For the purpose of this chapter and Chapter 1 (§ 2.2-100 et seq.) and §§ 2.2-2813 and 2.2-2814 of Title 2.2 only, the distance of the City of Richmond from any place in any county or city other than the courthouse thereof, shall be ascertained by adding to or deducting from the number of miles between the City of Richmond and such courthouse, as declared by law, so many miles as such place may be farther from or nearer to the City of Richmond than such courthouse may be.