From there , the observing activities could be extended , once the calculated cost of 4465 Thalers .
The plan was approved on 7 April 1800 and the required conversion was completed by June 1801 .
From there , the observing activities could be extended , once the calculated cost of 4465 Thalers and the plan was approved on 7 April 1800 and the required conversion was completed by June 1801 .