Homer and Tex went back to the hotel after the first day and had a good night, Homer remarked about the odd sensation of walking around Indianapolis and how busy it was, not just with traffic, etc., but also about how flat it was. The absence of the mountains was very strange to him.
After they went back to the convention hall in the morning, it was the absence of everything in his display that was of far greater concern. Apparently everyone locked up their gadgets overnight but no one told Homer so someone had come through and taken everything in his display.
Luckily they are able to get replacements for most things sent from home by bus after some serious work by the guys at the mine.