in chapter ten, how has the farm grown after several more years?

Here are a couple of excerpts from chapter 10 that answer your question perfectly!

The farm was more prosperous now, and better organised: it had even been enlarged by two fields which had been bought from Mr. Pilkington. The windmill had been successfully completed at last, and the farm possessed a threshing machine and a hay elevator of its own, and various new buildings had been added to it......But the luxuries of which Snowball had once taught the animals to dream, the stalls with electric light and hot and cold water, and the three-day week, were no longer talked about. Napoleon had denounced such ideas as contrary to the spirit of Animalism. The truest happiness, he said, lay in working hard and living frugally. Somehow it seemed as though the farm had grown richer without making the animals themselves any richer-except, of course, for the pigs and the dogs.