It shall be unlawful for any person, firm or corporation to keep or cause to be kept, any beef cattle within the boundaries of the City and County of San Francisco, excepting as hereinafter provided:
For the sole purpose of loading, unloading and confining in corrals of beef cattle enroute to the slaughtering houses, the provisions of this Section shall not apply to that part of the City and County bounded and described as follows:
Commencing at the intersection of the southerly line of Islais Creek with the southwesterly line of Authur Avenue and running thence southeasterly along the southwesterly line of Arthur Avenue to the northeasterly line of Ingalls Street; thence southwesterly along the northeasterly line of Ingalls Street to the southwesterly line of Galvez Avenue; thence northwesterly along the southwesterly line of Galvez Avenue to the southeasterly line of Third Street; thence southwesterly along the southeasterly line of Third Street to the northeasterly line of Jerrold Avenue; thence northwesterly along the northeasterly line of Jerrold Avenue to the northwesterly line of Phelps Street; thence along Phelps Street in a southerly direction to Newcomb Avenue; thence along Newcomb Avenue to Quint Street; thence along Quint Street in a southerly direction to Scotia Avenue; thence along Scotia Avenue to Silver Avenue; thence along Silver Avenue to Augusta Street; thence along Augusta Street to Elmira Street; thence along Elmira Street to Islais Creek Channel; thence westerly to the tracks of the Ocean Shore Railway; thence northerly along the tracks of the Ocean Shore Railway to Napoleon Street; thence along Napoleon Street to Islais Creek; thence along Islais Creek to Third Street; thence along Third Street to the point of commencement.