TWELFTH ANNUAL REPORT 43 



two of the outbuildings in the rear of the east wing of the main 

 laboratory building — and has provided each with a new cement 

 floor which greatly improves their appearance and usefulness. 

 The tar pits in the rear of the power house have been encased 

 in cement, and a storm drain connecting with the storm sewer on 

 Taft Avenue has been laid to drain the rear of the premises and 

 to receive the water pumped from the tunnel. The filling of 

 the swamp at the corner of Calle Herran and Taft Avenue, next 

 to the east wing, has been completed to a sunken garden grade 

 and will soon be planted to lawn. 



The following figures show that the amount of routine work 

 in practically all divisions and sections of the Bureau has in- 

 creased greatly, and would have seriously interfered with our 

 research work except for the devotion of our scientists who 

 have worked in the afternoons during the hot season, after 

 hours on week days, and on Saturday afternoons and holidays. 

 In view of the great diff'erence in the relative value and neces- 

 sity of research as compared with most routine work, I regret 

 that our employees have been occupied so largely with the latter, 

 especially as many requests for routine work are founded 

 on a false impression of the value of the specified test. For 

 example, the presence or absence of amoebae in surface water 

 is being regarded of less and less sanitary significance. The 

 organisms which live in surface water are incapable of living as 

 parasites in the intestines of man, and consequently are not 

 concerned in the production of dysentery. There is no doubt 

 as to the distinction between the pathogenic and the nonpatho- 

 genic amoebae. It follows that the mere presence or absence of 

 amoebae has little sanitary significance, and the examination 

 should be omitted where practicable. Often the ability of a 

 cement to pass the requirements of specifications does not prove 

 either its actual or relative value ; the purity of a paint does not 

 fix its value as a protective coating; the percentage of chlorine 

 does not establish the potability of water ; and the bacteria count 

 of a water several hours in transit to the laboratory, unless 

 packed on ice, has no value. We are requested to make chemical 

 analyses of samples and from the results obtained make definite 

 statements concerning such complicated considerations as the 

 rapid corrosion of a piece of galvanized iron, the relative suit- 

 ability of paints for use in sea water, the value of a mineral paint, 

 of creosote oil, or of tars, asphalts, and bitumens for paving pur- 

 poses, of Babbitt metals, of lubricating oils, etc. Obviously, it is 

 often impossible to give such information, and inability to do so 

 is sometimes considered as incompetency. My endeavor to dis- 



