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1850-1899
TELEPHONE TRANSMITTER 1881
Telephone 1881NEW TELEPHONE TRANSMITTER.
BY GEO. M. HOPKINS.
The microphone, with pendants, figured and described by the writer in the SCIENTIFIC AMERICAN of Nov. 16, 1878, was among the earliest of telephone transmitters, and although the device was crude in appearance and exceedingly simple in its construction, it contained the germ of a successful instrument, and was favorably noticed in the scientific papers of Europe.
Self-Winding Watch 1881
SELF-WINDING WATCH.
The annexed engraving represents a device for winding a watch by means of the motion of the wearer's body in walking, which has been patented by A. R. Von Loehr, of Vienna, and described in the Horological Journal.
It will be observed that the mechanism is in principle the same as that which constitutes the pedometer. The inventor is aware that the motion of a weighted lever has been used before for winding a watch, but he claims to have overcome the objections existing in former arrangements.
Scratch Brushes
Scientific American February 26, 1881SCRATCH BRUSHING.
The scratch brush is often used to remove the dead luster on, or to impart a smooth surface to an object. They are usually made of brass or steel wire and of a variety of shapes to suit the object. Some of the forms are shown in the figure.
The wheel brushes are used on the lathe, the objects being manipulated in contact with the rapidly revolving brush. The brush is usually kept moistened by a small stream of water while in use.
Air Conditioning Machine 1881
Scientific American February 19, 1881
Refrigerating called cold air machine or vapor compression method
Air Refrigerating Machine 1881
IMPROVED AIR REFRIGERATING MACHINE.
Scientific American February 19, 1881
We illustrate a machine constructed by Messrs. Hall (John Hall and Edward Hall or J & E Hall), of Dartford, (England) for use in the Australian meat trade. The engraving is very nearly self-explanatory.
Victoria Steamer by The Duquesne Engine Works 1881
AMERICAN BUILT STEEL STEAMER FOR THE RIVER
MAGDALENA.
BY H. L. BEIDWELL.
1881 Scientific American