Tonnage and poundage to be one of the complaints of his Long Parliament. The refusal of and subsequent disputes about tonnage and poundage rights is seen as one of the many events bearing responsibility for the English Civil War. Tonnage and poundage Tonnage and Poundage were certain duties and taxes first levied in Edward II's reign on every tun (cask) of imported wine, which came mostly from Spain and Portugal, and on every pound weight of merchandise exported or imported. Traditionally tonnage and poundage was granted by Parliament to the king for life until the reign of Charles I. Tonnage and poundage were
Gross tonnage the common or base-10 logarithm: Once "V" and "K" are known, gross tonnage is calculated using the formula, whereby GT is a function of V: which by substitution is: Note that the units of gross tonnage, which involve both meters and log-meters, have no physical significance, but were rather chosen for historical convenience. The "inverse", on the other hand, is not as simple. Newton's method may be used for obtaining an approximation to a ship's volume given its gross tonnage. The exact formula is: where ln is the natural logarithm and W is the Lambert W function. Gross tonnage Gross