Jean Cras was the inventor of the Cras rule and a major general in the French navy. He also led a life as a composer, with around a hundred opuses ranging from simple melody to grand opera.
His abundant work is in the vein of a French school of composition which, at the beginning of the last century, was able to grasp orchestration with a visionary pictorial force. The Logbook, which he composed at the end of 1927, aboard the battleship La Provence, of which he was in command, has nothing to envy of certain commanders.