Answers to the Practical Questions and Problems Contained in the Fourteen Weeks' Courses: In ...

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THE mUlllL SERIES OF SmilDllRDSCIIOOyi

HARVARD COLLEGE

LIBRARY """"'

THE ESSEX INSTITUTE
TEXT-BOOK COLLECTION

GIFT OF

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OF NEW YORK

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Jl DESOBIPTirS CATALOOVE or «ll Ibesa uil many more nuT Iw DbUlned hj eKhuliic I

■ A. S. BARNES fcCOHPAHY,
ITatlonel Bdueatlonal TulUsherB,
& 113 WILLIAM STREET, NEW YORK.

THE f ORMAM SERIES IN MODE RN LANaUAfiE.

k Complete Course in German.

By JAMES H. WORMAN, A.M.

xmiiiAoina
O-KRMIA-N' COPY-BOOKS, OERMIAI^ ECHO.

IN FRBPARATIOir,

HISTORY OW GS-BlR]yU?LN- LITICRATXJRE,

GESRMIAN" JLNT> EIsra-XiISH LKXICOK".

J. TKE GBJtMAN GHAMMARS of Worinan are widely preferred on ac-
coant of their clear, explicit method (on the conversation plan), iutrodncing a eyptem
of analogy and comparison with the learners* own langoage and others commonly
studied.

The arts of speaking, of understanding the spoken language, and of correct pronnn-
elation, are treated wuh great success.

The new cLassilications of nouns and of Irregular yerbs are of great value to the
pupil. The use of heavy type to indicate etymological changes, is new. The Yocahu-
lary is 8jfnonymical--9ii»o a new feature.

II. WOTIMAN'S OKItMAN JlEAI>Ell contains progressive selections
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which are usually purchased in separate form for advanced students who have com-
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It has Biographies of eminent authors. Notes after the text. References to all Ger-
man Qrammars in common use, and an adcq,uate Vocabulary; also, Exercises for
trani>lation into the Qerman.

III. WOnnrAN'S GEBMAX echo {DeuUehes Echo) Is entirely a new
thing In this country. It presents Ihmlliar colloquial exercises without translation,
and will teach fluent conversation in a few months of diligent study.

No other method will ever make the student <U home in a foreign langnaee. By this
he thinks in, as well as speaks it. For the time being he is a German through and
through. The laborious process of translatiiig his thoughts no longer impedes free
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■ ■ ♦ •■

¥OBHAS'S COIFLETI FBEHGI mm

IS INAUQURATEB BT

Xi'JBCiarO IDE 3P.A.K.IS,

Or, "Fie&ch Eoho;^* on a plan identical with the German Echo described above.
This will bQ fouowod in due course by the other volumes of

TBCB3 ITRKlSrCH: SB3RIK8,

VIZ.:
A COMPIjBTE GJlAMlfAR, \A FItlSNCIl ltEAI>JSJi,

Air JEIiEMENTABT GRAMXA ft,\ A FRJEfyCIl ZEXJCOJT^
A aiSTOMX OJF EMJEJfCH ZJTJEILATUME

I* ♦ •'

WORMAN'S WORKS

are adopted as ftist as published by many of the best instttntloos of the coiintry. In
comx)letenesg, adaptation, and homogeneity for conslatent courses of instruction, thej

are simply

3 2044 097 017 123

/tc

/

/ Y I ^J .

/

/

a-:

4 %

/

. .'It

^ . ' \ .■' f ^ f *

ANSWERS

90 TBB

PRACTICAL QUESTIONS AND PROBLEMS

ooirrAiinED in

THE FOURTEEN WEEKS COURSES

IN

[atural fihiki^hg, fcrniatrg, and ptronomg.

BT

J. DORMAN STEELE, A.M., PIlD.,

PBIKOIFAL OF tbt-vtha PREB ACADEXT.

Ankhor ot"X Fburteen Weeks Conne In Fhnoaoptay," ** A Fourteen Weeks Comm In
Cbemisti7," and ** A Foorteen Weeks Course In Astronomy."

NEW YORK AND CHICAGO:
A. S. BAENES & CO., PUBLISHEEa

1870.

IMfPO'k TJJ^T AJ^J^O Uil'CEMEUT.

FOURTEEN WEEKS

or

[k'Ll. TlKlfi ©©DdM©

BY J. D. STEELE AND OTHERS.

•»•

The iixipftrs!lel«d soeceM of the flnt pablbhed voliime of this seriec, ** 14
WnxB n CBBMisTmr/* has encoanged the pablishera to prepare the foilow-
Ing Tolomes cm a like plan, comprising a complete course fai Natural Science
f jr those haying bnt a limited period to give to these branches. They are
especial^ adapted to Public and High Schools.

I^-^FourUen Weeks in J^'atural IPkiioeop^ ^f SO

Il.^rourieen Weeks in Ckemitify f SO

Ill^—I'ourieen Weeks in sisii'onottty / SO

ly.^Fourteen Weeks tn Geotogy f CO

y,-^Fourleen Weeks it* l^^sioiogy. In preparation.

VI»^Sieeie*s Key to all kis Manuals f SO

VII. ^ Wood's Object Lessons in Botany /SO

Till,— Ckambers^ JSlements of Zoology f SO

These books may be fomid at any of the leading bookstores in the United
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A. S. BARNES & CO..

j\r^w roSA\

Entered, according to Act of Congress, in the year i86q, by

A. S. BARNES & CO.,

In the Clerk's Office of the District Court of the United States for the Southern District

of New York.

STSKLB^S KBT.

PREFACE.

' fc"

This little work is designed to aid teachers who are using
the Fourteen Weeks' Course. The problems contained in
all the books are fully, and, it is thought, accurately solved.
Great pains have been taken to revise and compare them
carefully. The practical questions are answered, often not
in full, yet enough so to give the key to the more perfect
reply. The use of the text-books is presupposed, and the
statements merely supplement, or apply the fuller theories
therein contained and explained. On many points there
may be a difference of opinion. The author often finds in
his own classes a wide diversity. On mooted questions he
has merely advanced one view, leaving the subject open
for the discussion of other theories. Minute directions are
given, at the close of the book, for performing a course of
experiments in Chemistry. It is hoped that these may be
of service to teachers who, with incomplete apparatus, are
trying to illustrate to their pupils some of the principles of
that science. In all cases of doubt or misunderstanding
with regard to the answers or solutions, the author will be
pleased to correspond with any teacher using the Series.

Elmira, March 19, 1870.

ANSWERS

TO THE PEACTIOAL QUESTIONS

IN THX

FOUETEEN WEEKS' OOUESE

IN

NATURAL PHILOSOPHY.

[The bold-fkced flgnres refer to the pages of the FhUosophy ; the others to
the number of the Practical Questions.]

INERTIA.

30. I. If one is riding rapidly^ in which direction will he
be thrown when the horse is suddenly stopped f

In the same direction in which he is going. He has the
motion of the carriage, and his inertia carries him forward.

2. When standing in a boat, why, as it starts, are we thrown
backward f

Because the inertia of our bodies keeps them stationary,
while the boat carries our feet forward.

3. When carrying a cup of tea, if we move or stop quickly,
why is the liquid liable to spill f

The inertia of the tea tends to keep it still or in motion, as
the case may be. If we move the cup quickly, the motion is
not imparted to the liquid soon enough to overcome the
inertia. When, therefore, we start, the tea spills out back-
ward; or, when we stop, it spills out forward. We under-
stand this if we can tell why a cup of tea is more liable to spill
than one of sugar.

6 ANSWERS TO PRACTICAL QUESTIONS

4. Wky^ when closely pursued, can we escape by dodging?

We turn sharply. Our pursuer, ignorant of our design,
cannot overcome his inertia so as to turn as quickly, and
hence is carried past.

5. Why is a carriage or sleigh, when sharply turning a
comer, liable to tip over f

Because its inertia tends to carry it directly forward. A
puzzling question in this connection is — Why is a sleigh more
liable to tip over than a wagon ?

6. Why, if you place a card on your finger, and on top of it
a cent, can you snap the card from under the cent without
knocking the latter off your finger?

Because tlie friction between the card and the cent is so
slight that, by a quick snap, you can overcome the inertia of
the former without imparting any force to the latter.

7. Why J after the sails of a vessel are furled, does it zt^ll
continue to move; and why, after the sails are all spread,
does it require some time to get under full headway?

Its inertia must be overcome in the one case by the resist-
ance of the air and water,- and in the other by the force of the
wind.

COHESION.

40, I. Why can we not weld a piece of copper to one of
iron ?

Cohesion acts only between molecules of the same kind.

2. Why is a bar of iron stronger than one of wood?
Because its force of cohesion is stronger.

3. Why is a piece of iron, when perfectly welded, stronger
than before it was broken ?

By the hammering,, more particles are brought within the
range of cohesion.

4. Why do drops of different liquids vary in size ?
Because they vary in cohesive force.

5. Why, when you drop medicine, will the last few drops
contained in the bottle be of a larger size than the others ?

m NATUBAL PHIL080PHT, f

The pressure of the liquid in the bottle is less, and therefore
they form more slowly.

6. Why are drops larger if you drop them slowly ?

There is more time for the adhesive force of the bottle to
act on the liquid, and so a larger drop can be gathered.

7. Why is a tube stronger than a rod of the same weight f

Let a rod supported at both ends be broken in the middle.
"NVe shall see that it yields first on the circumference. So true
is this, that long beams heavily loaded have been broken by a
mere scratch of a pin on the lower side. The particles along
the centre break last. * They rather aid in the fracture, since
they afford a fulcrum for the rest of the rod, acting as the long
arms of a lever, to act upon. In a tube the particles at the
centre are removed and all concentrated at the outside, where
the first strain is felt.

8. Why, if you melt scraps of zinc ^ will they form a solid
mass when codledf

The heat overcomes, in part, the attraction of cohesion, so
that the particles flow fireely on each other. They now all
come within the range of cohesion, so that when the metal
cools they are held by that force in a solid mass.

9. /// what liquids is the force of cohesion greatest f
Mercury, molasses, etc.

10. Name some solids that will volatilize without melting f
Wood, coal, arsenic, camphor.

ADHESION.

47. I. Why does cloth shrink when wetf

By capillary attraction the water is drawn into the pores ot
the cloth. The fibres are thus expanded sidewise and short-
ened lengthwise. The cloth ^^ fulls up*^ or thickens while it
shortens and narrows (shrinks) in the process.

2. Why do sailors at a boat-race wet the sails f

The pores being full and expanded make the sails more com-
pact. They will therefore hold the wind better.

8 JLNSWBna to practical qVESTIONS

3. Why does not writing-paper blotf

Because the pores are tilled with size. (See Chemistry^
p. 161.)

4. Why does paint prevent wood from shrinking?
Because it fills the pores of the wood.

5. What is the shape of the surface of a glass of water and
one of mercury f

Ordinarily the former is concave and the latter convex.

6. Why can we not dry a towel perfectly by wringing f

Because of the strength of the capillary force by which the
water is held in the pores of the cloth.

7. Why will not water run through a fine sieve when the
wires have been greeted?

Because the grease repels the water and so prevents capil-
lary action.

8. Why will camphor dissolve in alcohol and not in water f

Because there is a strong adhesion between the alcohol and
camphor, and little, if any, between the water and camphor.

9. Why will mercury rise in zinc tubes as water .does in
glass tubes f

Because of the strong adhesion between zinc and mercury.

10. Why is it so difficult to lift a board out of water?
Because of the adhesion between the board and the water.

11. Why will ink spilled on the edge of a book extend further
inside than if spilled on the side of the leaves?

Because the capillary pores of the paper are short, being
only the thickness of a leaf, while the capillary spaces between
the leaves are longer and continuous.

12. If you should happen to spill some ink on the edge of
your bookf ought you to press the leaves together?

No. Because you would make the capillary spaces between
the leaves smaller, and so the ink would rise in them further.

13. Why can you not mix oil and water ?
Because there is no adhesion between them.

IN NATURAL PHILOSOPHY. 9

1 5 . Why will water wet your hand while mercury will notf

Because in the former case there is an adhesion, in the
latter none.

16. Why is a tub or pail liable to fall to pieces if not filled
with water or kept in the cellar f

Because the moisture dries out of the pores, and the wood
shrinks so as to let the hoops fall off.

17. Name instances where the attraction of adhesion is
stronger than that of cohesion.

Wood fastened by glue will often split before the glue will
yield. Paper stuck with paste, and bricks with mortar, are also
examples.

GRAVITATION.

©3. I. When an apple falls to the ground y how much does
the earth rise to meet itf

The earth falls as much less distance than the apple, as its
weight is greater.

2. What causes the sawdust in a mill-pond to collect in large
masses f

The attraction of gravity which exists between all bodies,
whereby they attract each other. All bodies on the earth
would tend to approach each other, and the bi^ ones would
gather all the little ones around them were they as free to move
as the sawdust floating on water.

3. Will a body weigh more in a valley than on a mountain f
It will, because the attraction of the earth is greater.

4. Will a pound weight fall more slowly than a two-pound
weight?

They will both fall in the same time, except the slight
difference which is caused by the resistance of the air. Galileo
propounded this view and proved it, in the presence of a vast
crowd, by letting unequal weights fall from the leaning tower
of Pisa.

TO ANSWESS TO PRACTICAL QUESTIOyS

5. I/ow deep is a welly if it takes three seconds for a stone to
fall to the bottom ofitf

(S) equation of fiBOling bodies, d = IG^ ; hence d = 16 x 8" =s 144 feet.

6. Is the centre of gravity always within a body — as , for
example y a ring?

It is not. In the case given it is at the centre of the circle.

7. If two bodies, weighing respectively 2 and 4 pounds, be
connected by a rod 24 inches long, where is the centre of gravity f

To be in eqailibrinm the weight of one multiplied by its distance from the
centre of gravity must eqnal the weight of the other miiliiplied by its dit«tancc.
21 -H 6 = 4 ; hence 4 in. is the unit for each poand. Therefore the centre of
gravity is 8 in. from the lai^r weight and 16 iiv from the smaller.

8. In a ball of equal density throughout, where is the centre
of gravity ?

At the centre of the ball.

9. Why does a ball roll down hillf

Because the line of direction falls without the small base of the
ball,

10. Why is it easier to roll a round body than a square one ?
Because the base of the ball is so much smaller, and therefore

the centre of gravity need not be raised to bring the line of di-
rection without.

1 1. Why is it easier to tip over a load of hay than one of
stone f

Because the centre of gravity in a load of hay is very high,
and in a load of stone very low. Therefore the centre of
gravity in the former need not be raised much to bring the
line of direction without the base, while in the latter it must be.

1 2. Why is a Pyramid the stablest of structures f

Because the base is so broad and the centre of gravity so
low. The centre of gravity must therefore be lifted very high
before the line of direction will fall without the base.

