter of doubt in England. It is stated that Messrs. Hopkins, Gilkes & Co., the well known iron makers of the North of England, have succeeded in turning out from it from Cleveland pig alone iron capable of bearing tests which Staffordshire iron has not yet surpassed. The English iron manufacturers in their struggle with us are wisely taking advantage of every improvement in their line to keep ahead of us, and are likely to be successful unless our manufacturers arouse from their fancied security.

We are now underselling the English at home and abroad in many articles of manufacture, because so much of our work is done by machinery, and is consequently better and cheaper than can be produced by hand labor at the lowest living rate of wages; but so soon as the English masters and workmen shall fully appreciate this fact, the same machines run there with cheaper labor will deprive us of our present advantages.

Already we notice several instances in which the workmen, renouncing their prejudices, have willingly consented to the substitution of machine for hand work, and we doubt not that the success of these innovations, conjoined with the pressure of the times, will ere long create a complete revolution in the ideas of the British workmen, so that instead of longer opposing they will demand the improved appliances and facilities for work, converting them from rivals or opponents to allies. Such a radical change is not necessarily far in the future, for the logic of it has long been working in the brains of both masters and men and may reasonably bear fruit at any time. We fear that when this time arrives our makers of iron, especially, will wake up to the consciousness that they have not kept up with the advance.

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=THE TELEPHONE AS A PROMOTER OF SCIENCE.=

Every new thing, whether it be in the realm of mind or matter, has an influence on whatever existed before, of a similar kind, to modify, develop, and improve it, or to doom it to oblivion. Whatever is new necessitates a better knowledge of the old, so that the world gains not only by the acquirement of the new thing, but also by a better understanding of things already known.

A discovery, published, sets a thousand minds at work, and immediately there is a host of experimentalists who, in their desire to make and try the new thing for themselves, begin without a knowledge of the science or art to which the discovery pertains, and inevitably fail. After failure comes research, which to be of value must be extended. Every investigator can recall the novelty that induced his first experiments, and can recount his trials in his search for information.

Among the inventions or discoveries that have induced extended experiment, the telephone may, without doubt, be mentioned as the chief, for no sooner was the first speaking telephone brought out than here and there all over the country it was imitated. Persons who never had the slightest knowledge of electrical science had a desire to see and test the telephone. To do this first of all requires a degree of mechanical skill. Acoustics must be understood, and a knowledge of the four branches of electrical science is requisite, as the telephone involves galvanism, magnetism, electrical resistance, induction, and many of the nicer points which can be understood by investigation only, and this not only in the direction indicated, but in the allied branches of physics and also in chemistry. Familiarity with these things develops a scientific taste that will not be easily satisfied. The characteristic avidity with which the American people seize upon a novelty has been wonderfully exemplified by the manner in which the telephone mania has spread. In consequence of this science has received an impetus, and now we have everywhere embryo electricians and experimentalists, where before were only the unscientific.

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=LETTER FROM PROFESSOR HUGHES.=

We print in another column a letter received from Mr. D. E. Hughes concerning the distinction he finds between his microphone and Mr. Edison's carbon telephone. Mr. Hughes is very confident that the two inventions have nothing in common, and that they bear no resemblance to each other in form, material, or principles.

We would not question Mr. Hughes' sincerity in all this. No doubt he honestly believes that the invention of Mr. Edison "represents no field of discovery, and is restricted in its uses to telephony," whilst the "microphone demonstrates and represents the whole field of nature." But the fact of his believing this is only another proof that he utterly fails to understand or appreciate the real scope and character of Mr. Edison's work.

To those familiar not only with Mr. Edison's telephone but with the long line of experimental investigation that had to be gone through with before he was able to control the excessive sensitiveness of the elements of his original discovery, it is very clear that Mr. Hughes has been working upon and over-estimating the importance of one phase, and that a limited phase, of Mr. Edison's investigations.

We propose shortly to review at length the evidence of Mr. Edison's priority in the invention or discovery of all that the microphone covers; this purely as a question of scientific interest. For the personal elements of the controversy between Mr. Edison on the one side and Messrs. Preece and Hughes on the other we care nothing.

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=THE SCIENTIFIC AMERICAN EXPORT EDITION.=

The inquiry for American manufactured products and machinery abroad seems to grow in volume and variety daily. And though, in comparison with our capacity to produce, the foreign demand is yet small, its possibilities are unlimited. To increase the demand the immediate problem is to make known throughout the world in the most attractive fashion possible the wide range of articles which America is prepared to furnish, and which other nations have use for. As a medium for conveying such intelligence the monthly export edition of the SCIENTIFIC AMERICAN is unequaled. The table of contents of the second issue, to be found in another column, will give an idea of the wide range and permanent as well as timely interest of the matter it circulates. It is a magazine of valuable information that will be preserved and repeatedly read. The handsomely illustrated advertising pages supplement the text, and make it at once the freshest, fullest, and most attractive periodical of the sort in the world. An examination of the index of advertisers will show how widely its advantages for reaching foreign buyers have been appreciated by leading American houses. In the advertising page XXV. appears a list of some eight hundred foreign commercial places in which the circulation of the paper is guaranteed, as evidence that it reaches those for whom such publications are intended.

