Before revision: Re-measurement of the Hounslow baseline General Roy's baseline: map as about 1935 For the 1784 measurement of the original base-line across Hounslow Heath, Roy had ordered three deal rods cut from a new mast in the Admiralty dock yards.
After revision: Re-measurement of the Hounslow baseline General Roy's baseline: map as about 1935 For the 1784 measurement of the original baseline across Hounslow Heath, Roy had ordered three deal rods cut from a new mast in the Admiralty dock yards.