Diorama

“ It has already been stated, that the effect of such glasses in looking at near pictures, is obtainable in a considerable degree without a glass, by making the pictures very large and placing them at a corresponding distance. The rule of proportion in such a case is, that a picture of one foot square at one foot distance from the eye, appears as large as a picture of sixty feet square at sixty feet distance. The exhibition called the Diorama is merely a large painting prepared in accordance with the principle now explained. ”

“ The lid, e, when open, as in the diagram, admits the light to the front of the picture, the back being covered with an opaque screen. As the lid is closed, the picture becomes darkened, and by the gradual removal of the screen at the same time, it is changed into a transparency. This portable Diorama can be most conveniently shown by lamplight, the flame of an argand lamp, the wick of which111 can be heightened and lowered, being best adapted for the purpose. The effect by daylight is, however, superior, but the room must then be darkened, and the admission of light confined to the picture. ”

“ That such hard cutting points were known and used is proved by clean cut fine hieroglyphs on diorite, engraved without a trace of scraping; and by the lathe work, of which I found pieces of turned bowls with the tool lines on them, and positive proof that the surface{28} had not been ground out. The lathe tools were fixed as in modern times, to sweep regular arcs from a centre; and the work is fearless and powerful, as in a flat diorite table with foot, turned in one piece; and also surpassingly delicate, as in a bowl of diorite, which around the body is only as thick as stout card. ”

“ A ring of diorite, 41/4 inches in diameter, with a central hole of 11/4 inches, sharp at the edge, but 13/8 inches thick at the border of the perforation, and of nearly triangular section, was found at Wolsonbury, Sussex, and was in the collection of the late Mrs. Dickinson of Hurstpierpoint. A somewhat similar ring of serpentine, 51/2 inches in diameter, is in the Museum at Clermont Ferrand. Another was found near Dijon. A ring of black stone, found above the stalagmite in Kent's Cavern, is shown in Fig. 384. It is slightly rounded at its edges. ”

“ Orthoclase is rarely entirely absent, and when it is fairly common the rock becomes a tonalite; in this way a transition is furnished between diorites and granites. It is rare to find the pure types of “hornblende-diorite,” “augite-diorite,” &c., but in most cases the rocks contain two or more ferromagnesian silicates, and such combinations as “hornblende-biotite-diorite” are commonest in nature.
The felspar of the diorites ranges in composition from oligoclase to labradorite, and is often remarkably zonal, the external layers being more alkaline than the internal. ”

“ The account of Diodorus is as follows:—King Chemmis of Memphis reigned fifty years, and built the largest of the three pyramids, which in height measures more than six plethra, and along the sides more than seven plethra. It is entirely constructed of solid stone, very difficult to work, and therefore of endless durability. Even now, although not less than a thousand, or as some say even more than 3,400, years have passed, the structure is uninjured, and the joints of the stones unloosened. ”

“ Staite, on or about the year 1844-5, invented an incandescent lamp in which the current passed through a slender stick of carbon, enclosed in a vacuum bulb of glass. Faraday discovered that electricity could be generated by the relative motion of a magnet and a coil of wire, and hence the dynamo-electric generator, or 'dynamo,' was ere long invented and improved. ”

“ DIORITE (from the Gr. διορίζειν to distinguish, from διά through, ὅρος, a boundary) , in petrology, the name given by Haüy to a family of rocks of granitic texture, composed of plagioclase felspar and hornblende. As they are richer in the dark coloured ferromagnesian minerals they are usually grey or dark grey, and have a higher specific gravity than granite. They also rarely show visible quartz. But there are diorites of many kinds, as the name applies rather to a family of rocks than to a single species. Some contain biotite, others augite or hypersthene; many have a small amount of quartz. ”

“ Cast your glance upon the interior of that immense diamond which we call a dioptric apparatus. The first object which strikes our attention is the lamp. As the fire which shone on the summit of the edifice was the soul of the pharos, so the lamp is the soul of the modern lighthouse. It was to this lamp Teulère first directed his attention, when he brought the catoptric system to perfection; and it was to this lamp that Arago and Fresnel addressed themselves when engaged, in their time, in improving the work of Teulère, Argand, and Borda. ”

