SOUTHERN CALIhORNIA ACADEMY OF SCIENCES 163 



granites, which appear to work well, but they are less attractive 

 to most persons. 



Red granites are not so common. These must pass muster 

 on more points lof criticism, and probably few of those in this 

 neighborhood are really desirable for general application. 



Marbles are extremely variable in quality and in appearance. 

 The desire to utilize local material has carried some of our 

 architects beyond the bounds of prudence. Fortunately the 

 uses made of this rock are mainly decorative, which places 

 them wholly in the class of veneering materials, where they can 

 be replaced if found unsatisfactorily. Much of the Catalina 

 marble which has gone into prominent office buildings of late 

 is regarded as bizarre by persons of refined taste, but its bold, 

 bad lines might still be forgiven were it not for the inevitable 

 result. It will certainly "paint the town red" in streaks in 

 the districts where it is used. The black markings contain 

 some ferrous mineral, which must oxidize to a rusty brown on 

 exposure to the weather, staining the white lime-rock for some 

 inches on either side. This action, aside from the unpleasant 

 discoloration, will develop liiies of weakness; and, if carried 

 far enough, the slabs will fracture and separate along these 

 lines. No serious danger threatens, because the thin veneer of 

 marble sustains little besides its own weight, and it can be 

 removed without weakening the building to which it is at- 

 tached. The white body of this rock is of fair tint and of good 

 grain. 



There are some choice marbles in use in Los Angeles which 

 contain black or greenish black streaks of resistant quality. 

 Some of these have withstod weathering agencies for years 

 without discoloration. The determination whether the particu- 

 lar mineral compositon in any given case will be suitable or 

 otherwise is not very difficult ; but the test should be applied 

 beforehand. Otherwise, as has been evident locally, time may 

 demonstrate the disadvantage most expensively. 



Red granites and red marbles usually contain iron in ferric 

 oxidation, and if they possess the requisite strength, even if 

 streaked with red, there is not usually any liability to change. 



The rocks which form the masses of the high mountains in 

 Southern California are not usually such as will attain popu- 

 larity for building purposes. An experiment in the new Cali-« 

 fornia Club building in Los Angeles, using a rock from near 

 Chatsworth, gives hope of substantial success with this substi- 

 tute for light buff sandstone. It is a fine grained, mixed rock, 

 rather tender in fracture, rubbing smooth without polish, show- 

 ing little or no difference between exposed and newly fractured 

 surfaces. There are diffused grains of a black mineral, which 



