Oak had been the prevailing material up to this time, but now mahogany took its place. An interesting account of the introduction of mahogany for furniture is given by Frederick Litchfield in his "History of Furniture." He says, "Mahogany may be said to have come into general use subsequent to 1720, and its introduction is asserted to have been due to the tenacity of purpose of a Dr. Gibbon, whose wife wanted a candle-box, an article of common domestic use at the time. The doctor, who had laid by in the garden of his house in King Street, Covent Garden, some planks sent to him by his brother, a West Indian captain, asked the joiner to use a part of the wood for this purpose; it was found too tough and hard for the tools of the period, but the doctor was not to be thwarted, and insisted on harder-tempered tools being found, and the task completed. The result was the production of a candle-box which was admired by every one. He then ordered a bureau of the same material, and when it was finished invited his friends to see the new work; amongst others the Duchess of Buckingham begged a small piece of the precious wood, and it soon became the fashion." [Illustration] The Jacobean and cognate styles, consisting fundamentally of "framing" based on rectangular forms and decorated with characteristic carving and turning, may be described as essentially suitable for oak, of which the open character of the grain forbids any extreme minuteness of detail. The particular qualities of the work of Chippendale and his successors demanded, on the other hand, the use of a very different material. Chippendale's delicate carving and his free use of curves, even in constructive members of his design, could have only been satisfactorily wrought out in a wood of fine, hard and close grain, and one which also possessed great lateral tenacity, such as mahogany. It is scarcely too much to say that, but for the introduction of this beautiful wood the specialty in the work of the cabinet-makers of the eighteenth century would have been impossible. Together with the refinement of design came a perfection of construction and workmanship which has rendered the furniture of this period practically indestructible. It is said that Chippendale never carved a fret without gluing together three thicknesses of wood with opposing grain, and his work is so joined with tenons and pegs that it stands as well today as when first put together. Sheraton devoted whole pages of his book to constructive directions for the most simple table. This excellence of construction, and the eminently practical and usable character of the best of the eighteenth century work have been potent factors in helping to preserve the many examples of it which we fortunately possess today. [Illustration: PLATE XXXVIII CHIPPENDALE CHAIRS]