From Cleansing the City, p. 28; (originally from Mayhew).
"It was the task of these men to excavate and cart off the human excreta deposited in cesspools, labor referred to as "nightwork" because by law it could only be performed after twelve o'clock at night. As Mavhew acknowledges, the work of emptying cesspools was "sometimes severe" (2:451). The "ropeman" of the gang would lower a tub down into the reeking pit of refuse, where the "holeman" waited to fill it; two "tubmen" then carried the load to a cart, destined for one of the city's dust yards, laystalls, or manure wharves that accepted deposits of human waste. Not only was the work necessarily strenuous, but it was also dangerous, since the noxious fumes generated by decomposing refuse could cause instantaneous death by asphyxiation." [continued below]