Part 52 (1/2)

What is the Druht?

It is one of the en and one of hydrogen under pressure are brought together and mixed within a few inches of the end of a blowpipe, theintense heat If this flame be made to play upon a ball of carbonate of liives off a powerful incandescence

_Incandescence_, the glohiteness of a body caused by intense heat

What is a Blowpipe?

A tube, usually bent near the end, terh the fla thereby a s intense heat It is used in soldering silver, brass, etc A nited constitutes the hydrogen blowpipe, invented by Dr Hare of Philadelphia

What is Magnesiunesium is rolled out into a fine ribbon and heated to red heat it burns with a dazzling light

Which is the ht?

The so-called Electric light This light, whether produced by a series of galvanic cells or by dynamic power, is the most brilliant and useful

What is a Rainbow?

The rainbow is that beautiful semi-circular band or arc of different colors in the clouds during the occurrence of rain in sunshi+ne When the clouds opposite the sun are very dark and rain is falling from them, the rays of the sun are divided by the raindrops as they would be by a prism There are often two rainbows at the saain reflected to another layer of clouds

What is a Prislass, on which if a ray of light be cast it will be distinctly divided into the seven colors we see in a rainbow By this fact we see that white light is composed of different rays which have different reflective susceptibilities

What is a Spectrum?

It is this beautiful band of seven colors obtained by the refraction of a ray of light through the prism

Whence come the colors in the objects we see in nature?

They all coht; every object has a power to absorb certain rays and to reflect others A red cloth, for example, absorbs all the other colored rays except red, and this it gives off, thus appearing red

Why are the leaves of plants green?

Because a peculiar chemical substance called chlorophyl, forht, reflecting only blue and yellohich reen tints

What is Photography?

The wordon certain substances the lights and shades of any object by means of a lens inserted in a cauerreotype frouerre A plate of copper thinly coated with silver is exposed to the vapor of iodine, then placed in a cae of the object to be presented through a lens is cast upon it Alass There are now different variations of raphy consists in taking the ilass coated with a silvered collodion (gun-cotton dissolved in alcohol and ether) file is taken on silvered paper, which we call the positive ie There are also other chemicals used instead of silver