Visweswaraya,K L Rao, Arthur cotton

It seems great Engineers have an affinity for 15.Visweswaraya,K L Rao, Arthur cotton- All these great Engineers were born on 15th - Sept,July and May.What is yours?
By the way have you studied from R.C.C. Text book of K L Rao in ur college? It makes a delightful reading. I used to love it.
M.H.V.Subbarao