not recall lost opportunities for solar observations, did find a substitute for meteorological records in the statistics of the prices of grain during the various epochs. It is clear that the price of wheat must have depended upon the supply, and the supply, in turn, largely upon the character of the season. The method, as ingenious as it is, failed in Herschel's hands on account of the paucity of solar statistics; but it has since proved of value, and has taken its place as a recognized method of research.
Researches on Nebulæ and Clusters.
When Herschel first began to observe the nebulæ in 1774, there were very few of these objects known. The nebulæ of Orion and Andromeda had been known in Europe only a little over a hundred years.
In 1784 Messier published a list of sixty-eight such objects which he had found in his searches for comets, and twenty-eight nebulæ had been found by Lacaille in his observations at the Cape of Good Hope. In the
