Windmills were used to grind grain, salt and even clay, and to extract water from the ground. There are two types of windmills
on Mallorca: square buildings topped by pinwheels that pump water, and classic flour mills with their round stone towers,
some dating back to the 14th century, with revolving roofs and six sails as opposed to the usual four, a unique feature of
Mallorca's windmills. Heavy chains inside the mills regulated the speed and direction of the sails, which can move hard and
fast enough to kill a man.
Flour mills and oil mills were widespread, most often as part of a farm or country estate, and where there was no wind or
water, donkeys continued to provide the power. These animal traction mills are known as blood mills in Catalan. In the 19th century
travellers would have seen numerous flour mills lining both sides of the city of Palma, some fifty at El Molinar and seven,
almost in a line, at Es Jonquet. Their white sails made an indelible impression. It is said that a boat carrying Pope Pius IX,
as a young man, was forced to shelter in the bay and, later, when giving audiences to Mallorcans, he would always ask if
those white windmills were still there.