220 
Instructions for Parents. 
a drawing in my next number, as I apprehend it is a 
great improvement on the common form. 
But there is some similarity to Mr. WoolPs ideas in 
the patents of Mr. Sadler and Mr. Trevethick, as will ap- 
pear from the description of his engine in the second vo- 
lume of Nicholson’s Journal, quto. series, p. 231. 
Mr, Sadler’s improvements consist in 
1st. His working without a lever or beam. 
2dly. Part of the steam previous to condensation, is 
employed a second time in another cylinder, the piston of 
which is depressed by the atmosphere. By this second 
application, it performs the office of an air pump, and adds 
to the total force of the machine. 
Mr, Trevethick ’s engine worked by the force of a co- 
lumn of water inclosed in a pipe, may be understood 
from the description of it in 1 Nicholson’s Journal, 8vo. 
p. 161. But his steam engine appears to be worked by 
steam of very high temperature, which is not condensed 
but permitted to escape. 
The article Steam Engine,” to be concluded in the 
next. 
INSRUCTIONS FOR PARENTS. 
By Ch. Gotth. Salzmann. 
^ 1. How to make yourself hated by your children.— 
Treat them with injustice, their hatred will naturally fol- 
low. Or this purpose may be effected by one parent’s 
setting the children against the other.’ Mr. S. here in- 
stances the very common practice of mothers threatening 
children with being punished by their father, or condoling 
with them when their father has corrected them. ‘ Be in- 
sensible to the caresses of your children, or take no share 
