Form No. 55. jM-3-'i5. 



THE COMMONWEALTH OF MASSACHUSETTS. 



JOHN R. RABUN, 



METROPOLITAN PARK COMMISSION, 



ENGINEERING DEPARTMENT, 



14 Beacon Street, 



Boston, June 5, 1915. 



Mr. Walter Dean, 



29 Brewster Street , 

 Cambridge, Mass. 



Dear Sir; 



The following table from the chemical examination of 

 water in the Charles River Basin, taken at West Boston and North 

 Beacon Street bridges in 1914, shows the number of parts in 

 100,000 of chlorine: 



lest Boston Bridge, Surface, July, 35.00; Oct. 174.00 



West Boston Bridge, Bottom, July, 65.50; Oct. 168.00 



North Beacon St. Bridge, Surface, July, 1.60; Oct. 140.00 

 North Beacon St. Bridge, Bottom, July, 1.50; Oct. 143.00 



Very truly yours , 



Engineer. 



