XI. APPLICATIONS. 363 



1629. Polarised Relay, with a horseshoe electro-magnet 

 and steel armature. Siemens, 1855. This form is still in use. 



1630. Induction Coil. 



1631. Induction Key. 



1632. Apparatus System, for submarine conduction. Sie- 

 mens. Constructed for the Red Sea Telegraph Cable. 



1633. Back Current Discharger for submarine conduction. 

 Siemens, 1857. Used first in the Red Sea. 



1634. Colour- writer by Siemens. First construction. A 

 small colour arm, fastened on a universal joint, dips into an open 

 reservoir of adjustable level. Patented in England in 1862. 



1635. Hair Needle Galvanoscope of Siemens, 1869. 



GENERAL TELEGRAPH APPARATUS. 



1576aa. Telegraph Apparatus, &c. 



General Direction of Russian Telegraphs. 



1. Atlas, containing details of the construction of the Central Telegraphic 

 Office in St. Petersburg. 



2. Lightning conductor, for cable. 



3. Lightning conductor, for station. 



4. Insulator, with double cup (large model), " KornilofFs." 



5. Insulator, with double cup (small model), same make. 



6. Insulator, with double cup (large model), " Belotine's." 



7. Insulator, with double cup (small model), same make. 



8. An element, " Meidinger's." 



1750a. Telegraphic Instruments. 



Messrs. Siemens Brothers. 



1. A B C telegraph instrument with finger keys (under glass cover to 

 show working parts). 



A magneto-electric instrument not requiring battery; used for house, 

 private, and railway telegraphs. 



2. A similar instrument in wooden case. 



3. A B C telegraph instrument with handle movement, in round case, not 

 requiring battery ; used for house, private, and railway telegraphs. 



4. A similar instrument in square case. 



5. Standard ink recording telegraph instrument with self-starting and self- 

 stopping arrangement ; for terminal stations. 



6. A similar instrument arranged for translation. 



7. Portable telegraph sounder for military purposes (Major Malcolm's pat- 

 tern), non-polarised. 



8. Polarised circular relay with double contact. 



9. Bi-polar relay with double contact under glass cover. 



10. Portable condenser of | microfarad .capacity, with 2 terminals and 

 short circuit peg. 



11. Sub-divided condenser of 1, 2, 2, 5, 10, 10, microfarad capacity, with 

 4 spring pegs and one short circuit peg. 



12. Sub-divided condenser of 10, 10, microfarad capacity, with 8 terminals 

 and short circuit pegs. 



