76 NOTES ON THE 



bodies may not yet be accurately determined, as it 

 would appear that Encke's comet has recently led to 

 a determination of a smaller mass for the planet 

 Mercury. 



129. Has the ocean of the planet Venus evapo- 

 rated consequent upon its proximity to the sun ? and 

 because of this, is the apparent disc of that planet 

 enlarged ? 



130. If the density of the planet Venus could be 

 determined apart from the atmosphere which sur- 

 rounds it, would it be found that the density of the 

 solid mass of Venus is greater than that of the 

 Earth ? 



131. If the densities of the planets could be respec- 

 tively determined apart from the water and atmo- 

 sphere which surround them, would it be found that 

 the density of the solid mass of a planet is always 

 the greater according to the proximity of that planet 

 to the sun ? 



132. In place of a nebula, according to the nebular 

 hypothesis, giving birth to a star, is it so, that every 

 star gives birth to a nebula or cluster of stars ? 



133. Are the unresolved nebulae or clusters of 

 stars, Figs. 18, 19, 20, the products of the visible 

 stars with which each is associated? 



