The caveat which Meucci filed contained the drawing made by Nestori, and as shown in the cut, which is a facsimile, represents two persons with telephones connected by wires and batteries in circuit.  The caveat, however, does not describe the invention very clearly; it describes the two persons as being insulated, but Meucci claims that he never made any mention of insulating persons, but only of insulating the wires.  To explain this seeming incongruity, it must be stated that Meucci communicated with his attorney through an interpreter, as he was not master of the English language; and even at the present time he understands and speaks the language very poorly, so much so that we found it necessary to communicate with him in French during the conversation in which these facts were elicited.

[Illustration:  FIG. 8.—­1864-65.]

In the summer of 1872, after obtaining his caveat, Meucci, accompanied by Mr. Bertolino, went to see Mr. Grant, at that time the Vice President of the New York District Telegraph Company, and he told the latter that he had an invention of sound telegraphs.  He explained his inventions and submitted drawings and plans to Mr. Grant, and requested the privilege of making a test on the wires of the company, which test if successful would enable him to raise money.  Mr. Grant promised to let him know when he could make the test, but after nearly two years of waiting and disappointment, Mr. Grant said that he had lost the drawings; and although Meucci then made an instrument like the one shown in Fig. 9 for the purpose of a test, Mr. Grant never tried it.  Meucci claims that he made no secret of his invention, and as instance cites the fact that in 1873 a diver by the name of William Carroll, having heard of it, came to him and asked him if he could not construct a telephone so that communication could be maintained between a diver and the ship above.  Meucci set about to construct a marine telephone, and he showed us the sketch of the instrument in his memorandum book, which dates from that time and contains a number of other inventions and experiments made by him.

[Illustration:  FIG. 9.—­1864-65.]

[Illustration:  FIG. 10.—­1865.]

When Professor Bell exhibited his inventions at the Centennial, Meucci heard of it, but his poverty, he claims, prevented him from making his protestations of priority effective, and it was not until comparatively recently that they have been brought out with any prominence.—­The Electrical World.

* * * * *

AN ELECTRICAL CENTRIFUGAL MACHINE FOR LABORATORIES.

[Footnote:  Paper read before Section B, British Association, Aberdeen meeting.]

By ALEXANDER WATT, F.I.C., F.C.S.

The late Dr. Mohr[1] of Bonn, advocated the use of a centrifugal machine as a means of rapidly drying crystals and crystalline precipitates; but although they are admirably adapted for that purpose, centrifugal machines are seldom seen in our chemical laboratories.