13. When a hammer is thrown^ on which end does it always
strike ?

On the heavy end or head, because that part is attracted by
the earth more strongly.

m NATUSAL PHILOSOPHY, 1 1

14. Why does a rope-walker carry a heavy balancing-pole f
Because in this way he can easily shift his centre of gravity.

15. What would become of a ball if dropped into a hole
bored through the centre of the earth f

In falling, it would gain a momentum which would carry it
past the centre of the earth. But as it is constantly coming
to a part having a slower axial revolution than itself, it would
scrape on the cast side of the hole until it reached the centre :
beyond that point it would scrape on the west side. This
friction would prevent its reaching the opposite side of the
earth. It would therefore vibrate to and fro, each time through
a shorter distance, until, at last, it would come to rest at the
centre of the earth.

16. Would a clock lose or gain time if carried to the top of
a mountain f

It would lose time, because the force of gravity would be
lessened. At the North Pole it would gain time, because there
the force of gravity would be increased.

17. In the winter y would you raise or lower the pendulum-
bob of your clock f

I would lower it, since the cold of winter shortens the pen-
dulum, and this' movement of the bob would counteract that
change.

18. Why is the pendulum-bob always made flat f
To decrease the friction of the air.

19. What beats off the time in a watch f
The vibration of the balance-wheel.

20. Is solved in the book.

21. What should be the length of a pendulum at New York
to vibrate half seconds ?

(1 sec.)' : (*/a sec.)* : : 39.1 in. : a? = 9.7 + inches.
To vibrate quarter-seconds f

(I 8ec.)« : (1/4 sec.)« : : 39.1 in. : « = 8.4 + inches.
To vibrate hours ?

(I 8ec.)« : (8600 sec.)« : : 89.1 in. : a? = 7997.7 miles.*

* Nearly the diametcr'of the earth.

c -■" ,

12 ANSWERS TO PRACTICAL qXTESTIONS

22. What is the proportionate time of vibration of two pen-
dulums, 1 6 and 64 inches long, respectively f

According to the third law of pendalams,
Time of Tib. of Iftt : Time of vib. of 3d : : -v/lB : \^el : : 4 : 8 : : 1 : S.

23. Why, when you are standing erect against a wall, and
apiece of money is placed between your feet y can you not stoop
forward and pick it up ?

By leaning forward you bring the centre of gravity in front
of your feet, and, as on account of the wall, you cannot throw
any part of your body back to preserve the balance, you fall
forward.

24. If a tower were i^Zfeet highy with what velocity would
a stone dropped from the summit, strike the ground ?

According to equation (3), v^ = 61 d. t;^ = 64 x 198. 9=112.5 feet.

25. A body falls in 5 seconds : with what velocity does it
strike the ground f

According to equation (1), 9 = 33 ^. v =32 x 5. 9 =160 feet.

26. How far will a body fall in 10 seconds f

According to equation (2), d = l^t^. (? = 16 x 10' = 1600 feet
With what velocity will it strike the ground?

According to equation (1), 9 = 33 ^. « = 32 x 10 = 330 feet.

27. A body is thrown upward with a velocity of 1^2 feet the
first second ; to what height will it rise f

Equation (1), v = 32 ^. 193 = 32 ^. ^ = 6 Bee.
" (2), rf = 16 <«. rf = 16 X 6«=576 feet.

. 28. A ball is shot upward with a velocity of 2^6 feet ; to
what height will it rise f How long will it contin ue to ascend ?

Usiug equations (1) and (2), as in the last problem, we hare :

< = 8 sec.
<l=1024 feet.

30. Are any two plumb-lines parallel ?

They are not, since they all point to the centre of the earth.
No two spokes of a wheel can be parallel.

m NATVBAL PBIL080PST. 1 3

31. -4 stone let fall from a bridge strikes the water in three
seconds. What is the height f

Equation (S),d = 16^. d =16 x 8« = 144 fecL

32. A stone falls from a church steeple in 4 seconds. What
is the height f

Eqaation (3), (f = 16^. (f = 16 x 4> = S56 feet.

33. How far would a body fall the first second at a height
of 12,000 miles above the earth^s surface f

(16,000 mi.)a : (40OO mi.)* :: 16 feet : « = 1 foot.

34. A body at the surface of the earth weighs 100 tons:
what would be its weight 1,000 myites above,

(5000 mi,)' : (4000 mi.)« : : 100 tons .: a? = 64 tons.

35. y4 boy wishing to find the height of a steeple lets fly an
arrow that just reaches the top and then falls to the ground.
It is in the air 6 seconds. Required the height.

Equation (2), d = 16 <«. d = 16 x 3« = 144 ft.

36. A cat let fall from a balloon reaches the ground in 10
seconds. Required the distance,

. Equation (2), d = 16 x 10* = 1600 ft.

37. In what time will a pendulum 40 feet long make a
vibration f

Accordins: to the third law of pendulums, and taking the length of a seconds*
pendulum as 39 in., we have :

1 sec. : « : : v^ : V40 x lit iu.

X = \/i^=12.30+
89

a; =3.6+ sec.

— In what time will a pendulum 52 feet long make a vi*

bration f

1 sec. ; X '.'. >/89 in. : i/52 x 12 in.

« = V ^ = 4 sec.

14 ANSWJSSS TO PSACTTCAL QUESTIONa

-^How long would it take for a pendulum one mile in length
to make a vibration f

— How long would it take for a pendulum reaching from,
the earth to the moon to make a vibration ?

— Required the length of a pendulum that would vibrate
centuries, (To be solved like problem 10.)

38. Two meteoric bodies in space are 12 miles apart. They
weigh 100 and 200 lbs, respectively. If they should fall
together by force of their mutual attraction, what portion of
the distance would be passed over by each body f

The distance passed over by the two bodies is inversely as
their mass; hence one nioves 8 miles and the ether 4 miles.

39. If a body weighs 2,000 lbs, upon the surface of the earthy
what would it weigh 2,000 miles above f

(6000 mi.)' : (4000 ml.)' : : 9000 lbs. : x = 888 V» lbs.

— How much 500 miles above f

(4S00 mi.)' : (4000 mi.)3 : : 2000 lbs. : x = 1580 +lbs.

The weight of bodies below the surface of the earth de-
creases as the distance increases. Ex, : What would the above
body weigh if carried 2,000 miles below the surface f i ,000 lbs.
— 1 ,000 miles below ? i , 5 00 lbs.

40. At what distance above the surface of the earth will a
body fall, the first second, 21 J inchest

A body foils 16 ft.* (192 Inches) at the sarfoce of the earth. VlX^/^vox^'&i^kc^
V9 of 192 inches : Now as the attraction is inversely as the square of the dis-
tance, the distance mast be >/9, or % times that at the surfoce. Hence the body
mast be 12,000 miles from the centre, or 8,000 miles from the sarface of the
earth. The problem may be solved directly by proportion, thas :

ar' : 40003 : : 192 inches : 21 Vj inches.

X = 12000 miles (distance fh>m the centre)

12000 miles— 4000 miles=8000 miles.

41. How far will a body fall in 8 seconds? 1,024 ft- — ^^^
the Zth second f 240 ft. — In 10 seconds f 1,600 ft. — In the
2,0th second f 944 ft.

* According to the best aathorities the distance is more exactly 16Vis ft*

m NA TCJtA t PBIL OSOPHT. 1 5

MOTION.

80. I. Can a rifle-batl be fired through a handkerchief %US'
pended loosely from one comer f

No. The wind of the ball will lift the handkerchief.

2. A rifle-ball thrown against a board standing edgewise
will knock it down ; the same bullet fired at the board will
pass through it without disturbing its position. Why is this?

The ball which is thrown has time to impart its motion to
the board ; the one fired has not.

3. Why can a boy skate safely over a piece of thin ice, when^
if he should pause y it would break under him directly f

In the former case there is time for the weight of his body to
be communicated to the ice ; in the latter, there is not.

4. Why can a cannon-ball be fired through a door standing
ajar, without moving it on its hinges f

Because the cannon-ball is moving so quickly that its motion
is not imparted to the door.

5. Why can we, drive on the head qf a hammer by simply
striking the end of the handle f

This can only be done by a quick, sharp blow which will
drive the wooden handle through the socket before the motion
has time to overcome the inertia of the iron head. A slow,
steady blow will be imparted to the head, and so fail of the
desired effect.

6. Suppose you were on a train of cars moving at the rate
of 2P miles per hour : with what force would you be thrown
forward if the train were stopped instantly f

With the same velocity which the train had, 01 44 feet per
second. Your momentum would be your weight avoirdupois
multiplied by this velocity.

7. In what line does a stone fall from the mast-head of a
vessel in motion f

In a curved line, produced by the two forces — gravity and
the forward motion of the vessel.

l6 AirSWeBS TO PRACTICAL QUESTIONS

%, If a ball be dropped from a high tower it will strike the
earth a little east of a vertical line. Why is this f

In the daily revolution of the earth" on its axis, from west to
east, the top of the tower moves faster than the bottom, be-
cause it passes through a larger circle. When, therefore, the
ball falls, it retains that swifter easterly motion and so strikes
east of the vertical.

9. // is stated that a suit was once brought by the driver of
a light-wagon against the owner of a coach for damages caused
by a collision. The complaint was that the latter was driving
so fast, that when the two carriages struck, the driver of the
former was thrown forward over the dash-board. Show how
his own testimony pro^jed him to have been at fault.

When the ligfit-wagon was suddenly stopped, its driver went
on by his inertia with the same speed at which the wagon was
moving. That this threw him forward over the dash-board,
proves his speed to have been unusual.

10. Suppose a train moving at the rate of 2^0 miles per hours
on the rear platform is a cannon aimed parallel with the track
and in a direction precisely opposite to the motion of the car.
Let a ball be discharged with the exact speed of the train,
where would it fall?

In a vertical line to the track. The two equal, opposite
motions would exactly destroy each other.

1 1 . Suppose a steamer in rapid motion and on its deck a
man jumping. Can he jump further by leaping the way the
boat is moving or in the opposite direction f

It will make no difference as long as he jumps on the deck.
Should he jump off the boat, then the effect would be different

12. Why is a running jump longer than a standing one f
Because the motion gained in running is retained in the

jump and adds to its distance.

i^. If a stone be dropped from the mast-head of a vessel in
motion^ will it strike the same spot on the deck that it would if
the vessel were at rest f

It will. It falls with the motion of the vessel, and goes just
as fax forward while falling as the vessel does.

m NATURAL PBILOSOPHY. 1 7

14. Could a party play ball on the deck of the Great Eastern
when steaming along at the rate of 20 miles per hour^ without
making allowance for the motion of the shipt

They could. The ball would have the motion of the ship,
and would move with it in whatever direction they might
throw it.

15. Since ^^ action is equal to reaction y^ why is it not as dan-
gerous to receive the ^^ kick^^ of a gun as the force of the bullet f

The striking force is as the square of the velocity; and the
velocity with which the gun moves backward is as much less
than that with which the bullet moves forward, as the gun is
heavier than the bullet. For this reason a heavy gun will
kick much less than a light one.

16. If you were to jump from a carriage in rapid motion,
would you leap directly toward the spot on which you wished
to alight?

No ; because as one jumps from the wagon he has its for-
ward motion, and will go just as far ahead, while leaping, as
he would if he had remained in the carriage. He should,
therefore, aim a little back of the desired alighting-place.

17. If you wished to shoot a bird in swift flight, would you
aim directly at it f

No. The bird will fly forward while the bullet is going to
it. One should, therefore, aim a little in advance.

iS, At what parts of the earth is the centrifugal force the
least f

The poles. They simply turn around in 24 hours.

19. What causes the mud to fly from the wheels of a carriage
in rapid motion f

The centrifugal force.

20. What proof have we that the earth was once a soft mass f

It is flattened at the poles. This effect is produced upon a
ball of soft clay by simply revolving it on a wire axis.

21. On a curve in a railroad, why is one track always
higher than the other?

i8 Ajrswxsa to pjuctical qtssTioNa

The outer track is raised that gravity may balance the cen-
trifugal force.

22. What is the principle of the sling t

The sling is whirled until a strong centrifugal force is
generated ; the string, the centripetal force, is then released,
when the stone flies off at a tangent.

23. The mouth of the Mississippi river is about 7.\ miles
further from the centre of the earth than its source. What
causes its water to thus *'run up hillV*

The centrifugal force produced by the revolution of the earth
on its axis tends to drive the water from the poles toward the
equator. Were the earth to stand still in its daily rotation, the
Gulf of Mexico would empty its waters back through the Mis-
sissippi to the northern regions.

24. Is it action or reaction that breaks an egg when I strike
it against the table f

The reaction of the table.

25. Was the man philosophical who said ^^ it was not the
falling so far but the stopping so quick that hurt him f"

He was.

26. If one person runs against another, which receives the
greater blow ?

Action is equal to reaction : hence the blows must be equal.

27. Would it vary the effect if the two persons were running
in opposite directions f

The blow would then be the sum of both their momenta.

If they were running in the same direction ?
' The blow would be equal to the difference of their momenta.

28. Why can you not fire a rifle-ball around a hillf

Because a single force always produces motion in a straight
line.

29. Why does a heavy gun " kick^* less than a light one?
See problem 15.

30. A man on the deck of a large steamer draws a small

nr NATUHAL PSILOaOPHT, 19

boat toward him. Haw much does the ship move to meet the
boat?

The ship moves as much less distance than the boat, as it is
heavier than the boat.

31. Suppose a string, fastened at one end, will just support
a weight 0/2^ lbs. at the other. Unfasten it, and let two per-
sons pull upon it in opposite directions. How much can each
pull without breaking it f

25 lbs. The second person, in the latter case, can pull as
much as the nail did in the former.

32. Can a man standing on a platform-scale make himself
lighter by lifting up on himself f

He cannot ; because action is equal to reaction, and in an
opposite direction. As much as he lifts up, so much must he
press down.

33. Why cannot a man lift himself by pulling up on his
boot-straps ?

See last problem.

34. If from a gun pUued vertically, a ball were fired into
perfectly still air, where would it fall f

It would return into the gun.

35. With what momentum would a steamboat weighing
1,000 tons, and moving with a velocity of 10 feet per second,
strike against a sunken rock ?

1000 tons X 10« = 100,000 tons.

^6, With what momentum would a train of cars weighing
100 tons, and running 10 miles per hour, strike against an
obstacle f

The Telocity per Becond is UVt ft. 100 tons x (14V»)* = 21,611 Vt tons.

37. What would be the comparative striking-force of two
hammers, one driven with a velocity of 2.0 feet per second, and
the other 10 feet f

so* = 400. 10* = 100. 400 : 100 : : 1 : 4. Hence one will strike fonr times as
hnrd a blow as the other. Thin principle is of great importance in chopping
wood, splitting rails, and in all cases where percussion is concerned. Th«
highest attainable velocity is to be songht.

20 ANaWBRS TO PRACTICAL qUESTIONS

— There is a story told of a man who erected a huge pair of
bellows in the stem of his pleasure-boat, that he might always
have a fair wind. On trial the plan failed. In which di-
rection should he have turned the bellows, f

In the manner adopted at first, of turning the nozzle toward
the sails, the action of the wind against the sails and the re-
action of the bellows against the boat just balanced each other.
If the man had turned the nozzle backward he could have
saved the reaction of the bellows to move the boat. This
would, however, have been a most costly and bungling way
of navigation.

