The surface of the roof is constructed of sawn slabs or tiles of Bermuda stone about one and a half inches thick, by some ten inches to a foot in width with a length slightly greater, known locally as "slates." These are fastened to strips of cedar set transversely to the rafters at proper intervals. An occasional slate is slightly raised, to secure necessary ventilation of enclosed roof space. These roof tiles usually overlap in the fashion of slates or shingles in horizontally parallel rows, but sometimes are laid flat with butting edges. The eaves have but a small projection of six to ten inches, and are supported on stubby square sectioned jack-rafters projecting from above the plate line to the edge of the tiling above. With the plate on the inside of the wall, this arrangement gives a shadow at the eave line that is decorative in its varying intensity, without the use of any mouldings whatever. In all likelihood, however, this type of eave, so different from the greatly projecting eaves of other sunny climates, was adopted to prevent the occasional hurricanes from unroofing the houses.[1] [Footnote 1: In spite of this a hurricane of unusual violence destroyed many roofs in September, 1922, uprooted hundreds of fine cedars and other trees and did thousands of pounds damage generally.] The whole roof surface is heavily coated with semi-liquid cement, which when it hardens serves to make the roof water-tight and softens the edges and angles to the eye. This, when freshly whitewashed, gives to the roofs the resemblance to "icing on a cake" spoken of by Mark Twain. From the engineering point of view, the construction of the roofs may not be mechanically scientific, but whatever the deficiencies, the lack of precision and exactness has given to them that delightful quality of accidental irregularity and unevenness that is the despair of architects for new work, and can hardly be obtained by even obvious affectation. One of the characteristic and frequent adjuncts to Bermuda dwellings are the butteries. These are sometimes joined to the main building, but are often detached elements, and are, I believe, in the form that they appear on the islands, peculiar to Bermuda though Sicily is said to have somewhat similar out buildings. They are small two-story buildings with thick walls and small openings, with high pyramidal roofs, built by a series of inwardly encorbled courses of heavy masonry and present a decidedly monumental appearance. They were built before the days of ice, as a place to keep perishable food cool. Elevated and pierced with small shuttered openings to catch the breezes, they had thick walls and roofs as defense against the sun's rays. The chimneys area prominent feature, particularly in the smaller houses. Open fireplaces with hearths waist high were used for cooking, and are still in use for this purpose in some places, although oil stoves are generally replacing them.