Ventilator for sewers and drains
A Proposed Sewer System for San Francisco, 1875
Section of Manhole, plan two of four
Ventilator for sewers and drains
|
|
|
Ventilator for sewers and drains A Proposed Sewer System for San Francisco, 1875 Section of Manhole, plan two of four
Ventilator for sewers and drains
|