What are the allowances given to a retired Judge sitting as an ad hoc judge?
Based on the context provided, there is no specific information about the allowances given to a retired Judge sitting as an ad hoc judge. The only detail mentioned regarding compensation for such judges is that "every such person so requested shall, while so sitting and acting, be entitled to such allowances as the President may by order determine". This suggests that the exact amount or nature of the allowance would be determined by the President.