 By autumn , its population had grown to thirteen ; the group built a 16 @-@ by @-@ 18 @-@ foot ( 4 @.@ 9 m × 5 @.@ 5 m ) log house and planted a small turnip garden and a 9 @-@ acre ( 3 @.@ 6 ha ) wheat field . By this time most of the plot had been surveyed , and surveying was completed on October 11 . 
