Houses. Houses in Trees. Among the earliest types of human habitation were tree-huts of branches and leaves; which were dry and out of the reach of prowling animals. As he became better matched with his animal foes primitive man became a dweller in caves and underground shelters. Tree-houses are in use to-day on the N Guinea coast. Modern "Skyscraper." Until the latter half of the 19th century; few city buildings exceeded five or six storeys in height. The adoption of steel construction; particularly in the USA; has made it possible to erect the great tower-like buildings which are a feature of American cities. Our picture shows a large hotel in New York. Illustration for one of a set of cigarette cards on the subject of Past & Present issued by Wills in 1929.