Read "Northern Lights, Volume 5" by Gilbert Parker online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
The "Error of the Day" may be defined as "The difference between the distance or range which must be put upon the sights in order to hit the target and the actual distance from the gun to the target. " -- Admiralty Note.
A great naval gun never fires twice alike. It varies from day to day, and expert allowance has to be made in sighting every time it is fired. Variations in atmosphere, condition of ammunition, and the wear of the gun are the contributory causes to the ever-varying "Error of the Day."