Kepler has also supplied us with another mode of arriving at the distance and size of the sun and the planets: he has hazarded a conjecture, that the squares of the times of the revolution of the earth and the other planets are in proportion to the cubes of their distances from the sun, their common centre; and, as by observation we can arrive with tolerable certainty at a knowledge of the times of their revolutions, we may from hence proceed to the other matters we are desirous to ascertain. And that which Kepler seemed, as by a divine inspiration, to hazard in the way of conjecture, Newton professes to have demonstratively established. But the demonstration of Newton has not been considered as satisfactory by all men of science since his time. Thus far however we proceed as we may, respecting our propositions on the subject of the solar system. But, beyond this, all science, real or pretended, deserts us. We have no method for measuring angles, which can be applied to the fixed stars; and we know nothing of any revolutions they perform. All here therefore seems gratuitous: we reason from certain alleged analogies; and we can do no more. Huygens endeavoured to ascertain something on the subject, by making the aperture of a telescope so small, that the sun should appear through it no larger than Sirius, which he found to be only in the proportion of 1 to 27,664 times his diameter, as seen by the naked eye. Hence, supposing Sirius to be a globe of the same magnitude as the sun, it must be 27,664 times as distant from us as the sun, in other words, at a distance so considerable as to equal 345 million diameters of the earth(60). Every one must feel on how slender a thread this conclusion is suspended. (60) Encyclopaedia Londinensis, Vol. 11, p. 407. And yet, from this small postulate, the astronomers proceed to deduce the most astounding conclusions. They tell us, that the distance of the nearest fixed star from the earth is at least 7,600,000,000,000 miles, and of another they name, not less than 38 millions of millions of miles. A cannon-ball therefore, proceeding at the rate of about twenty miles in a minute would be 760,000 years in passing from us to the nearest fixed star, and 3,800,000 in passing to the second star of which we speak. Huygens accordingly concluded, that it was not impossible, that there might be stars at such inconceivable distances from us, that their light has not yet reached the earth since its creation(61). (61) Ibid, p. 408.