EEPOET OF ASSISTANT DIRECTOR. 29 



through the messenger call-boxes to the District messenger headquar- 

 ters every hour during the time when the buildings are closed. 



The electrical-light system is comprised of one six-light dynamo and 

 governing dial run by a twenty horse-power engine. This supplies a 

 current to six electric arc lamps of 1,500 candle-power, for which suita- 

 ble wires and connections are placed in all the main exhibition halls. 

 The dynamo is used principally for supplying current to two i)hoto- 

 graphic electric lamps. There is also a single-light dynamo and lamp 

 used as a reserve. One Brush storage battery, consisting of sixty-three 

 elements, is used for supplying current to forty incandescent lamps, which 

 supply light to the lecture hall. 



In connection with the electrical service there is at the Armory build- 

 ing an electric hydrostatic indicator for the purpose of giving the height 

 and depth of the water in the reservoir in the building. 



The telephone system now consists of forty separate lines. These 

 include two lines to the city exchange, and lines connectiug the resi- 

 dences of the chief officers, and all annexes and branches of the Museum 

 and Smithsonian buildings. The lines connect to a switch-board in the 

 Museum building, through which communication can be had at any time 

 either day or night. The number of communications transmitted and 

 received through these lines daily averages one hundred and twenty- 

 five. 



"Nature," commenting upon the electric service in the Museum, in 

 an article of the issue dated June 28, 1883, says : 



''The National Museum at Wasliington is one of the best examples in the United 

 States of the practical application of electricity. In so large a building it was found 

 advisable to take advantage of the best means of communication, first being its system 

 of telephones and call-bells, by which those in any room can communicate with every 

 room in the building. Twenty-six telephones are connected by a local telephone ex- 

 change, which in turn is connected with the main telephone office of the city. The 

 j-esult is that but three messengers are needed in this vast establishment. The photo- 

 graphic laboratory is independent of the sun, owing to the electric light there used. 

 If one of the 850 windows or 230 doors is opened, a bell rings, and an annunciator shows 

 to an attendant at the main office which window or door it is. This system is soon to 

 be applied to every case of specimens. The watchmen at night, also, are kept to their 

 posts by hourly releasing an electric current at certain stations, which pierces a dial 

 and records their visit. The sixteen clock-dials are likewise run by electric currents." 



The following is a complete list of the electrical property of the 

 National Museum on June 30, 1885 : 



2 100-drop Museum annunciators. 

 2 25-drop Museum annunciators. 

 1 6-drop Eosseau annunciator. 

 1 Howard time and watch clock. 

 18 Howard time and watch clock sta- 

 tions. 



6 Howard 30-second clocks. 



7 Howard 15-second clocks. 

 50 celLs Howard clock battery. 



1 Brush storage battery. 



1 Brush single light dynamo. 



5 Brush electric lamps. 



1 Brush reflecting lamp. 

 40 Swan incandescent lamps. 



1 How.ird tower clock. 

 13 Western Electric Company's bells. 

 30 LeClanche battery cells. 



1 Barnes's foot-lathe. 



1 bench vise. 



1 set of lathe drills. 



2 lathe chucks. 

 1 set taps dies. 

 1 step-ladder. 



3 post-magneto bells, 



