When Ramanujan was sixteen and still in high school an elderly friend who knew of
his precocious mathematical talent gave him
George Carr's Synopsis of elementary results in pure and applied mathematics.
This two-volume encyclopedic tome contained six thousand theorems on all fields of
mathematics. As Ramanujan read and worked his way through these theorems
he discovered that he could derive results that were not in Carr.
This was the beginnings of Ramanujan's mathematical productions and
set the tone for his mathematical career.