sylleptic parentheses

Here's a quote from Wikipedia:

the triple point of Vienna Standard Mean Ocean Water (VSMOW, 273.16 K and 0.01 °C)

Now, "VSMOW" refers to "Vienna Standard Mean Ocean Water", while "273.16 K and 0.01 °C" refers to "the triple point of Vienna Standard Mean Ocean Water". To me, the writing here seems to be in error: one shouldn't combine parentheses like that if they refer to two different things. Either use

the triple point of Vienna Standard Mean Ocean Water (VSMOW) (273.16 K and 0.01 °C)

or (preferably) recast the sentence. But maybe I'm wrong: maybe standard practice is, or usage guides suggest, that such 'sylleptic' (if you will) parenthetical explanations are fine to use. Does anyone know?

Solution 1:

The Chicago Manual of Style is mute on the subject of consecutive parentheses, but, I note, doesn't use them in any of its examples. (EDIT: I found their reference regarding back to back parentheses, and expanded my answer.)

To apply their guidelines to your sentence, I would use the parentheses for the gloss of VSMOW, and use em dashes to set off the triple point values:

the triple point of Vienna Standard Mean Ocean Water (VSMOW) — 273.16 K and 0.01 °C — ...

The Chicago Manual also notes:

Parentheses may appear back to back (with a space in between) if they enclose entirely unrelated material; sometimes, however, such material can be enclosed in a single set of parentheses, usually separated by a semicolon.

By this dictum, the phrase becomes:

the triple point of Vienna Standard Mean Ocean Water (VSMOW; 273.16 K and 0.01 °C)

If VSMOW and the temperatures were entirely unrelated material, the Chicago Manual would give your sylleptic parentheses their blessing; by my reading, however, they are not.

Solution 2:

I would prefer to see:

'One effect of defining the Celsius scale at the triple point (273.16 K and 0.01 °C) of VSMOW (Vienna Standard Mean Ocean Water) . . .'

Solution 3:

I think it should be "the triple point of Vienna Standard Mean Ocean Water (VSMOW (273.16K/ 0.01C))". But I also think there is a point beyond which precision becomes pedantry. [I can't believe I just typed that over my own name.]