The Mummy and Miss Nitocris by George Griffith

Events now began to move with an almost bewildering rapidity, at least, so far as they affected the immediate temporal concerns of Nitocris and her father. For days and weeks a furious storm raged round the famous lecture, and the atmosphere of the scientific world was thick with figures and formulae, diagrams and disquisitions; but since none of the learned disputators proved himself capable of detecting the slightest flaw in the lecturer's mathematics, it had very little interest for him, and therefore has none for us. In fact, so little did he seem concerned with the tempest he had raised, that a few days later, to the astonishment and chagrin of his baffled critics, he and Nitocris bade adieu to their more intimate friends and disappeared on a wandering trip of undetermined destination for change of air and scene and a much-needed holiday for the over-worked Professor.

At least, that is the reason which Nitocris gave to Lord Leighton and the Van Huysmans, and the few others to whom she thought it necessary to give any explanation at all.