1 10 Dr. Masmts Description. 



spinning and weaving succeed best in air which rather in- 

 clines to dampness. The manufacturer is at present en- 

 tirely guided by observing the effects produced by stoves, 

 and hence the goods are often shrivelled, or otherwise in- 

 jured before he can discern any alteration in the state of 

 the medium. Wool and corn have their weight augmented, 

 sometimes as much as 10 or even 15 per cent, by the pre- 

 sence of moisture, &c." 



I will conclude by briefly enumerating some of the more 

 prominent purposes to which this Hygrometer may be 

 applied. 



1st. For meteorological purposes generally. 



2nd. For medical uses, to regulate the dryness of rooms, 

 hospitals, &;c. 



3rd. For regulating the dryness or humidity of certain 

 manufactories ; when a constant and particular state of dry- 

 ness or humidity is required in the preparation of many ar- 

 ticles of commerce ; and especially in numerous chymical 

 and pharmaceutical operations. 



4th. In ascertaining the quantity of moisture absorbed by 

 grain, wool, &c., where the weight of those articles is in- 

 creased by absorbing moisture ; by keeping them in damp 

 situations ; for fraudulent purposes, or otherwise. 



5th. In regulating the dryness of hot-houses, green- 

 houses, &c. 



6th. In the navy and merchant service, when used in 

 conjunction with the Barometer, or Sempysometer, to as- 

 certain with more certainty the probability of severe gales, 

 storms, &c., an advantage hitherto, unhappily, beyond the 

 reach of seamen, since both Mr. Daniell's and Sir J. Leslie's 

 Hygrometers have been comparatively useless on board 

 ship. 



The combined use of a simple and convenient Hygro- 

 meter, such as I have proposed, and acting with a fluid 

 always at hand, will be of great utility in removing the ob- 

 jections raised by naval men to the Barometer, as it will 

 enable them readily to determine, whether a fall in the 

 mercurial column in the barometer indicates the approach 

 of rain or wind, which the Barometer alone will not do. 

 Thus if a fall of the Barometer is accompanied by the indi- 

 cation of a relative degree of dryness on my Hygrometer, 



