E F G a Prism, casting its oblong colour'd Image upon a Lens, or double Convex Glass; which collects all those Rays into its Focus.
Parallel rays of light falling upon such an arrangement of prisms would be bent from their course, as shown by the arrows, and this is just what happens with a double convex lens.
Illustration] Now lenses are made of various shapes, and those with two outwardly curved surfaces are known as double convex lenses.
A double convex lens is usually made with both its surfaces equally curved and in the finer optical work great care is taken to ensure that this is the case.
Let us see what will happen if the light is polychromatic, say, for example, sunlight, and let a beam of sunlight be intercepted on a screen after passing through a double convex lens.
Let us now see how an image is formed by a convex lens, and suppose that CD is the section of a double convex lens (fig.
Such a combination gives an achromatic lens, which is usually composed of a double convex of crown glass cemented to a diverging meniscus of flint glass, as shown in section in figure 24.
As their cor'nea is not sufficiently convex, they must use double convex glasses, to enable them to see objects near at hand.
Illustration: The figure A is double convex, or convex on both sides.
If the Lens be double Convex, the difference is less; if a Meniscus, greater.
If the Lens be double Concave, the Focus of converging Beams is negative, where it was affirmative in the Case of diverging Beams on a double Convex, viz.
That which burns by refraction, as a double convex lens, or the sun's rays concentrated by such a lens, sometimes used as a cautery.
So named from the resemblance in shape of a double convex lens to the seed of a lentil.
If a beam of parallel light--such as light from the sun--be passed through a double convex lens L, Fig.
Let L represent a double convex lens, with an object, AB, placed between it and the point F, which is the principal focus of the lens.
From this they are thrown to a focal point, where the image is viewed through a double convex lens.
It consists of a tube, having at the further end a double convex lens, which concentrates the rays at a focal point within, where the image is viewed through a microscopic lens, placed at the other end.
In the construction of reflecting telescopes, concave mirrors, or specula, are combined with a double convex lens.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "double convex" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
