sage, when the first streams of light were seen to shoot out from the nucleus towards the sun. The two streams diverged from one another, like hair parted on the forehead. Six days afterwards the appearance of a fan-like bright sector was presented. This was surrounded by a darkish arc, and next by a brighter semicircle of nebulous light. At the perihelion, the fan still continued—its axis making with the axis of the tail an angle of 25°. The dark division of the latter was very black towards the nucleus. Immediately after the perihelion, the second stage commenced, and a totally new class of phenomena was presented in the shape of luminous envelopes. Three envelopes were discovered, with the nucleus in the centre. These did not quite encircle the nucleus—a sector, of about 90° in the direction of the tail, being cut out of each of them. The comet was now approaching the earth, and, three days before the minimum distance, great distortions were observed in the form of the outer envelope. It appeared like the ragged ends of heavy rain-clouds during a violent shower. Two days before the nearest approach, a new fan was formed, and the streams from the nucleus shewed a tendency to return into the tail—thus restoring to the comet the form it had before the developing process began. According to Father Secchi's theory, these disturbances were caused by the action of the earth. At the nearest approach on the 11th of October, the comet was half the dis-
