Saturday, February 25, 2012

French Naval Ensign and National Flag

Naval ensign

This is to me an amusing perceptual phenomenon: the French tricolour comes in two varities: the navel ensign above, and the national flag below. The naval ensign was designed to be better distinguished by having unequal sized bands in a ratio.  The French national flag's bands are equal:

French National Flag

National flag:  1:1:1.

Naval ensign:  30:33:37

Currently, the flag is 50 percent wider than its height (i.e. in the proportion 2:3) and, except in the French Navy, has stripes of equal width.  Initially, the three stripes of the flag were not equally wide, being in the proportions 30 (blue), 33 (white) and 37 (red). Under Napoleon I, the proportions were changed to make the stripes' width equal, but by a regulation dated 17 May 1853, the navy went back to using the 30:33:37 proportions, which it continues to use.

Where the 30:33:37 ratio came from, I could not find any experimental basis for it.  Perhaps they worked it out by trial-and-error.  Or wild guessing.
The reason why they went back to the 30:33:37 ratio is because the flapping of the flag in the wind makes portions farther from the halyard seem smaller, and the red might not show well if there's little breeze.

I looked to determine whether other national flags also used disparate bands, and could not find other examples.  For example, Ireland and Coté d'Ivorie uses green, white, and orange bands of the same size (1:1:1).  Belgium used black, yellow and red bands in the 1:1:1 ratio.  But then, do those countries have a navy?  Italy has one; but its naval ensign has a crest in the middle of the white part.

Flag of Ireland

Naval Flag of Italy


Big Sky Heidi said...

Maybe the French navy did that just to be perverse, like their waiters.

Mike said...

Somebody must have taken a picture of the navy flag and done some quick calculations so that it would look correct.

Elvis Wearing a Bra on His Head said...

Is this due to some kind of illusion, like the horizontal-vertical illusion?

Bilbo said...

I think Heidi has the right idea. Who else but the French would do such an odd thing?

eViL pOp TaRt said...

Thanks for your thoughts, Heidi, Mike, Elvis, and Bilbo. There does not seem to be any information on why the 30:33:37 ratio was chosen, or why the navy would do it different from the rest of the country.

Duckbutt said...

Very interesting historical note.

Bilbo said...

Actually, Angelique, it may be as much a navy thing as a French thing. The US Navy is noted for going its own way in most things, so maybe having a specially-sized flag is just another way of saying "we're special and you're not, Army."

Grand Crapaud said...

Would it have something to do with the number of red and blue photoreceptors in the eyes? I understand there's more red and green ones.