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National Mazda Daylight Blue

National Mazda Daylight Blue

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Daylight blue lamps were introduced around 1914 to better simulate the colour rendering of daylight. Their development is attributed to Matthew Luckiesh, one of the greatest engineers of GE's National Lamp Works. The design was not patentable because decorative lamps had been made with a similar hue many decades earlier, but Luckiesh was first to recognise the value of pale blue glass for approximating daylight. He was responsible for introducing a full range of lamps for home and industrial use, and promoted them extensively as part of his research into improved lighting conditions, which led to him becoming known as the 'Father of Light for Seeing'. They became very popular in shops, printing plants, cigar factories, laundries and homes.

The glass is naturally tinted with cobalt oxide to reduce the luminous flux of incandescent lamps by about 34%. This results in the absorption of yellow and red wavelengths and a modest increase in correlated colour temperature. The result is that most colours are rendered more closely to natural daylight than under ordinary incandescent lamps.

This example is one of the earliest daylight lamps. Its basic construction is the same as the ordinary 200W argon-filled coiled tungsten lamps that were first introduced in October 1914. The filament is bent into multiple V-shaped sections and only supported at one side, and can therefore only be burned in the vertical cap-up orientation. The first 200W lamps used large skirted caps at least until 1916, whereas this lamp has a small non-skirted cap and was therefore made at a later date. However the glass bulb has an evacuation tip on its crown, a process which was dropped after 1919. The stem marks identify its date as 1919.

IN WC D GE 105-200PS30DAY-E26.jpg IN R GE 120-100A21SB-E26.jpg IN R GE 125-200PS30WB-E26.jpg 1C9CBF3E-2CF4-4E54-8323-0A9E0AFE7A59.jpeg

Light Information

Light Information

Manufacturer:National Lamp Works of GE
Model Reference:Mazda C Daylight 200W
Lamp Type:Incandescent
Filament/Radiator Type:Tungsten C-7/3s
Service Life:750 h
Wattage:200 W
Voltage:105 V
Current:1.9 A
Lumen Output:1850 lm
Lumen Efficacy:9.5 lm/W
Color Temperature:4100 K
Color Rendering Index:Ra 96
Dimensions:95 x 213 mm
Factory Location:Ohio Lamp Plant, Warren OH, U.S.A
Fabrication Date:1919 September

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Date added:Nov 04, 2018
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Nov 04, 2018 at 01:15 PM Author: rjluna2
I can certainly see how fragile these Tungsten filament as it ages.

Pretty, please no more Chinese failure.


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GLS on Tesla Coil

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Nov 04, 2018 at 02:00 PM Author: tuopeek
Interesting how far back the quest for a day-light emitting lamp goes. I have looked at more modern lamps with neodymium glass where it's not really a tint but absorption of part of the spectrum around the yellow frequencies. Very noticeable if the light is viewed through a spectroscope. I wonder if cobalt oxide also creates a similar absorption spectrum? I have also looked a some obviously tinted lamps that don't remove any lines from the spectrum.
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Mainly the electrical side of things

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Nov 04, 2018 at 05:32 PM Author: sox35
Yet another amazing find James, this is beautiful

Ria in Aberdeen
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Nov 14, 2019 at 10:13 PM Author: wide-lite 1000
Very nice lamp James !

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fluorescent lover 40
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Lights are awesome! :)

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Nov 14, 2019 at 10:35 PM Author: fluorescent lover 40
Cool lamp!

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-Date decoder of some US lamps 1960-present.
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in my house is not used led and if I can avoid it

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Nov 15, 2019 at 03:55 AM Author: Daniel f
very nice !! I like very much
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