Stewaet. — Experiments in Hydraulic Mortar 



101 



Medicago lupiilina, L. 



„ maculata, Sihthorp. 

 Kosa rubiginosa, L. 

 Lytlirum hyssopifolium, L. 

 Apiiim leptophyllum,* F. Muell. 

 Erigeron canadeiise, L. 

 Seuecio vulgaris, L. 

 Carduus marianus, Gcertn. 



„ lanceolatus, Jj. 

 Hypoclireris radicata, JJ. 

 Xautliium spinosum, L. 

 Anagallis arveusis, i. 

 Physalis peruviana, L. 

 Lycium barbarum, L. 

 Veronica serpyllifolia, L. 

 Mentha aquatica, Z. 

 Stachys arvensis, I/. 

 Marrubium vulgare, L. 

 Prunella vulgaris, L. 

 Plantago major, L. 



Rumex obtusifolius, L. 



„ acetosa, L. 

 Chenopodium murale, L. 

 Amaranthus blitum, JO. 

 „ retroflexus. 



Euphorbia peplus, L. 



„ helioscopia, L. 

 Iris germanica, L. 

 Agave americana, L. 

 Phalaris canariensis, L. 

 Holcus mollis, L. 

 Anthoxanthu.m odoratum, L. 

 Panicum sanguinale, Scop. 

 Cyuodon dactylon, i. 

 Agrostis vulgaris, With. 

 Poa annua, L. 

 Daetylis giomerata, L. 

 Festuca bromoides, Sm. 

 Lolium perenne, L. 



Art. XI. — On some Experiments in Hydraulic Mortar, in At!,cMand. 



By James Stewart, Assoc. Inst. C.E. 



[llead Ijefore the Aiiclcland Institute, oth July, 1868.] 



The importance of obtaining, in Anckland, a lime of sufficient hydraulicity 

 to enable it to be used in mortar intended for wet situations, bas long- 

 impressed tbe writer. Tbe absence of such, in regular supply, leads to great 

 expense in tbe employment of cement, wbich is always, wben obtainable, very 

 dear, and, so far as bas come witbin tbe writer's experience, of not more 

 tban one-balf tbe value of tbe best as used in England. 



Tbe Hme commonly used in tbe making of mortar in Auckland, is obtained 

 from sea shells, or limestone from Maburangi. Tbe sbell lime is, of course, 

 ricb lime, and possessing no bydraulieity more tban tbat from pure cbalk. 

 Tbe stone lime usually worked is not in any appreciable degree bydraulic, 

 neitber is it so ricb as tbe sbell lime. If properly used, bowever, it is 

 preferable to sbell lime for all work. In dry situations it sets very bard, 

 and takes a good surface by tbe gradual reversion to tbe state of carbonate 

 of litne. Tbe writer bas never seen an analysis of tbis lime, but be bas 

 tried, mecbanically, several samples of it in tbe state of bydrate of lime, by 

 separating tbe sand mecbanically combined, and bas usually found about 

 20 per cent, of sand present. 



Having ascertained tbat lime bad, on several occasions, been obtained at 

 Maburangi and Wbangarei, possessing some qualities very different from 



* This plant was observed in the forest at Kawau, and is not unlikely to prove indigenous. 

 It is found in East Australia and North and South America. 



