"The problem of course was that all these horses produced huge amounts of manure. A horse will on average produce between 15 and 35 pounds of manure per day. Co

"The problem of course was that all these horses produced huge amounts of manure. A horse will on average produce between 15 and 35 pounds of manure per day. Consequently, the streets of nineteenth-century cities were covered by horse manure." Just imagine how many people were left out of jobs when cars appeared! (in relation to the recent topic of automation)