xii AMERICAN HOMES AND GARDENS June, 1911 
| 
Coldwell Lawn Mowers 
Hand, Horse and Motor 
Coldwell’s Motor Lawn Mowers 
Will do the work of three horse 
lawn mowers—and do it better 
@ They will mow up 20 per cent grades. @ They leave 
no hoof-prints as horses do. They will roll the lawn 
smoothly. They do away with the expense of two 
men and three horses. They are of no expense 
when not in use. They are simple to operate and 
economical. They are a necessity on every large lawn 
Catalogue sent on request 
Manufactured by 
Coldwell Lawn Mower Co. 
Newburgh, N. Y. 
The New Building Estimator 
BY WILLIAM ARTHUR 
A PRACTICAL guide to estimating the 
cost of labor and material in building 
construction from excavation to finish, with 
various practical examples of work pre- 
sented in detail, and with labor figured 
chiefly in hours and quantities. A hand-book for 
architects, builders, contractors, appraisers, engi- 
neers, superintendents and draftsmen. Size, 434x634 
inches, 437 pages, cloth bound. Price, $2.50 postpaid 
AN INDISPENSABLE AID TO CONTRACTORS 
A circular describing this book will be mailed on application 
MUNN & CO., Inc. | 361 BROADWAY, NEW YORK 
THE JUMPING BEAN 
HAT extraordinary product of the 
vegetable kingdom, the “jumping 
bean,” is derived from a_ bush, 
closely resembling the coffee bush, that 
grows in the Yaqui River country of 
western and northern Mexico. The bush 
attains a height of from three to four feet, 
and the hundreds of blossoms that it puts 
forth are of an olive-green tint which, 
after ripening, turns to a buff gray. 
Within each blossom are two “fertile” 
seeds, and a third, which is the home of a 
small, exceedingly active worm, whose 
performances are responsible for the 
queer conduct of the bean. When this 
worm merges from its prison it becomes 
a beautifully colored moth. 
The seeds of the jumping bean blossom 
in the month of May. Then the female 
moth deposits one egg on the pollen of 
the flower. As the flower develops it 
forms a triangular-shaped shell on two 
sides, with a convex shape on the other. 
Within this the chrysalis develops into a 
grayish-brown worm about one-tenth of 
an inch in diameter and about half an inch 
in length. This worm lives inside its cell 
for a period of six months, or until the 
middle of November. Then, climatic 
conditions being favorable, it bores a hole 
through the end of its shell and flies away 
as a moth, to mate in its turn and perpet- 
uate the species. 
If, however, it is brought in the bean 
to a colder climate the worm will die in 
the shell. Cut a small hole in the end of 
a jumping bean about an eighth of an inch 
in diameter, and in less than one hour the 
worm will cover the break with a white 
fibre-like exudation from its stomach, 
working the mouth round the opening 
until the hole in the shell shall become 
completely closed. 
Kept in a moderately warm place, and 
not packed too tightly, the jumping beans 
will live for five or six months to mystify 
and amuse. The jumping is caused by 
the worm’s curling itself into a ball and 
then springing out to full length against 
the side of the shell, thus making the bean 
jump from the hand into the air. 
AGE OF FISH 
NTIL within recent years there had 
been ascertained no trustworthy 
way of finding out the age of fish. 
It has been shown that mere size does 
not indicate the age. Reibisch, Heincke, 
and others have discovered that many of 
the bones, scales and otoliths of fishes 
have annual age-rings, resembling those 
in tree-trunks, and by means of these 
Wallace and others have determined the 
rate of growth of plaice, showing that 
some specimens attain the age of twenty- 
five or even as much as_ twenty-nine 
years. Age can now be correlated with 
size and weight, although it appears 
that the sexes have a different rate of 
growth. 
PAINTING WINDOW SCREENS 
HEN repainting window screens 
and screen doors, give them a 
couple of coats of white paint, 
or else use a light tint, in place ‘of 
the conventional black or dark green. 
Screens painted in this way possess the 
peculiar advantage of presenting an un- 
obstructed view to a person on the inside 
looking out, while a person on the outside 
is prevented from looking into the hous2 
by the reflection of the light from the wire 
of the screen. 
