He was gradually given more responsibilities in the business, and also studied English and French language, and eventually passed the necessary examinations for getting a trading licence.
[1] Hiorth co-founded the company Nydalens Compagnie in 1845,[6] along with wholesaler Hans Gulbranson, bailiff Ole Gjerdrum and engineer Oluf Nicolai Roll.
[8] Hiorth also founded Christiania Mekaniske Væveri in 1847, together with Gulbranson, Roll, Peter J. K. Petersen and Iver Olsen.
[9] In 1857 Hiorth was a co-founder of the association Akerselvens Brugseierforening, a coordinating body for factories exploiting the waterfalls of the river Akerselva.
Hiorth chose to resign as manager for the spinning mill in 1860, but was still a member of the board of directors.