Put sugar, water, syrup and salt into heavy saucepan.
Stir over medium heat until dissolved.
Boil slowly, without stirring, until hard ball stage 260°F (128°C), or until a small amount dropped into ice water forms a hard ball that is still pliable.
Just before hard ball stage is reached, beat egg whites in good size bowl until stiff.
Pour syrup mixture slowly in a thin stream into egg whites beating all the time until almost stiff.
When it appears dull and a small spoonful will hold its shape when dropped on dish, it is ready to pour into pan.
Stir in vanilla and cherries.
Scrape into greased 9 x 9 inch (22 x 22 cm) pan.
Cut into squares.