This paper deals with limes and lime mortars and is presented in two parts. Part One (Volume 1, Number 3) identified the sources and qualities of limes in England and Wales, and traced the burning of lime, the development of kiln design and the search for hydraulic cements from ancient times up to the end of the nineteenth century. Part Two examines the slaking and use of lime for mortar mixes and compares the qualities of lime-based mortars with composition and ordinary Portland cement mixes. General advice is offered on mortar mixes for the repair of historic fabric and three case studies are provided to illustrate the importance of determining appropriate mortar compositions for repair work.