Upon arrival in April 1865, Coolsma was sent by the Netherlands Missionary Union (Netherlandsche Zendingsvereeniging, NZV) to the town of Cianjur.
Setibanya bulan April 1865, Coolsma dikirim oleh Serikat Misionaris Belanda (Netherlandsche Zendingsvereeniging, NZV) ke kota Cianjur.