GROUPS OF STATUARY FOR THE PEDIMENT OF THE HOUSE OF PARLIAMENT IN VIENNA.

The pediment of the central pavilion and the two side pavilions of the new House of Parliament, at Vienna, are to be ornamented with groups of statuary. The group in the middle pediment represents the granting of the constitution by the Emperor Francis Joseph, and was executed by Professor Helmer.

STATUARY FOR THE VIENNA HOUSE OF PARLIAMENT.—SCIENCE AND LITERATURE. (GROUP TO THE LEFT.)

The pediment of the left wing is ornamented by a group representing Justice, and the pediment of the right wing by a group representing the Home Government.

Johannes Benk, the well known Austrian sculptor, designed and executed the last mentioned group. The two figures at the left hand end of this group represent Science and Literature, and those at the right hand end, Industry and Commerce. The entire group consists of nine figures, the middle figure being seated and the rest standing, sitting, and lying, as the space in the pediment allows.

A seated female figure studying a papyrus roll represents Science, and the adjacent female figure, resting one arm on the figure representing Science, and the other, on a lyre, represents Literature or Poetry.

Industry is represented by a strong and powerful woman holding a hammer, and the figure of Mercury and the prow of a vessel represent Commerce.

STATUARY FOR THE VIENNA HOUSE OF PARLIAMENT.—INDUSTRY AND COMMERCE. (GROUP TO THE RIGHT.)

The modulation and formation of each figure conform strictly to Grecian models, as does also the entire arrangement of the figures in the group; and yet there is much of modern life in the figures, especially in the faces, in which the stereotyped Grecian profile has not been adopted. The attitudes of the figures are also freer and more easy than those of the Grecian period.—Illustrirte Zeitung.

ON THE FRITTS SELENIUM CELLS AND BATTERIES.[^[1]]

By C.E. FRITTS, 42 Nassau St., New York, N.Y.

In all previous cells, so far as I am aware, the two portions or parts of the selenium at which the current enters and leaves it have been in substantially the same electrical state or condition. Furthermore, the paths of the current and of the light have been transverse to each other, so that the two forces partially neutralize each other in their action upon the selenium. Lastly, the current flows through not only the surface layer, which is acted upon by the light, but also the portion which is underneath, and not affected thereby, and which therefore detracts from the actual effect of the light upon the selenium at the surface.

My form of cell is a radical departure from all previous methods of employing selenium, in all of these respects. In the first place, I form the selenium in very thin plates, and polarize them, so that the opposite faces have different electrical states or properties. This I do by melting it upon a plate of metal with which it will form a chemical combination, sufficient, at least, to cause the selenium to adhere and make a good electrical connection with it. The other surface of the selenium is not so united or combined, but is left in a free state, and a conductor is subsequently applied over it by simple contact or pressure.

During the process of melting and crystallizing, the selenium is compressed between the metal plate upon which it is melted and another plate of steel or other substance with which it will not combine. Thus by the simultaneous application and action of heat, pressure, chemical affinity, and crystallization, it is formed into a sheet of granular selenium, uniformly polarized throughout, and having its two surfaces in opposite phases as regards its molecular arrangement. The non-adherent plate being removed after the cell has become cool, I then cover that surface with a transparent conductor of electricity, which may be a thin film of gold leaf. Platinum, silver, or other suitable material may also be employed. The whole surface of the selenium is therefore covered with a good electrical conductor, yet is practically bare to the light, which passes through the conductor to the selenium underneath.[^[2]] My standard size of cell has about two by two and a half inches of surface, with a thickness of 1/1000 to 5/1000 inch of selenium. But the cells can, of course, be made of any size or form. A great advantage of this arrangement consists in the fact that it enables me to apply the current and the light to the selenium in the same plane or general direction, instead of transversely to each other as heretofore done, so that I can cause the two influences to either coincide in direction and action, or to act upon opposite faces of the selenium and oppose each other, according to the effect desired.

By virtue of the process and arrangement described, my cells have a number of remarkable properties, among which are the following:

1. Their sensitiveness to light is much greater than ever before known. The most sensitive cell ever produced, previous to my investigations, was one made by Dr. Werner Siemens, which was 14.8 times as conductive in sunlight as in dark. In table A, I give results obtained from a number of my cells.

