「私」の(の)不快感(ふかいかん)を気にせず、必死(ひっし)に重たい汽車の窓を開けよう(まどおあけよう)とした

When the train entered one of many dark tunnels, soot and smoke (coal smoke) flowed into the carriage, making 'I' feel choked and cough. At that moment, the girl, paying no attention to 'I's gaze, began struggling with all her might to open the heavy window of the carriage. 'I' could not understand at all why she would open the window in such heavy smoke, growing even more irritated.