HAY RICK COVERS. 57 



from the changes of the atmosphere, and dust, and it is asserted 

 by the most celebrated instrument makers, that the tone of in- 

 struments is preserved by the use of these covers. They are 

 manufactured in the shape of bags or cases, quite air-tight, or 

 otherwise, to fit the various instruments for which they are 

 intended. 



MATRES.S COVERS. 



These are made of impervious plated fabrics, and are intended 

 expressly for camp or ships' use, for the protection of beds and 

 matresses. The mouth of the cover may be tied tight enough 

 to exclude water when immersed in it. A number of matresses 

 protected by these covers, when thrown into, and secured to a boat 

 ever so leaky,will make it a complete life-boat, much safer to rely 

 upon than if the same matresses were filled with air. The same 

 covers will, upon occasion, serve as ships' letter-bags, or for the 

 preservation of property, and when filled with light articles will 

 answer the same purpose as above specified as floats or life-pre- 

 servers. 



COFFEE, GRAIN AND FRUIT COVERS. 



These are made of plated caoutchouc fabrics, of a conical 

 form, at the factories, and are well suited for the protection of 

 coffee, grain, or fruits, but more particularly coffee, when gath- 

 ered and left for a time in the fields. See plate , fig. 



HAY RICK COVERS. 



These are made at the factories, of the same material, in the 

 same way as coffee covers, already described. For such a use, 



