If you are looking for a lollipop type candy 235 degrees is nowhere near rock candy.
The link above that Doug listed lists ingredients and instructions. Very good resource.
It is all explained in chapter 7 section 6 page 98.
Temperature needed for rock candy is 300 to 305 degrees. Pure maple syrup burns at this temperature and these instructions list two different ways to overcome this.
12 x 16 Sugarhouse, 12 x 16 Woodshed
2 x 8 “The Mutt” Evaporator with Marcland Drawoff
Leader oil fired arch, Dallaire raised flue, Smoky Lake syrup pan and hoods with pre-heater
New Leader Clear Filter Press/Air Diaphragm Pump
5” Hand Pump Filter Press from Daryl-One of the first three! On loan to a friend.
Deer Run 250 gal/hr RO
A Very Understanding Wife
"At any time during the day you're only 10 seconds from disaster!"