If the old _Savannah_ could be placed beside the _Lusitania_, the giantess of the Cunard line of ocean steamers, a comparison would demonstrate the triumphs of the century in ocean navigation. If you were to cross the ocean on the _Lusitania_ or her sister-ship the _Mauretania_, you would enter a vast floating mansion seven hundred ninety feet long, eighty-eight feet wide, eighty-one feet high from keel to boat deck, and weighing thirty-two thousand five hundred tons. Her height to the mastheads is two hundred sixteen feet; each of her three anchors weighs ten tons; and her funnels are so large that a trolley car could easily run through them. The _Lusitania_ has accommodation for three thousand passengers, officers, and crew, and is driven by mighty turbine engines of sixty-eight thousand horse power. The steamer was built at a cost of $7,500,000. She has traveled the three thousand miles across the Atlantic in about four and a half days--the quickest trans-Atlantic voyage ever made. She moves through the great waves of the ocean with such steadiness that passengers can scarcely tell whether they are on water or land. A telephone system connects all parts of the ship; there are electric elevators, a special nursery in which children may play; a gymnasium for exercise, shower baths, and an acre and a half of upper deck. There are five thousand electric lights, requiring two hundred miles of wire. Wireless telegraphy flashes messages to the moving ship from distant parts of the world, and bears back greetings from her passengers. A daily illustrated newspaper of thirty-two pages is published on board ship. CHAPTER IV ELECTRICITY: THE TELEGRAPH AND THE TELEPHONE The great miracle of the twentieth century is electricity. If the printing press is the brain of civilization and the steam engine is its heart, electric wires are its nervous system. Steam is a giant; electricity is a witch. There is something uncanny about it. Man writes volumes about electricity; calls it positive and negative and measures it in ohms and volts; gives courses to explain it in his schools and universities; kills criminals, cures the sick, and scatters darkness with it; makes it whirl him through space; compels it to bear his whisper through hundreds of miles, and can make it fly around the entire earth with his written word--and yet no man knows what electricity is. Electricity exists, and has always existed, from the back of a cat to the infinite arch of the sky.