It is speculated that this helmet may have belonged to Cook 's second in command , Charles Clerke .
He sailed with Captain Cook on his first journey of exploration and continued to keep in contact with Cook 's further explorations .
It is speculated that this helmet may have belonged to Cook 's second in command , Charles Clerke .
He sailed with Captain Cook on his first journey of exploration and continued to keep in contact with Cook 's further explorations .