“ Overhead travelling cranes are installed here and in the engine-room for ready and quick handling of all apparatus. Through the centre of the dynamo-room is located the electrical gallery. From here are con- trolled the workings of all the dynamos and other apparatus, also all outside lines. Everything in connection with handling, generation, and furnishing of current is directly under the eye of one man in this gallery, and from which he has a general view of the dynamo-room floor and the workings of the dynamo, a second man being on the floor to see to the bearings and brushes. ”

“ The standard works on the sources of Diodorus are C. G. Heyne, De fontibus et auctoribus historiarum Diodori, printed in Dindorf’s edition, and C. A. Volquardsen, Die Quellen der griechischen und sicilischen Geschichten bei Diodor (1868) ; A. von Mess, Rheinisches Museum (1906) ; see also L. O. Bröcker, Untersuchungen über Diodor (1879) , short, but containing much information; O. Maass, Kleitarch und Diodor (1894– ) ; G. J. Schneider, De Diodori fontibus, i.-iv. (1880) ; C. Wachsmuth, Einleitung in das Studium der alten Geschichte (1895) ; Greece; Ancient History, “Authorities.” ”

“ It is true that in an electric-lighting system there is also a fall or loss of electrical pressure which occurs in overcoming the much greater resistance of the filament in an incandescent lamp. In this case there is also a translation of the energy, but here it accomplishes a USEFUL purpose, as the energy is converted into the form of light through the incandescence of the filament. ”

“ The high lines of houses which lead down to the Embankment were all dark and deserted, or illuminated only by the glimmering lamp of the caretaker. At one point, however, there shone out from three windows upon the second floor a rich flood of light, which broke the sombre monotony of the terrace. Passers-by glanced up curiously, and drew each other’s attention to the ruddy glare, for it marked the chambers of Francis Pericord, the inventor and electrical engineer. ”

“ The fact that when a conductor, in an electric current, is severed, a spark will follow the drawing part of the broken ends, led many scientists to believe, even before the dynamo was in a practical shape, that electricity, sooner or later, would be employed as the great lighting agent.
When the dynamo finally reached a stage in development where its operation could be depended on, and was made reversible, the first active steps were taken to not only produce, but to maintain an arc between two electrodes. ”

“ An arc lamp, radiating light-waves, gets its energy from the wire which is heated, which in turn gets its energy from the electric current; that from a dynamo, the dynamo from a steam-engine; that from a furnace and the chemical actions going on in it. Let us call the chemical actions a, the furnace b, the engine c, the dynamo d, the electric lamp e, the ether waves f. ”

“ Diamond, topaz, and tourmaline are powerful enough, when electrified by friction with a cloth, to attract fragments of paper, the electrification being positive. Amber develops considerable negative electricity when treated in a similar manner.
Diamond is translucent to the Röntgen (X) rays; glass, on the other hand, is opaque to them, and this test distinguishes brilliants from paste imitations. Diamond also, unlike glass, phosphoresces under the influence of radium, a property characterizing also kunzite. ”

“ The ends should project just a little way beyond the point or line of contact, and when the dynamo is running, there should be very little sparking. I am supposing that our plant consists of an alternating-current dynamo with a small exciter. The wires leading from the exciter to the other dynamo remain always connected, as there is no need for meddling with them. ”

“ Our domestic lighting is now done almost entirely by electricity, or the brilliant little phosphorescent lamps, gas having long been banished from dwelling-houses; and our method of lighting the streets is a grand advance, indeed, upon the flickering yellow gas lamps of old. The great glass globes, which we see suspended from the beautiful Gothic metal framework at the intersections of streets, contain a smaller hollow globe, about eighteen inches in diameter, of hard lime, or some other refractory material, which is kept at white heat by a powerful oxyhydrogen flame inside. ”

