Leaving England, with its highly-developed and well-understood systems of construction as they existed in the seventeenth century, let us turn to the colonial work of the early settlers of America, keeping in mind the difficulties which surrounded them, and which not only influenced, but determined by absolute necessities, many of the constructive peculiarities which we note in their domestic buildings. In the English colonies of North America we find, between the first settlement and the opening of the Revolution, three distinct periods or types of domestic building following each other in regular and clearly-defined sequence, from rude and massive structures of stone and timber to carefully-constructed and artistically-designed mansions. The first period of colonial architecture embraces the greater part of the seventeenth century. Numerous edifices of this period may still be seen in Providence and Newport, Rhode Island, as well as in the western portions of the State. In Newport County I may instance the Governor Henry Bull house, built in 1639, the Sueton Grant house, built about 1650, the Governor Coddington house, erected in 1647, and the "Captain Kid" house, so called, on Conanicut Island. These houses show all the peculiarities of the constructive science of their day, which aimed simply to attain solidity and protection from the elements. The chimneys and end-walls were generally built of stone, laid up as random rubble, with mortar composed of shell lime, sand, and gravel, and flakes of broken slate pounded fine. The sides of these buildings, and the ends above the line of roof-plate, were of frame construction, made of heavy oak timber, rudely squared, put together with treenails and boarded with oak, usually at an angle of forty-five degrees, thus making of every board a separate brace. This boarding was sometimes covered with coarse stucco, as on the Bull house, or with split shingles, as on the Governor Coddington house, put on with wrought nails.