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University of California Publications. [Geology 



scheme was finally evolved, and was considered satisfactory. 

 One end of a piece of No. 8 copper wire (diameter about y$ 

 inch) was filed to a long point and the wire was bent into the 

 shape shown in fig. 2. A hollow glass cone was then fitted 



Fig. 1. Fig. 2. 



around the point, and stuffed full of a pasty mixture of plaster 

 of Paris and asbestos fibre. This dried firm. The Bunsen 

 burner flame was applied at the point B. As a further precau- 

 tion against radiation from the flame, a piece of 6"X6" asbestos 

 sheeting, with a one-inch hole in the center, was slipped around 

 the glass cone from below until it was held safe by the friction. 

 This was soon dispensed with as an unnecessary refinement. 



The apparatus, when in use, was clamped in a vise at D. 

 The weight W was removed. The Bunsen burner was adjusted. 

 The section E was placed, with the aid of ring-stand and clamp, 

 directly underneath the point of the wire and about one-fourth 

 inch from it ; the prepared surface was then leveled so that it 

 would be parallel with the plane surface at the end of the wire 

 when the latter was lowered through the intervening one-fourth 

 inch. This lowering was accomplished by replacing the weight 

 W. On again removing the weight, the wire resumed its orig- 

 inal position, the melted wax solidified, and the ring-stand was 

 shifted so as to bring a new portion of the surface underneath 

 the point of the wire. This cycle of operations was repeated 

 until the entire surface was covered with wax figures. (See 

 Plates 26 and 27.) 



This method is simple, inexpensive, and, if used with care 

 and a little skill, effective ; moreover, it required but little appa- 

 ratus which was not at hand either in the petrographical or in 

 the physical laboratories. 



