- Messier 48 or M48, also known as NGC 2548, is an open cluster of stars in the equatorial constellation of Hydra. It sits near Hydra’s westernmost limit with Monoceros, about 18� 34’ to the east and slightly south of Hydra’s brightest star, Alphard. This grouping was discovered by Charles Messier in 1771, but there is no cluster precisely where Messier indicated; he made an error, as he did with M47. The value that he gave for the right ascension matches, however, his declination is off by five degrees. Credit for discovery is sometimes given instead to Caroline Herschel in 1783. Her nephew John Herschel described it as, “a superb cluster which fills the whole field; stars of 9th and 10th to the 13th magnitude � and none below, but the whole ground of the sky on which it stands is singularly dotted over with infinitely minute points”.
- I remarked, moreover, with respect to experiments, that they become always more necessary the more one is advanced in knowledge; for, at the commencement, it is better to make use only of what is spontaneously presented to our senses, and of which we cannot remain ignorant, provided we bestow on it any reflection, however slight, than to concern ourselves about more uncommon and recondite phænomena: the reason of which is, that the more uncommon often only mislead us so long as the causes of the more ordinary are still unknown; and the circumstances upon which they depend are almost always so special and minute as to be highly difficult to detect.