PHYSICAL AGENTS 



129 



raised to 60° and by "retarders" is kept at this temperature 

 for twenty to thirty minutes (Figs. 89 to 92). In another 



Fig. 84. — Steam chambers in hold of U. S. quarantine station barge 

 "Protector." Disinfected space. 





Fig. 85.— Municipal disinfecting station, Washington, D. C. 



