In order to institute a comparison between the various articles under discussion, I give the following table of tensile strength per square inch in pounds on limes, cement, and mortar one year old. Cement and Limes neat. Portland cement 500 pounds Roman " 185 " Good hydraulic lime 170 " Ordinary " " 120 " Rich lime 40 " Mortars. Portland cement with 1 of sand 310 pounds " " " 2 " 205 " " " " 3 " 140 " " " " 4 " 100 " " " " 5 " 50 " Good hydraulic mortar 140 " Ordinary " " 85 " Good mortar of rich limes 50 " Bad " " " 20 " Geographical Distribution. It was shown in a former paper that limestone as a geological formation occupies an immense area of Otago, but it does not follow that the supply of lime for industrial purposes is equally extensive, many of the calcareous rocks being incapable of producing lime of good quality. There is, however, no scarcity of lime suitable for building and agricultural purposes throughout the province. It is known to exist in considerable quantities in the following districts:—Oamaru, Otepopo, Waihemo, Maniototo Plains, Waikouaiti, Lower Harbour, Peninsula, Waihola, Waimea, Winton, Aparima, Waiau, and Wakatipu. These localities are so widely dispersed that we may safely calculate on a supply being available for any demand that can arise. The only natural cement hitherto discovered in Otago is the well-known Septaria or cement boulders of the Moeraki district, which resemble in every respect the English stones from which Roman cement was originally manufactured. According to Dr. Haast, the boulders follow the coast from Shag Point to the Terapupu Creek, then run in a straight line to the Little Kiwi Creek, which is struck at a point about half a mile from the sea. In the first four miles the deposit is a mere line of boulders lying on the beach or imbedded in the cliffs, but on leaving the coast it expands into a belt from 20 to 30 chains wide and 5 ½ miles long. Many of the volcanic clays that exist in such profusion along the sea board from Saddle Hill to Oamaru possess cementitious properties similar