The postscript to the letter read in connection with the previous paragraph "my sonne is composing wherin you will be chiefly concern'd" is clearly a jocose reference to Gostling's exceptionally low voice. Purcell not only wrote double F (F faut) and double E (E lamy) for him, as in the anthem, "Behold I bring you glad tidings," but in another anthem commencing, "They that go down to the sea in ships," he carried the bass solo part down to double D. The history of the composition of the latter anthem is somewhat remarkable:-- "Charles the Second had given orders for building a yacht, which as soon as it was finished he named the _Fubbs_, in honour of the Duchess of Portsmouth, who, we may suppose, was in her person rather full and plump. The sculptors and painters apply this epithet to children, and say, for instance, of the boys of Flammengo, that they are fubby. Soon after the vessel was launched the King made a party to sail in the yacht down the river and round the Kentish coast; and to keep up the mirth and good humour of the company Mr. Gostling was requested to be of the number. They had got as low as the North Foreland, when a violent storm arose, in which the King and the Duke of York were necessitated, in order to preserve the vessel, to hand the sails and work like common seamen. By good providence, however, they escaped to land: but the distress they were in made an impression on the mind of Mr. Gostling which was never effaced. Struck with a just sense of the deliverance, and the horror of the scene which he had but lately viewed, upon his return to London he selected from the Psalms those passages which declare the wonders and terrors of the deep and gave them to Purcell to compose as an anthem, which he did, adapting it so peculiarly to the compass of Mr. Gostling's voice, which was a deep bass, that hardly any person but himself was then, or has since, been able to sing it; but the King did not live to hear it." Charles the Second became extremely partial to the singing of Gostling, and was heard to say, "You may talk as much as you please of your nightingales, but I have a _gosling_ who excels them all." At another time he presented Gostling with a silver egg filled with guineas, saying, "He had heard eggs were good for the voice." Gostling was a devoted admirer of, and a performer on, the _viol da gamba_, an instrument which Purcell detested. We can therefore readily imagine that his musical susceptibilities were frequently severely taxed by the persistent practice of his friend. He accordingly composed a round for three voices to the following words,[25] which he presented to Gostling:--