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=FOUNTAIN PENS.=

For several days we have had in use in our office examples of the Mackinnon Fountain Pen, and find it to be a very serviceable and effective instrument. This is a handsome looking pen, with a hollow handle, in which a supply of ink is carried, and the fluid flows from the point in the act of writing. The necessity of an inkstand is thus avoided. One of the difficulties heretofore with pens of this character has been to insure a free and certain delivery of the ink, and also to bring the instrument within the compass and weight of an ordinary pen. The inventor seems to have admirably succeeded in the example before us. The ink flows with certainty, and there is no scratching as with the ordinary pen; it writes with facility on either smooth or rough paper; writes even more smoothly than a lead pencil; may be carried in the pocket; is always ready for use; there is no spilling or blotting of ink. The construction is simple, durable, and the action effective. One filling lasts a week or more, according to the extent of use. These are some of the qualities that our use of the pen so far has seemed to demonstrate; and which made us think that whoever supplies himself with a Mackinnon Pen will possess a good thing. The sole agency is at No. 21 Park Row, New York city.

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=THE SUN.=

BY S. P. LANGLEY, ALLEGHENY OBSERVATORY, PA.*

When, with a powerful telescope, we return to the study of the sun's surface, we meet a formidable difficulty which our first simple means did not present. This arises from the nearly constant tremors of our own atmosphere, through which we have to look. It is not that the tremor does not exist with the smaller instrument, but now our higher magnifying power exaggerates it, causes everything to appear unsteady and blurry, however good the glass, and makes the same kind of trouble for the eye which we should experience if we tried to read very fine print across the top of a hot stove, whence columns of tremulous air were rising. There is no remedy for this, unless it is assiduous watching and infinite patience, for in almost every day there will come one or more brief intervals, lasting sometimes minutes, sometimes only seconds, during which the air seems momentarily tranquil. We must be on the watch for hours, to seize these favorable moments, and, piecing together what we have seen in them, in the course of time we obtain such knowledge of the more curious features of the solar surface as we now possess.

The eye aches after gazing for a minute steadily at the full moon, and the sun's light is from 300,000 to 600,000 times brighter than full moon light, while its heat is in still greater proportion. The object lens of such a telescope as the equatorial at Allegheny is 13 inches in diameter, and it is such light, and such heat, concentrated by it, that we have to gaze on. The best contrivance so far found for diminishing both, and without which our present acquaintance with the real appearance and character of sunspots would not have been gained, depends upon a curious property of light, discovered by a French physicist, Malus, in the beginning of this century. Let A (Fig. 10) be a piece of plane unsilvered glass, receiving the solar rays and reflecting them to a second similar one, B, which itself reflects them again in the direction C. Of course, since the glass is transparent, most of the rays will pass through A, and not be reflected. Of those which reach B again most will pass through, so that not a hundredth part of the original beam reaches C. This then, is so far a gain; but of itself of little use, since, such is the solar brilliancy, that even this small fraction would, to an eye at C, appear blindingly bright. Now, if we rotate B about the line joining it with A, keeping always the same reflecting angle with it, it might naturally be supposed that the light would merely be reflected in a new direction unchanged in quantity.

But according to the curious discovery of Malus this is not what happens. What does happen is that the second glass, after being given a quarter turn (though always kept at the same angle), seems to lose its power of reflection almost altogether. The light which comes from it now is diminished enormously, and yet nothing is distorted or displaced; everything is seen correctly if enough light remains to see it by at all, and the ray is said to have been "polarized by reflection." It would be out of place to enter here on the cause of the phenomenon; the fact is certain, and is a very precious one, for the astronomer can now diminish the sun's light till it is bearable by the weakest eye, without any distortion of what he is looking at, and without disturbing the natural tints by colored glasses. In practice, a third and sometimes a fourth reflector, each of a wedge shaped, optically plane piece of unsilvered glass, are thus introduced, and by a simple rotation of the last one the light is graded at pleasure, so that with such an instrument, called "the polarizing eyepiece" (Fig. A), I have often watched the sun's magnified image for four or five hours together with no more distress to the eye than in reading a newspaper.

