|
|
Most Viewed- Never-yielding Cement- The Deforming Mirrors - Aigrettes - A More Powerful Fulminating Powder - A Liquid That Shines In The Dark - Balloon Wheels They Are Made To Turn Horizontally: They Must Be - A Lamp That Will Burn Twelve Months Without Replenishing - To Make Artificial Coruscations - Another Way - Artificial Illuminations - The Magnifying Reflector - The Hour Of The Day Or Night Told By A Suspended Shilling - Another Invisible Green Ink - Another - To Spin Sealing-wax Into Threads By Electricity - Easy And Curious Methods Of Foretelling Rainy Or Fine Weather - A Powder Which Catches Fire When Exposed To The Air Least Viewed- Stars With Points- Winter Changed To Spring - To Take Impressions Of Coins Medals &c - To Tell A Person Any Number He May Privately Fix On - The Boundless Prospect - Vegetable Air-bubbles - The Electric Aurora Borealis - To Tell The Number Of Points On Three Cards Placed Under Three - To Tell The Amount Of The Numbers Of Any Two Cards Drawn From A - To Tell The Amount Of The Numbers Of Any Three Cards That A Person - The Divining Card - The Card In The Opera Glass - To Make Pictures Of Birds With Their Natural Feathers - To Diversify The Colours Of Flowers - Caduceous Rockets They Are Such As In Rising Form Two Spiral - Swans And Ducks In Water - The Mysterious Writing |
Imitative Fire-worksTake a paper that is blacked on both sides, or instead of black, the paper may be coloured on each side with a deep blue, which will be still better for such as are to be seen through transparent papers. It must be of a proper size for the figure you intend to exhibit. In this paper cut out with a penknife several spaces, and with a piercer make a number of holes, rather long than round, and at no regular distance from each other. To represent revolving pyramids and globes, the paper must be cut through with a penknife, and the space cut out between each spiral should be three or four times as wide as the spirals themselves. You must observe to cut them so that the pyramid or globe may appear to turn on its axis. The columns that are represented in pieces of architecture, or in jets of fire, must be cut in the same manner, if they are to be represented as turning on their axis. In like manner may be exhibited a great variety of ornaments, ciphers, and medallions, which, when properly coloured, cannot fail of producing the most pleasing effect. There should not be a very great diversity of colours, as they would not produce the most agreeable appearance. When these pieces are drawn on a large scale, the architecture or ornaments may be shaded; and, to represent different shades, pieces of coloured paper must be pasted over each other, which will produce an effect that would not be expected from transparent paintings. Five or six pieces of paper pasted over each other will be sufficient to represent the strongest shades. To give these pieces the different motions they require, you must first consider the nature of each piece; if, for example, you have cut out the figure of the sun, or of a star, you must construct a wire wheel of the same diameter with these pieces; over this wheel you paste a very thin paper, on which is drawn, with black ink, the spiral figure. The wheel thus prepared, is to be placed behind the sun or star, in such a manner that its axis may be exactly opposite the centre of either of these figures. This wheel may be turned by any method you think proper. Now, the wheel being placed directly behind the sun, for example, and very near to it, is to be turned regularly round, and strongly illuminated by candles placed behind it. The lines that form the spiral will then appear, through the spaces cut out from the sun, to proceed from its centre to its circumference, and will resemble sparks of fire that incessantly succeed each other. The same effect will be produced by the star or by any other figure where the fire is not to appear as proceeding from the circumference of the centre. These two pieces, as well as those that follow, may be of any size, provided you observe the proportion between the parts of the figure and the spiral, which must be wider in larger figures than in small. If the sun, for example, have from six to twelve inches diameter, the width of the strokes that form the spiral need not be more than one-twentieth part of an inch, and the spaces between them, that form transparent parts, about two-tenths of an inch. If the sun be two feet diameter, the strokes should be one-eighth of an inch, and the space between, one quarter of an inch; and if the figure be six feet diameter, the strokes should be one quarter of an inch and the spaces five-twelfths of an inch. These pieces have a pleasing effect, when represented of a small size, but the deception is more striking when they are of large dimensions. It will be proper to place those pieces, when of a small size, in a box quite closed on every side, that none of the light may be diffused in the chamber: for which purpose it will be convenient to have a tin door behind the box, to which the candlesticks may be soldered, and the candles more easily lighted. The several figures cut out should be placed in frames, that they may be put, alternately, in a groove in the forepart of the box; or there may be two grooves, that the second piece may be put in before the first is taken out. The wheel must be carefully concealed from the eye of the spectator. Where there is an opportunity of representing these artificial fires by a hole in the partition, they will doubtless have a much more striking effect, as the spectator cannot then conjecture by what means they are produced. It is easy to conceive that by extending this method, wheels may be constructed with three or four spirals, to which may be given different directions. It is manifest also that, on the same principle, a great variety of transparent figures may be contrived, and which may be all placed before the spiral lines. Next: To Represent Cascades Of Fire Previous: To Produce The Appearance Of A Flower From Its Ashes
Viewed 131 |
||||||||||||||||||||
