Simplify the following text for a Grade 4 native English-speaking person.
Original: The most famous is H. G. Wells 's 1895 novel The Time Machine , which uses a vehicle that allows an operator to travel purposefully and selectively , while Twain 's time traveler is struck in the head .
Simplified: The most famous is H. G. Wells 's 1895 novel The Time Machine . Well 's book uses a machine that allows an operator to travel to an exact time .