With this, in favorable moments, we see that the sun's surface away from the spots, everywhere, is made up of hundreds of thousands of small, intensely brilliant bodies, that seem to be floating in a gray medium, which, though itself no doubt very bright, appears dark by comparison. What these little things are is still uncertain; whatever they are, they are the immediate principal source of the sun's light and heat. To get an idea of their size we must resort to some more delicate means of measurement than we used in the case of the watch. The filar micrometer consists essentially of two excessively fine strands of cobwebs (or, rather, of spider's cocoon), called technically "wires," stretched parallel to each other and placed just at the focus of the telescope. Suppose one of them to be fixed and the second to be movable (keeping always parallel to the first) by means of a screw, having perhaps one hundred threads to the inch, and a large drum shaped head divided into one hundred equal parts, so that moving this head by one division carries the second "wire" 1/10000 part of an inch nearer to the first. Motions smaller than this can clearly be registered, but it will be evident that everything here really depends upon the accuracy of the screw. The guide screw of the best lathe is a coarse piece of work by comparison with "micrometer" screws as now constructed (especially those for making the "gratings" to be described later), for recent uses of them demand perhaps the most accurate workmanship of anything in mechanics--the maker of one which will pass some lately invented tests is entitled at any rate to call himself "a workman."

Since the "wires" are stretched precisely in the focus, where the principal image of the sun is formed, and move in it, they, and the features of the surface, form one picture, as magnified by the eye lens, so that they appear as if moving about on the sun itself. We can first set them far enough apart, for instance, to take in the whole of a spot, and then by bringing them together measure its apparent diameter, in ten thousandths of an inch. Then, measuring the diameter of the whole sun, we have evidently the proportion that one bears to the other, and hence the means of easily calculating the real size. A powerful piece of clockwork, attached to the equatorial, keeps it slowly rotating on its axis, at the same angular rate as that with which the sun moves in the sky, so that any spot or other object there will seem to stay fixed with relation to the "wires," if we choose, all day long. The picture of "wires," spots, and all, may be projected on a screen if desired; and Fig. 11 shows the field of view, with the micrometer wires lying across a "spot," so seen on the 6th of March, 1873. Part of a cambric needle with the end of a fine thread is represented also as being projected on the screen along with the "wires" to give a better idea of the delicacy of the latter.

Now we may measure, if we please, the size of one of those bright objects, which have just been spoken of as being countable by hundreds of thousands. These "little things" are then seen to be really of considerable size, measuring from one to three seconds of arc, so that (a second of arc here being over 400 miles) the average surface of each individual of these myriads is found to be considerably larger than Great Britain. Near the edge of the disk, under favorable circumstances, they appear to rise up through the obscuring atmosphere, which darkens the limb, and gathered here and there in groups of hundreds, to form the white cloudlike patches (_faculæ_), which may sometimes be seen even with a spy-glass--"something in the sun brighter than the sun itself," to employ the expression by which Huyghens described them nearly two hundred years ago. They are too minute and delicate objects to be rendered at all in our engraving; but this is true also of much of the detail to be seen at times in the spots themselves. The wood cuts make no pretense to do more than give an outline of the more prominent features, of which we are now about to speak. The wonderful beauty of some of their details must be taken on trust, from the writer's imperfect description of what no pencil has ever yet rendered and what the photograph has not yet seized.

Bearing this in mind, let us now suppose that while using the polarizing eyepiece on the part of the spot distinguished by the little circle, we have one of those rare opportunities when we can, by the temporary steadiness of our tremulous atmosphere, use the higher powers of the telescope and magnify the little circle till it appears as in Fig. 12. We have now nearly the same view as if we were brought close to the surface of the sun, and suspended over this part of the spot. All the faint outer shade, seen in the smaller views (the _penumbra_) is seen to be made up of long white filaments, twisted into curious ropelike forms, while the central part is like a great flame, ending in fiery spires. Over these hang what look like clouds, such as we sometimes see in our highest sky, but more transparent than the finest lace vail would be, and having not the "fleecy" look of our clouds, but the appearance of being filled with almost infinitely delicate threads of light. Perhaps the best idea of what is so hard to describe, because so unlike anything on earth, is got by supposing ourselves to look _through_ successive vails of white lace, filled with flower-like patterns, at some great body of white flame beyond, while between the spires of the flame and separating it from the border are depths of shade passing into blackness. With all this, there is something crystalline about the appearance, which it is hard to render an idea of--frost-figures on a window pane may help us as an image, though imperfect. In fact the intense whiteness of everything is oddly suggestive of something very cold, rather than very hot, as we know it really. I have had much the same impression when looking into the open mouth of a puddling furnace at the lumps of pure white iron, swimming half-melted in the grayer fluid about them. Here, however, the temperature leaves nothing solid, nothing liquid even; the iron and other metals of which we know these spot-forms do in part at least consist are turned into vapor by the inconceivable heat, and everything we are looking at consists probably of clouds of such vapor; for it is fluctuating and changing from one form into another while we look on. Forms as evanescent almost as those of sunset clouds, and far more beautiful in everything but color, are shifting before us, and here and there we see, or think we see, in the sweep of their curves beyond, evidences of mighty whirlwinds (greater by far than the largest terrestrial cyclone) at work. While we are looking, and trying to make the most of every moment, our atmosphere grows tremulous again, the shapes get confused, there is nothing left distinct but such coarser features as our engraving shows, and the wonderful sight is over. When we consider that this little portion of the spot we have been looking at is larger than the North and South American continents together, and that we could yet see its parts change from minute to minute, it must be evident that the actual motion must have been rapid almost beyond conception--a speed of from 20 to 50 miles a _second_ being commonly observed and sometimes exceeded. (A cannon ball moves less than ¼ of a mile per second.) I have seen a portion of the photosphere, or bright general surface of the sun, drawn into a spot, much as any floating thing would be drawn into a whirlpool, and then, though it occupied by measurement over 3,000,000 miles in area, completely break up and change so as to be unrecognizable in less than twenty minutes.

