عبارت than which a more disagreeable one I never travelled in در جمله زیر به چه معناست؟

 I was consequently forced to desist, and in the evening was so ill with a slow fever, that I could not sit on horseback, and was obliged to proceed in a cajava. These are panniers made of wood, with plank bottoms, and covered with cloth: a mule carries two of them. They are four feet in length, therefore the person carried is forced to remain in an upright sitting posture during the whole journey, with the constant risk of getting his head broken against the sides of the conveyance, than which a more disagreeable one I never travelled in.