Herschel's application of his principle led him to the conclusion that there was a tendency among the stars to widen out from the constellation Hercules, and to crowd together towards the opposite constellation of Argo Navis in the southern hemisphere, and the point which he fixed upon as the apex of the sun's path was near the star Lambda Herculis. Subsequent discussions of the problem have confirmed, to a great extent, his rough estimate, which was derived from a comparatively small number of stars. So far as general direction was concerned, he was entirely right; the conclusion which he reached as to the exact point towards which the motion is directed has, however, been slightly modified by the discussion of a much larger number of stars, and it is now considered that the apex of the solar journey 'is in the general direction of the constellation Lyra, and perhaps near the star Vega, the brightest of that constellation' (Newcomb, 'The Stars,' p. 91). There are but few stars more beautiful and interesting than Vega; to its own intrinsic interest must now be added that arising from the fact that each successive night we look upon it we have swept more than 1,000,000 miles nearer to its brilliant globe, and that with every year we have lessened, by some 400,000,000 miles, the distance that divides us from it. There can surely be no thought more amazing than this! It seems to gather up and bring to a focus all the other impressions of the vastness of celestial distances and periods. So swift and ceaseless a motion, and yet the gulfs that sever us from our neighbours in space are so huge that a millennium of such inconceivable travelling makes no perceptible change upon the face of the heavens! There rise other thoughts to the mind. Towards what goal may our world and its companions be voyaging under the sway of the mighty ruler of the system, and at the irresistible summons of those far-off orbs which distance reduces to the mere twinkling points of light that in man's earliest childlike thought were but lamps hung out by the Creator to brighten the midnight sky for his favourite children? What strange chances may be awaiting sun and planet alike in those depths of space towards which we are rushing with such frightful speed? Such questions remain unanswered and unanswerable. We are as ignorant of the end of our journey, and of the haps that may attend it, as we are helpless in the grasp of the forces that compel and control it. APPENDIX I The following is a list of the Lunar Formations numbered as on the Key-map, Plate XIX.: