A letter sent from S.H. Hill to R.C. Newton dated 19 October 1862 describes how Etter's Battery was to be kept at Little Rock until properly equipped and instructed for the field. The battery was to remain there for at least a month. Perhaps it took longer than one month?
(http://cdm.sos.mo.gov/cdm4/item_viewer.php?CISOROOT=/mack&CISOPTR=9422&CISOBOX=1&REC=3)