Part 51 (1/2)

It is the most necessary substance for our life; it is the vehicle of all odors and ss to our ear and so to our e of the outside world; it is the cause of the beauty of the blue firreat nurse of the whole vegetable kingdom by clouds, rain, and dew

What is an Aneroid Barometer?

It is a barometer in the construction of which no quicksilver or other liquid is used It consists of a metal box, exhausted of air, the top of which is of thin metal, so elastic that it readily yields to alterations in the pressure of the atmosphere When the pressure increases, the top is pressed inwards; when, on the contrary, it decreases, the elasticity of the lid, aided by a spring, tends to move it in the opposite direction These motions are transmitted by delicate levers to an index whichportable

What is the Ear-trumpet?

A tru Its forer end is of a bell shape; the small end is placed in the ear, and the person talks in the large end It acts by concentrating the voice on the listener's ear

What is a Stethoscope?

An instru the action of the lungs, judging by the sound of their motion whether they are healthy or not

Describe the Audiphone

It is a fan-shaped instrument to help deaf people, and is made of flexible carbonized rubber Fine silk cords attached to the upper edge bend it over, and are fastened by a wedge in a handle The top edge of this fan rests upon the upper teeth, and the sound waves strike its surface; the vibrations are thus conveyed by the teeth and the bones of the face to the acoustic nerve in the ear

Describe the Telephone

It is an instrument by which conversation may be carried on at a distance, and is composed of three parts--a thin disk of soft metal, a small coil or bobbin of silk-covered copper wire, and a s The bobbin is placed on one pole of the netic space round the pole The metal disk is placed face close to the pole and bobbin, so that when it vibrates in front of the pole a series of wave currents will be set up in the coil of wire on the bobbin The whole is encased in wood, and a ainst the disk The coil of wire on the bobbin is of course connected by its two ends into the circuit of a telegraph line

Who invented the Telephone?

It was invented, almost simultaneously, by Alex Grahay in the Boston University, and Elisha Gray, of Chicago

What is a Phonograph?

It is an instru the vibrations of sounds, and consists of a revolving cylinder covered with tin-foil To this cylinder is attached a mouth-piece, fitted with a thin plate or disk, on the outer side of which, next to the cylinder, is a needle or point The cylinder runs on a screw, so that the whole length of it, fro into the mouth-piece the voice causes the disk to vibrate, and the point to traceto these vibrations on the tin-foil By turning the cylinder so that the point again passes into the marks in the tin-foil, the sounds that entered at the mouth-piece can be reproduced at any tiraph invented?

By Thomas A Edison, as born in Ohio in 1847 Mr Edison is the inventor of raphy, which have been adopted into general use, and are to hie incoaphone, microphone, tasimeter, an i, and many other inventions