Digital hourly mean values of the Geomagnetic field elements from Lerwick, Eskdalemuir, Abinger and Hartland Observatories. Eskdalemuir data are available from 1911, Lerwick from 1926, Hartland from 1957 and all three are available up to yesterday's date. Values from Abinger (1926-1956) are available on request. Most data are definitive, but recent data (within the last 203 years) are provisional and may be corrected in the future. Values of declination (D), horizontal intensity (H) and vertical intensity (Z) are available. The units of declination are degrees. Declination is negative when west of true north. The units of horizontal intensity and vertical intensity are nT (nanotesla). Vertical intensity is positive in the downwards direction. The data from these observatories will not only aid scientific research into rates of change of the magnetic field and increase the accuracy of the BGS Global Geomagnetic Model, but will also provide data to exploration geophysicists engaged in current and future oil exploration.