When we come to discuss the subject of the sun's heat, we shall find that the temperature of a blast furnace or of the oxyhydrogen blowpipe is low compared with that which obtains all over such a vast region, and remembering this, it is evident that its disappearance is a cataclysm of which the most tremendous volcanic outburst here gives no conception. We cannot, by any terrestrial comparison, describe it, for we have no comparison for it in human experience. If we try to picture such an effect on the earth, we may say in another's words that these solar whirlwinds are such as, "coming down upon us from the north, would in thirty seconds after they had crossed the St. Lawrence be in the Gulf of Mexico, carrying with them the whole surface of the continent in a mass, not simply of ruin, but of glowing vapor, in which the vapors arising from the dissolution of the materials composing the cities of Boston, New York, and Chicago would be mixed in a single indistinguishable cloud."

These vast cavities then in the sun we call spots are not solid things, and not properly to be compared even to masses of slag or scoria swimming on a molten surface. They are rather rents in that bright cloud surface of the sun which we call the photosphere, and through which we look down to lower regions. Their shape may be very rudely likened to a funnel with sides at first slowly sloping (the _penumbra_), and then suddenly going down into the central darkness (the _umbra_). This central darkness has itself gradations of shade, and cloud forms may be seen there obscurely glowing with a reddish tinge far down its depths, but we never see to any solid bottom, and the hypothesis of a habitable sun far within the hot surface, suggested by Sir William Herschel, is now utterly abandoned. We are able now to explain in part that mysterious feature in the sun's rotation before insisted on, for if the sun be not a solid or a liquid, but a mass of glowing vapor, it is evidently possible that one part of it may turn faster than another. _Why_ it so turns, we repeat, no one knows, but the fact that it does is now seen to bear the strongest testimony to the probable gaseous form of the sun throughout its mass--at any rate, to the gaseous or vaporous nature of everything we see. We must not forget, however, that under such enormous temperature and pressure as prevail there the conditions may be--in fact, must be--very different from any familiar to us here, so that when we speak of "clouds," and use like expressions, we are to be understood as implying rather an analogy than an exact resemblance.

We must expect, with the great advances photography has lately made, to know more of this part of our subject (which we may call solar meteorology) at the next spot maximum than ever before, and by that time it may be hoped that some of the wonderful forms described above so imperfectly will have been caught for us by the camera.

* For parts 1 and 2 see SCIENTIFIC AMERICAN for July 20 and July 27.

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IN the notice in our issue for July 27 of a new screw cutting lathe made by Messrs. Goodnow & Wightman, the address should have been 176 Washington street instead of 128, and the diameter of the tail spindle, which was given as 5/16, should have been 15/16 inch.

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THE Olympia (Wyoming Territory) _Standard_ announces that a company has been formed there to bring ice from a glacier. The deposit covers a number of acres, is seventy or eighty feet deep, and is supposed to contain a hundred thousand or more tons, some of which may have been there as many years. The ice can be cut and sold at one and one half cents a pound, and by the ship load at five dollars a ton.

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=MECHANICAL PUDDLING IN SWEDEN.=

The accompanying engravings, which we take from _Iron_, give plan and section of the puddling apparatus invented by Mr. Oestlund, as used at the Finspong Ironworks. The gas generator, A, is of the common Swedish type, as used for charcoal. The tube, _k_, conducts the gases into the refining pot, _a_. This pot has a lining of refinery slag, which is melted, as the apparatus revolves, to get it to adhere to the sides. The revolution of the pot, _a_, on its axis, _d_, is effected by the action of the beveled wheels, _b_ and _b'_, and the pulley, _c_, which takes from an iron chain the power given off by a turbine. The spindle, _d_, is supported in the bearings, _e_ and _e', c_ carrying a pair of trunnions which form the axis of oscillation, and allow the apparatus to rise or fall, the whole of this mechanism being supported on the plummer blocks, _f f_. One of the trunnions, _e''_, is prolonged so as to form the axis of the beveled wheel, _b_, and the pulley, _c_, the latter sliding along the trunnion so as to put _b_ in or out of gear. The bush, _e_ is tied by means of the stay, _g'_ to the upper end of the toothed segment, _g_, the lower extremity of which is connected with the second bush at the end of the spindle. By means of the pinion, _h_, revolving on standards, _i i_, and the segmental rack, _g_, the pot can be raised or lowered without interfering with the action of the beveled wheels.

