Simplify the following text for a Grade 9 native English-speaking person.
Original: He climbed to the top the next day , writing in his journal : `` Took Kekwick and the flag , and went to the top of the mount , but found it to be much higher and more difficult of ascent than I anticipated .
Simplified: Stuart climbed to the top on 23 April 1860 , writing in his journal : `` Took Kekwick and the flag , and went to the top of the mount , but found it to be much higher and more difficult of ascent than I anticipated ... Near the top of the cone I placed a small bottle , in which there is a slip of paper , with our signatures to it , stating by whom it was raised .