1. Bring lemon juice, sugar and 2 rosemary skewers to a boil.
2. Reduce heat to a simmer and simmer for 5 minutes.
3. Remove from heat and let cool.
4. Fill 4 glasses with ice and divide simple syrup among glasses.
5. Divide vodka into the glasses.
6. Top with Pellegrino.
7. Garnish with a fresh rosemary skewer.