Il transito di Venere. Il 9 dicembre 1874 il pianeta Venere passerà tra la terra e il sole e apparirà come un round macchia nera che viaggiano attraverso il sole del viso. Questo phenome non è ciò che si intende per il transito di Venere e ci si aspetta che dalla sua attenta osservazione dati saranno ottenuti mediante i quali in generale si deve essere in grado di misurare le distanze dei corpi celesti il loro peso e le loro dimensioni. Nella situazione attuale la nostra conoscenza del mondo celeste nel rispetto di cui sopra non è esatta anche se una scala di Fig 1. ly costruito. L'ultimo osservata di transito
Questa immagine potrebbe avere delle imperfezioni perché è storica o di reportage.
THE TRANSIT OF VENUS. On the 9th of December 1874 the planet Venus will pass between the earth and the sun and will appear as a round black spot traveling across the sun's face. This phenome non is what is meant by the transit of Venus and it is expected that by its careful observation data will be obtained by which generally speaking we shall be able to measure the distances of the heavenly bodies their weight and their dimensions. As matters now stand our knowledge of the celestial world in the above respect is not exact although a scale of Fig 1. ly constructed. The last observed transit of Venus which took place in 1769 gave us data on which our ideas of celestial distances are now based. But errors have been dis covered in the observations owing perhaps to the primitive instru ments used. For example the sun's distance then estimated at about 92000000 miles is now believed Naturally the finding of such seri ous errors has caused great anxiety in the scientific world to make the coming observations perfectly accu rate and hence the transit will be watched with the greatest care by some two hundred observers sta tioned in seventy different places where it will be visible : that is in Northern India Australia New Zea land Mauritius Japan etc. but not in the United States. Now by means of the transit of Venus it is expected that we shall be able accurately to measure the distance between the sun and our earth ; and with this gage once es tablished it will be a very easy mat ter to apply it to the spaces between the orbits of all the other bodies of the solar system. The most direct and valuable practical result of the determination of the sun's distance is that which enables us to tell the exact attraction of the sun for the moon and hence to predict the motions of our satel lite. Our lunar tables by the aid of which we can determine longitude will then be rendered instead of approximately absolutely correct. The result will be that the moon will become not only ou