— If we whirl a pail of water swiftly around with our hand^
why will the water all tend to leave the centre of the pailf
Why will the foam all collect in the hollow at the centre f

THE MECHANICAL POWERS.

R9. I. Describe the rudder of a boat as a lever.

The water is the F, the boat the W, and the hand the P.
As the W is between the F and the P, it is a lever of the
second class.

2. Show the change that occurs from the second to the third
class of levers, when you take hold of a ladder at one end and
raise it against a building.

At first the ground is the F at one end, the hand the P at
the other, and the ladder the W hanging between ; hence this
is a lever of the second class. After a little, the F remaining
the same, the P is applied at one end, near the F, and the
ladder is the W hanging at the other ; hence this is now a
lever of the third class.

3. Why is a pinch from the tongs near the hinge more
severe than one near the end f

Because in the former case the tongs are a lever of the first
class — in the latter, of the third. In the first class there is a
gain of power, in the third a loss.

4. Two persons are carrying a weight of 250 lbs,, hanging

IS NATURAL PHILOSOPHY. 2 1

between them from a pole lo feet in length. Where should it

be suspended so that one will lift only 50 lbs. ?

One lifts 50 lbs. ; the other 200 lbs. The proportionate length of the arms
of the lever should be the same as the proportionate weights— i. «., 1 to 4.
10 -«- 6 = 2, the unit of measure. Hence one arm is 2 feet long and the other
8 feet long. Pboof.— (See Prob. 7, p. 10.) 60 x 8 = 200 x 3. This is the
substance also of the equation P x Pd = W x Wd.

$. In a lever of the first class, 6 feet long, where should the
F be placed so that a Pofilb. will balance a IV of 2^ lbs. ?

6 feet = 72 Inches. 73 -•- 24 = 8, the unit of distance. The W must be
placed 8 in. and the P 69 in. fh>n^ the F. Pnooi'. 23 x 3 = 1 x 69 (Prob. 4).

6. What P would be required to lift a barrel of pdrk with a

windlass whose axle is one foot in diameter and handle ^ft,

long?

P : W : rad. of axle : : rad. of wheel.

e : 200 lbs : : Va ft- : 8 ft

X = 88Vt 11m>-

7. What sized axle, with a wheel 6 feet in diameter, would
be required to balance aW of \ ton by a P of 100 lbs. t

P : W : : rad. of axle : rad. of wheeL

100 lbs. : 2000 lbs. : : se : 8 ft.

X s Vao ft* = t^o isd* f hence the diameter = s/io ft*

8. What number of movable pulleys would be. required to
lift a W of 200 lbs. with aPof2$ lbs. f

w

TTs P X twice the no. of mor. pulleys ; hence — = twice the no. of mor. pul^s.
200 -► 25 = 8. 8 -► 3 = 4 = the no. required.

9. How many lbs. could be lifted with a system of \ movable
pulleys y and one fixed pulley to change the direction of the
force, by a P of 100 lbs. f

W=3 P X twice the no. of mor. pulleys.
100 lbs. X (4 X 2) = 800 lbs. = the W.

10. What weight could be lifted with a single horse-power
(SStOOO lbs.) acting on the tackUrblock? (Fig. 62.)

This block has 3 movable pulleys, and using the equation of the pulleys given
In the last two problems, we have, making no allowance for fHction,

88,000 lbs. X (3 X 2) = 198,000 lbs.

22 ANSWERS TO PRACTICAL QUESTIONS

11. What distance could there be between the threads of a
screw, that a Pof2$ lbs., acting on a handle 3 ft. long, may
lift I ton weight?

P : W : : Intenral : Circumference.

85 lbs. : 9000 lbs. :: a; : 73 in. X 8.1416.

a: = 8.83 — in.

12. How high could a Pof\i lbs,, moving 16 ft, along an
iticlined plane, lift a Wof^ Ibs.f

F : W : : height : length.

IS lbs : 96 Ibd. : : a; : 16 ft.

a; = 2 ft.

13. I wish to roll a barrel of flour into a wagon, the box of
which is ^ft. from the ground, I can lift but 24 lbs. How
long a plank should I get?

F : W : : height : length.
84 IbB : 196 IbB. : : 4 ft. : a; = 32>/s ft

1 4. The * ' evener'^ of a pair of whiffletrees is ^ft, 6 in, long ;
how much must the whiffletree be moved to give one horse the
advantage of \ over the other ?

For erery 3 Ibe. one horse pnllp, the other mast pall 4 lbs. : hence 7 represents
the proportion in which the load is to be divided. 8 ft. 6 in. = 48 inches. 48
in. -1-7 = 6 inches, the nnit of measure. Hence one arm of the evener mast be
6 in. X 3 = 18 in. long, and the other 6 in. x 4 = 84 in. long. Or, if we prefer, wo
may say 81 in. — 3 in. = 18 in. lonsr, and 31 in. + 8 in. = 84 in. long. Prooi*.—
(See Prob. 4, p. 80.) 18 x 4 = 84x 3 = 73.

15. In a set of three horse whiffletrees, having an " evener'^

^ft, long, at what point should the plough-clevis be attached

that the single horse may draw the same as each one of the

span of horses?

For every lb. drawn by the single horse the span shonld draw 8 lbs. : hence
8 represents the proportion in which the load is to be divided. 60 in. -»- 3 = 30
in., the nnit of measure. 80 in. x 1 = 80 in., and 80 in. x 8 = 40 in. Hence one
arm mnst be 80 in., and the other 40 in. long.

To give i advantage ?

The single horse should draw 8 lbs. and each of the others 4 lbs. : hence the
span should draw 8 lbs. 60 in. -1- 11 = 5Vii in.i the nnit of measare. 5Vit in*
X 3 = I6V11 ii»M and BVn in. x 8 = 48Vii in-

16. What W can be lifted with a P of lOO lbs. acting en a
screw having threads \ of an inch apart and a lever handle 4
ft, long?

m NATXTRAL PHILOSOPHY. 23

F : W :: Interval : Circamference.
100 IbB. : a; :: V4 in. : 96in. X 8.1416.
a; = 130,637-1- lbs.

17. What is the object of the big balls cast on the ends of the
handle of the screw used in copying-presses ?

By their inertia and centrifugal force they make the motion
more uniform and continuous.

18. In a steelyard 2 ft, long, the distance from the weight-
hook to the fulcrum-hook is 2 in. How heavy a body can be
weighed with a i lb. weight at the further end f

84in. — Sin. =22ii^ 1 lb. x 33 = 33 lbs. = P. 23 lbs. -► S = 11 lbs. = W.

19. Describe the change from the \st to the ^d class of levers,
in the different ways of using a spade.

When digging, the ground at the back of the spade is the
F ; the ground lifted is the W ; and the hand at the other end
is the P. As the W is at one end, P at the other, and the F
between, this is a lever of the ist class. When throwing
dirt, the left hand at one end of the spade is the F ; the dirt
at the other end is the W, and the right hand between the
two is the P. As the P is between the F and the W, this is a
lever of the 3d class.

2a Why are not blacksmiths^ and fire tongs constructed on
the same principle f

The former are of the ist class, as power is required: the
latter of the 3d class, as rapidity only is necessary.

21. In a lever of the ^d class, what W will a P of ^o lbs,
balance, if one arm is 12 ft. and the other 3 ft. long?

P : W : : Wrf : Pd.

60 lbs. : a; : : 12 ft. : 8 ft.
X = 12 Va lbs.

22. In a lever of the 2d class, what W will a P of $0 lbs.
balance, with a lever 12 feet long and W^ feet from the Ff

60 lbs. : a; : : 8 ft. : 13 ft.
x = 200 lbs.

24 ANaWXSa TO PSAOTICAL QUSaTIOITa

23. /n a lever of the \st class^ what Wwill a P of $0 lbs,
balance, zf^itk a lever lift long and the F "^ ft, from the Wf

60 lbs. : a; : : 8 ft. : 9 it.
a; = 1501b8.

24. In a wheel and axle, the P=40 lbs., IV =^60 lbs,,

diameter of axle = 8 in. Required the circumference of the

wheel,

P : W : : diuneter of axle : diam. of wheel

40 IbB. : MO lbs. : : 8 in. : a; s 7S in. = 6 ft., the diameter of wheel.

4S ft. X 8.1416 = 18.85 ft., the circomference of the wheel.

25. In a wheel and axle the P^2o lbs,, the W^^ 240 Ibi,,
and the diameter of wheel ^ \ft. Required the circumference
of the axle,

80 IbB : 840 IbB : : a; : 48 in.

a; = 4 in. (diameter of axle).
4 in. X 3.1416 = 18.56 in. (circumference).

26. Required^ in a wheel and axle, the diameter of the wheel,
the diameter of the axle being 10 inches y P=ioo lbs, and IV
= I ton,

100 lbs. : 8000 lbs. :: 10 in. : a; = 800 in. = 16Vt ^

27. What P would be necessary to sustain a weight of
3,780 lbs,y with a system of 6 movable pulleys and one ropef

W = P X twice the no. of mov. pnlleys.
8,780 lbs. = P X (6 X 8). P = 815 Ibe.

28. How many movable pulleys would be required to sustain
a IV of 420 lbs, with a P of 210 lbs, f — Ans. i.

HYDROSTATICS.

121. I. Why do housekeepers test the strength of lye^ by
trying whether or not an egg will float on itf

The potash dissolved in the water to form lye increases the
density of the liquid. When enough has been dissolved to
make its specific gravity greater than that of the egg, the egg
will float. This becomes, therefore, a simple means of testing
the amount of potash contained in the lye.

m NATURAL PHILOSOPHT, 25

2. How much water will it take to make a gallon of strong
brine f

A gallon. The salt does not increase the bulk of the liquid.

3. Why can a fat man swim easier than a lean one ?

Because muscles and bones are heavier than fat The speci-
fic gravity of a fat man is therefore less than that of a lean one.

4. Why does the firing of a cannon over the water sometimes
bring to the surface the body of a drowned person f

One answer is given in the Philosophy. It is probable, also,
that the firing of the gun produces a partial vacuum, or in
some way takes off, for an instant, a part of the pressure of the
air on the water. The gases in the body would then expand
and bring it to the top.

6. If we let bubbles of air pass up through a jar of water,
why will they become larger as they ascend f

The pressure of the water is less as they near the top, and
so they expand.

7. What is the pressure on a lock-gate \\feet high and 10
feet wide, when the lock is full of water f

14 X 10 X 7 X 1000 oz. = 960,000 os. =61,360 Ibe.

8. Will a pail of water weigh any more with a live fish in
it than without f

If the pail were full before the fish was put in, then it will
make no difference, since the fish wilMisplace its own weight
of water, which will run over. If the pail is only partially
filled, then, though the fish is upheld by the buoyancy of the
water, since action is equal to reaction, it adds its own weight
to that of the water.

— If a man and a boy were riding in a wagon, and, on com-
ing to the foot of a hill, the man should take up the boy in his
arms, would not that help the horse t

9. If the water filtering down through a rock should collect
in a crevice an inch square and 7.^0 feet high, opening at the
bottom into a closed fissure having 7.0 square feet of sutface^
what would be the total pressure tending to break the rock t

2

26 ANSWSS8 TO PBACTICAL QUKSTIOITS

Th» pnumn Is propct ti o— I to th% height and not the t\xe of the colmmi,
hence the pieMure fo

90 X Sae X 1000 OS. sS,000,000 ox. = 812,600 Ihe.

la H^Ay can stones in water he moved so much more easily
than on landf

Because the water buoys up about one-half of their weight.

1 1. Why is it so difficult to wade in the water where titer e
is any current f

Because the buoyant force of the water makes us so light
that we are easily carried away from our footing.

12. Why is a mill-dam or a canal embankment small at the
top and large at the bottom f

Because the pressure of the water increases with the depth.

13. In digging canals and building railroads^ ought not the
engineer to take into consideration the curvature of the earth f

Certainly. If he should build on a true level he would find
his embankment pointing up to the stars.

14. Is the water at the bottom of the ocean denser than that
at the surface f

The immense pressure must condense it very much at great
depths. There is a certain point beyond which divers cannot
penetrate.

15. Why does the bubble of air in a spirit-level move as the
instrument is turned f

Because the air is lighter than the alcohol and rises con-
stantly to the highest point. For this reason, also, the tube
is curved upward at the centre.

16. Why can a swimmer trecul on glass and other sharp
substances at the bottom of the water without harm f

See problem 11.

1 7. Will a vessel draw more water in salt or in fresh water t
In fresh, because its specific gravity is less.

18. Will iron sink in mercury f

No. It will float, like a cork on water.

19. The water in the reservoir in New York is about ^feei

IN NATVRAL PHILOaOPHT. ZJ

above the fountain in the City Hall Park, What is the pres-
sure on a single inch of the pipe at the latter point f

(1000 oz. X 80) -I- 144 = 34.7 lbs.

20. Why does cream rise on milk f
Because it is lighter than the milk.

21. If a ship founders at sea, to what depth will it sink t
Until its specific gravity becomes equal to that of the water?

22. There is a story told of a Chinese boy who accidentally
dropped his ball into a deep hole, where he could not reach it.
He filled the hole with water, hut the ball would not quite float.
He finally bethought himself of a lucky expedient, which was
successful. Can you guess it f

H6 put salt in the water.

23. Which has the greater buoyant force, oil or water?
Water, because its density is greater.

24. What is the weight of \ cu. ft, of cork f

1000 oz. = the weight of 1 en. ft. of water.
.940 = the spec. gray, of cork.

940 oz. = the weight of 1 ca. ft. of cork.

4

060 oz. = »» »» 4 »» "

= 60 lbs.

25. How many oz, of iron will a cubic foot of cork float in

water f

1000 oz. = weight of a cubic foot of water.
.840 = spec. gray, of cork.

940 = weight of a cubic foot of cork.
1000 oz. — 940 oz. s 760 oz., the buoyant force of a cubic foot.

26. What is the specific gravity of a body whose weight in
air is 30 grs, and in water 20 grs, f

80 grs. — 90 grs. = 10 grs.
aOgrs. -t-lOgrs. = 3.

The body is three times as heavy as water.

27. Which is heavier, a pail of fresh water or one of salt^
water?

A pail of salt-water is as much heavier than one of fresh-
water as the weight of the salt added to make the brine.

38 AurawEBa to practical qussTioNS

28. The weights of a piece of syenite-rock in air and in
wcUer were 3941.8 grs, and 2607. 5 grs. Find its spec, grav,
— Ans. 2.954.

29. A specimen of green sapphire from Siam weighed in
air 2 1. ^S grs,, and in water 16.33 grs. Required its spec,
grav, — Ans. 4.189.

