The repaired telescope

An original fiction passage set in the nineteenth century.

The school telescope had lain unused since its lens cracked. Mr Broome, the teacher, had collected money for a replacement but found that the sum was insufficient. A travelling repairer offered to mend it for half the price. He polished the brass while explaining that the instrument would be as good as new. The pupils watched its surface shine.

Clara asked whether they could look through it before paying. The repairer said the daylight was unsuitable for stars. Mr Broome suggested a distant weather vane instead. Through the lens, the vane appeared twice, its two shapes refusing to meet. The repairer said old instruments sometimes required patience. Clara handed the telescope to another pupil without describing what she had seen.

The second pupil reported the same double image. Mr Broome asked the repairer to adjust it while they waited. After several attempts, the man admitted that one mounting was bent and would need a part he did not carry. He offered to return the following month. The teacher kept the payment in its envelope.

The brass remained bright when the telescope was placed back in its box. The children were disappointed; their planned evening observation would still have to wait. Mr Broome said the repair might yet be completed, but the promise should be checked when the instrument worked. Clara put the weather-vane drawing beside the money so they would remember what to test.

“The passage effectively shows why an attractive appearance should not replace evidence of function.”

Evaluate how successfully the writer presents this idea. Support your judgement with detailed references to the passage.