STARS OF THE PLOUGH, AS THE WINNOWING FAN.[ToList]
If Prof. Schiaparelli is correct in his supposition, then the word translated "north" in our versions is literally the "two winnowing fans," names which from the form suggested by the stars we may suppose that the Jews gave to the two Bears in the sky, just as the Chinese called them the "Ladles," and the Americans call them the "Big Dipper" and the "Little Dipper." The sense is still that of the north, but we may recognize in the word employed another Jewish name of the constellation, alternative with ‘Ash or ‘Ayish, or perhaps used in order to include in the region the Lesser as well as the Greater Bear. We should not be surprised at finding an alternative name for this great northern constellation, for we ourselves call it by several different appellations, using them indiscriminately, perhaps even in the course of a single paragraph.
What to Job did the question mean which the Lord addressed to him: "Canst thou guide the Bear and his sons?" To Job it meant, "Canst thou guide this great constellation of stars in the north, in their unceasing round, as a charioteer guides his horses in a wide circle, each keeping to his proper ring, none entangling himself with another, nor falling out of his place?"
What would the same question mean to us, if addressed to us to-day? In the first place we might put it shortly as "Canst thou turn the earth on its axis regularly and continuously, so as to produce this motion of the stars round the pole, and to make day and night?" But modern astronomy can ask the question in a deeper and a wider sense.
It was an ancient idea that the stars were fixed in a crystal sphere, and that they could not alter their relative positions; and indeed until the last century or two, instruments were not delicate enough to measure the small relative shift that stars make. It is within the last seventy years that we have been able to measure the "annual parallax" of certain stars,—that is, the difference in the position of a star when viewed by the earth from the opposite ends of a diameter of the earth's orbit round the sun. Besides their yearly shift due to "annual parallax," most stars have a "proper" or "peculiar motion" of their own, which is in most cases a very small amount indeed, but can be determined more easily than "annual parallax" because its effect accumulates year after year. If, therefore, we are able to observe a star over a period of fifty, or a hundred or more years, it may seem to have moved quite an appreciable amount when examined by the powerful and delicate instruments that we have now at our disposal. Observations of the exact positions of stars have been made ever since the founding of Greenwich Observatory, so that now we have catalogues giving the "proper motions" of several hundreds of stars. When these are examined it is seen that some groups of stars move in fellowship together through space, having the same direction, and moving at the same rate, and of these companies the most striking are the stars of the Plough, that is ‘Ayish and his sons. Not all the stars move together; out of the seven, the first and the last have a different direction, but the other five show a striking similarity in their paths. And not only are their directions of movement, and the amounts of it, the same for the five stars, but spectroscopic observations of their motion in the line of sight show that they are all approaching us with a speed of about eighteen miles a second, that is to say with much the same speed as the earth moves in her orbit round the sun. Another indication of their "family likeness" is that all their spectra are similar. A German astronomer, Dr. Höffler, has found for this system a distance from us so great that it would take light 192 years to travel from them to us. Yet so vast is this company of five stars that it would take light seventy years, travelling at the rate of 186,000 miles in every second of time to go from the leading star, Merak—Beta of the Bear—to Mizar—Zeta of the Bear—the final brilliant of the five. So bright and great are these suns that they shine to us as gems of the second magnitude, and yet if our sun were placed amongst them at their distance from us he would be invisible to the keenest sight.
Dr. Höffler's estimate may be an exaggerated one, but it still remains true that whilst the cluster of the Pleiades forms a great and wonderful family group, it is dwarfed into insignificance by the vast distances between these five stars of the Great Bear. Yet these also form one family, though they are united by no nebulous bands, and are at distances so great from each other that the bonds of gravitation must cease to show their influence; yet all are alike, all are marshalled together in their march under some mysterious law. We cannot answer the question, "By what means are ‘Ayish and his sons guided?" much more are we speechless when we are asked, "Canst thou guide them?"
