REPORT ON MOSQUITOES. 373 



nearly parallel to the Dead Creek which is now used as an outlet 

 for the Tenth ward sewer. At this point the Lehigh Valley 

 Railroad curves to the south and meets the Peddie street sewer 

 at its crossing with the Pennsylvania Railroad as the apex of a 

 triangle. This triangle is a solid cattail area in which the open 

 water is completely covered with duckweed, making it impossi- 

 ble for mosquito larvse to breed. 



There are some breeding places along the edge of the high- 

 land norh and west of the Lehigh Valley Railroad, but these are 

 in process of elimination by being filled with ashes, etc. So the 

 space from the Pennsylvania Railroad to Frelinghuysen Avenue, 

 south of the Lehigh Valley Railroad, is made safe by the work 

 done in building the Pennsylvania Railroad freight station. 



There remains an oblong into which there is an intrusion of 

 highland crossing the Lehigh Valley Railroad and extending 

 almost half way across to the Peddie street sewer. On this high- 

 land is the sewer pumping- station which forces sewage through 

 a box sewer diagonally across the marsh beneath Pierson's 

 Creek, the Central Railroad dam, Peddie street sewer and into 

 the bay at the mouth of ]\Iaple Creek some 700 feet from shore. 

 This sewer is in bad condition and the sewage flows to a great ex- 

 tent over the meadow which is low and not much above tide 

 water. The railroad dams are three or four feet above the 

 marsh level and the Peddie street sewer bank is almost equally 

 high, hence this low area is enclosed by high banks. Originally 

 it w^as drained by Pierson's Creek, which was then a branch of 

 Maple Creek and a clean tidal stream. Its head was cut off as 

 already stated by the Lehigh Valley Railroad. Its mouth was 

 cut off by the Peddie street sewer, to which it is now a tributary, 

 and instead of clean tide water and fish it now carries sewage 

 and mosquito larvae. It crosses the eastern part of the oblong 

 not far west of the Central Railroad and as a whole parallel with 

 it and to this creek all the drainage of this depressed area must 

 come. There is a tide gate or sluice at the entrance of the Dead 

 Creek into the Peddie street sewer; there is none at the point 

 where Pierson's Creek enters into the sewer. The former is 

 in bad condition and practically useless, as the water gets under 

 and around it everywhere. The result is that whenever there 

 is an extra high tide the sewer water is forced over the low areas 

 in the marsh and whenever a heavy rain brings down an extra 

 amount of surface water it overflows and backs into the creeks 

 and over the meadow, \\nien once there is an overflow the 

 drainage out is ven^ slow, because there is only the Pierson 



