Definition of "stonesthrow"

He ordered his outposts, therefore, to be advanced within a stonesthrow of the breach, but exhorted the soldiers to maintain the utmost vigilance.

1829, Washington Irving, A Chronicle of the Conquest of Granada. From the MSS. of Fray Antonio Agapida., volume II, London: John Murray, […], page 74

His (Stephen’s) mind was not exactly what you would call wandering but a bit unsteady and on his expressed desire for some beverage to drink Mr Bloom, in view of the hour it was and there being no pumps of Vartry water available for their ablutions, let alone drinking purposes, hit upon an expedient by suggesting, off the reel, the propriety of the cabman’s shelter, as it was called, hardly a stonesthrow away near Butt Bridge where they might hit upon some drinkables in the shape of a milk and soda or a mineral.

1922 February, James Joyce, “[Episode 16: Eumaeus]”, in Ulysses, Paris: Shakespeare and Company, […], part III [Nostos], page 569

It’s only a stonesthrow to Chicago.

1991, Malcolm Macdonald, The Captain’s Wives, Coronet Books, published 1992, page 265