-B^ 



IMPKOVED WATER BEDS. 167 



pose, they are really such, and answer quite as well as those 

 which are sold expressly for that purpose only. The cylinders, 

 being placed parallel to each other, are buttoned to a strap, as 

 represented in plate vii., fig. 1, or they may be covered with 

 a case, or tick, of the common sort, or of coated cloth, or vellum. 

 These beds have one very great superiority over those in which 

 the compartments are connected, as they can be easily repaired. 

 When one cylinder is damaged by a small leak it can be de- 

 tected by immersing it in water, when it might be impossible to 

 discover it in a whole "bed where all the compartments are con- 

 nected, and in this case the injury only extends to a fifteenth or 

 twentieth part, according to the number of cylinders. Besides, 

 a damaged cylinder may be replaced by another, or dispensed 

 with altogether, until it can be mended. 



Another' recommendation of this article is, that one or more 

 of the cylinders may be collapsed, or taken out from under an 

 invalid, so as to I'elieve any part of the body from pressure, or to 

 give a circulation of air. 



HOSPITAL WATER BED. 



This bed is made as represented in plate vii., fig. 2, by filling a 

 box with water, and spreading over it a cloth coated with gum, 

 which is nailed to the edge of the box. 



These beds are more troublesome to fill than air beds, and, 

 when filled, they are very heavy ; but they are without any other 

 objection, and are much easier and more comfortable, especially 

 for the sick and lame, than any kind of air bed. 



IMPROVED WATER BEDS. 



These are represented by fig. 3 in plate vii. The improve- 

 ment over an ordinary water bed consists in the addition of a 



y^ 