The gas from the generator is brought to the mouth of the pot by the tubes, _k_ and _m_. The air necessary for the combustion of the gas is brought in by a tube, _l_, branching from the air main, _l''_. The air tube, _l_, passes into the gas tube and is continued concentrically within the latter. The gas and air tubes both have joints at _m'_ and _m''_. By means of the bar, _n_, which has a counterpoise to keep the moving parts in position, the tubes can be brought from or toward the mouth of the pot, so as to make it free of access to the workman. With a key fitting on the stem, _n'_, the tubes can be turned in _m'_, so as to give the currents of gas and air a more or less oblique direction. To screen the workmen from the heat of the pot a disk of iron, _o_, lined with fire clay on the side next the pot, is fitted to the end of the tubes.

Before running the metal into the pot, the latter must be heated, to such a degree that the slag lining is pasty or semi-fluid at its surface. Generally an hour and a half will be spent in heating with gas to this point. There should be sufficient live coal in the pot when the gas is first let in to keep up its combustion; should it be extinguished by excess of air or gas, it must be relit. As soon as the pot begins to get red hot the full heat can be put on.

The gas generator is tended in the usual way with the ordinary precautions. To keep ashes and dust out of the gas tube, lumps of charcoal are heaped up to the height of the top of the flue. The wind pressure for the generator was 33 to 41 millimeters of mercury, that of the wind for the combustion of the gas (at Finspong the blast is not heated) being only 16½ millimeters. The pressure of the gas in the tube near the pot was 6.2 millimeters of mercury. The method of working, viewed chemically, does not sensibly differ from puddling; although giving as good, perhaps better, results at a much less cost. There are three principal periods in the operation: 1. The period before boiling. 2. The boiling itself. 3. The end of the boiling, and the formation of balls. When cast metal is poured into the pot a shovelful or two of refinery slag is added. The temperature of the bath is thus brought down; it thickens and boils, the pot revolving at the rate of 30 or 40 revolutions a minute. The metal is worked with a rabble, either to cool it or to get the slag to incorporate with it, as is done in puddling. Note must be taken of the temperature of the melted metal and that of the pot, at the moment of charging, the heat during working being regulated accordingly by increasing or diminishing the inflow of air and gas. When circumstances are favorable, boiling begins five minutes after the metal is run into the pot, and it lasts about ten minutes.

Boiling having begun, the batch swells, the iron forms, granulates, and seems to cling to the rabble and the sides of the pot. The rotation of the pot is continued, as well as the working, to separate out parts which are not yet refined; but no more cold cinder is put in. While boiling goes on the temperature is regulated so that the pig does not cling to the side of the pot during a complete revolution, but so that the particles next the side fall back into the bath when the side comes uppermost in the revolution. The heat is raised a little when the iron can be felt by the rabble to be completely refined, when shining lumps make their appearance in the bath, and the iron begins to cling to the walls. At the moment, therefore, that the temperature is brought to its highest point, and the iron begins to agglutinate, the rotation of the pot should be stopped, and either immediately, or after the delay of a couple of minutes, it is removed. If the iron does not ball well, it is not completely refined, and the pot may be started again. If the iron is firm enough already, the isolated particles are exposed to the hottest flame possible, the blast being carried to its maximum. The refining is thus completely finished, and all the particles are agglomerated. The mobility of the gas tube at _m''_ is of advantage in this operation. It is sometimes useful to start the pot again to round up the puddled ball, but it is best if this has been formed with the rabble.

The iron from a charge of 75 kilos. of pig may be divided with advantage into a couple of balls; a third may be made of the iron separated from the walls of the pot. To get out the balls the pot is lowered, and the workmen use tongs, pointed rabble, and hooked bar. If things have gone well the balls ought to come out soft at a welding heat, filled with cinder like puddled balls, but a little more resisting and solid under the hammer. They are forged into bars, and these are at once passed to the rolls. If nothing hinders the balling and shingling, these operations will not consume more than fifteen minutes.

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=Photographic Engraving.=

Scamoni's process is as follows: The original drawings are carefully touched up, so that the whites are as pure and the blacks as intense as possible, and then the negative is taken in the ordinary way, the plate being backed in the camera with damp red blotting paper, to prevent reflection from the camera or back of the plate. The negative is developed in the ordinary manner, intensified by mercuric chloride, and varnished. A positive picture is taken in the camera, the negative being carefully screened from any light coming between it and the lens. This is intensified by pyrogallic acid, and afterward washed with a pure water to which a little ammonia has been added. It is then immersed in mercuric chloride for half an hour, and again intensified with pyrogallic acid. This is repeated several times. When the intensity of the lines is considerable, the plate is well washed, treated with potassium iodide, and finally with ammonia, the image successively appearing yellow, green, brown, and then violet brown. The plate is then thoroughly drained, and the image is treated successively with a solution of platinic chloride, auric chloride, ferrous sulphate, and finally by pyrogallic acid, which has the property of solidifying the metallic deposits. The metallic relief thus obtained is dried over a spirit lamp, and covered with an excessively thin varnish. This varnish, which is evidently a special preparation, retains sufficient tackiness to hold powdered graphite on its surface (the bronze powder now used may be employed instead), which is dusted on in the usual manner. After giving the plate a border of wax, it is placed in an electrotyping bath, and a perfect facsimile in intaglio is obtained, from which prints may be taken in a printing press.

