Final answer:
Dr. Manette is engaged in shoemaking when Lucie and Mr. Lorry find him in the attic near the wine shop. This serves as a therapeutic outlet for him and helps him maintain a sense of purpose.
Step-by-step explanation:
When Lucie and Mr. Lorry find Dr. Manette in the attic near the wine shop, he is engaged in a repetitive and rhythmic activity known as shoemaking. As a result of his long imprisonment, Dr. Manette suffers from mental and emotional distress, and his fixation on shoemaking serves as a therapeutic outlet for him. This activity helps him maintain a sense of purpose and relieves his anxiety.
By engaging in the familiar and skilled practice of shoemaking, Dr. Manette finds solace and a temporary escape from his traumatic past.