1) Introducton
The appearance of gas-filled electric lamp which gets heated to higher temperature than the vacuum lamp, rendered the lighting fixture of previous design unfit.
2) Evolution of Socket.
a) Improvements upon the construction of metal socket. The insulation material be tween the outside shell and screw shell was once felt paper dipped in paraffin but is now replaced by a good fibre sheet. For nozzle and key handle, the moulding compound in which shellac was binder has been replaced by the compound with copal chips or Bakelite as binder.
The filling compound for screw head has been improved to that which would not melt by heat into fluid.
b) When gas filled lamp is fitted into the improved metal socket with ordinary glass shade, no rise of temperature that would damage the socket is observed.
c) Improvements upon moulded socket.
The socket that was moulded previously of the compound with shellac binder has been replaced by that made of the compound with copal binder.
However, even with latter it can't be said safe enough in all cases and the socket moulded of Bakelite compound is coming forward.
3) Same observances upon the temperature rise and the construction of the lighting fixture of inclosed type.
a) Certain caution upon the chain drop fix tures is given.
b) Certain caution upon the ceiling fixtures is given.
c) In the lighting fixture of inclosed type where the socket of non heat resisting con struction is fitted, it is necessary to use ada pter in order to increase the distances between the lamp and the socket.
d) In the lighting fixture of inclosed type, the relation between the wattage of lamp and the sizes of globe is explained. For light opal glass globe, it is safe to plan 12 sq. cm. or more per watt.
4) The heat resisting quality and ltemperature ranges of various finishes of the lighting fixtures are described.

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I got a chance to see the lighting practice in America recently, and wasigiven a chance to talk about it. But I fear it may not correct obser vation.

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The statistics of electric incandescent lamps ursed in japan up to 1927 - are shown and compaed with those of the past ten years.
Carbon filament lamps for lighting purpose almost disappeared from the market and were only 0.003% of total number of lamps used in 1927.
The lamp size becomes larger and larger: about 32.4% of total number of lamps are those of larger than 20 cp.
The degree of popularization of electric lamps shows the tendency of making rapid progress. Similar statistics are shown for six largest cities in our c ountry.
The diagrams may be read in English.

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