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=A NEW DEEP SEA THERMOMETER.=

Perhaps some of our readers may have seen a description of a form of thermometer devised by MM. Negretti and Zambra for the purpose of ascertaining the temperature of the ocean at great depths. This consisted of a tube bent into the shape of a siphon, which when it had reached the desired depth was made, by means of an ingenious arrangement, to pour all the mercury found above a certain point near the reservoir into the second arm of the siphon. This second arm, which, like the other, was a capillary tube, carried a scale of divisions on which might be read the temperature of the depths to which the instrument had been lowered. This thermometer gave all the results that might have been expected. The ship Challenger during its polar expedition had on board a certain number of these instruments. The report of Capt. G. S. Nares made to the English Admiralty describes all the benefits that we may hope to reap from a serious study of the temperature of the ocean at different depths, and not the least of these are those that pertain to the fishery interest. Notwithstanding the good results given by this instrument, its inventors have endeavored to render it still more practical and more within the reach of all by diminishing the cost of construction, and increasing its compactness.

Fig. 1 represents the thermometer isolated from its case. It is an ordinary thermometer furnished at A with a little device that M. Negretti has already made use of in the construction of his larger instrument, and which allows the liquid to run from the reservoir into the capillary tube when the temperature rises, without letting it flow back when it lowers, if moreover the precaution has been taken to incline the tube slightly, reservoir upward. At B there is a bulge in the tube in which a certain quantity of mercury may lodge; this bulge is placed in such a way that the mercury resulting from the dilatation of the reservoir may come to it and continue its ascension in the capillary tube when the reservoir is down (the thermometer being vertical), but cannot get out when the reservoir is upward.

We should add that these thermometers are constructed so as to give the variations of temperature within determined limits.

The small reservoir, B, is indispensable to the well working of the apparatus; for in seeking the temperature at a certain depth the instrument may, on being drawn up, pass through warmer strata, and it is necessary, therefore, to provide the reservoir with a means of diffusing the small quantity of mercury resulting from this excess of temperature. The tube has also a small bulge at its upper extremity at C.

The thermometer is placed in a small wooden case having a double bottom throughout its length. In this double bottom are placed a certain number of lead balls that can run from one end of the case to the other, and of sufficient weight to render the instrument buoyant in sea water. To use the apparatus, one end of a cord is passed through a hole in the case under the reservoir of the thermometer, and the other end is tied to the sounding line at a certain distance from the lead (Fig. 2). While the line is descending the thermometer will remain reservoir downward (Fig. 2); but when it is again drawn up the thermometer case will take the position indicated in Fig. 3, and the column of mercury breaking at A will fall into the capillary tube, the divisions of which, as will be seen at Fig. 1, are reversed.

As to the thermometer itself, it is important to protect it against the pressure which becomes so considerable at great depths; to do this the reservoir is surrounded by an envelope of thick glass about three quarters full of mercury. The mercury serves to transmit the temperature to the reservoir, and should the exterior envelope yield to the effects of pressure, the reservoir proper would not be affected, the mercury not exactly filling the annular part which surrounds it.

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=New Inventions.=

George E. Palmer, of Cedar Rapids, Iowa, has patented an improved Ironing Board, on which the garments may be held in stretched state while being smoothed with the irons, and readily adjusted thereon to any required degree of tension by a simple attachment.

William B. Rutherford and Joel T. Hawkins, of Rockdale, Texas, have patented an improved Bale Tie, which is formed of the plate provided with a longitudinal groove and cross ribs or loops, and having projections or keys to adapt it to receive and hold the notched ends of the bale band.

An improvement in Composition Pavements has been patented by John C. Russell, of Kensington, Eng. This invention relates to the treatment of peat and spent tan for the manufacture of an improved product or material suitable for paving roads and other places and for roofing, etc. The most important steps in making the composition consist in drying bruised or finely ground peat or spent tan, heating the same _in vacuo_ to degree of 150° Fah., and adding sulphur and gas tar, gas pitch, and stearine pitch in the proportions specified, then kneading the mixture while heated and adding carbonate of lime and furnace slag.

Louis Blanck, of New York city, has patented an improved Safety Brake or attachment for locomotives and railroad cars, by which the entire train, either by a collision with another train or by contact with any obstruction, is first raised from the rails, and then moved in backward direction for the distance of a few feet, so that all danger of accident is avoided, and no other sensation than that of a slight rocking motion exerted. The attachment is constructed so as to admit of being worked by the engineer from the cab or the locomotive, or, if desired, from any car of the train.

An improved Evaporating Pan had been patented by Andrew D. Martin, of Abbeville, La. This invention consists in a tapering sheet metal tank having transverse partitions and longitudinal tapering flues that extend through all of the partitions and terminate at the ends of the tank.

Lloyd Arnold, of Galveston, Texas, has patented an improved Bale Tie, which is formed of a block of iron, with a space or opening running longitudinally through its breadth from one end nearly to the other, and having the alternate edges of the two plates thus formed notched, the notch of the lower plate being square and of a width equal to or a little greater than the bale band, and the notch of the upper plate being narrower at its bottom than the bale band, and with its sides inclined and beveled to an edge, to adapt it to receive and hold the bale band.

An improved Tie for Letter Packages has been patented by John Mersellis, of Knowersville, N. Y. The object of this invention is to provide a tie by means of which letter packages may be quickly and securely fastened or tied. It consists in a plate apertured to receive one end of the string and also to receive the hook upon which the tie is hung when not in use, and having a button and clasp spring for engaging the string in the process of tying.

Fred P. Hammond, of Aurora, Ill., has patented an improved Inking Pad, which consists in a novel arrangement of layers of cloth or felt, chamois skin, oiled silk, and printing roller composition, which enables a clean impression of the stamp to be made. The pad retains the desired rounded surface and proper degree of softness, and is easily manipulated when necessary to replenish the supply of ink.

William J. Clark and Thomas W. Roberts, of Coffeeville, Miss., have patented an improved Trap for Catching Fish in streams, which will allow the fish to be conveniently taken out without taking up the trap.

John W. Cooper, of Salem, Ind., is the inventor of an improved Alcohol Lamp for soldering and similar purposes; and it consists in a reservoir pivoted in a supporting frame, and provided with two wick tubes, and an extinguisher secured to a spring support, and capable of closing the larger wick tube when it is in a vertical position. It has an independent extinguisher for the smaller wick tube, and is provided with a novel device for projecting the wick from the larger tube as it is moved out of a vertical position.

Benjamin Slater, of Attica, N. Y., has invented a simple and effective device for Renovating Feathers by the combined action of steam and hot air. It consists of a cylindrical receptacle, partly surrounded by a steam jacket, and having a hot air box, a perforated bottom, a cover or damper for the same, and an aperture in the top, to which is fitted a perforated cover and a close cover.

An improved Blind Fastening has been patented by George Runton and John Runton, of Hoboken, N. J. This fastening is so constructed as to fasten the blind or shutter automatically when swung open, and in such a way as to prevent all rattling or shaking of the blind or shutter from the action of the wind.

David R. Nichols, of Alexandria Bay, N. Y., has patented an improved Animal Trap, which is so constructed as to set itself after each animal has been caught, and leave no trace of the trapped animal to frighten away those that may come afterward.

William A. Doherty, of Fall River, Mass., has patented an improved Loom Shuttle Attachment, by which the weaving of bad cloth is prevented, and in case any false shed is made by any irregularities in the warp, and that part of the shed carried lower than usual, the attachment is released and thrown over the spindle point, so as to render it impossible to draw out the filling from the shuttle, and thus break it and stop the loom.

Jonas Bowman, of Somerset, O., has patented an improved Vehicle Spring, which permits of dispensing with side bars, thus taking less space to turn on, and by which the tilting and pitching motion usual with springs as heretofore constructed is avoided.

Hiram Unger, of Germantown, O., is the inventor of an improved Gate Latch, which is so constructed that the gate cannot be opened accidentally by being lifted or by rebounding of the catch or latch.

Madison Calhoun, of Ocate, Ter. of New Mex., has patented an improved Hame Fastening, which is not liable to become accidentally unfastened, and is easily and quickly fastened and unfastened, even with cold or gloved hands.

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The Downer well at Corry, Pa., is now down over 1,300 feet, and an oil bearing sand has been struck of about five feet thickness.

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=Our Patent Law.=

_To the Editor of the Scientific American_:

While I cannot handle this subject with any master talent, nor afford to devote the time which should be given to so important a subject before expressing an opinion, yet I can less afford to keep quiet and allow shrewd avarice to manipulate or titled ignorance to legislate my property out of existence. "Property! There is no property in patents," I often hear said. And how about the invention covered by a patent? Is that property? A large majority of people may say no, and deny the justice of a patent law. On the contrary, I, as an inventor, think an invention is genuine property, and as such should be under the same protection in common law as all other property, instead of requiring a special law by which the people magnanimously grant me the privilege for a short time of using what was never theirs, what they never knew of until I brought it into existence.

But what is real property, and by what title is it held? Mother earth, from which we sprung, by which we exist, and to which we return, is, without question, real estate. How is it obtained; how held? History answers, By conquest, by subjugation. But these words, conquest and subjugation, have a more significant meaning than the spoiling of one people by another; they are the actual price of possession. He who, toiling, subjugates the soil, is undoubted owner of its production, by virtue of the highest blessing on record--"By the sweat of thy brow shalt thou obtain bread." And this principle is so far acknowledged that the laborer holds a lien on the product of his labor, even though the property belongs to another.

