Houston. ] 146 [April 20, 
the record-surface, or the degree of temperature employed for the 
softening. 
(4.) The record-surface consists of a glass plate covered with a thin 
layer of wax. Either the record-surface itself, or the marking stylus, is 
locally heated as before, only the layer of wax is so thin as to leave the 
glass exposed after the passage of the tracing-point. The cooling blast of 
air, and the separating diaphragm described in (3) are applicable to this 
process. 
A permanent record is then etched in the surface of the plate so pre- 
pared either by the sand-blast process, or, preferably, by the action of 
hydro-fluoric acid. 
Before the application of either the sand-blast or the acid, care should 
be taken to see that the lines traced are free from wax. 
(5.) Instead of employing the records on the lamp-blackened glass sur- 
face as a photographic negative for the purpose of reproducing them by 
photo-engraving or etching, they may be used for transferring the record 
to a glass surface covered with a film of sensitized gelatine. The por- 
tions of the, glass that are left uncovered after the plate is fixed are then 
deeply cut or etched by treatment with either gaseous or diluted liquid 
hydro-fluoric acid. 
I have treated a gelatine-covered glass plate printed from a photo- 
graph by means of this process, and find that it produces a very fair and 
permanent picture on the glass. 
It is evident that this process will leave the design either in relief or 
intaglio according as a photographic negative or positive is used. 
(6.) The recording diaphragm, in its movements to and fro, is caused to 
deposit, on the surface of the record-plate, a uniformly thick line or layer 
of some rapidly hardening substance. This substance is contained in a 
vessel provided with a pointed outlet tube, and attached to the diaphragm, 
The material either runs out by its weight and is deposited on the record- 
surface, or is forced out by the movements of the diaphragm itself. 
The substance may be rendered fluid while in the containing vessel by 
the action of heat, hardening on cooling, which latter may be hastened by 
a suitably directed blast of cooled air. 
A record, thus prepared, would consist of a uniformly thick, sinuous 
ridge of the hardened material. The reproducing stylus, or that giving 
motion to the diaphragm that reproduces the speech, could, it is evident, 
be operated either from the upper or the lower surfaces of the sinuous 
ridge independently, or from both simultaneously. 
(7.) If the movements of the receiving diaphragm of a telephone be 
sufficiently amplified or intensified to permit it to trace or cut a sinuous 
record on a suitably prepared record-surfuce by any of the methods pro- 
posed in this article, or by any other method, then there would be pro- 
duced a simple, yet effective method for obtaining not only a permanent 
record of a telephonic dispatch, but as well a means of reproducing it as 
often as might be desired. 
