This lawn shoe would have been put on a horse's hoof to protect lawns when horse-drawn grass mowers or rollers were used.
This design was developed by H.Pattison of Streatham in the late 19th Century.
These boots / shoes appear in a 1909 catalogue from William Wood & Son, Wood Green at the Garden Museum in London.
It has a thick leather sole with a metal ridge at the front and a brass screw and bar at the back.

Dimensions : 7¾" (19.5cm)wide, 9¾" (24.5cm) front-to-back, 2" (5cm) tall.
Weight 3lb 4oz (1.46kg)

Ref : Pattison Lawn Boot