New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1877-07-02

crown glass; magnificent dispersion is attalned There
cuou- facts about this prism II u Is turner
end end only oncthrd of It's dispersion Is occasohe
that the positions OF the co0rs i reversed III lI
spectrum. The Fmucnhofcr lines are vsi e III u VIII
ont lens aud without slit. Before thls Discovery "s
made il had always been conceded that the lucs WcI
images OF the SIT TIE circumstance remains dlilcu on
explanation although II was at INST suppo-sI 20 nc
merely consequence oi narrow inc the beam OF lgh ny
receiving IL at peculiar angle or course tue o oN'nr
ence Of using such ohect VISION Is very EIeat Us
her enhanced ny the absence that curvature Oi
tn rays which Is inevitable In the use oil long u" Vi
prisns set partly around circle.
The so-called Seventeen year locust has
appeared Lston. Penu aud has been examined Oy
Prof L,idy lie confirms the statement that the cicada
Is lncauabc OF damaging the cereal crops, and he thinks
that the admit,d injury to the wheat in that vicinity
bo oscb,d to other insects and especially TO the
Hcssi.u Gy The female clcada does not sing. Much III
formation is already presented 10 the pubic III
the Bulletins Of the United states Eatomoiogicai
Commission. concerning the Rocky Mountain To-
Gust, CGioyfHvs sDTeiUS. The Commissioners are
Professors G. V. Riley. A. :. Packard JF' ana !r"s
Thomas Careful descriptions Of the circumstances ana
mode Of life OF the young locu-t are given Before Cd
tanning wings ard when most IaycEOus while uaVehS
j. swatms II is calculated that the insects cannot make
a progress Of more than thirty miles from their haichhs
place in season. when food fails they become e'hl-
balls After acquiring wings they lose aplcute 10 Co"-
siderable extent and cease be destructive; they
sioncrs recommend several methods Of destroying the
insects for eut stages Of their growth Before Inc
egg, hatch hcy should be lowcd under, ana the gro
thoroughly compressed by narrowing ana rolling A''r
hatclng the young ocss be driven in numbers al
most as readily sheep; wtndrOWs or pics OF burning
hey or straw should then he prepared and the locust can
be driven into them enectual method at TINS stage
Is 10 drive them into ditch two feet wide and two iee
deep with pcrpcndicular Sides out OF when II appears
That they cannot readily jump If the width OF the dl'ch
is increased the depth should be also ana the stcephss
of the sides is essential but il water can ne let INTO the
ditcies tlIey need not be deep Where tie Wlnos
are high the insects are apt TO escape from Tue
ditch especially /. it be shallow. Large opcnmouihed
bag driven 10y horses over field, does good service,
peciiy if the end Of the bag or net DC made of Wre
gauze instead OF cloth when the horses are htched al
he sides Of the bag net II 10 l6 feet apart Icy
help drive the l0cus,s inward toward the net Our
elective cnutriyanccs stds sometimes hadc ol OIL
cloiu zinc sheets or IRON smcared with coat tar; SOME
times carving open furnace made Oi WIG anu NC
with burning pine the latter plan requires hoi ire
"A the ana lic neat Wllih lHo
sorcnng that The grain beneath gets ouy makes 10
da, atrc. SiuOOtu-DaIkcd tees can he pr itctcd N
LIBERAL wntrwashmE if The bark is rough or the tiuhklS
lacked around thr pun pose thc spaces "ciMte
The bark and the in bOcncd with colh an TIE Ddlh
below the TN is sncsed with grease TAR OF hc'she' vi
course the lin must he put nlgh enough, 50 mat Tue
.OpgcIS cannot jump over 10 from thc ground 'oltoh
batting sh paper, aud glazed paper answer Inc Ilfioe
of tim To an inferior extent. Missouri auH hhhcs"t"
struciou o. tie Insects ant Tn IL eggs ana Kansas max
tne work Gcs ucilUn compulsory upOH al aDi -bOttd
males between the ages O II and 80 years i lic us
ricis attacked. The various prices G ny the - esHc
Tor eggs - pcr bushel ana 30 CENTS per eaAOhi Tor
grassopp rs from ~ down 20 GEMS per busie the
highest prices being paid early III Tue season