6 to 8 and 17 to 16
The New York City Department of Public Works continued to extent the sewer system of the city in 1874 on a block by block basis, with the selected blocks chosen in a rather straight forward, if technically illegal process, bribery. On the street the DPW produced these handsome badges to let one and all know who was bringing them their new amenities.
This design from 1874 closely resembles the one produced in 1872 with some key differences. The number of "spokes" on the perimeter of the lid was reduced from the a idiosyncratic 17 to the much more mundane and symmetrical 16, while the spokes in the center circle grew from 6 to 8. Notice also the the inscription now has a definite top and bottom. The letters DPW SEWER are aligned along their bottoms to the inner circle, while the numbers 1874 dangle from their tops.
Nothing says sewer better than SEWER.
This cover was spotted on Amsterdam Ave and W 122nd St. but there are many others from this and other years on the Upper West Side. (I'm still looking for 1873 however!)