Electricity

Although the science of electricity is of comparatively recent date, electricity itself has existed from the beginning of the world. There can be no doubt that man’s introductio...

The amount of electricity produced by the rubbing of glass or sealing-wax rods is very small, and experimenters soon felt the need of apparatus to produce larger quantities. In...

If the Leyden jars of a Wimshurst machine are connected up and the discharging balls placed at a suitable distance apart, the electricity produced by rotating the plates is disc...

In the previous chapters we have dealt with electricity in charged bodies, or static electricity, and now we must turn to electricity in motion, or current electricity. In Chapt...

If we had two large water tanks, one of which could be emptied only by allowing the bottom to fall completely out, and the other by means of a narrow pipe, it is easy to see whi...

In many parts of the world there is to be found a kind of iron ore, some specimens of which have the peculiar power of attracting iron, and of turning to the north if suspended...

In the previous chapter attention was drawn to the fact that there are many close parallels between electric and magnetic phenomena, and in this chapter it will be shown that ma...

The voltaic cell and the accumulator provide us with currents of electricity of considerable volume, but at low pressure or voltage. For many purposes, however, we require a com...

Most of my readers will have seen the small working models of electric tramcars which can be bought at any electrical supply stores. These usually require a current of about one...

It is apparently a very simple matter to fit up a power station with a number of very large dynamos driven by powerful engines, and to distribute the current produced by these d...

The electric tramcar has become such a necessary feature of our everyday life that it is very difficult to realize how short a time it has been with us. To most of us a horse-dr...

In the first year of the nineteenth century one of the greatest of England’s scientists, Sir Humphry Davy, became lecturer on chemistry to the Royal Institution, where his brill...

The light of the electric incandescent lamp is produced by the heating to incandescence of a thin filament of metal or carbon, and the heat itself is produced by the electric cu...

The most familiar of all electrically worked appliances is probably the electric bell, which in some form or other is in use practically all over the world. Electric bells are o...

Amongst the many little worries of domestic life is the keeping in order of the various clocks. It ought to be a very simple matter to remember to wind up a clock, but curiously...

We come now to one of the most important inventions of the nineteenth century, the electric telegraph. From very early times men have felt the necessity for some means of rapidl...

The story of submarine telegraphy is a wonderful record of dogged perseverance in the face of tremendous obstacles and disastrous failures. It would be of no interest to trace t...

In our younger days most of us have amused ourselves with a toy telephone consisting of a long piece of string having each end passed through the bottom of a little cardboard bo...

In telegraphy messages not only may be received, but also recorded, by the Morse printer or one of its modifications, but in ordinary telephony there is no mechanical method of...

Wireless telegraphy is probably the most remarkable and at the same time the most interesting of all the varied applications of electricity. The exceptional popular interest in...

A fairly good idea of the principles and apparatus of wireless telegraphy should have been gained in reading Chapter XX., but so far little has been said about its practical use...

In our chapter on the accumulator or storage cell we saw that a current of electricity has the power of decomposing certain liquids; that is to say, it is able to split them up...

The metal copper, as obtained from copper ore, contains many impurities of various kinds. For most purposes these impurities greatly affect the value of the copper, and before t...

In the chapter on electricity in the atmosphere we saw that whereas air at ordinary pressure is a bad conductor, its conducting power increases rapidly as the pressure is lowere...

One of the most remarkable things about electricity is the immense number of different purposes for which it may be used. We have already seen it driving trams and trains, light...

The great difference between the atmospheric conditions before and after a thunderstorm must have been noticed by everybody. Before the storm the air feels lifeless. It does not...

The petrol motor, which to-day is busily engaged all over the world in driving thousands upon thousands of self-propelled vehicles or automobiles, belongs to the important class...

About thirty years ago a Swedish scientist, Professor Lemström, travelled extensively in the Polar regions, and he was greatly struck by the development of the Polar vegetation....

One of the great advantages of living in a town is the abundant supply of gas and water. These necessary substances are conveyed to us along underground pipes, and a large town...

One of the most striking features of modern naval warfare is the absolute revolution in methods of communication brought about by wireless telegraphy. To-day every warship has i...

The question which heads this, our final chapter, is one which must occur to every one who takes even the most casual interest in matters scientific, and it would be very satisf...