30. A specimen of granite weighs in air 534.8 grs,^ and in
water ^^^.6 grs. What is the spec. grav. ? — Ans. 2.671.

31. What is the bulk of a ton of iron f

1000 OS. = weight of 1 ca. ft. of water.
7.S =^ spec. grav. of iron.

7800 oz. = weight of a en. ft. of iron.
S8,000 oz. (a ton of iron) -•- 7,800 (weight of a ca. ft.) = 4 Vw <■• ^

A ton of gold?

1,000 oz. = weight of a ca. ft. of water.
19.84 = spec. grav. of gold.

19,840 oz.* = weight of a ca. ft. of gold.
82,000 oz.* -•- 19,840 oz. = 1.6, the no. of ca. It

A ton of copper?

1000 QZ. X 8.9 ■= 8900 oz.
82,000 oz. -•- 8900 oz. = 8.6 (nearly) the no. of en. ft.

32. What is the weight of a cube of gold 4 feet on each

sidef

4* = 64, the no. of ca. ft.

19,840 oz.* (no. of oz. in 1 ca. ft.) x 64 = 77,860 lbs.

33. A cistern is 12 ft. long, 6 ft. wide, and 10 ft. deep.
When full of water, what is the pressure on each side f

On one side, 13 x 10 x 6 x 1000 oz. = 600,000 oz. = 37,600 lbs.
On one end, 6 x 10 x 6 x 1000 oz. = 800,000 oz. = 18.750 lbs.

34. Why does a dead fish always float on its back f

It Kas its swimming-bladder located just under the spine;
and this is the lightest part of its body, and, of course, comes
to the top as soon as the fish dies.

* in these eolations the student shonld notice that avoirdupois weight is nsetl
In weighing the go\<l. To be exnct, 1,000 nz., the weiffitt of a cu. ft. »r wator,
sliould be reduced to Troy weiirht, and the Ih. g<»lil taken as 12 uz. Troy, when
the ans. would be about 1.86 cu. ft

IN NATURAL PEILOSOPHT. 20

36. A vessel holds 10 Ids. of water: how much mercury
would it contain f

Mercnry is 13.5 times lieavier than water. Hence the yessel would contida
10 lbs. X 18.5=.1851b8. of mercary.

^J. A stone weighs 70 lbs. in air and 50 in water. What
is its bulk ?

70 — 60 = 90. so X 16 oz. = 830 oz., the weight of water displaced.

820 oz. is "/,» of a ca. ft.

38. A hollow ball of iron weighs 10 lbs. : what must be its
bulk, to float in water f

10 lbs. = 160 oz. As a cubic ft. of water weighs 1,000 oz., the ball mnst dis-
place sQch a part of a en. ft. of water as 1,000 oz. is contained times in 160 oz.,
which is .16 ca. ft.

HYDRAULICS.

1. I. How much more water can be drawn from a faucet
Zfeety than from one 4 feet below the sutface of the water in a
cistern t

V =i%Vgdi hence v = 3v^l6 x8 = S2.6.
t> = 2vl6x4 = 16.

Hence 6.6 cu. ft. more would flow from one than from the
other in each second.

2. How much water would be discharged per second from
a short pipe having a diameter of 4 inches and a depth ofifi^
feet below the surface of the water f

4"=16. . 16 X .7851=13.57 sq. incheB=.087 sq. ft. (area of the tnbe).

9 = %yjgd = %>/W^ = 55.4
.067x55.4 = 4.8 en. ft.

3. When we pour molasses from a jug, why is the stream so
much larger near the nozzle than at some distance from it f

Because, according to the law of falling bodies, the further
the molasses falls the faster it falls. The stream, therefore,
becomes smaller as it moves more swiftly, until, at last, it
breaks up into drops.

36 ANaWBRS TO PBACTICAL qUB3TlON8

4. Ought a faucet to extend into a barrel beyond the staves?

No ; because cross currents would be produced, which would
interfere with the free passage of the liquid.

5. What would be the effect if both the openings in one of
the arms in Barker's Mill were on the same side f

It would cease revolving. The pressure in each direction
would then be equal, and the arms would balance.

PNEUMATICS.

14§« I. Why must we make two openings in a barrel of
cider when we tap itf

One to let out the cider, and one to admit the air.

2. What is the weight of 10 cubic feet of air f

100 ca. Id. weighs 81 gm. ; hence 10 en. ft. will weigh 81 gn. x 17S.8 = .769i
Ihs. ayoirdnpols.

3. IVhat is the pressure of the air on one square rod of land f

S72V« X 144 X 15 lbs. = 588,000 lbs.

4. What is the pressure on a pair of Magdeburg hemispheres
4 in. in diameter!

8.1416 < 4" X 15 lbs. = 753.9 lbs. on each hemie>phere.

5. How high a column of water can the air sustain when
the barometric column stands at 28 in, f

28 in. X 18Vi = 81 Va feet.

6. If we should add a pressure of two atmospheres^ what

would be the bulk of 100 cu, in, of common airf

The preesore is trebled, and according to Mariotte^s law, the volume will
be reduced in the same proportion ; hence it will be 100 ca. in. -•- 3 = 33 Vs
en. in.

7. If while the water is running through the siphon, w^
quickly lift the long arm, what will be the effect on the water in
the siphon f

It will all run back through the short arm into the vessel

8. If we lift the entire siphon f

The water will all run out the long arm. The reason of this

m NATUSAL PHILOSOPHY. 3 1

difference is, that when we lift the long arm we make it in
effect the short arm, and the other arm the long one.

8. Wh^n the mercury stands at 29^ in, in the harometery
how high above the surf ace of the water can we place the lower
pump-valve f

In theory, 29^ in. X I3i ^398i in.; in practice, the distance
is much less than this.

9. Why cannot we raise water, by means of a siphon, to
a higher level f

There is no power in a siphon ; it is only a way of guiding
the flow of water to a lower level.

10. If the air in the chamber of a fire-engine be condensed
to ha its former bulk, what will be the pressure due to the ex^
pansive force of the air on every square inch f — Ans. 240 lbs.

11. What causes the bubbles to rise to the surface, when we
put a lump of loaf-sugar in hot tea f

The bubbles of air contained in the pores of the sugar rise
because they are lighter than the water.

12. 7^ what height can a balloon ascend?

Until its specific gravity is the same as that of the air m
which it floats.

— What weight can it lift ?

A weight equal to the difference between its own weight and
that of the air it displaces.

13. Why is the air lighter in foul and heavier in fair
weather ?

This question is answered in the Philosophy. Another
reason may be, that the upward currents of air partly remove
the pressure in foul weather.

14. When smoke ascends in a straight line, is it a proof of
the rarity or density of the air f

Of its density, because it shows that the smoke is much
heavier than the air, and so rises immediately to the top.

15. Why do we not feel the heavy pressure of the air on our
bodies f

32 ANSWERS TO PRACTICAL qCBSTIONS

Because it is equally distributed within and without our
bodies. The pressure on a person of ordinary size is about i6
tons.

1 6. Is a bottle empty when filled with air?

No ; because we must empty the air out before we can fill
the bottle with anything else.

1 8. How does the variation in the pressure of the air affect
those who ascend lofty mountains f

The outward pressure is there partly removed, and the
inner pressure remaining the same, the blood is often forced
through the ears, nostrils, etc. When one descends into a
deep mine the conditions are reversed : the outer pressure be-
comes in excess of the inner ; severe pain is felt in the ear-
drum, and ringing noises in the head become almost intoler-
able. These, however, disappear after a time, where the
equilibrium between the internal and external pressure, is
restored. It is said that Humboldt ascended where the mer-
curial column fell to 14 inches, and descended in a diving-bell
where it rose to 45 inches — ^thus making a variation of 31 inches,
or a difference of 3 1,000 lbs. pressure on his body.

— If the atmosphere in a diving-bell were of the same density
as that at the surface of the earthy how deep in the water
would it be necessary to sink the bell in order to reduce the
volume of the air one-half or, in other words, for the bell to
half fill with water? — Ans, 34 feet.

How near would the bell be filled at a depth of 1,020
feet. — Ans. «V».

If the bell were then raised, would the water stay in till it
reached the surface ?

The elasticity of the air would cause it to gradually expand
and drive out the water as it rose.

ACOUSTICS.

1§4. I. Why cannot the rear of a long column of soldiers
keep time to the music ?

m NATURAL PHlLOaOPBY, 33

* Because it takes time for the sound-wave to pass down the
column, and hence those in the rear do not hear the music as
soon as those in front.

2. Three minutes elapse between the flask and the report of a
thunderbolt: how far distant is itf

If the air is at the freezing point, the distance is

1090 ft. X 60 X 3 3 196,200 ft.

3. Five seconds expire between the flask and report of a gun :
what is the distance f

1090 ft. x5s 6450 ft

4. Suppose a speaking-tube should connect two villages 10

miles apart. How long would it take a sound to pass that

distance f

63,800 ft. -•- 1000 ft. s 48.4 (eec.)

5. Tke report of a pistol-skot was returned to the ear from
the face of a cliff in 4 seconds. How far was itf

1000ft.x3sS180ft.

6. What is ike cause of tke difference in tke voice of man
and woman f

It may be a difference in the length of the vocal chords, or
in the power of lengthening and shortening them ; but it is not
yet fully understood. The difference between a bass and
tenor, as between a contralto and soprano voice, is probably
that of quality only, like that between different kinds of musical
instruments.

7. Wkat is tke number of vibrations per second necessary to
produce the fifth tone of the scale of Cf

(p. 176.) C| = 138 vibrati9ii8. G of that scale = 192 vibrations per second.

8. Wkat is tke lengtk ofeack sound-wave in tkat tone wken
tke temperature is zero f

1090 ft.— 33 ft. 31058 ft. 1058 ft -1-193=6 ft. 6-1- in. (the length of each vibration).

9. Wkat is tke number of vibrations in thefourtk tofte above
middle C (CJ f

36
Gb=s 336 vibrations . — _. (the proportionate no. for the 5th of the tcala),

866 X 2? s 834 (the namber of vibrationa per second).

34 AN8WWRB TO PBACTICAL qtmSTIOITS

10. A meteor of Nov, 13, 1868, is said to have exploded at
a height of 60 miles : what time would have been necessary for
its sound to reach the earth f

6880 ft. xeOs 810,800 ft.
810,800 ft. -•- 1000 ft. = 290 (sec.) = 4 min. 60 tec.

11. A stone was let fall into a well^ and in 4 seconds was
heard to strike the bottom. How deep was the well?

(See p. 480 ci = 16 x /*. <f s 16 x 4> a SS6 ft.

12. What time would it require for a sound to travel 5 miles
in the still water of a lake f

6380 ft. X 5 = 36,400 ft.
26,400 ft. -•• 4700 ft. = 6.0 (pec.)

13. How much louder will be the report of a gun to an
observer at a distance of 20 rods than to one at half a mile?

160 rodp are 8 times 90 rods. The inteni^ity of the soaod is inversely as the
square of the distance = ^/e4. Hence the soand is 64 times loader to the
observer at 90 rods that to the one at half a mile.

14. Does sound travel faster at the foot or at the top of a
mountain f

The density and elasticity of the air vary in the same pro-
portion ; hence if the temperature were the same on the top of
a mountain that it is at the foot, the velocity of sound would
be the same, but as it is always colder, the velocity is less.

15. Why is an echo weaker than the original sound?

Because the intensity of the sound-wave is weakened at each
reflection.

16. Why is it so fatiguing to talk through a speaking-
trumpet?

Because so much more air must be set in motion by the
vocal chords. The column of air in the resonant cavity of
the throat is re-enforced by all the air in the trumpet.

— When we hear a goblet or a wine-glass struck with the
blade of a knife, we can distinguish three sounds, the funda-
mental and two harmonics.*

* Is not the ear the mo^t perfect sense ? A needlewoman will distingaisb by
the sound, whether it is silk or cotton that is torn. Blind people recQgniaa

m NATUBAL PHILOSOPHT. 35

OPTICS.

334* I. Why is a secondary bow fainter than the primary ?
The primary is produced by one reflection and two refrac-
tions; the secondary, by two reflections and two refractions.

The additional reflection weakens the ray.

Why are the colors reversed?

We can understand this by looking at Fig. 159. In one
bow we see that the rays enter the drops at the top, and are
refracted at the bottom to the eye ; in the other, that the rays
enter at the bottom, and are refracted at the top to the eye.

2. Why can we not see around a house or through a bent tube f
The rays of light move in straight lines.

3. What color would a painter use if he wished to represent
mn opening into a dark cellar f

Black.

4. Is black a color?

No ; it is the absence of color

Is white ?

Yes ; it is the presence of all color — 1. ^., it is the compound
effect produced on the brain by seven different impressions.

5. By holding an object marer a light, will it increase or
diminish the size of the shadow ?

It will increase it, because more rays are intercepted.

7. Where will we see a rainbow in the morning?
In the west

the age of pereons by their voices. An arcMtect, Qomparing ttie lengtli of
two lines sepftmted fix>m eacli other, if he estimate within the 80th part, we
deem very accurate ; hnt a mosician woald not be considered very precise
who only estimated within a quarter of a note. (138-1-90 = 4, nearly.) In a
large'orchestr&i the leader will distinguish each note of each instnunent. We
recognize an old-time fHend by the sound of his voice, when the other senses
utterly &il to recall him. The musician carries in his ear the idea of the
mftt4cal key and every tune in the scale, though he is constantly hearing a
multitude of sounds. A tune once learned will be remembered when the
words of the song are forgotten. Prof. Pepper tells us that he tuned a fork
which corresponded to 64,000 vibrations per second. The flrst harmonic is
produced by one-half the whole cord, the second by one-thiid, Ac.

36 ANBWBS8 TO PRACTICAL qVESTIONS

8. Can any two spectators see the same rainbow f

They cannot, because no two persons can be at the right
angle to get the same color from a drop.

9. IVhy^ when the drops of water are falling through the
air J does the bow appear stationary f

Because the drops succeed each other so rapidly that they
keep a constant impression on the retina.

10. Why can a cat see in the night?

Because the pupils of its eyes are larger, and so admit more
light.

Why cannot an owl see in daylight?

The pupils of its eyes are large enough to admit of clear
vision in the night, but they cannot be contracted, and so in
daylight the owl becomes dazzled with the excess of light
received.

1 2. Why are we blinded when we pass quickly from a dark
into a brilliantly lighted room ?

The pupils of our eyes admit too much light, but they soon
contract to the proper dimensions, and we can then see dis-
tinctly. When we pass out from a lighted room into the dark
street, the conditions are reversed.

13. If the light on a distant planet is only yJo that which we
receive, how does its distance from the sun compare with ours ?

As the light is inversely as the square of the distance, the
distance is \/ 100= 10 times greater than ours.

14. If when I sit 6 feet from a candle I receive a certain
amount of light, how much will I diminish it if I sit back 6
feet further?

As my distance from the light is doubled, the light is in-
versely as 2', or only \ as bright.

15. Why do drops of rain, in falling, appear like liquid
threads ?

The impression the drop makes on the retina remains until
the drop reaches the ground.

