(Transport / Nautical Terms) Nautical a log for determining a vessel's speed, consisting of a wooden chip tossed overboard at the end of a line that is marked off in lengths of 47 feet 3 inches; the speed is calculated by counting the number of such intervals that pass overboard in a 28-second interval
The power to which a base, such as 10, must be raised to produce a given number. If nx = a, the logarithm of a, with n as the base, is x; symbolically, logn a = x. For example, 103 = 1,000; therefore, log10 1,000 = 3. The kinds most often used are the common logarithm (base 10), the natural logarithm (base e), and the binary logarithm (base 2).