Four panels comparing the variometer declination measurements in the Netherlands to the magnetograms from Greenwich and Kew. From top to bottom the comparisons are: Greenwich (blue line) to Utrecht (red dots), Greenwich (blue line) to Den Helder (black dots), Kew (green line) to Utrecht (red dots) and Kew (green line) to Den Helder (black dots). All variometer measurements have been shifted to match the corresponding magnetograms.