16. Why does a towel turn darker when wetf

m NATUSAL PHILOSOPHY, 37

More of the light is transmitted, and less reflected. We see
this illustrated in greasing a bit of paper. It becomes semi-
transparent because more light passes through it, but looks
darker itself because less light is reflected to the eye.

17. Does color exist in the object or in the mind of the ob-
server f

In the mind. Color in the object can be only a peculiar
property whereby a body absorbs some colors, and reflects or
transmits others.

18. Why is lather opaque y while air and a solution of soap
are each transparent?

By repeated reflections and refractions in passing through
the unhomogeneous mass of lather, the rays are weakened.
The principle is the same as that of deadening floors with tan-
bark. (Phil., p. 161.)

19. Why does it whiten molasses candy to pull it?

Because the candy tends to take on the crystalline form.
Crystals are homogeneous, and are, therefore, more trans-
parent than uncrystallized bodies.

20. Why does plastering become lighter in color as it dries f

Because, as the water evaporates, the mortar transmits less
light, and reflects more light to the eye.

21. Why does a photographer use a kerosene oil-lamp in the
** dark-room r*

Kerosene oil-flame emits only heat and color, but no actinic
rays. Some * * dark-rooms" are lighted with yellow glass windows.

22. Is the common division of colors into **cold** and
** warm^^ verified in philosophy f

Yes ; red contains more heat than violet.

23. Why is the image on the camera^ Fig, 167, inverted?

The rays cross each other at the focus of the double convex
lens.

24. Why is the second image seen in the mirror, Fig. 134,
brighter than the first?

The first is formed by reflection from the glass, and the
second from the mercury. As the latter is a better reflector.

38 AN8WEBS TO PSACTICAL QUESTIONS

the second image will be brighter. Each image after that will
be weakened by the repeated reflection.

27. Which can be heard at the greater distance, noise or
music f

Other things being equal, music will penetrate much further
than noise. Boatmen call to each other, at a distance, in a
musical tone. A band is heard above the noise of the rabble.
It seems to be a wise provision of Providence that all harsh,
discordant noises should perish as soon as possible, and only
harmonious ones survive.

28. Why are some bodies brilliant^ and others dullf

Some reflect the light better than others. A piece of stone
coal lying in the sun's rays will shine so brilliantly that one
will cease to see the coal at all, and will judge it to be a bright
metal.

29. Why can a carpenter looking along the edge of a board
tell whether it is straight f

If the edge is straight, the light will be reflected uniformly
to his eye from the whole length. Any uneven places will
make dark and light spots.

30. Why can we not see out of the window after we have
lighted ike lamp in the evening f

The glass reflects the light of the lamp back to our eyes,
and they adapt themselves to the increased amount.

31. Why does a ground-glass globe soften the light?
It scatters the rays.

32. Why can we not see tkrougk ground-glass or painted
windows f

They transmit the light irregularly to the eye, and not
uniformly, like a transparent body.

33. Wky does tke moon^s surface appear flat t

Because it is so distant that the eye cannot detect the dif^
ference between the distance of the centre and the circumfer*
ence.

IN NATUnAL PSTL080PSY. 39.'

* 34. Why can ive see further with a telescope than with the
naked eye f

Because it furnishes us more light with which to see a dis-
tant object

35. Why is not snow transparent^ like ice f
Because it is unhomogeneous. See problem 18.

36. Are there rays in the sunbeam which we cannot see f
We cannot see the heat or the chemical rays.

37. ( I ) Make two marks on a sheet of white paper, at a
distance of about three inches from each other. Then closing
one eye and looking steadily at one mark (though we can see
both), move the paper toward the eye, A point will be
reached where the eye can perceive only one of the marks j on
coming nearer, both will be seen again,

38. (2) Prick with a pin, through a card-board, two Holes
closer together than the diameter of the pupil of the eye. Hold-
ing the card pretty near the eyes, look through these holes at
the head of a pin. There wiU seem to be two pin-heads,

39. (3) Press the finger on one eyeball and we shall see
objects double.

Since an impression is made on the retina of each eye, it
would seem that we ought always to see objects double. The
nerves from both eyes are so joined, however, before they,
reach the brain, that this effect is avoided. If, now, we cause
the image on the retina to be made on parts of the eye which
do not correspond to each other, we shall obtain a double image.

40. Why is a rainbow in the morning a sign of foul, and
in the evening of fair weather f

In the morning it indicates a formation of clouds when the

. temperature is rising, and therefore shows a determination to

moisture. In the evening it indicates a clearing away when

the temperature is falling, and hence shows a determination

to dryness.

41. Why is a red, lowering sky in the morning a sign of
rain, and a brilliant red sky at night, of fair Weather f

40 ANBWXSS TO PRACTICAL QVESTIOm

42. Why dots a distant light , in the nighty seem like a start

43. Why does a bright light, in the night, seem so much
nearer than it isf

44. Why does a ray of light, passed through a small hole,
of any shape, in a card, make a round, bright spotf

45. Why are these spots crescent-shaped during an eclipse f

46. What color predominates in artificial lights f
Yellow.

47. Why does yellow seem white, and blue green, when seen
by artificial light f

Because the white takes on, in the yellow rays, a yellow
hue, and the yellow added to the blue gives a green, hence
there is no white for comparison. So, also, dark blue be-
comes purple, and red has a tawny hue. Magnesium light
possesses all the colors of the spectrum, and hence all objects
retain their natural appearance when illuminated by it.

48. Why are we not sensible of darkness when we wink f

Because the impression of the light is retained upon the
retina during the brief interval of darkness.

HEAT.

358. I. Why will one's hand, on a frosty morning, freeze
to a metallic door-knob sooner than to one of porcelain f

Because the metal is a better conductor of heat than the
porcelain, and hence conducts the heat from the hand faster.

2. Why does a piece of bread toasting curl up on the side
toward the fire f

The water being expelled from the pores on that side causes

the bread to shrink.

3. Why do double windows protect from the coldf

The non-conducting air enclosed between the window-panes
keeps in the heat and keeps out the cold.

4. Why do fumetce-men wear flannel shirts in summer to
keep cool, aftd in winter to keep warm f

JN NATXTRAL PHILOaOPHT, 4 1

In summer the non-conducting flannel keeps out the fur-
nace-heat, and in the winter keeps in the body-heat.

5. Why do we blow our hands to make them warm^ and
our soup to make it coolf

Our breath is warmer than our hands, but cooler than our
soup.

6. Why does snow protect the grass ?

The air enclosed between the flakes of snow is a non-con-
ductor. No infant in its cradle is tucked in more tenderly
than the coverlet of snow about the humble grass that nestles
down for its winter's nap on the bosom of mother Earth.

7. Why does water " boil away'* more rapidly on some days
than on others f

Because the atmospheric pressure varies.

8. What causes the crackling sound in a stovCy when a fire
is lighted?

The expansion of the iron by the heat.

9. Why is the tone of a piano higher in a cold room than in
a warm one f

The steel wires lengthen in a warm room, and so lower the
tone.

10. Ought an inkstand to have a large or a small mouth f
A small mouth, to prevent evaporation.

1 1. Why is there a space left between the ends of the rails on
a railroad track?

To allow room for the expansion and contraction of the rails
with the changes in temperature.

12. Why is a person liable to take cold when his clothes are
damp ?

The water which evaporates from his clothes, in drying,
absorbs heat from his body.

13. What is the theory of corn-popping f

The air in the cells of the corn expands by the heat and
bursts the outer coating of the corn.

42 AJrSWEHa TO PRACTICAL QUFSTIOITM

14. Could vacuum-pans be employed in cooking f

They could not, because the heat would not be sufficient to
cook the food.

15. Why does the air feel so chilly^ in the springs when
snow and ice are melting f

When the ice is passing into the liquid state, it absorbs heat
from all surrounding objects.

16. Why^ in freezing ice-cream^ do we put the ice in a
wooden vessel, and the cream in a tin one f

The non-conducting wooden vessel prevents the ice from
absorbing heat from the external air, and the conducting tin
vessel enables it to absorb the heat from the cream.

1 7. Why does the temperature generally moderate when the
snow falls f

The vapor passing into the solid form gives off heat

19. Why does sprinkling a floor with water cool the airf

The water turning to vapor absorbs heat.

30. How hw a degree of temperature can be reached with
a mercurial thermometer f

Nearly to the freezing point of mercury, —39* F.

21. If the temperature be 70** /^, what is it C f

70*- W=38*. 38+1.8=21.1* C.

— If the temperature be 70" C, what is it F, f

70* X 1.8=126*. 126*+32*=158* F.

22. Will dew form on an iron bridge f
Yes, because iron is a good radiator.
On a wooden bridge ?

Not so readily, because wood is a poorer radiator.

23. Why will not corn pop when very dry f

The pores shrink, and the corn becomes compact; only
porous, tender-celled corn will pop.

24. The interior of the earth being a melted mass^ why do
we get the coldest water from a deep -wcllf ' ^

IN NATVRAL PBIL080PHT. 43

The well extends below the influence of the sun, and not
deep enough to reach the internal heat of the earth.

25. Ought the bottom of a tea-kettle to be polished f

No, since a polished surface would reflect the heat. We
need a black, rough, sooty surface to absorb the heat rapidly.

26. Which boils the sooner y milk or water f

Milk, because it is so adhesive that the bubbles of steam
which are formed at the bottom of the dish cannot easily
escape. They therefore pile up on top of each other, and the
milk boils over readily.

27. Is it economy to keep our stoves highly polished?

The stove-blacking used is a good radiator, but the surface
should not be highly polished, as that hinders radiation.

28. If a thermometer be held in a running stream^ will it
indicate the same temperature that it would in a pailful of
the same water ?

It will. For the same reason that a thermometer, in the
wind, will indicate the same temperature as in the still air,
although the former seems to us much colder.

29. Which makes the better holder^ woollen or cotton f
Woollen, because it is so poor a conductor of heat.

30. Which will give out the more heat, a plain stove or one
with ornamental designs f

The latter, since it has more radiating surface

3 1 . Does dew fall?

No ; it forms directly where it is found. The vapor merely
collects on the cold surface.

32 . What causes the ' * sweating** of a pitcher f

The vapor of the air condenses on the cold pitcher. It is
often a sign of rain, since it shows that the air is full of vapor
easily deposited.

33. Why is evaporation hastened in a vacuum t
Because the pressure of the air is removed. ._

44 ANSWERS TO PSACTICAL qUESTIONS

34. Does stirring the ground around plants aid in the depo-
sition of dew f

It does, since it facilitates radiation.

35. Why does the snow at the foot of a tree melt sooner than
that in the open field f

The dark-colored tree absorbs the sun's heat, and then
radiates it out in slow, dull waves, which are absorbed by the
snow.

36. Why Is the opening in a chimney made to decrease in
size from bottom to top f

Because as the heated air rises it cools and shrinks. If the
chimney did not diminish in size correspondingly, currents of
cold air would set down from the top.

37. Will tea keep hot longer in a bright or in a dull tea-pot f
In a bright one, since a polished surface retards radiation.

39. Why is one's breath visible on a cold day f

The vapor in the breath is condensed by the cold air.

41. Why is light-colored clothing cooler in summer and
warmer in winter than dark-colored f

It does not absorb the heat of the sun in summer, nor the
heat of the body in winter ; dark-colored clothing has neither
of these desirable properties.

42. How does the heat at two feet from the fire compare
with that at four feet f

S»:4«::l:4.

Hence it is four times greater.

43. Why does the frost remain later in the morning upon
some objects than upon others f

Those objects which are good absorbers of heat soon become
warm enough to melt the frost upon them : poor absorbers
heat more slowly, and so retain the frost longer.

44. Is it economy to use green wood?

It is not, since the sap must be changed to vapor, and watet

m NATURAL ^BILOSOPHT. 45

in turning to vapor renders latent over 900" of heat. This is,
of course, entirely lost to the consumer.

45. Wiy does not green wood snap f

The pores are filled with water instead of air. The water
does not expand rapidly enough to burst off the coverings of
the cells, and so simply oozes out gradually and is vaporized.

46. Why will a Jfiece of metal dropped into a glass or porce-
lain disk of boiling water facilitate the ebullition f

The rougher surface of the metal aids in the formation and
disentanglement of the steam-bubbles. The bubbles cling
longer to a smooth than to a rough surface. This is one
cause of that bumping sound often noticed when liquids are
boiling in glass dishes.

47. Which can be ignited the more easily with a burning-
glassy black or white paper f

Black paper, since it is a much better absorber of heat.

48. Why does the air feel colder on a windy day ?

Because fresh portions of cold air are brought constantly in
contact with our bodies.

49. In what did the miracle of Gideon* s fleece cofisistf
Both the fleece and the hard threshing-floor were poor radi-
ators; hence the dew would not readily form on either. The
miracle consisted in its gathering each time on only one of
two objects, on both of which it should gather, if on either.
(Judges, vi. 37-40.)

50. Could a buming-letis be made of ice t

Burning-lenses have been made of that material. The rays
have no heating power until the waves of ether are stopped.
They do not elevate the temperature of the medium through
which they pass.

5 1 . Why is an iceberg frequently enveloped by a fog ?
The moisture of the air is condensed upon its cold surface.

52. Would dew gather more freely on a rusty stove than oh
a bright kettle f

It would, because the rusty iron surface is a good radiator.

53. Why is a clear night colder than a cloudy one f

46 AN8WSSS TO PRACTICAL QUESTIONS

On a cloudy night the clouds reflect the radiated heat of the
earth back again, and thus act as a blanket to keep the earth
warm. On such a night there can be no frost or dew. On a
clear night, the heat which the earth radiates passes out freely
into space, and thus the earth cools rapidly.

54. Why is no dew farmed on cloudy nights f
See last question.

55. Water boiled at a certain place at 200° F, ': what was
ihe height above the sea f

56. On Mont Blanc boiling water is only 84* C, : what is
the height?

57. Why do we use a longer tube of mercury for a barometer
than a thermometer f

58. Which is the hottest part of a room f

59. Why is it hotter above a flame than at the side f

60. What is the difference between dew and rainf

61 . Why will ashes keep fire overflight f

62. If a pane of glass and a similar plate of polished steel
were laid upon the ground^ in the nighty upon which would
the dew form most abundantly f

The glass is a poor conductor of heat, and so would absorb

little heat from the earth, while the metal would absorb it
freely ; the glass is a better radiator than the polished metal,
and thus would become drenched with dew, while the metallic
surface would be scarcely dimmed.

63. Why is there but little dew formed in cities f

64. Is an abundant dew a sign of rain f
It is. See question 32.

65. Is there any dew formed out at sea ?

66. Why are gardens in a valley often touched with frosty
while those on the hills escape unharmed?

The cold air settles into the valley, while the warm air rises
to the hills.

