126 Transactions.—Miscellaneous. 
» 15 to 18. Brickwork in partitions and plastering. 
» 19 to 28. Low thin brick walls in a dry situation. 
Hydraulic Limes.— 
Nos. 11 to 18. Ordinary walling above ground. 
14 * 16 Be of ordinary buildings, concrete, and 
i: ' lengineering structures above ground. 
Nearly all the higher class masonry for which 
cement is usually employed. 
The rich limes are well dispersed throughout the province, but the 
hydraulic ones are confined to the vicinity of Dunedin, except we include 
the Lake Wakatipu deposits, the hydraulicity of which has not been proved. 
Although lime has been burnt on the Peninsula for many years, none of the 
good seams have been utilised. "The proprietors inform me that there is no 
market for this quality. Builders will not use it in preference to the rich 
lime, as the latter carries more sand, and in the absence of any information 
on the subject, professional men and the publie generally have no choice. 
In order to institute a comparison between the various artieles under 
discussion, I have. prepared the following statement, showing the strength 
and cost of mortars now used in Dunedin, together with am estimate of 
other kinds prepared from the hydraulic limestones. 
» 17 to 20.1 
Mortar. 
Tensile strength |Cost of egeta ae a 
per square inch in| cubic 
pounds, nan 
Now in use— s.d. 
Portland cement with 2 of sand ^p Wer 205 14 6 
zs n » me TA m 140 ll 0 
» » » 4 » $e. an 100 9 0 
” ” ” ” pe =. 50 8 0 
Rich Lime 4 4 os m zi 15 8 9 
tations for new mortars-— 
k hydraulic lime slaked PE 50 4 0 
inary ,, ground in mixing ee 100 4 6 
Soon i » shell lime ground  .. 140 7 9 
In contrast to the above it should be stated that ordinary hydraulic 
mortar in England costs from 1s. 10d. to 2s. per cubic yard. 
Judging by the quality of the ingredients, and the manner in which they 
are manufactured, I should not estimate the tensile strength of our ordinary 
lime mortars at more than ten pounds per square inch, which is less than 
half the strength of European mortars that are designated * bad." Their 
defects are quite apparent to any one who takes the trouble to examine the 
southern side of a building. It will be found that, after a lapse of years, 
the mortar even on the surface is often quite soft and friable. A good 
