Watkins[15] showed, by the account books of Stephen Vail, owner of the Speedwell Ironworks near Morristown, New Jersey, that the engine was built by Vail, but apparently to designs by Daniel Dod. The latter built the _Savannah's_ boiler at Elizabeth, New Jersey, and made some parts of the engine, which he furnished, incomplete in some instances, to Vail. These account books, which were in the possession of John Lidgerwood of New York City in 1890, show the steam cylinder to have had an inside diameter of 40-3/8 inches and a 5-foot stroke. Reference in the account books to an error in Dod's draught of a piston proves that Dod designed the engine. Watkins states that the engine was rated at 90 horsepower. He does not give the diameter of the pump cylinder, but, judging by the scaling of Marestier's drawing and by a rather indefinite entry in the Vail account book, it appears to have been between 17 and 18 inches. Quoting Captain Collins at some length, Watkins writes that the mainmast was placed farther aft than was usual in a sailing ship, and that the vessel had a round stern. Collins apparently based his opinion upon an unidentified "contemporaneous lithograph" and upon "all other illustrations of this famous vessel." Collins' conception of the appearance of the _Savannah_ is shown in a drawing by C. B. Hudson that is reproduced as the frontispiece in Watkins' publication. A statement by Stevens Rogers that was published in the _New London Gazette_ in 1836 appears to have been the original source for statements regarding the _Savannah's_ fuel capacity, her sale, and her loss in 1821 while owned and commanded by Capt. Nathaniel Holdridge, "now master of the Liverpool packet ship _United States_." Watkins also gives a picture of Stevens Rogers' tombstone, on which there is a small carving purported to be of the _Savannah_. The tombstone was made in 1868. From a Russian newspaper contemporary with the _Savannah's_ visit to St. Petersburg, Frank Braynard found a statement that the vessel had two boilers, each 27 feet long and 6 feet in diameter.[16] It was also shown she had at least one chain cable. Considerable information on the cabin arrangement and the method of folding the wheels was also obtained from this Russian source. In spite of a very extensive bibliography on the _Savannah_, the basic sources for reliable technical description are Marestier's report on American steamers, the logbook of the ship, Watkins' extracts from the Speedwell Iron Works account book, the customhouse records, and some of the statements made by Stevens Rogers between 1836 and 1856. Plans of the ship, or a builder's half-model, have not been found. Marestier's sketch of the _Savannah_, which is not a scale drawing, and his drawings of the engine and paddle wheels were the only available illustrations upon which reconstruction could be based.