R plot: adding a title to the y-axis

Question

I would like to add a title for the y-axis of the top plot. Of course, in the toy example below, I can use the ylab argument. But I am looking for another option to fit with my actual problem. It appears that mtext() does not do the job in this case. Any other idea?

x11()
par(mfrow=c(2, 1))
plot(1:10, ylab = " ")
mtext(text = "y-label", side = 2, line = -2, outer = TRUE)
plot(1:10, ylab = " ")

Answer 1

mtext(text = "y-label", side = 2,line=2, at=26, outer = FALSE)

You will have to play around where at= is to find the sweet spot for both graphs but this will do what you are asking. 6 seems to be a good number for the bottom graph if anything. (Using the example)

If you imagine line to be an x co-ordinate and at to be ay co-ordinate then you can just play around until you find what fits.

Probably not as clean and cut as you wanted but it will work.