Answer
The height would be less.
Work Step by Step
If the liquid in a barometer were a factor of X as dense as mercury, atmospheric pressure could support a column $\frac{1}{X}$ times as high as it could support a mercury column (which at sea level is 0.76 m).
Therefore, a barometer using a liquid denser than mercury (X greater than 1) would be shorter ($\frac{1}{X}$ is less than 1) than the height of a standard mercury barometer.
This is discussed on page 268.