It will be observed that I have produced one cell which was 337.5 times as conductive in hazy sunlight as in dark. The tremendous change of resistance involved in the expression "337.5 times" may perhaps be more fully realized by saying that 99.704 per cent. of the resistance had disappeared temporarily, under the joint action of light and electricity, so that there remained less than 3/10 of 1 per cent. of the original resistance of the selenium in dark.

In order to obtain these high results, the cells must be protected from light when not in use. The resistance is first measured while the cell is still in total darkness. It is then exposed to sunlight and again measured. It is also necessary to send the current in at the gold electrode or face, as the cell is much less sensitive to light when the light acts upon one surface of the selenium and the current enters at the opposite surface. When the two influences, the light and the current, act through the gold, in conjunction, their forces are united; and, as every atom of the selenium is affected by the light, owing to the extreme thinness of the plate, we have the full effect shown in the measurements.

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TABLE A.
SENSITIVENESS TO LIGHT.
-----------------------------------------------------------------
Selenium | Battery | Resistance in | Resistance in |
cell. | power. | dark. | sunlight. | Ratio.
----------+-----------+---------------+---------------+----------
| | ohms. | ohms. |
No. 22 |5 elements.| 39,000 | 340 |114 to 1
" 23 [³] |5 " | 14,000 | 170 | 82.3 " "
" 24 [⁴] |5 " | 648,000 | 2,400 |270 " "
" 25 |5 " | 180,000 | 930 |196.5 " "
" 26 |5 " | 135,000 | 710 |190 " "
" 107 |5 " | 118,000 | 740 |159 " "
" 108 |5 " | 200,000 | 900 |222 " "
" 122 |5 " | 56,000 | 220 |254.5 " "
" 129[³] |5 " | 200,000 | 940 |212 " "
" 137 |5 " | 108,000 | 320 |337.5 " "
-----------------------------------------------------------------

Cells which are sensitive to light improve by being used daily, and their sensitiveness becomes less if they are laid aside and not used for a considerable length of time, especially if allowed to become overheated. They should be kept cool, and exposed to light frequently, whether they are used or not.

Mode of measuring cells.—So great is the sensitiveness of these cells to external influences, that it is necessary to adopt some particular system in measuring their resistance and to adhere strictly to that system, as every change in the method of measurement produces a difference in the result, and the different measurements would not be comparable with each other. The reason for this will be explained presently.

The system I have adopted is the Wheatstone's bridge arrangement, with equal sides, never using multipliers except for some experimental purpose. In each multiplier wire I have 500 ohms resistance. When the bridge is balanced, one-half of the current flows through the cell and acts upon the selenium. Between the bridge and the cell is a reversing switch, so that the current can be reversed through the cell without changing its course through the bridge. A Bradley tangent galvanometer is used, employing the coil of 160 ohms resistance. The Leclanche battery is exclusively used in measurements for comparison.

2. The kind of battery employed has a marked effect upon the sensitiveness to light, which is largely reduced or entirely destroyed when the bichromate battery is used. The same cells again become extremely sensitive with the Leclanche battery. We might expect that a change in the current employed would cause a change in the resistance of a cell, but it is not clear how or why it should affect the sensitiveness of selenium to light.

"If one kind of battery current destroys its sensitiveness, may we not suppose that another kind might increase its sensitiveness? Although the Leclanche has operated well, some other may operate still better, and by its special fitness for use on selenium cells may intensify their actions, and so bring to light other properties yet unthought of. Is not here a promising field for experiment, in testing the various forms of battery already known, or even devising some new form especially adapted to the needs and peculiarities of selenium cells?"

One year ago I made the foregoing suggestion in a paper on A New Form of Selenium Cell, presented before this Association at Minneapolis. I am now at liberty to state that my photo-electric battery, presently to be described, marks an advance in the direction indicated. The current from this battery increases the sensitiveness of the cells to light, and also to reversal of current. One cell whose highest ratio in light was about 83 to 1, with the Leclanche battery, when measured with my battery gave a ratio of 120 to 1. It seems to make the resistance of the cell both higher in dark and lower in sunlight than with the Leclanche battery. But the field is yet open to others, for the discovery of a battery which may be still better for use with selenium cells.

3. The two surfaces of the selenium act differently toward currents sent into them from the contiguous conductors. One surface offers a higher resistance to the current than the other. The former I utilize as the anode surface, as I have found that the cell is more sensitive to light when the current enters at that surface, which is ordinarily the one covered by the gold or other transparent conductor. Some cells have this property but feebly developed; but in one instance the resistance offered to the current by the anode surface was 256 times as high as that offered by the cathode surface to the same current. In the majority of cases, however, the ratio does not exceed ten times. Table B gives some recent results.

