88. SPECTRA OF STARS IN PLEIADES 231 89. SPECTRUM OF ALDEBARAN 235 90. SPECTRUM OF VEGA 235 91. GREAT NEBULA IN ORION 239 92. A FALLING MAN 243 93. A FLASH OF LIGHTNING 245 THE NEW ASTRONOMY. I. SPOTS ON THE SUN. The visitor to Salisbury Plain sees around him a lonely waste, utterly barren except for a few recently planted trees, and otherwise as desolate as it could have been when Hengist and Horsa landed in Britain; for its monotony is still unbroken except by the funeral mounds of ancient chiefs, which dot it to its horizon, and contrast strangely with the crowded life and fertile soil which everywhere surround its borders. In the midst of this loneliness rise the rude, enormous monoliths of Stonehenge,--circles of gray stones, which seem as old as time, and were there, as we now are told, the temple of a people which had already passed away, and whose worship was forgotten, when our Saxon forefathers first saw the place. In the centre of the inner circle is a stone which is believed once to have been the altar; while beyond the outmost ring, quite away to the northeast upon the open plain, still stands a solitary stone, set up there evidently with some special object by the same unknown builders. Seen under ordinary circumstances, it is difficult to divine its connection with the others; but we are told that once in each year, upon the morning of the longest day, the level shadow of this distant, isolated stone is projected at sunrise to the very centre of the ancient sanctuary, and falls just upon the altar. The primitive man who devised this was both astronomer and priest, for he not only adored the risen god whose first beams brought him light and warmth, but he could mark its place, and though utterly ignorant of its nature, had evidently learned enough of its motions to embody his simple astronomical knowledge in a record so exact and so enduring that though his very memory has gone, common men are still interested in it; for, as I learned when viewing the scene, people are accustomed to come from all the surrounding country, and pass in this desolate spot the short night preceding the longest day of the year, to see the shadow touch the altar at the moment of sunrise.