Mr. A has an unpromising piece of land on which he would like to raise corn. He analyzes the soil, experiments upon it chemically, reads up on the properties and components of corn, the effects of fertilizers and acids upon the soil, and makes himself a fool and laughing-stock generally among his neighbors because he steps out of the beaten track by which they have succeeded in making the ground barren. He does not have much success the first year, and is sympathizingly consoled with "I told you so." But he perseveres and wins the reputation of being "visionary" and "as stubborn as a mule." In the meantime he becomes more familiar with his subject, sees more clearly the requirements of the case, finds he must post himself more thoroughly in certain branches of science in order to conduct his experiments, wrestles with this obstacle and that, and finally discovers a fertilizer based on some natural law of rotation, and produces a crop of corn never before equaled. Now his neighbors come out with this very intelligent question, "How did you happen to think of it?" And they further very condescendingly remark, "That is a rousing crop; I guess I'll try the same thing myself. How did you say you mixed the stuff?" This man is the true conqueror. He has endured privation and scorn, fought obstacles, and in subduing them has eliminated a new principle in agriculture that is an engine of power to all generations. Shall his crops be his only reward? Shall they who laughed him to scorn step into his reward without sharing the labor that produced it?

This is a simile for thousands of inventions, only that the inventor is seldom situated to plant the corn on his own land and reap the harvest. Then which of you will say that he has not a just lien on every man's crop raised by his process for a per cent of the gains thereby? There is a bill before Congress favoring a periodical taxation of patents under the pretext of removing useless patents from the path of later inventors. Let me show you how one inventor looks at that. My neighbor has a vacant lot on which he is unable to build; but joined to mine it would increase the value of my property vastly. Now can't you legislate that old heap of rubbish into my possession somehow? Of course he is waiting for the rise of property around him to sell his lot well; but can't you make that appear unnatural, and that he is a dog in the manger? It is also said that sharpers get control of old patents and lay an embargo on legitimate business. I reply, first, no one could be damaged by the owner of a patent unless he infringed that owner's right; second, if he does infringe, it shows that said patent is valuable, otherwise he need not infringe; and if valuable why should not he pay for it? Mr. B, in the employ of Mr. C, watches the machine he uses, and spends his leisure hours in working out an improvement, which he patents and offers to C for sale; but as the invention is useless except as attached to C's machine, he thinks B can't help himself, and adopts the improvement without paying for it. When a few years have built up a great industry, and C is rich from his spoils, B steps in with a few friends at his back, incorporated especially to make C shell out.

Of course this is bad and ought to be legislated against. If it were not valuable C need not use it. It is not becoming to the Congress of a great nation to spend its time in legislating worthless patents out of existence. All such will die a natural death. And if there is sufficient worth in any patent to claim your consideration, the inventor is entitled to its price, whether he waits four years or fifteen for his pay.

I speak of myself, not as an individual, but as representing in this letter a class, without whose achievements America, in her proud length and breadth, could not to-day have been. For the last half of my past life, over twenty years, I have been an inventor. Schooled in adversity, accustomed to disappointment, sometimes successful, enjoying no luxuries but the conquest of obstacles, and often forced to simple pursuits to keep the pot boiling, yet I expect to spend the rest of my life inventing, feeling strong in the school of experience, and hoping for such prosperity as will enable me to work out some of the larger problems in view.

If those in power would really aid the inventor, let them increase his facilities for information. Circulate the Patent Office _Gazette_ at one dollar a year, a nominal subscription to insure _bona fide_ readers, and pay the balance out of the Patent Office surplus now accumulated. This both to educate and to save inventors from going over old ground, bringing more talent up to the standard of to-day. Lessen rather than increase Patent Office fees. Enable the Commissioner to give the strictest possible examination on every application for a patent, that when issued it shall bear a _bona fide_ value, by retaining the most competent examiners at a salary adequate to keep them. Reduce the cumbrous machinery of patent litigation to about this text, in two headings: First, Is plaintiff the first inventor? Allow one month to find that out. If not disproved in that time, allow it. Second, Does defendant infringe? Allow one month to decide that. If not proven, discharge the case, with cost to plaintiff. If proved, cost and damage to be settled by defendant in thirty days.

The ability of wealthy corporations to absorb with impunity the product of all talent within their reach, and put off the day of reckoning until plaintiff is swallowed in cost, is the greatest present discouragement to inventors. Our patent law is now better than any amendment yet proposed will leave it. If you must tinker over it, remember all laws are for protection of the weak. The bulldog does not need law to take the bone from the spaniel. Just in proportion as you damage the patent law, you destroy the accomplishments and purpose of my life. Therefore I have spoken; so could a thousand more. W. X. STEVENS. East Brookfield, Mass.

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=The Edison Carbon Telephone and Hughes' Microphone.=

_To the Editor of the Scientific American_:

Mr. Edison finds a resemblance between his carbon telephone and my microphone.