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TABLE B.
SENSITIVENESS TO REVERSAL OF DIRECTION OF CURRENT.
-----------------------+--------------+------------------+---------
| | Resistance |
No. of cell. | Battery. | "gold | "gold | Ratio
| | anode."|cathode."|
-----------------------+--------------+--------+---------+---------
| | ohms. | ohms. |
3/8 inch square. No. 4 | 5 elements. | 20,000 | 1,000 | 20 to 1
" " " 3 | Se. cell. | 6,500 | 400 | 16.2 "
Full size, No. 13 | 1 element. | 9,000 | 800 | 11.2 "
" " " 14 | 5 " | 2,440 | 130 | 18 "
" " " 15 | 5 " | 4,640 | 210 | 22 "
" " " 27 | 5 " | 6,900 | 440 | 16 "
" " " 126 | 1 " | 5,000 | 330 | 15 "
-----------------------+--------------+--------+---------+---------

The direction of the current is always indicated by stating the position of the gold electrode, by the terms "gold anode" and "gold cathode." The above measurements were made in dark.

4. Sensitiveness to change of battery power.—My cells are extremely sensitive to any change in the strength or character of the current flowing through them, which is shown by a corresponding change in the resistance of the cell. I can, therefore, vary the resistance of one of my cells in many ways, and the following may be specified—

(a) By changing the potential or electromotive force of the current through the cell.

(b) By changing the "quantity" of the battery or current.

(d) By dividing the current, by one or more branch circuits or shunts around the cell.

(e) By varying the resistance in any or all of said circuits.

A cell whose resistance becomes greater as the battery power becomes greater, and vice versa, I call an "L B cell" signifying Like the Battery power. A "U B cell" is one whose resistance becomes greater as the battery power (or strength of current) becomes less, and vice versa, being Unlike the Battery power, or current strength.

These changes of resistance are not due to heating of the conductor or the selenium, and the following instance will illustrate this. I have one cell in which the selenium has about one-fourth inch square of surface melted on a brass block one inch thick. This cell measured, with 25 elements of Leclanche, 40,000 ohms. On changing the battery to 5 elements the resistance fell instantly to 30 ohms, and there remained. On again using the current from 25 elements, the resistance instantly returned to 40,000 ohms. Had these results been due in any degree to heating, the resistance would have changed gradually as the heat became communicated to the brass, whereas no such change occurred, the resistances being absolutely steady. Moreover, even the fusion of the selenium would not produce any such change.

The "U B" property does not ordinarily change the resistance of the cell to exceed ten times, i.e., the resistance with a weak current will not be over ten times as high as with a strong one. But I have developed the "L B" property to a far higher degree. Table C gives some recent results obtained with L B cells, including one whose resistance, with 25 elements Leclanche, was 11,381 times as high as with 8 elements, and which, after standing steadily at 123 ohms (and then at 325 ohms with 1 element), on receiving the current from 25 elements again returned to its previous figure of 1,400,000 ohms.

---------------------------------------------------------------
TABLE C.
SENSITIVENESS TO CHANGE OF BATTERY POWER.
-----------------------+------------+------------+-------------
| Resistance | Resistance |
No. of cell. | with 25 | with 5 | Ratio of
| elements. | elements. | Change.
-----------------------+------------+------------+-------------
| ohms. | ohms. |
3/8 inch square, No. 1 | 40,000 | 30 | 1,333 to 1
3/8 " " " 2 | 13,000 | 40 | 325 "
1/4 " " " 1 | 1,400,000 | 123 [⁵] | 11,381 "
1/2 " " " 2 | 500,000 | 62 | 8,064 "
1/2 " " " 5 | 3,500 | 21 | 167 "
Full size, No. 81 | 68,000 | 121 | 561 "
" " " 82 | 9,000 | 64 | 140 "
" " " 83 | 17,300 | 74 | 233 "
" " " 119 | 35,600 | 19 | 1,894 "
-----------------------+------------+------------+-------------

The results in the table were obtained by changing the strength of current by throwing in more or less of the battery. Like results can be obtained by varying the current through the cell by any of the other methods before specified. The above measurements were in dark.

