The Letter Series and the Golden Years of IH. The F-series tractors lasted until 1939. In late 1939, the famous Letter series of Farmall tractors was introduced. The model name letters were A, B, BN, C (which replaced the B and BN in 1948), H, M, and MD(M diesel).
Japan has had a long history of earthquakes and seismic activity. It is an area of high seismicity because it is located near major tectonic plate boundaries and is situated on the Pacific Ring of Fire.n July 16, 2007, an earthquake measuring 6.6 M, the 2007 ChÅ«etsu offshore earthquake hit about 29 kilometres (18 mi) west of Niigata in the northwest Niigata region of Japan. ) was a powerful magnitude 6.6 earthquake The earthquake shook Niigata and neighbouring prefectures.
It was only in 1885 that a seismograph in Europe detected an earthquake in Japan, and we have global coverage, even for very large events, only since 1900 or so. Below is a graph, based on USGS data, for the annual number of M=7.5 and M=8 earthquakes from 1900 to 2001. The high levels between 1900 and 1918 were real. The instruments might have overrated some events, but also it is still possible that some events were missed in those years.