Paul Sandby R.A. (1731-1809) - Three studies of river landscapes

A delightful set of three drawings by the artist Paul Sandby of river landscapes. Each drawing is inscribed and they are all likely from the same 1766 sketchbook. They were exhibited with the art dealers Spink and were previously sold through Abbott & Holder.
 
Medium: pen and ink with pencil, various inscriptions with one being dated [17]66', individually 7.5 x 6cm, framed. 
 
Provenance: Abbott & Holder, 30 Museum Street, London (label verso); 
Exhibited Spink; Private collection U.K.
 
Condition report: generally all drawings are very good for their age. Old mount lines obvious on a couple of the works. Frame shows some wear.