480 Notes and Memoranda. 



many curious chromatic effects. Immense natne3 and flame-coloured clouds of 

 highly luminous orange and red tints made the moon (about 11 days old) look 

 positively blue. Sirius, which was flashing splendidly, varied in hue from blue 

 to deep violet. 



Fecundity; of the Axolotls. — These curious amphibians, of which in 

 1864 the museum in Paris possessed five males and one female, have multiplied 

 in captivity, so that more than 3300 have been produced from their eggs in two 

 years and nine months. Some have been consumed in experiments, others died 

 young, but at least 2500 have survived. Axolotls may be seen in the tanks of 

 the Zoological Gardens. 



Paballax of the Sun. — Notwithstanding the efforts hitherto made by 

 astronomers, the exact parallax, and consequently the exact distance of the sun 

 from the earth is not fully settled, and great interest is felt in the opportunities 

 that may be afforded by the transit of Venus in 1874 and 1882. Meanwhile Mr. 

 Simon Newcombe (U.S.) has been at work discussing minutely the observations 

 of Mars in 1862. His results, communicated by M. Delaunay to the French 

 Academy, make the solar parallax 8".85, with a probable error of + 0".013. 

 This corresponds with a distance of the sun from the earth of a little more than 

 23,307 terrestrial radii, rather more than 148 millions of kilometres. Taking the 

 earth as unity, the mass of the sun will be 326,800 + 1360, and that of the 



moon 81 44 4- 33 • Taking the sun's mass as unity, the mass of the earth and 



moon together will be" 322 80Q . 



Eruption op Vesuvius.— M. Pisani, writing from Eesina, 13th November, 

 1867, says : " At half-past twelve to-night, Vesuvius has opened a new crater, to 

 the right of the two cones of last year. At the half (a la moitie) of the great 

 cone on the side of Bosco Reale, another crater has opened, pouring forth a 

 current of lava. In the same direction, and precisely in the plane of the lava of 

 last year, two other little craters, which cast up many streams, have been formed. 

 The principal cone is full of crevasses, through the strong shocks it has 

 received. 



Egyptian Land Surveying. — The British Museum has obtained possession 

 of a papyrus containing, in hieratic characters, a fragment of a treatise on geo- 

 metry applied to land surveying, with illustrative figures. It shows how to 

 measure squai'es, parallelograms, and various triangles. It is supposed to belong 

 to the date of the twelfth dynasty, contemporary with Solomon, and it is copied 

 from a more ancient treatise. 



