Before satellite navigation, the backstaff allowed a navigator to find a ship's latitude at sea, either reading the sun's height above the horizon, or cross-referencing star positions with specialised ...

Dr Kinrade’ s chosen object is a backstaff from the collection of Lancaster Maritime Museum. This measures the elevation of the sun above the horizon by the projection of a shadow and was vital for ...

𝗖𝗼𝗹𝗹𝗶𝘀𝗶𝗼𝗻 𝗘𝘀𝘁𝗶𝗺𝗮𝘁𝗲 𝘄𝗿𝗶𝘁𝗶𝗻𝗴 - 𝗢𝗻 𝗗𝗲𝗺𝗮𝗻𝗱 On demand Estimate writers for your private or insurer ...