LA 
» 
D.Se., Lecturer on botany at University College, London; and he has 
furnished the very full and able report upon the whole investigation 
which is now published. 
In order to complete the documentary histery of the weather plant, it 
will be convenient to quote from the specification of the patent taken out 
by Mr. Nowack, the preamble in which he states the exact nature of 
his invention. 
“ Date of application, 31 December 1887. 
* Specification accepted, 12 October 1888. 
« A.D, 1887, 31st December, No. 18,026. 
« Complete Specification. 
“ A WEATHER INDICATOR. 
“ We, Joseph F. Nowack, manufacturing chemist, and Ernst Bahlsen, 
market gardener, both of Prag, in the Austro-Hungarian empire, do 
hereby declare the nature of our invention for ‘a Weather nee 
and in what manner the same is t to be particularly 
described and ascertained in and by the following statement : 
& Qur invention is based on the discov he said Joseph F. 
of the leaves corresponds always to a certain condition o the weather 
48 hours afterwards, and is therefore a reliable means of predicting the 
S 
e. 
« Tt is necessary to remark, ) 
observed in order to cultivate Nowack's weather plant in such a manner 
that it can be used as a weather indicator. In or 
maintain these conditions, we have constructed an appara s of 
combination with the weather plant, constitutes the principal sub) 
our invention. m 
& The conditions for the successful cultivation of the weather plant 
are— 
« 1. A temperature of at least 18° Reaumur. : 
« 9. Access of atmospheric air, with exclusion of wind. 
« 3. Protection against direct solar rays." 
After setting out the nature of the | ! : 
: em, he conc des :— 
Mire plant and the method of interpreting th rained the nature of 
same may be performed, we 
is— z | 
s . . Li * a ; E ture, such 
«]. An apparatus for indicating in advance changes in nature, o 
as changes of the weather, magnetie and electrical upon bier oi 
of Nowack’s weather plant (Abrus precatorius), Sal appara hen 
prisi nt vessel containing the ed geni closed. ENS 
rotected against injurious external fluences, S lent 
tini o ventilated and maintained at a temperature of at 
