We have just completed a set of mortar analyses for the mid-19th century classical garden buildings at Ripley Castle. As is often the case with many older ashlar mortars, the original mix is likely to comprise by volume of 3-parts lime: 1-part fine cream/iron rich silica sand. The lime appears to have a small hydraulic component within itself, or it reacted with the fine ash content. Close by Magnesium Limestone may have been burnt to produce the quick lime, which would then have been slaked to a putty, with perhaps the unslaked residue was crushed and added back into the mix.