Introduction:
In the short story "The Third Level" by Jack Finney, Charley, the protagonist, discovers a secret and mysterious third level at a subway station in New York City. As he explores this hidden level, he encounters various intriguing sights and people.

Answer:

Charley's Observations:
Charley sees a variety of interesting things at the third level, including flickering gaslights, brass spittoons, men wearing a tan gabardine suit and a straw hat, and people with funny mustaches. These observations create an atmosphere of nostalgia and transport Charley to a different time period.

Flickering Gaslights:
Charley notices the presence of flickering gaslights, which were commonly used as a source of illumination in the past. This detail suggests that the third level exists in a different era, perhaps the early 20th century. The gaslights create a warm and nostalgic ambiance, adding to the charm of the third level.

Brass Spittoons:
Another sight that catches Charley's attention is the presence of brass spittoons. Spittoons were used in the past as containers for people to spit tobacco or chewed tobacco. The presence of these spittoons further reinforces the notion that the third level belongs to a time period different from Charley's present.

Men in a Tan Gabardine Suit and a Straw Hat:
Charley encounters men wearing a tan gabardine suit and a straw hat at the third level. This particular attire was popular during the early 1900s, further supporting the idea that the third level is a portal to the past. These men are depicted as calm and content, seemingly unaffected by the hustle and bustle of the modern world above.

People with Funny Mustaches:
Charley also notices people with funny mustaches at the third level. This detail adds to the overall characterization of the third level as a place that exists out of time, where people from different eras can coexist. The funny mustaches suggest that these individuals may belong to a bygone era when such facial hair styles were more prevalent.

Conclusion:
In conclusion, Charley's observations at the third level include flickering gaslights, brass spittoons, men in a tan gabardine suit and a straw hat, and people with funny mustaches. These details collectively create an atmosphere of nostalgia and transport Charley to a different time period. The presence of these elements suggests that the third level is a magical place where the past intersects with the present, allowing individuals to escape the modern world momentarily.