Celesta Company to Secretary. Shanghai, August 6, 1928. Source: SMA (SMC), U1-3-1081 (1172).  

We have recently imported the Capitol Daylight Projector, which we ask the privilege of demonstrating to show its usefulness in crime suppression, health and traffic ordinances etc. 

This machie is portable and weighs only a few pounds, and could be used to great advantage in tea shops, market places, and other suitable locations without the expense of installation each time it is set up. Anyone without knowledge of cinema projection can use it. The film used is noninflammable, and through its system of continuous projection, suitable stories can be shown many hundreds of times per day, thereby reaching many thousands of people who would be otherwise overlocked with any other form of propaganda.

Commissioner of Police to Acting Secretary. Shanghai, October 8, 1928. Source: SMA (SMC), U1-3-1081 (1173).  

Whilst doubtless this machine may prove a useful medium for commercial advertising, I do not consider that results would justify first cost ($850) plus cost of constant change of films. 

If placed in places of public amusement, teashops, etc., it would be liable do damage if not constantly watched by police specially detailed, whilst if so placed as to be within of persons passing along a street, congestion on the sidewalk would probably occur. 

Acting Commissioner of Public Health. "File 2172 - Daylight Projector". Shanghai, October 9, 1928. Source: SMA (SMC), U1-3-1081 (1174)
 
With reference to the letter from the Celesta Company, I regret that, at present, there is no scope for such a machine in the Public Health Department.