. The art of projecting. A manual of experimentation in physics, chemistry, and natural history, with the porte lumière and magic lantern. Fig, 71^ LIGHT, 97 —Of Fig. 72. Project any object that is three or four inches long,—a lead pencil or an arrow cut out of paper. A singlelens is all that is needed. Then hold in front of theobject a piece of glass three or four inches long,half an inch broad, and the thicker the better. If theglass is held exactly perpendicular to the beam of lightno refraction will be observed \ but turn one end of ittowards the opening, and at once t
. The art of projecting. A manual of experimentation in physics, chemistry, and natural history, with the porte lumière and magic lantern. Fig, 71^ LIGHT, 97 —Of Fig. 72. Project any object that is three or four inches long,—a lead pencil or an arrow cut out of paper. A singlelens is all that is needed. Then hold in front of theobject a piece of glass three or four inches long,half an inch broad, and the thicker the better. If theglass is held exactly perpendicular to the beam of lightno refraction will be observed \ but turn one end of ittowards the opening, and at once the picture upon thescreen will appear as if a piece of the object had beencut out and was held to one side of it. The thickerthe glass is the greater will be the displacement; but apiece that is an eighth of an inch will quite likely makeas much difference as the thickness of the object pro-jected. Two pieces of glass may be put together and held asbefore, or turned in various directions with referenceto each other and the object. 2 — Of Watkr. A hand mirror held at r will reflect the light down-ward into the chemical tank (Fig. 73), which should befilled with water in wh
Size: 2099px × 1190px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, bookpublisherbosto, bookyear1877
