1. Personification: The horse is given human-like qualities and emotions. It is described as "old" and "wise," and it has "sad" eyes. This personification helps the reader to empathize with the horse and to see it as a sentient being.
2. Imagery: The poem uses concrete and sensory imagery to create a strong sense of place and atmosphere. The reader can almost see and feel the old horse as it walks through the snow, and the harsh winter landscape is vividly depicted.
3. Similes: The poem uses several similes to compare the horse to other things, such as a "stump of a tree" and a "ship at sea." These similes help the reader to visualize the horse and to understand its unique qualities.
4. Alliteration: The poem uses alliteration, or the repetition of consonant sounds, to create a sense of rhythm and musicality. For example, the "s" sound is repeated in the line "Sad is his walk through the winter snow." This alliteration helps to enhance the poem's musical quality and to create a memorable experience for the reader.
5. Repetition: The poem uses repetition of certain words and phrases, such as "old brown horse" and "gone his strength," to emphasize the main ideas and to create a sense of continuity and unity.
Overall, the use of these poetic devices in "Old Brown Horse" contributes to the poem's powerful emotional impact and its ability to evoke a strong sense of empathy for the old horse.