1888.] 145 [ Houston. 
may, in certain cases, By. slight modifications, be applied also to those ver- 
tically traced. 
In order to place some of these methods on record, a brief description * 
will be given of a few of the most promising. At the same time, the 
author admits that serious difficulties may lie in the way of practically 
carrying out some of the methods proposed. 
Mr. Berliner, as is well known, prepares his record-surfaces by moving 
the tracing point over the surface of a plate of inked glass or metal, cov- 
ered with a uniform deposit of lamp-black. The record thus obtained is 
either mechanically copied on a metal surface, or is reproduced thereon by 
the process of photo-engraving, or etching. I would suggest the follow- 
ing methods, viz.: 
(1.) After the record on smoked glass is obtained in the usual manner, 
expose the plate to the action of a regulated sand-blast so as to obtain cut- 
tings or groovings on the surface of the plate, suitable for the movements 
of the reproducing diaphragm. Roughness in the edges of the lines so 
obtained would probably cause screaming sounds in the words reproduced, 
which might be removed by a few applications of an emery- cover ed trac- 
ing point. 
Should the action of the sand-blast remove the coating of lamp-black 
and ink on the covered portions of the plate, these portions might be ren- 
dered more adherent by the freer use of a more viscous ink, and the depo- 
Sition of finer spiculee of carbon. 
(2.) The phonogram record-surface is composed of a smooth surface of 
hardened wax, on a composition of wax and resin which is locally heated 
so as to slightly agree the surface directly under the tracing point or 
stylus. 
In order to ensure the rapid cooling and hardening of the surface, im- 
mediately after the impression has been impressed thereon, the heating 
must be local and not general. To more thoroughly ensure local cool- 
ing, a light blast of cool air might be directed on the surface almost im- 
mediately after the tracing has been made. To prevent the air so applied 
from cooling the surface that is being warmed in order to receive the 
record, a suitably arranged diaphragm may separate adjacent cooled and 
heated portions. 
(8.) Instead of heating the record-surface itself, a local source of heat 
may be used to heat the tracing point or stylus. This heat may be either 
ordinary heat, or that of electrical origin. When the stylus, instead of the 
record-surface, is heated, the latter may be made of much harder material. 
Any tendency of the record-surface to run and thus mar the correctness 
of the recorded sounds, may be checked by the use of a properly directed 
blast of cold air as already suggested under (2). 
It is evident that the use of cold air, or its equivalent, is much more 
Suitable in this case than where the record-surface itself is heated. 
Any tendency of the surface or tracing-point to clog may be remedied 
by suitably shaping the cutting-surface of the point, or the composition of 
PROC, AMER. PHILOS. SOC. xxv. 127. 8. PRINTED MAy 15, 1888. 
