The first great storm in modern times was the Leonids of November 1833. One estimate is over one hundred thousand meteors an hour,[3] but another, done as the storm abated, estimated in excess of two hundred thousand meteors an hour[4] over the entire region of North America east of the Rocky Mountains. American Denison Olmsted (1791−1859) explained the event most accurately. After spending the last weeks of 1833 collecting information he presented his findings in January 1834 to the American Journal of Science and Arts, published in January–April 1834,[5] and January 1836.[6] He noted the shower was of short duration and was not seen in Europe, and that the meteors radiated from a point in the constellation of Leo and he speculated the meteors had originated from a cloud of particles in space.[7] Work continued, however, coming to understand the annual nature of showers though the occurrences of storms perplexed researchers.