JN NSTUBAL PHILOSOPHY. .47

67. How are hailstones formed f

There are two separate currents of air, one hot and charged
with moisture, the other cold. The former is displaced by
the latter and driven up in the atmosphere. There its vapor
is condensed at the centre of the cloud into snow, and at the
extremities into ice-cold water. In this cloud there is a whirl-
ing motion which collects the snow into little balls, each of
which is the nucleus of a hailstone. Each of these is carried,
alternately, by the whirling currents, into the snow-cloud at
the centre, and the ice-cold water outside. Both give it a
coating, one of snow-like, spongy ice, and the other of trans-
parent ice. This is done with great rapidity, until at last its
weight overcomes the violent upward motion which sustains it
in the air, and the hailstone falls to the ground. When a
hailstone is carefully examined we can see this nucleus, and
these concentric layers, like the coats of an onion.*

68. Why do we have hailstorms in summer^ and not in

winter t

The small spongy hail or sleet of winter has the same origin
as hailstones in summer, but there is not enough vapor in the

cold air to give them the size of summer hailstones.

69. Is the sweating of a pitcher a sign of rain f
See question 32.

70. Where should ice be applied^ to cool water t
At the top, because cold water falls.

71. Why is evaporation hastened in a vcLcuumf
Because the pressure of the air is removed.

72. Is a dusty boot hotter to the foot than a polished one f
It is, because it is a better absorber of heat.

* The above theory is that advanced by Prof. Loomis, in his ** Treatise on
Meteorology." The teacher will find thia work invaluable on all meteorologi-
cal qnestionB.

48 ANSWEBS TO PRACTICAL QUESTIONS.

(Key, p. 34, Prob. ii.) The method adopted in solving
this problem is merely the rough one in common use, and
gives only an approximate result. If an exact answer is de-
sired, we should take in account the time required for the sound
to reach the ear. The following method may be employed :

X = No. sec. for stone to &I1.
4— £= " " Bound to reach the ear.
16a;> = (4— a;)1090.
lfiir> = 4860 — KXXte.

From this, by completing the square, we have

X = 8.789S+ seconds.
Then the equation (2) d= i6/> gives the depth.
d= 16(8.7a»4-)« = 8S9 ft. and 8.7V5 in.,
which is the answer exact Mdthin a small fraction.

A second method (more exact) —

d = depth of the well = 16^.

16 4 ^
4— i V^^= No. of sec. for sound to reach the ear.

(4-i v^rf)l090 =4360 -^^ V^JT

4360-^f^V^J==tf.

J^i^i/5^4360-d.

<!«_ aaiaoAtf -_ 19009600.
<f= 220.73+ feet.

ANSWERS

TO THE PRACTICAL QUESTIONS,

AlTD SOLUTIONS OP THE PROBLEMS,

IN THB

FOUETEEN WEEKS' COUESE

IN

CHEMISTRY.

[The bold-fiiced fignres refer to the pages of the Chemistry ; the others to
the number of the Practical Questions.]

1. Is it likely that all the elements have been discovered f

It is not, since several have been found lately by means of
spectrum analysis. The ancients held that there are but four
elements — earth, water, air, and fire; the first representing
the solid form of matter, the second the liquid, the third the
gaseous, and the fourth the force which changes matter from
one form to another. Few of the sixty-five elements are com-
mon. Those italicised, in the table on page 12, are rare.
The remarkable phenomena of allotropism would seem to in-
dicate that, perhaps, what we now consider distinct elements
may be only allotropic states of the same element. Indeed,
it is possible to conceive that all substances are only allotropic
forms of one universal essence. In the present state of
chemistry this view cannot be proved, and is only a specula-
tion as to what may be discovered in the future.

2. What is the origift of the term ^^ gasV^

This word was first used in the 17th centur>\ Explosions,
strange noises, and lurid flames had been seen in mines, caves,
&c. The alchemists, whose earthen vessels often exploded

2

50 AimWBRS TO PRACTICAL QVESTIONS

with terrific violence, commenced their experiments with
prayer, and placed on their crucibles the sign of the cross —
hence the name crucible from crux (gen. cruets), a cross. All
these manifestations were supposed to be the work of invisible
spirits, to whom the name gahst or geist, a ghost or spirit,
was applied. The miners were in special danger from these
unseen adversaries, and it is said that their church service con-
tained the petition, "From geists, good Lord, deliver us I"
The names — spirits of wine, nitre, &c., are a relic of the
superstitions of that time.

3. If the air were pure O, what bodies would escape com-
bustion in a conflagration f

The stones, mortar, &c., which being already combined
with O and other elements, and having their chemical affinities
satisfied, are hence termed "burnt bodies."

4. IVhy will lime added to hard water often so/ten it f

The lime will combine with the free carbonic acid absorbed
by the water. This renders the water incapable of holding in
solution as much carbonate of lime as before, which is then
precipitated, and the water thus partly softened.

5. Why will stirring a wood fire quicken the flame, but a
coal fire, will deaden itf

Stirring a fire lets in more O, which quickens a wood fire
but reduces the temperature of a coal fire below the point of
union between O and coal. It is really based on the fact that
a higher temperature is requisite to bum coal than wood.

6. IVhy does blowing on a fire quicken the flame, but on a
lamp extinguishes it f

The same principle applies as in the last question. In ad-
dition, the force of our breath often drives the fiame off the
wick mechanically.

7. Why will oyster-shells placed on the grate of a coal firt
prevent the formation of clinkers f

The lime of the shells forms a flux with the silicates con-
tained in the coal, and thus renders them more fusible.

m OHEMiaTRT, 51

8. What alkali abounds in sea-we^df
Soda.

9. What alkali abounds in land-plants f

Potash. The former salt is a constituent of sea-water, and
the latter of rocks which decompose to form the soil.

10. How is lime-water made from oyster-shells f

The oyster-shells, in burning, lose their CO,. This leaves
the lime uncombined ; hence it readily dissolves in water.

1 1. What other tests of lead than HS ?

KI gives a yellow precipitate, NH^S a black, and SO, a white
one.

12. Will not lime lose its beneficial effect upon soil after a
timet

Lime acts in vinous ways to improve the fertility of a soil.
It corrects its acidity, aids in the decomposition of the rocky
constituents, hastens the decay of the humus, and also makes
the soil more porous. It does not, however, benefit the
growing plant directly, but works up other materials in the
soiL It therefore loses its effect after a time. The Belgian
farmers have a proverb :

** Much lime and no manare
Make flurm and flirmer poorer."

13. What is the derivation of the term zincf

The name is probably derived from the German zinken,
signifying ''nails,'' and is applied to this metal on account of
its frequently forming pointed particles somewhat resembling
nails, when melted and suddenly poured into water. (Griffiths. )

14. What is the action of permanganate of potash (chame-
leon mineral) as a disinfectant f

It gives up its O to oxydize the organic impurities of the
water in which they collect.

15. Do all fish die when taken out of the water?

No. Some fish have an apparatus for moistening theii
gills. They can therefore crawl about in the grass, and even
migrate from one stream to another.

tf

52 ANaWERS TO PRACTICAL QUESTIONS

16. IVAaf Proof have we that H is a metal f

Besides that given in the Chemistry, the '' sodium amalgam
is thought by some to be an additional proof. Heat moderate-
ly in a test-tube a little mercury with a grain or two of sodium.
The two metals will combine, forming a pasty amalgam.
When cold, pour over it a solution of sal-ammoniac. The
amalgam will immediately swell up to eight or ten times its
original bulk, retaining^ however^ its metallic lustre. It is
thought that H is the metal which puffs out and combines
with the mercury, since otherwise we would be compelled to
suppose that NH^ is a metallic element, instead of a com-
pound radical, as is generally believed.

17. Why does not frozen meat spoilt

The cold protects from chemical change. The bodies of
mammoths have been found in the frozen soil of Arctic regions
so perfectly preserved that the dogs ate the flesh. How long
the animals had been there we cannot tell, but certainly for
ages. In 1861 the mangled remains of three guides were
found at the foot of the Glacier de Boissons, in Switzerland.
They had been lost in an avalanche on the grand plateau of
Mont Blanc, forty-one years before.

18. Give an illustration of the effect of food on the disposi-
tion of animals.

Bears which feed on acorns are mild and tractable, while
those of the polar regions, which live on flesh alone, are fierce
and ungovernable.

19. Compare the chemical action of the animal with that of
the plant.

The animal lives on organized materials, taking up O and
evolving CO,, and other oxydized products. The plant lives
on unorganized materials, CO,, HO, NH„ and salts, organ-
izing them and evolving O. The function of the animal is
oxydation ; that of the plant, reduction. The food of the
plant serves merely to increase its bulk ; that of the animal is
employed to replace the material worn out by the active opera-
tions of life. The animal obtains the energy necessary for its

IN CHEMI8TRT. 53

existence from the oxydation of its own body ; the plant ob-
tains the energy necessary for the organization of its food di-
rectly from the sun.

20. Show how man is made mainly of condensed air.

Science has demonstrated that man is formed of condensed
air ; that he lives on condensed as well as uncondensed air,
and clothes himself in condensed air, that he prepares his
food by means of condensed air, and by means of the same
agent moves the heaviest weights with the velocity of the
wind. But the strangest part of the matter is, that thou-
sands of these tabernacles formed of condensed air, and going
on two legs, occasionally, and on account of the production
and supply of these forms of condensed air which they re-
quire for food and clothing, or on account of their honor and
power, destroy each other in pitched battles by means of con-
densed air. — LlEBlG.

17. I. In making O from chlorate of potash (KO,ClOJf
how much can be obtained from two pounds of the saltf

60=48=:eqaiyalent of constltaent.
KO.G10»=122.5= " ** compound.

a;=weight of constitoent.
Sllw.s " ** compound.
60 : KO.ClOt : : a; : 2 lbs.

48: 132.5 :: xi 21bs.

192
aj=^=.781b. (0).

2. In making H, zinc is used. How much sulphate of zinc
(ZnO,SO^+7HO) will be formed from 2 lbs, of the metal f

Zn = 32.6 = eqaivalent of the constltaent.
ZnO.SO,+7HO = 143.6=: " " compound.

2 lbs. = weight of the constituent.
«= " " compound.

Zn : (ZnO.SOs+THO) :: 2 lbs. : a;.

32.6 : 143.6 : : 2 lb. : a?.
«=8.8 lbs. (white vitriol, snip. zinc).

3. How much SO, will be required to make 50 lbs, sulphate
tf iron (FeO.SO^^jHO) ?

54 ANSWERS TO PRACTICAL qURSTIONS

t90t = 40 =3 eqniyalent of the constitaeiit.
yeO.SO,-i-'7HOs=189= " '* compoand.

X = weight of the constitaent.
601bs. =s " " compoand.
80t : (FeO.SO,4-7HO) :: a; : SOlbs.
40 : 189 : : « : 60 Ibe.
« = 14 -fi^ lbs. (green vitriol, enlpbate of Iran).

4. The equivalent of the chloride qf sodium (salt) tr 58.5.
In 10 lbs. there are 6i1t lbs, of chlorine : what is the equiva^

lent of at

X = equiyalent of the given constituent.

66.5= " ** " compoDud.

6 tIt Ihs. s weight of the given conBt!taent«
20 lbs. = ** " " compound.

X : 68.6 : : Offr lbs. : 10 lbs.
X = 85.6.

5. In 20 grains of bromide of potassium there are 6-ff^
grains of potassium : the equivalent of potassium being 39,
what is the equivalent of the bromide of potassium t

89 = equivalent of the given constituent
«=: *♦ " »* compound.

t^ffggn, = weight of the given constituent.
aOgrs. = ** ** " compound.
89 : a; : : 6-^fg grs. : SO grs.
= 119.

6. In 14 lbs, of iron-rust (Fe^Oj how much Of

so = SI = equivalent of the given constituent.
FeaOt = 80= " " " compound.

X = weight of the given constituent.
14 lbs. s " " " compound.

24: 80:: a;: 141bs.
aj = 4V»lb8. (O).

7. In 7,6 lbs, of glass (NaO,SiO^-{-CaO,SiOJ how many
lbs. of sand (SiOJ t

S SiO, = 60 = equivalent of the given constituent.
(NaO.SiO,+CaO.SiO,) = n9= " " " compound.

X = weight of the given constituent.
S01b«.= " " " compound.
60: 119:: a;: SO lbs.

a; = 10i^lbs. (SiO,)

m CHEMISTRY, 55

8. In a 25 lb, sack of salt (NaCl) how many lbs, of tke
metal sodium f

Na = 38 = eqaivalent of the coxiBtitaent
NaCl = 58.6= " ** compound.

X = weight of the constituent.
S5 lbs. = ** ** compound.
28 : 68.6 : : a; : 26 lbs.
« = 9-i¥Tl^8.(Na).

229, 5. What weight of O is contained in 60 grs. of
KOXIOJ

60 = 48 = equivalent of constitaent
EO.CIO« = 122Vs = " " compound.

X = weight of constituent.
60 grs. = " ** compound.
48 : 122Vt : : a; : 60 grs.
aJ = 28Hg«.(0).

6. How much KCl will be formed in preparing 80 grs, of Of

First find how much KO.CIO, will be required to make 80
grs. of O, and then subtract the 80 grs. of O from the amount,
and the remainder will be the KCl. The constituent and
compound are the same as in the last problem.

48: 123Vs :: 80 grs. : a;

X = 204.16 grs.

204.16 grs. — 80 grs. = 124.16 grs. (KCl).

7. How much H can be made from 10 lbs, of Zn f

First find how much ZnO 10 lbs. of Zn will form ; second,
subtract the 10 lbs. of Zn, and the remainder is the O which
came from the water. This O formed f of the water, and
the remaining i is the H set free.

Zn = 82.6 = equivalent of the constituent.
ZnO = 40.6= " " compound.

10 lbs. = weight of the constituent.
«= " " compound.

36.6 : 40.6 : : 10 lbs. : x,
m = 12.461 lbs. (ZnO). 12.461 lbs. ZnO — 10 lbs. Zn = 2.461 lbs. (0).

3.461 lbs. -^ 8 = .807 lbs. (H).

8. Haw much H can be made from 50 lbs, of water f

56 AN8WES8 TO PRACTICAL QUESTIONS

H = 1 = eqnlTalent of given constituent
HO = 9= " " compound.

X = weight of giyen oonstitnent
50 IbB. = " ** oomponnd.

1 : : : a; : 60 lbs.
aj = 6Vt lbs. (H).

More simply, i of water is H ; hence

60Ib8.'^9 = 6Vt lb8.(H>.

9. I/ow much saltpetre will be required to make 18 lbs.
of aquafortis f

NOs = 64 = equivalent of given conBtituent.
KO.NOg = 101= ** " compound.

18 lbs. = weight of given constituent.
«= " " compound.

54 : 101 : : 18 Ibn. : x,
a; = 83 Vs lbs. (ealtpetre).

10. Haw much oil of vitriol will be required to decompose 6
lbs, of saltpetre ?

First find how much KO in 6 lbs. of KO.NO,, next how
much KO. SO, that amount of KO will make, and lastly sub-
tract the KO from the KO. SO,, and the remainder will be the
SO,. In both cases we neglect the HO combined in the salts
and the acid.

