Going up and down stairs is a duty every man, woman and child finds it necessary to perform daily and in many cases hourly, and some means for doing this is necessary in every modern household. Even in the old-time one-story house, steps from the outside to the inside were usually necessary, and when the two or more storied houses came into use the stairway became an indispensable feature. In modern times the art of building has had such an upward trend that edifices looming far into the air, hotels, stores, apartment houses, office buildings, etc., have come into use, one notable specimen, the Woolworth building in New York, towering upwards to fifty-four stories in height. This upward tendency has rendered the elevator, or lifting apparatus, an indispensable necessity, alike for passengers and freight, and it has been installed abundantly in all our large cities. [Illustration: IN ORDER TO ASCEND MORE EASILY, MAN DEVISED THE STAIRWAY, FROM WHICH, IN TURN, WAS DEVELOPED THE ESCALATOR, IN ORDER TO FURTHER ELIMINATE PHYSICAL EFFORT] [Illustration: PRIMITIVE MAN PULLED HIMSELF UP A LADDER WHEN HE WANTED TO GO FROM ONE LEVEL TO ANOTHER] The elevator is not exactly a new idea. Its pioneer form may be traced back to the Middle Ages, when heavy weights were lifted by aid of an apparatus worked by hand power. But it was not until well on into the nineteenth century that the steam-power elevator came into service. The first example is said to have been produced by Elisha Graves Otis, who applied steam power to an elevating machine in a little shop at Yonkers, on the banks of the Hudson, New York. A few years later, at the International Exhibition of 1853 in New York, he displayed the first elevator with a safety device to prevent the car from falling in case of a broken cable. The elevator was then a novelty. It has long since grown into a necessity. It is to be seen in all hotels and high buildings, and the art of getting up stairs has in very many cases changed into that of being lifted up by a moving car in an enclosed shaft or cage. The steam elevator, at first used, has now in great measure been replaced by the electric elevator, the first moved by an electric motor being the Otis elevator installed in the Demarest Building, New York, in 1889. This is still in active use.