GEOLOGY AND TOPOCRAPTTY OK 1 1. \ WATT. 129 



In 1910 steam bricks were made at Moiliili fr-om imlviM-izcd Inva by nii ela])orate 

 process, but, owinsz' to unexpected chemicil chaii.m's, I lie l)i'icks wci'c found to 

 be inferior in (luality, and the process and product altered jil'ler an expensive 

 experiment. Lime manufactured from coral rock bas loim- been a common 

 commodity in the islands, but it has never been considered (juile eijnal 1n lliat 

 manufactured from limestone on the mainland. Sandstone of a fail- (|iiality 

 occui's at several points alxtnt tbe island. St. Andrew's Cathedi-ab in Ibuiohilu, 

 is made of sandstone imported from England long before Hawaii became an 

 integral part of the Ignited States. "When a few years ago it was decided to 

 enlarge the cathedral, the import duty made it impractical)]e to go to tbe same 

 source for more stone. A large part of tlie Thiited States was luisnccessfully 

 hunted over for a match to the English stone. It was finally found neai- P>ar- 

 ber's Point, about tv/enty miles from the cathedral site. This h)cal stone is ph'as- 

 ing in color and durable in quality. The hard, compact, dai'k l)luis]i-grey basalt 

 is much used in building operations whenever cut stone is reipiired. A lunu- 

 ber of the most substantial structures in the islands are made entirely of cut 

 stone derived from ciuarries usually opened in the vicinity of the particular 

 structure in which the stone is used. 



]\Iuch of the softer grade of basalt is used in concrete and in road construc- 

 tion. Beach sand is also used in mortar and to some extent on the roads, and 

 as road dressing. It is usually mixed with coral rock, the whole being rolled 

 together and oiled to form a smooth surface. Sand from beds in the neighl)or- 

 hood of the Waianae Mountains is also used extensively in building operations, 

 but being formed from coral and shells it is undoubtedly inferior in quality 

 when compared with tbe sharp sand brought from the mainland. Salt is still 

 manufactured on the island by evaporating the sea water in shallow ponds along 

 the sea shore, but the main supply is imported. The use of the loose rough field 

 stone or "moss stone" has recently come much into vogue for foundation and 

 trim work and has added much to the rustic as well as permanent appearance 

 of the bungalow homes, in the building of whicii it is being exlensively nse.l. 



This already lengthy chapter on the geology of Oalui wonld be inconq)lete 

 without some brief reference to a few of the more interesting, though minor, 

 natural features of the island which are obiects of interest to residents and 

 tourists alike. Among these may be mentioned the iiunierous natural caves 

 formed in the volcanic rock. One at the west end of .Judd street, a portion of 

 which was once used as a burial cave, extends back for several Innulred feet by 

 a winding, narrow passage. Other l)urial caves are found above the roail at 

 AVailupe Valley, and beyond, while along the sea coast, beyond !\oko lleiid, are 

 caves in which several interesting stone carvings iiave been found. 



Points of Geologic Interest About Oaiiit. 



The coast-line from Koko Head to Makapnu Point is a I'eiion of iinich 

 gee>logic interest, with spouting horns, olivine crystal beaches, and much coast 

 scenery. The dash of waves against the exi)ose<,l lieadlands at Koko ITead and 



