TRACT No. 2. ON ASTRONOMICAL AND GEOLOGICAL ΡΗΕΝΟΜΕΝΑ. 41. MIGHT it not be said that our Education has become so much an Education of Words, that we cannot get at the truth for verbiage? and what with verbiage, and involved processes of reasoning-not only may something be said for anything, but a great deal may be said for everything. As the corrective to this, must man revert to the ancient Socratic method of interrogatories, which leaves to those to whom the questions are put, to work out their own convictions as to what is truth? OF NEBULE. 42. Do self-luminous stars within determinate distances repel each other, but beyond those distances have they a tendency to gravitate towards each other? And is it because of these antagonist forces, that stars are found associated together in clusters, and not concentrated into one self-luminous or incandescent mass? 43. Does the form of those nebula (Fig. 8) point out the direction in space to which they trend? Does each visible star in its motion of translation in space draw after it the nebula with which each is associated? 44. Do those visible stars, which are so often found associated with unresolved nebulæ, determine in any way the forms of those nebulæ ? 45. Has the form of the reticulated nebula (Fig. 9) been determined by the position of the visible stars with which it is associated? 46. Is it so, that the unresolved nebulæ (Fig. 8) are made to converge towards the visible star with which each is associated, but to diverge in the opposite direction, because no star is there situated by which the nebulæ might be made to converge in that direction? 47. Is it so, that the nebula (Fig. 10) because of the attraction of the binary stars with which they are associated, converge in opposite directions towards those stars? 48. If so, how is it that the unresolved nebula (Fig. 11) which is only associated with one visible star, situated at one of its extremities, does not diverge in the opposite direction as the nebula (Fig. 8), but is made to converge at both extremities as the nebula (Fig. 10) which are associated with binary stars? Is it from this cause the nebula (Fig. 11) is also associated with a binary system, of which the star at one of the extremities is self-luminous, but the star at the other extremity is dark or benighted? 49. In what circumstances might we infer that dark stars do exist in the sidereal heavens ? 50. Were a visible star to disappear from one of the extremities of one of the nebulæ (Fig. 8), and were the nebula from which the star had disappeared to maintain the same convergence as before, towards the point at which the star had ceased to be visible -would the inference be legitimate, that the star which had disappeared was not annihilated, but had ceased to be self-luminous ? 51. If at the starless extremity of the nebulæ (Fig. 11) a star became visible, might we not infer that this new star was not a new creation; but, before its appearance, had existed at the extreme point of this nebula, a non-luminous body? 52. Were one of the stars, of a binary system, that revolved about a common centre of gravity, to disappear from our firmament, and were the star which remained visible to preserve the same orbit that it maintained while revolving with its partner before the disappearance took place-would not this go to prove, that the star, which had disappeared, was not annihilated but only darkened? 53. The great astronomer, Bessel, has demonstrated that both Sirius and Procyon are binary systems, that each has a revolution about a common centre of gravity, but that the partner of each is a dark or benighted star. 54. Since the fact has been revealed to us that dark stars do exist in the firmament, when therefore |