EO : EO.NOft : : a; : 6 lbs.

47 : 101 : : a; : 6 Ibe.

X = 3.79 lbs. (EO).

EO : EO.SO, : : 2.79 lbs : x.

47 : 87 : : 2.79 IbB. : x,

a; = 6.161bs. (KO.SO,).

&16 lbs. CEO. SO,) — 8.79 lbs. (EO) = 2.87 IbB. (SO,).

II. How much HO will be decomposed , by one drachm of
Ky and how much KO will be formed f

First find how much KO i dr. of K will form, then sub-
tract from the KO the drachm of K, and the remainder is the
0, which must be i of the water from which it is obtained.

m CHEMISTST. 57

K : KO : : 1 dr. : «.

89 : 47 : : 1 dr. : jB.

X s 1 A drs. (KO).

l/l drt. — 1 dr. s -/^ dr., the ftmooiit of O.

The HO is •/• of •/•• dr. = Vii dr. (HO).

12. fF^tf/ weight of nitrous oxyd will be formed from tke
decomposition of doz, of nitrate of ammonia ?

% NO : NHfO.NOe : : « : 6 os.
« = 8Vi«o«. (NO).

13. How much sal-ammoniac would be required to make 2
lbs.ofNH^f

NH, : NH4CI : : S Ibe. : «.

17 : 58.5 : : 8 Ibe. : x,

fl; = 6ViT I^- (sal-ammoniac).

14. How much C0% will be formed in the combustion of 30
grs, of cot

CO : CO, : : 80 gn. : «.
14 : SS : : 80 gra. : «.
« = 47Vt«»-(CO,).

15. What weight of carbonate of soda (sal-soda) would be
required to evolve 12 lbs. of CO^f

COt : NaO.CX)a : : 18 Ibe. : «.

28 : 58 : : 18 Ibe. : x,

S = 88 > Vn ll>8. Cl^aO.CO,).

16. What weight of bicarbonate of soda (Na0.2C0^
**soda^^) would evolve 12 lbs, of CO^ f

SCO, : Na0.8C0, :: 181be. : x.

44 : 75 : : 18 Ibe. : x,

a? = a0Viilb8. ("soda").

17. What weight of C is there in a ton of CO^ t

C : CO, ;: XI SOOO lbs.
6 : 88 : : « : aooc lbs.

fl; = 545Vii llM- (P).

l8* How much O is consumed in burning a ton of Ct

3»

.■^- V

58 ANSWEBB to PRACTICAL qvxaTiom

C ! COt : : SOOO lbs. : x.

6 : B : : SOOO lbs. :

C«7SS8>/,lbs.(COB).

T888 Vt-SOOO lbs. s 6888 >/• Ibt. (O).

More simply : —

C : so : : 9000 lb«. : x,
Cs=6888Vtll»-

19. In burning a charge of 10 lbs, of gunpowder, find tke
weight of the several products formed.

CBm ptg« lOT.) (1.) KS : (KO.NO»-i-S -1-8C) : : : 10 Hm.

66: 186:: a; : 10 lbs.

fl;=:4Vit Ibfl. (KS).

Ci) N : (K0.N0g+S+8C) : : « : 10 lbs.

14: 186:: a;: 10 lbs.

aj=lVtTlbB. (N;.

(I.) aCOt : (K0.N0ft+S+8C) : : « : 10 lbs.

66 : 186 :: a; : 10 lbs.

a; = 4«Vt7lbB. (CO,).

20. What weight of common salt would be required to form
35 lbs, of muriatic acid (HCl ) f

Cl : Hd : : a; : S5 lbs.
86.6 : 86.6 : : a; : 95 lbs.

a;s94.81be. (Cl).
d : Nad : : 94.8 lbs. : as.
86.6 : 66.6 : : 94.8 Ibe. : x.
= 4040. 044 lbs. (NaCI).

21. HCl of a Specific gravity of 1,2 contaitis about 40 per
cent, of the acid. This is very strong commercial acid. What
weight of this acid could be formed by the HCl acid gas pro-
duced in the reaction named in the preceding problem f

It 96 lbs. = 40 per cent., then 100 per cent. = 3.6 times 96 lbs. = 69 Vt lbs*

22. What weight of hydriodic acid (HI) is formed from
a drachm of iodine f

I : HI :: Idr. : x,
197 : 198 : : 1 dr. : OB.
ajBlTirdrs. (HI).

m. CHEMiaTBT, 59

23. What weight of Glauber salt can be formed from 100
lbs, of oil of vitriol f •

SO, : NaO.SO, : : 100 lbs. : c

40 : 71 : : 100 Itw. : jB.

C = 177.5 lbs. (NaO.SO,).

24. Wk(U weight of S is there in 10 grs, of sulphide of
hydrogen f

S : HS :: «: 10 gn.

16 : 17 : : a; : 10 gn.

« = 9ViTg«. (8),

25. How much O is required to change a lb. of SO^ to
SO.f

80, : SO, : : 1 lb. : z:

8S : 40 : : 1 lb. : a^

« = 174 lb. (SO,).

1V4W>.— lll>. = V«lb. (O).

26. How much phosphorus in 40 &s, of phosphate of timet

(See page M5.) P : 8CaO.P05 : : « : 40 lbs,

81 : 166 : : a; : 40 Ibe.
c = 8 lbs. (F).

27. How much P in 40 lbs. of the superphosphate of lime t

P : CaO.FO, : : a; : 401be.
81 : 90 : : a; : 40 Ibe.
a; = 12*V„lbe. (P).

28. How much phosphate of lime will an 02, of P make t

P : SCaO.PO, : : 1 ox. : x.
81 : 165 : : 1 oz. : a;,
c = 6 OS. OCaO.PO,).

29.. How many lbs. of HO in 186 lbs. of SO^,iHO t

|S0 : SO,.8HO : : a; : 186 lbs.
27 : 67 : : a; : 186 lbs.
a: = 74w/„ib8. (HO).

* In this, as in the other problems, the HO contained in the acid and in
the salt is ne^^ected, since it is a variable quantity, and the examples are
merely for practice.

6o ANSWERS TO PR ACTIO AL qVESTlOWi

30. How much CO^ is formed in the combustion of i torn

of Cf

C : CO9 : : 9000 lbs. : x,

C : » : : 9000 lbs. : jb.

« = 7888 V» lbs. (00,).

31. What weight of S is there in a ton of iron pyrites t

9S : FeS, : : a; : 9000 lbs.

89 : 60 : : SB : 9000 lbs.

a; = 1066Vt 1^- (S).

32. What weight of copperas could be mcuie from 500 lbs.
of iron pyrites f

In forming FeO. SO, from FeS, only one atom of S is re-
quired ; hence the 500 lbs. of iron pyrites really contain but
366 Vi lbs. of FeS, which will, at a single reaction, form cop-
peras ; by oxydation from the air, the remaining atom of S
would doubtless be used afterward. The problem might be
solved as well, perhaps, by taking either the Fe or the S alone
as the constituent.

FeS : (FeO.SO,+7HO) : : 866 Vs lbs. (FeS) : x,

44: 180 :: 866Vs Ibe. : a;.

a;= 1168.3 lbs. (FeO.SO,+7HO).

33. What weight of H is there in a pound of heavy car-

buretted hydrogen f

4H: C4H4 :: a;: lib. *

4 : SB : : a; : : lib.
X = Vt 11>- (H).

34. How much O would be required to oxydize the metallic
copper which could be reduced from its oxyd by parsing over
itf when white-hot^ 20 grs, of H gas ?

The same amount of O would be required to oxydize the
copper that was taken from it when it was reduced from its
oxyd. The H passing over it when white-hot takes out its O
and forms HO. H is always i of the HO. The H = 20 grs.;
hence the HO =9 times 20 grs. = 180 grs'. 180 grs. (HO)
— 20 grs. (H) = 160 grs. (O).

35. How much O would be required to oxydize the metallic
iron which could be reduced in the same manner by 10 grs. of
Hgasf

tw CBMansTMT. 6l

Following the same reasoning as in the last prabkm, we

have

H = IQ giH. ; knee Ike BO - f ttea 1

»SiH. (BQ>— MpaL (H) =flienL fO).

36. Wkatwtigkttf NisOurtiMXO&s.^ NH^MOt

H : KH,AO : : X : It IkiL
M: X:: x : « Ibn

37. /fiinir macrA KO.CIO^ ^vouldbe required to evolve suffi-
cient O to bum the H produced by the decomposition, of 2 lbs,
of HOf

f of HO is O ; hence 2 lbs. of HO will producey when dc*
composed, 1} lbs. O. The problem is, then, how much
KO.ClOg would be required tp Aimish i) lbs. O ?

69 : KO.CIO, : 1.77 Hmu : x.

48: 1&5:: LTTIbs. i x.

x=s4^nis.(KO.GIOk).

(If the conmion fractions are used in solving this problem,
the answer is 4}} lbs.)

38. How much H must be burned to produce *a ton of

water t

H : HO : X : SOQO Ibe.
1:9 :: x : aoooilM.

x=sssVt n».(H).

39. How much S is there in a lb. of SO^ t

8 : SO, : : « : 1 lb.

16 : 3S : : z : 1 lb.

« = Vtlb.(S).

40. Find how much ''soda^^ is formed from 500 lbs, of
salt.

41. Find the amount of Glauber salt produced in the first
step, with the charge just named.

42. Find the amount of HCl produced.

43. Find how much sulphuret of sodium is formed in the
second step. .

]

62 AN8WEBS TO PBAOTICAL QUESTIONS

44. Find kcw much sulphurtt of calcium is madi

45. Find haw much sulphur could be saved (if none were
lost) from the CaS,

The following reactions show the chemical changes which
take place in the various stages :

(1) Nad-fSOsHOsNaO.SOa+Hd
Na0.80,-f 9C sKaS-i-SOOt.

NaS+CsO.CX), = CaS+N*O.00t.

«|

From the (i) reaction we find how much Glauber salt will
be made from 500 lbs. of common salt. To do this we first
find how much Na there is in 500 lbs. NaCl; and^ secondl/i
how much NaO.SO, that amount of Na will make.

Na : NaCl : : a; : 600 IbB.

28 : 66.5 :: a; : 600 lbs.

fl;sl96^^lbB. (Na).

Ka : NaO.SOa :: 196-^ lbs. : »,

S8: 71 :: 196-^: «.

Bie06-^lbe. (NaO.SOs). Ana, to Ha pnl^.

Na : NaO.COj : : 196-^ lbs. (Na) : «.
. 88: 68 : 196-/>A^Ibs. : 0.
•1^ lbs. (NaO.COa, '' Soda"). An», to 40th

a: NaCl :: x : 6OOlb0.

86.6 : 68.5:: SB : 600 Iba.

jr = 808T*ft'lbfl. (CI).

01: Ha:: 808-^ lbs. : w.
86.5:86.6:: 806-^ lbs. : x,

« s 811 Hf 1^-0301). An8,to4aapnb,

Na : NaS :: 196-^^ Iba. (Na) : «.

88: 80 :: 196-ffrlb8. : x,

\B2m^/^lhB,Q!(»S), Ani,to4Mpra.

IVtn)i.(NaS)-196-Mrll». (Na) = 186^1bi.(S). An$.totn^

S : CaS :^ 186^lbB. (S) : e.
cs 807 Vit Ibf. (CaS). Ant. to 44ih prob

m CHEMISTST. 63

46. Haw many lbs, of HCl would be required to neutralize
sufficient carbonate of ammonia to form a 30 lb, cake of sal-
ammoniac (NH^, CI) t

First find how much CI there is in a 30 lb. cake of sal-
ammoniac ; second^ how much HCl would contain that amount
of CL

Cl : "SH^Ci : : a; : 80 lbs.
8S.6 : 68.6 : : se : 80 lbs.

a; = 19.9 lbs. (d).

Gl : HOI : : 19.9 Ibf. : «.

86J& : 86.6 : : 19.9 lbs. : «.

fl;=;SO.41b0. (Ha).

47. How much S is there in a ton of plaster (gypsum) t

S : CaO.SO, : : « : 9000 Ibi.

16: 88 :: SB : SOOOlbf.

fB= 470.68 IbB. (8).

48. How much aluminum is there in a ton of clay t

SAl : Al,0,.SiO, : : a; : 9000 lbs.

S7.4 : 81.4 : : a; : 9000 lbs.

= 673.9 lbs. (Al).

49. How much Kis there in 10 lbs, of alum t

K : (KO.SO,+Al,0,.8SO,-f94HO) : x : 10 lbs.

89 : 474.4 : : a; : 10 lbs.

a; s .89 lb. (K).

50. How much white-lead (PbO.COJ could be made from
I lb. of litharge?

Pb : PbO : : a; : 1 lb.

108 : 111.6 : : a; : 1 lb.

« = .99 lb. (Pb) in 1 lb. of liUiarge.

Pb : PbO.COa : : .99 lb. : aj.

103 : 183 : : .99 : x,

a? = 1.1 lb. (PbO.OO^.

51. How many lbs, of C would be required to reduce 40
tons of brown hematite (2Fe^0^,^H0) ? ,

In the intense heat of the furnace the 3 HO would be de-
composedi and so only sufficient C would be required to burn

64 ANSWEBa TO PRACTICAL QUESTIONS, Ae,

the 6 atoms of O in the 2Fe,0,. In 40 tons of brown hema-
tite there are 34.22 of the base.

60 : 3Fe«Os : : a; : 84.33 toni.

48 : 160 : : a; : 84.22 tons.

X = 10.36 tons (O).

Eight-elevenths of CO, is O; if 10.26 tons is -ft-, it would
require 3.84 tons of C to burn 10.26 tons of O, and thus
reduce 40 tons of hematite.

52. In 60 &s, 0/ heavy spar (sulphate of baryta) haw much

S is there t

S : BaO.SO, : : a; : 60 lbs.

16 : 116.5 : : a; : 60 lbs.

a;=8.31be. (S).

53. How much alum can be made from i cwt, of potash t

KO : (K0.80, + A]aO,.3SO,-f34HO) : 1001b. : 0.

47 : 474.4 : : 100 lbs. i x,

X = 1009.3 + lbs. (alum).

ANSWERS

TO THE PBACTICAL QUESTIONS

HI TBX

FOURTEEN WEEKS' COUKSE

Ol

DESCRIPTIVE ASTRONOMY

1. Did Tycho Brake have a telescope f
No. Galileo invented the telescope.

2. Suppose one should watch the sky, on a winter* s evening,
from 6 p. M. to 6 A. M., what portion of the celestial sphere
would he see f

All that is ever seen in his latitude.

3. How do we find what proportion of the sun^s heat
reaches the earth f

Calculate the surface of a sphere whose radius is the dis-
tance of the earth from the sun, and then estimate what pro-
portion of that area the earth occupies.

4. How many real motions has the sun f

Two. One around its axis, and one with the solar system
around the Pleiades.

