If such things as criticism, experience, and comparative observation did not exist, the tone of exultation in which the above article indulges might be properly shared in by the astronomical student; but let the following extracts be carefully read, and it will be seen that such a tone was premature and unwarranted. “Paris, Sept. 15, 1848. The only sittings of the Academy of late in which there was anything worth recording, and even this was not of a practical character, were those of the 29th ult. and the 11th inst. On the former day M. Babinet made a communication respecting the planet Neptune, which has been generally called M. Le Verrier’s planet, the discovery of it having, as it was said, been made by him from theoretical deductions, which astonished and delighted the scientific public. What M. Le Verrier had inferred from the action on other planets of some body which ought to exist was verified, at least so it was thought at the time, by actual vision. Neptune was actually seen by other astronomers, and the honour of the theorist obtained additional luster. But it appears from a communication of M. Babinet that _this is not the planet_ of M. Le Verrier. He had placed his planet at a distance from the Sun equal to thirty-six times the limit of the terrestrial orbit; Neptune revolves at a distance equal to thirty times of these limits, which makes a difference of nearly _two hundred millions of leagues_! M. Le Verrier had assigned to his planet a body equal to thirty-eight times that of the earth; Neptune has only _one third_ of this volume! M. Le Verrier had stated the revolutions of his planet round the Sun to take place in two hundred and seventeen years; Neptune performs its revolutions in one hundred and sixty-six years! Thus then Neptune is not M. Le Verrier’s planet; and all his theory as regards that planet falls to the ground! M. Le Verrier may find another planet, but it will not answer the calculations which he had made for Neptune. In the sitting of the 14th, M. Le Verrier noticed the communication of M. Babinet, and to a great extent admitted his own error! He complained indeed that much of what he said was taken in too absolute a sense; but he evinces much more candour than might have been expected from a disappointed explorer. M. Le Verrier may console himself with the reflection that if he has not been so successful as he thought he had been, others might have been equally unsuccessful, and as he has still before him an immense field for the exercise of observation and calculation, we may hope that he will soon make some discovery which will remove the vexation of his present disappointment.”[34] [34] “Times” Newspaper, Monday, Sept. 18, 1848.