Maps and survey . s. The connection between Wales and Ireland involved greatdifficulty owing to the rarity with which very long rays can beobserved in the moist climate of the west. The difficulty wasovercome in the end by the invention of the limelight, andobservation at night. The extension northwards to the Shet-lands was possible only because of the fortunate situation of thesmall islands Faira and Foula. Further extension to the Faeroesis impossible. The triangulation of the United Kingdom rests on the twobases of Salisbury Plain and Lough Foyle ; it was not foundpossible to measure a goo
Maps and survey . s. The connection between Wales and Ireland involved greatdifficulty owing to the rarity with which very long rays can beobserved in the moist climate of the west. The difficulty wasovercome in the end by the invention of the limelight, andobservation at night. The extension northwards to the Shet-lands was possible only because of the fortunate situation of thesmall islands Faira and Foula. Further extension to the Faeroesis impossible. The triangulation of the United Kingdom rests on the twobases of Salisbury Plain and Lough Foyle ; it was not foundpossible to measure a good base in Scotland. Indeed it was theopinion of the surveyors that there was not in the whole of Scot-land a site on which a base could be measured with possibilityof connection to the triangulation. Modern improvements inbase apparatus have at last removed from Scotland this reproach. The breaking down of the principal triangulation into thesmaller secondary and tertiary triangles eventually covered the Plate XXI. I. Measurement of the Lough Foyle Base.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectsurveying, bookyear19
