Avraham Sacks asks:
On 51b in Mesechtah Sukkah Rava mentions that the rows of stones of the Beis Hamikdash protruded every other row in order to receive the Sida. How did the recessing of the rows of stones help? Where exactly was the Sida placed?
Avraham Sacks, Israel
The Kollel replies:
If I understand correctly, the lime is placed between the two rows when the middle row is set back. The lime was specifically placed there in order to embellish it with gold, which apparently does not stick to stones ((Aruch la'Ner), but the other view is that there is no need to place gold there as the lime used together with the darker stones produces an effect of a wave crested with white.
Yoel Domb