5. Dual state of selenium.—My cells, when first made seem to have two states or conditions. In one, their resistance is very low, in the other it is high. When in the low state they are usually not very sensitive, in any respect. I therefore raise the resistance, by sending an intermittent or an alternating current though the cells, and in their new condition they at once become extremely sensitive to light, currents, and other influences. In some cases they drop to the low state again, and require to be again brought up, until, after a number of such treatments, they remain in the sensitive state. Occasionally a cell will persist in remaining in the insensitive state. The before mentioned treatment raises it up for a moment, but, before the bridge can be balanced and the resistance measured, it again drops into the low or insensitive state. Some cells have been thus stimulated into the high or sensitive state repeatedly, and every means used to make them stay there, but without avail; and they have had to be laid aside as intractable.

In the earlier stages of my investigations, before the discovery of this dual state and the method of changing a cell from the insensitive to the sensitive condition, hundreds of cells were made, finished, and tested, only to be then ruthlessly destroyed and melted over, under the impression that they were worthless. Now, I consider nothing worthless, but expect sooner or later to make every cell useful for one purpose or another.

The most singular part of this phenomenon is the wide difference in the resistance of the cells in the two states. In the low state, it may be a few ohms, or even a few hundredths of an ohm. In the high state, it is the normal working resistance of the cell, usually between 5,000 and 200,000 ohms, but is often up among the millions. The spectacle of a little selenium being stimulated, by a few interruptions of the current through it, into changing its resistance from a fraction of an ohm up to a million or several millions of ohms, and repeatedly and instantly changing back and forth, up and down, through such a wide range, we might almost say changing from zero to infinity, and the reverse, instantly, is one which suggests some very far-reaching inquiries to the electrician and the physicist. What is the nature of electrical conductivity or resistance, and how is it so greatly and so suddenly changed?

6. Radio-electric current generators.—My cells can be so treated that will generate a current by simple exposure to light or heat. The light, for instance, passes through the gold and acts upon its junction with the selenium, developing an electromotive force which results in a current proceeding from the metal back, through the external circuit, to the gold in front, thus forming a photo-electric dry pile or battery. It should preferably be protected from overheating, by an alum water cell or other well known means.

The current thus produced is radiant energy converted into electrical energy directly and without chemical action, and flowing in the same direction as the original radiant energy, which thus continues its course, but through a new conducting medium suited to its present form. This current is continuous, constant, and of considerable electromotive force. A number of cells can be arranged in multiple arc or in series, like any other battery. The current appears instantly when the light is thrown upon the cell, and ceases instantly when the light is shut off. If the light is varied properly, by any suitable means, a telephonic or other corresponding current is produced, which can be utilized by any suitable apparatus, thus requiring no battery but the selenium cell itself. The strength of the current varies with the amount of light on the cell, and with the extent of the surface which is lighted.

I produce current not only by exposure to sunlight, but also to dim diffused daylight, to moonlight, and even to lamplight. I use this current for actual working purposes, among others, for measuring the resistance of other selenium cells, with the usual Wheatstone's bridge arrangement, and for telephonic and similar purposes. Its use for photometric purposes and in current regulators will be mentioned further on. It is undoubtedly available for all uses for which other battery currents are employed, and I regard it as the most constant, convenient, lasting, readily used, and easily managed pile or battery of which I have any knowledge. On the commercial scale, it could be produced very cheaply, and its use is attended by no expense, inasmuch as no liquids or chemicals are used, the whole cell being of solid metal with a glass in front, for protection against moisture and dust. It can be transported or carried around as easily and safely as an electro-magnet, and as easily connected in a circuit for use wherever required. The current, if not wanted immediately, can either be "stored" where produced, in storage batteries of improved construction devised by me, or transmitted over suitable conductors to a distance, and there used, or stored as usual till required.

7. Singing and speaking cells.—When a current of electricity flowing through one of my selenium cells is rapidly interrupted, a sound is given out by the cell, and that sound is the tone having the same number of air vibrations per second as the number of interruptions in the current. The strength of the sound appears to be independent of the direction of the current through the cell. It is produced on the face of the cell, no sound being audible from the back of the cell. An alternating current also produces a sound corresponding to the number of changes of direction. Experiments also show that, if a telephonically undulating current is passed through the cell, it will give out the speech or other sound corresponding to the undulations of the current—and, furthermore, that the cell will sing or speak in like manner, without the use of a current, if a suitably varied light is thrown upon it while in closed circuit.

My experiments having been devoted especially to those branches of the subject which promised to be more immediately practically valuable, I have not pursued this inquiry very far, and offer it for your consideration as being not only interesting, but possibly worthy of full investigation.