io Preface 



ing, stated that what was wanted was real 

 experience instead of theory. It is but fair 

 to state that Mr. Colcord has confined his 

 remarks to practical experience and proofs, 

 with corroborating testimony about the gov- 

 ernor." 



It may seem contradictory, or merely a mat- 

 ter of opinion, that capillary attraction should 

 be stated as the cause of bringing the juice 

 from the bottom to the top of the silo, and 

 holding it there, when it is also stated that 

 carbonic acid had taken the place of the air 

 in the silo, and that under pressure the car- 

 bonic acid was absorbed by the juice, causing 

 a partial vacuum, which is the cause of the 

 rising of the juice to the top of the silo ; but 

 both these statements are true, either separately 

 or combined. 



When I had 30 inches of juice at the bot- 

 tom of the silo, and was pressing heavily, it 

 happened that the juice began to disappear 

 very rapidly. I did not believe that capillary 

 attraction could be the cause of it, and sup- 

 posed that the pressure had burst a hole in 

 the bottom of the silo ; but, when the silo was 

 empty, I could find no leak. I allowed the 

 water from the aqueduct to run into the silo 

 for an entire day, kept the water in it for a 



