I am a power of double hundred thousand horses, and I can travel at the rate of forty

I am a power of double hundred thousand horses, and I can travel at the rate of forty miles an hour. I can carry as high as four hundred and forty passengers, and can convey that amount of steam pressure to a hundred and forty times that amount of power. I can travel exempted from all deductions of steam, and can be employed in day or night, in summer or in winter, and can be employed in a uniform rate of progress, up to a hundred and forty miles a day. I can be employed to convey a message, and can do it at a hundred and forty times the speed of a sailing ship. I can be employed to convey a ship, and can do it double the amount of power, and twice the amount of speed, as a ship can be carried by sails