“ It has been stated that modern theory recognizes two classes of electricity, the Static and the Dynamic. The difference is, however, solely noticeable in operation. Of the dynamic class there can be no more common and striking example than the now almost universal electric light. Yet, with a sufficient expenditure of chemicals and electrodes, and a sufficient number of cells, electric lighting, either arc or incandescent, can be as effectively accomplished as with the current evolved by a powerful dynamo. ”

“ The excess of current, as lights are turned off, being taken care of by introducing the resistance of the regulators up to the proper point, and then operating upon the fields of the dynamos, until the current necessary for the lamps in circuit falls to a point where it is expedient to cut out a pair of dynamos. ”

“ If a confirmation of the fact were needed after evidence of so decisive a character, it would be found in the correspondence between the remains found on the mound and the description left us of the “greater palace” by Diodorus. Diodorus relates that the walls of this edifice were adorned with colored representations of hunting scenes; and modern explorers find that the whole soil of the mound, and especially the part on which the fragment of ruin stands, is full of broken pieces of enamelled brick, varied in hue, and evidently containing portions of human and animal forms. ”

“ It would take thousands of hearts to light one electric light, hundreds of thousands to run one trolley car. Yet just that slight little current from the heart is enough to sway a gossamer strand of quartz fibre in what I may call my 'heart station' here. This current, as I have told you, passes from each of you over a wire and vibrates a fine quartz fibre in unison with it, one of the most delicate bits of mechanism ever made, recording the result on a photographic film by means of a beam of light reflected from a delicate mirror. ”

“ Volta of Pavia, took decided issue with Galvani and maintained that the pretended animal electricity was nothing but electricity developed by the contact of two different metals. Subsequent investigations and discoveries have established the fact that both theories have truth for their basis, and that electricity is developed both by muscular and nervous energy as well as by chemical action. In 1799 Volta invented his celebrated pile, consisting of alternate disks of copper and zinc separated by a cloth moistened with a dilute acid ”

“ DIODORUS, son of Diopeithes of Sardis, also called Diodorus the Younger, in distinction to Diodorus Zonas, is mentioned as a friend of his own by Strabo, and was a historian and melic poet besides being an epigrammatist. Seventeen of the epigrams in the Anthology under the name of Diodorus are usually ascribed to him, and include a few fine epitaphs. ”

“ They are put on to the outside of the windows and leaded into holes in the walls, and are strongly bound together with copper wires, that are soldered by means of fire into the leads of the windows. And in order that boys and other nuisances should not spoil the windows, a fine network of copper-wire is placed 272behind them. These works, if it were not for the too fragile material, would last in the world an infinite time. But for all this it cannot be said that the art is not difficult, artistic, and most beautiful. ”

“ The optical apparatus of a lighthouse is protected by an outer metal framework glazed with thick plate glass. This framework is made of iron, 605or of gun-metal—the latter being preferred on account of the frequent painting which iron needs in order to preserve it from corrosion. The glass is carefully fitted into the framework, so as to avoid exposure to strains from the shocks and vibrations to which a lighthouse is exposed. The keepers are always provided with a store of panes of glass, ready for fitting into their places in case of accidents. ”

“ The diorites are abundant as sheets and dykes amongst the older palæozoic and metamorphic rocks, and are sometimes exceedingly rich in magnetite. Mica, epidote, and chlorite are also present as accessories.
The rock occurs in North Wales, Charnwood Forest, Wicklow, Galway, and Donegal, and the Highlands of Scotland. There can be little doubt that amongst the metamorphic rocks of Galway, Mayo, and Donegal the great beds of (often columnar) diorite were originally augitic lavas, which have since undergone transformation. ”

“ We bend the ends of the platinum wires into hooks and hang upon them the wires bringing the dynamo direct current. There is no evidence of chemical action. Pure water is an exceedingly poor conductor of electricity. Let us now put about fifty-five ohms of resistance into the dynamo circuit, so that it will pass about two amperes, and put a very small pinch of salt into the water, which makes it so good a conductor that its resistance may be ignored. ”