Tombstone daily prospector., 1890-11-17
.InE PulsIoh TglEpnone.

A a-a ctAi Importance. IA new mech4nical telephone of extra ordinary power has recently been excit- ing considerable attention in London and some other cities and towns in this country, writes a correspondent of Nature. It is of American origin, like so many other modern Improvements of exceptional character, being the inyen- tion of one Lemuel Mellet, l believe, of Boston. There have been many previous mechanical telephones, as your readers are aware, some of which have obtained much publicity sc- . short time and then have been heard of but little more; but having had an opportunity of exper- imenting frequently with the new in strument and observing its vocal pow CT, so to speak, under very various cir cumstances, can not doubt it has . great future before it. 1
 It may be clearly stated at once that the pulsion instrument is absolutely in- dependent of all electrical aids or ap- pliances, and therefore needs neither battery power to bring it into play nor insulation of any of its parts to keep them effective. It consists solely of two cheap and simple instruments connected by an ordinary non-insulated wire of copper, or, better still, of double steel wire, the two parts being slightly intertwisted, say with about single turn in couple of feet. The wire tor wires) is simply looped to the instrument at either end, the connection being made in few seconds. The instrument consists of a disk in combination with \ series of small spiral springs inclosed in s case ct some three or four inches in diam stsz. These springs, arranged in a man ner that has been determined by ex- pertinent, and so as to produce harmo- niEed vibrations, appear 10 possess the power of magnifying or &ccumulsting upon the wire the vibrations which the voice sets up in the disk, and the wire seems to possess undoubtedly does possess-the power of transmitting to great distances, and giving out upon & second pulsion instrument the sounds of the voice. s-3 The ability Of this simple system of springs, disks and wires to convey con- versational and other sounds to con- siderable distances with great clearness and distinctness, reproducing the very tones of the voice and the qualities of musical sounds with but little reduction or modification, is most surprising, and to none more so than to the many men of science who have been recently eK. perimenting with it. saass The writer of this notice can not, per. haps, do better than state his own eIpe- riences with this system After exam ming and experimenting over several short lengths of wire, some Of them ex- ceeding a mile and half, he last week went to the Finchley Road Station of the Midland raiiSsy, from point near to which line had been conveyed to near the Welsh Harp Station, distance of three miles by the line of railway, and of more by the track of the wire, which for the larger part was carried by the telegrsph-posts, to which it was at tached by very simple means. Conver- sstion through this length of line, of over three miles, was exceedingly easy; indeed, so powerfully was the voice transmitted that an ordinary hat suf- feed for all the purposes of the second instrument, without going near to which conversation was carried on repeatedly by means of the hats of three gentlemen who were present, the tops of which were merely placed against the tele- phone wire. -~zT zTzH
 l then went into the garden of the "Welsh Harp" where a short length of wire had been led between two points, the wire on its way from one point to the other being twice tightly twisted, at an. interval of some yards, round small branches of trees of about one inch in diameter, being wound round and round the branch three times in each case. Strange to say, this tight twisting of the wires round the branches in no way interfered with the transmits sion of the voice from end to end of the wire. s<5
 A third and last experiment was made with wire laid obliquely across the Welsh Harp lake, and allowed to sink to and rest upon the lake bottom The length of the line as roughly estimated at about one-third of a mile, and from end to end (excepting few yards at each end where the wire was led from the waters edge to the telephone bo1) the wire was completely immersed, and without any other support than the bot tom of the lake offered it. Yet, not withstanding this immersion of the whole wire, conversation was carried on through it by means of the pulsiOn in- struments without the least difficulty. Tn fact, the voice csno through the im- mersed wire, and the longest wire toi over three milesl previously mentioned, with greater purity and mellowness than -l.. l-- L-