In Part I. the influence of high winds on the barometer is examined for all directions of wind taken together; but in Part II. the different directions of wind are treated separately. The question of the effect of wind on the readings of the barometer was first examined by Sir Henry James in a paper read to the Royal Society of Edinburgh on 15th March 1852. The observations were made during the succession of gales from the south-west which occurred in January and February of that year at Granton, near Edinburgh, with an aneroid barometer, laid horizontally in succession on the table of a room in a cottage, on the seat of an open summer-house, and on the surface of the ground close to the summer-house, all at the same level.