Again, I can probably get the original latin text if needed from Finnish National Library.
Hirvonen, K., Vilkuna K. 1977. Pohjoisten kansojen historia: Suomea koskevat kuvaukset. Otava, Helsinki:
P. 54-55. About sorcery at Hälsingland.
Quote:Magic or witchcraft is also practiced among the people of Hälsingland. One of their chiefs, Vitulf, could destroy one's sight so the victim couldn't even se the buildings nearby. Also a man called Visin, a famous swordman, could make dull one's weapon with his eyes. However he was slayed by a Swedish Berserker called Starkad. He always kept the sword covered with very fine coat which is generally known to be the only way to protect it against the dullness.
But even magic or spells can't protect rocks slinged with force from making damage.
P. 89. About the Muscovian pirates at the Gulf of Finland.
Quote:Encouraged by the previous success the Muscovians are so bold that they'll attack even the largest vessels slowed down by the calm wind. Then they try to bruise the planks at the waterline. But if the crew fires them from above with arrows they try to retreat. Rarely a victory will follow, usually they are chased away with cannons, crossbows and slings.
P. 91-92. About Finns and their weapons.
Quote:Due of the excessive wildness among the Finns or the Finno-Ugric people the Royal regulation has forbited them using weapons like lance, arrows, throwing spears or long daggers against themselfs during peace time. However one should't think they haven't got any defence weapons to protect themselfs against raiding Muscovians who live too close. The first attacks are averted with staff slings. At close combat the Finns defend themselfs with slinging stones stuffed to belts. They (Finns) are so strong and so accurate that they never miss their target. [...]
Some use fist-size rocks which are attached with rope four span (span is c. 15-20 cm) long (when they haven't got any iron or lead balls or iron chain). With these they entangle the arms of cavalrymen or the feet of horses and then tackle them with yanking the rope.