Final answer:
Alliteration in the given text serves to mimic the sound of the stream, engaging the reader's auditory senses and adding to the sensory richness of the narrative.
Step-by-step explanation:
Role of Alliteration in Describing the Stream
Alliteration, the literary device that repeats consonant sounds at the beginning of words, creates a musical quality in text that enhances its vividness and appeal to the senses. For instance, in the sentence, 'As the cool stream gushed over one hand, she spelled into the other the word water, first slowly, then rapidly', the alliteration on the 's' sound imitates the sound of water, which engages the reader's auditory senses. This sensory involvement is reinforced by the tactile image of water gushing over the hand and the rapid spelling of the word water, creating a vivid sensory experience for the reader.
The stream is thus described not just visually but also through the sounds and physical sensations it evokes. This approach to description using alliteration allows the author to generate a more immersive and engaging narrative for the reader and to convey the essence of the stream more effectively.