5. How fnany apparent motions has the sun ?

Three. One along the ecliptic, — its yearly motion ; one
through the heavens, — its daily motion ; and one N. and S.

6. How many real motions has the earth ?

Three. One on its axis ; one around the sun ; and a third,
its ''wabbling motion/' which causes Precession.

66 4J18WEB8 TO PRACTICAL QUESTIONS

7. Can any inferior planet have an elongation of^"" f
No. Venus recedes only 48" from the sun.

8. How do we knew the heat of the sun*s rays at any planet?
The intensity of the heat and light vary inversely as the

square of the distance.

9. Can you give any other proof than that named in the
book, of the rotundity of the earth f

Aeronauts, when at a proper height, can distinctly see the
curving form of the earth's surface.

10. In what way is the force which acts on a spinning-top
opposite to that which produces precession (p. 125) ?

Gravity, acting on the top, tends to draw C P (Fig. 34) y^^
the perpendicular. The attraction of the sun, acting on the
bulging mass of the earth's equator, tends to draw C P toward
the perpendicular.

1 1 . Why is the Tropic of Cancer placed where it is ?

Because it is the farthest place north where the sun is ever
seen directlv overhead.

12. Why is the Tropic of Cancer so called f

When named, the sun was probably in that constellation at
the time of the summer solstice. Now, owing to the preces-
sion of the equinoxes, the sun is in the constellation Gemini,
and to be exact, it should be called the Tropic of Gemini. It
is still, however, the sign Cancer, as before. The same reason-
ing applies to the Tropic of Capricorn, which is now in the
constellation Sagittarius.

13. In Greenland, at what part of the year will the mid-
night sun be seen due north f

At the summer solstice.

14. How do we know that the moon has little if any atmos-
phere f

Because when the moon occults a star, there is no refraction
of the star's true place.

15. When is the moon seen high in the ectstem sky in the
afternoon, long before the sun sets f

m DESCBIPTIVB ASTBOSOMT 67

During the second quarter before it comes into opposition.

16. Why is the Ecliptic so called f
Because eclipses always occur within it.

17. Why is it that the sun in summer shines on the north
side of some houses both at rising and settings but in winter
never does f

Since at the summer solstice the sun rises and sets north of
the £. and W. points, it will rise and set op the north side of
a house which stands exactly N. and S. At the winter solstice
the sun rises and sets S. of the £. and W. points

TABLE OF THE MINOR PLANETS.

No.

1
3
8
4
5
6
7
8
9
10
11
13
18
14
16
16
17
18
19
20
21
23
28
24
25
26
27
28
29
80
81
83
88
84
85
86
87
88
39
40
41
43
43
44
45
46
47
48
49
50
51
52
58
54
55

Jfanu.

Ceres

F&llae

Jano

Vesta

Astnea

Hebe

Iris

Flora

Metis

Hygieia

Parthenope
Victoria . . . ,

Bgeria

Irene ,

Eanomia . . .
Psyche . . . . ,

Thetis ,

Melpomene .

Fortaua

Massalia. . . .
Latetia . . . . ,

Calliope

Thalia

Themis

Phocsea . . . ,
Proserpine .
Eaterpe . . . .

Bellona

Amphi trite

Urania

Eaphrosyne

Pomona

Polyhymnia

Circe ,

Leucothea . ,

Atalanta

Fides

Leda ,

Lsetitia

Harmonia . .

Daplme

Ms

Ariadne . . . .

Nysa

Eugenia

Hestia

Aglaia

Doris ,

Pales ,

Virginia...,
Nemausa . . .

Enropa

Calypso

Alexandra . ,
Pandora ...

Data q^ JHtcoverff.

1801,

1803,

1801,

1807,

1845,

184T

1847

1847

1848,

1849,

1850,

1850,

1850

1851

1851

1863,

1868

1853,

1853,

1863,

1853.

1853

1863,

1868,

1^8.

1858,

1853

1864

1854:

1854,

1864

1»54,

1854,

1866

1856,

1855,

1855,

1856

1856

1856

1866

1866,

1857

1857

1867

1867

1857

1867

1867

1857

1858.

1858,

1858

1868,

1868,

Jannarr 1

March 38

Sept. 1

March 29
December 8

July 1

Aagneit 18

October 18

April 26

12
11
18
3
19
39
17
17
24

19

15

16

16

5

7

6

8

1

1

23

1

April

May

Sept.

Nov.

May

Jaly

March

April

Jane

Angnst

Sept.

Not.

Nov.

Dec.

April

April

May

Nov.

March

March

July

Sept.

October 36

October 38

April 6

April 19

October 5

October 5

January 13

February 8

March 81

May

May

April

May

June

August 16

Sept. 15

Sept.

Sept.

October

January ^

February 4

AprU 4

Sept. 10

Sept. 10

33
28
15
27
27

19

19

4

JHaeoverer.

Piajszl

Olbers

Harding

Olbers

Hencke

Hencke

Hind

Hind

Graham

Gasparis

Luther

Hind

Gasparis

Hind

Gactparis

Gasparis

Lutner

Hind

Hind

Gasparis

Golaschmidt.

Hind

Hind

Gasparis

Chacomac

Lather

Hind

Lather

Marth

Hind

Ferguson

Golaschmidt

Chacomac

Chacornac

Luther

Goldschmidt

Luther

Chacomac

Chacomac

Goldschmidt

Goldschmidt

Pogson

Po^on

Goldschmidt

Goldschmidt

Pogson

Lu ther

Goldschmidt

GK)ldschmidt

Ferguson

Laurent

Goldschmidt

Luther

Goldschmidt

Searle

Sidereal

BtvoltUipn

{Days.)

1680
1683
1596
1836
1513
1879
1346
1198
1346
3043
1403
1803
1511
1519
1570
18:28
1421
1371
1893
1866
1888
1818
1556
2036
1858
1580
1313
1693
1493
1839
2U48
15-^1
1778
1609
19U8
1664
1569
1657
1684
1347
1681
1393
1195
1879
163S
1470
1783
3003
1975
1576
1388
1993
1548
1684
1674

TABLJS OF THE MINOR PLANETS.

69

No.

66
W
58
69

eo

61

63

68

64

65

66

67

68

60

70

71

72

73

74

75

76

77

78

79

80

81

8-.>

83

84

85

»(

87

88

89

90

91

92

93

94

95

96

97

96

99

100

lUl

10'^

103

104

106

106

107

lOS

109

Name.

Melete*

Mnemueyne
Concordia. . .

Eipis

Echo

Danad

Erato

Aaeonia.

Angelina. . . .

CyBele

Maia

A»ia ,

Leto

Hesperia...,
Panopea ...

Niobe

Feronia....

Clytie

Galatea

Barydice...

Freia

Frigga

Diana ,

Earynome . .
Sitoppho ....
Terpsichore
Alcmene . . .

Beatrix

Clio

lo

bemele

Sjivia

Thisbe ,

Julia

Antiope....

JS^na

Undina

Minerva ...

Aurora

Arethnsa...

iBgle

Clotho

Fanthe

Hecate

Helena

Miriam

Camilla...'.'
Hecuba ....

DaU of Diacoftery.

1857,

1859

1860,

1660

]8ti0

1860,

1860

1861

1861

1861

1S61

1861

1861

18r>l

1861

1861

1861

1862,

1862,

186-i

1862

1862

1863

1863

1864

1864,

1864

1865

1865

1865.

1866,

1866,

1866

1866

1866

1866,

1867

1867,

1867

1867,

1863

1868

1868

1868

18H8,

1868

1868,

1868,

1868

1868,

1868

1868

1869

1869

Sept.

9

Sept.

S2

March

24

Sept.

12

Sept.

15

Sept.

9

Sept.
Febroaiy

14

10

March

4

March

8

April

9

April

17

April

29

April
May

29
5

August

13

May

29

April

7

August

29

Sept.

22

October

21

Nov.

12

March

15

Sept.

14

May
Sept.

2

80

Nov.

27

April

26

August

26

Sept.

19

January

4

May

16

June

15

August

6

October

11

Nov.

4

July

7

August

24

Sept.

6

Nov.

23

February 17

February 17

April
Itflay

18
28

July

11

August

15

August

22

Sept.

7

Sept.

13

Sept.

16

October

10

Nov.

17

AprU

2

Oct.

JH$eot«rer.

Qoldschmidt

Luther

Luther

Chacomac

Ferguson

Qoldschmidt

FOrster and Lesser

Oasparis

Tempel

Tempel

Tutile

Pogson

Luther

Schiaparelli

Qoldschmidt

Luther

Peters and Safford

Tuttle

Tempel

Peters ,

d^Arrest

Peters

Luther

Watson

Pogson

Tempel

Luther

Qasparis

Luther

Peters

Tietjen

Pogson

Peters

Stephan

Luther

stephan

Peters

Watson

Watson

Luther

Coggia

Tempel

Peters

Borelly

Watson ..

Watson

Peters

Watson

Watson

Watson

Watson

Pogson

Luther

Peters

Sidertul
RmoluUoH

1526
2049
1615
1634
1352
1902
2028
iai6
1601
2311
1588
1375
1695
1893
1542
1671
1215
1590
1691
1594
2080
1596
1554
1399
1270
1693
1659
1881
1330
1583
1983
2384
1675
1472
2^031
1495
2U86
16(i9
2050
1961

ia-)0

1607

• • • •

1892
1508
1587
162i
2071
1341
2092

• • ■ •

20S1

* Goldaehmidt at first belieyed it to be Daphne (41), but Schubert finding its period
different, called it PetudO'Daphne. It was not seen flrom 1857 to 1861, when Lulhtr
ndiscovered it, and named it Mdete.

The nnmerical order is that adopted by the authority of the Berlin Ephemeris.

SIMPLE DIREOTIOS'S

TO A BEGINNER
ron

PERFORMING THE EXPERIMENTS

IN THK

FOURTEEN WEEKS' COUESE

IK

CHEMISTRY.

[The large flgores refer to the page of the Chemistiy, and the pmall odm
to the namber of the experiment. Bead for additional directions, CThemiatry,
pp. 385-348.]

9. !• Put as much chlorate of potash (potassic chlorate)
as will lie upon the point of a knife-blade, and half as much
sulphur, into the mortar. Grind them slowly with the pestle
until the ingredients are thoroughly mixed and distributed
over the bottom of the mortar. Hold the mortar so that the
loose particles cannot fly into your eyes, nor the flame burn
your clothes, and then grind heavily with the pestle, when
rapid detonations will ensue. The mixture will last for days.
After use, clean out the mortar carefully for other experi-
ments. The powder can be wrapped with paper into a hard
pellet and exploded on an anvil by a sharp blow from a ham-
mer. Sometimes small bits of phosphorus are used instead
of sulphur. Great care is then necessary, as the particles of
burning phosphorus are apt to fly to some distance.

10. I. Two teaspoonfuls of common carbonate of soda and
one of tartaric acid should be dissolved separately in a wine-
glass of water. On being poured together in a larger glass,
they will violently effervesce. Use a glass large enough to

72 DIBECTIONS FOB PEBFOBMINQ

prevent any running over upon the table. Neatness in ex-
periments is essential to perfection, and often to success.

13. I. The cabbage solution is made by steeping purple cab-
bage leaves in water. A little lemon-juice or vinegar will turn
it to a bright red, and a little of the potash solution to a deep
green. Add a little alcohol to the red solution, to keep it
from freezing, and bottle it for use. Dissolve a little of the
dry litmus in water, filter and bottle it. These are to be used
in testing the alkalies and acids. Dissolve also a stick of the
potash in water, filter and bottle. Fill two test-tubes nearly
full of water ; color one with the cabbage and the other with
the litmus solution. Add a few drops of the potash solution
and of the sulphuric acid alternately to each. The color can
be changed at pleasure.

Take a small bit of tubing, and heating the ends in the
flame of the spirit-lamp (the greatest heat is near the tip of
the flame), seal up the opening. This will be useful to dip
into the acid or alkali, as it will remove a drop more readily
than by dropping from the bottle.

1§. Pulverize an ounce of the potassic chlorate very care-
fully ; stir in it one-fourth of its weight of the black oxyd of
manganese and place the mixture in the copper retort, at-
tach the tubing and gas-bag as shown in the figure of p.
234 ; or in the Florence flask, attaching a delivery tube, as
shown in figure on p. 18. The glass tubing may be heated
in the flame of the alcohol-lamp and bent to the desired
shape, or it can be broken into short lengths by simply start-
ing the break in the tube by a mere scratch with a three-cor-
nered file and then connecting the pieces of glass tubing with
a short bit of the small rubber tubing, as in the figure on
p. 18. The gas may be passed off from the gas-bag, or di-
rectly from the retort into the pneumatic cistern, 'C, across
which is placed a shelf perforated, to permit the gas to bubble
up into the receiver, J. The pneumatic cistern may consist
of a tub of water. The bottles for collecting the gas are sunk
into the water until filled, inverted, and then lifted up on
the shelf, carefully keeping the lower edge of the bottle be-
neath the water. A large tin pan, without any shelf, may be
used as a cistern by filling the bottles full of water in a deep

EXPERIMENTS IN THE CHEMISTRY, 73

pail, and then slipping a plate underneath each one, as shown
in the second figure on p. 20, leaving enough water on the
plate to cover the edge of the bottle ; it may then be lifted
out and placed in the cistern. In the same way the bottles,
when filled with gas, may be removed and kept for use. Gas
may be passed from one bottle to another by inverting one
over the other beneath the water in the pneumatic cistern,
or in a large pail, when the gas will bubble up from the lower
one into the upper one.

Apply the heat to the glass retort very carefully at first,
holding the lamp in the hand and moving it around so that
the flame may strike all the lower part of the flask, and thus
expand it uniformly. Be careful also that there is no draft of
cold air to strike against the heated retort. With the cop-
per retort no care of this kind is necessary. When the gas
ceases to come off, remove the stopper or lift the end of the
tube out of the water; otherwise, as the retort cools and a
vacuum is formed, the water in the cistern will set back into
the flask, and, if of glass, will break it. An ounce of the salt
will make over six quarts of oxygen gas. When the retort is
partly cooled, pour in some warm water to dissolve the residu-
um, which may then be poured out and the retort drained and
set away for future use. In order to test the purity of the
materials, and thus avoid any danger of an explosion, place a
little of the mixture for making oxygen in an iron spoon and
heat it over the spirit-lamp. If the gas passes off quietly, no
danger need be apprehended.

30. I. The experiment with the candle can be performed
most strikingly by filling a common fruit-jar with nitrogen
(see page 30) and another with oxygen. The covers will pre-
serve the gases until wanted for use. The covers may then
be laid loosely on top of the jars, and the lighted candle
passed quickly from one jar to the other. It will be ex-
tinguished in one and relighted in the other. With care, it
may be passed and repassed a dozen times. This strikingly
illustrates the difference between oxygen and nitrogen. Test
the carbonic acid, in this as in all similar experiments, with
the blue litmus and the green cabbage, or a slip of blotting-
paper wet with the litmus solution. A few drops of the sola-

74 DUUBCTIOm FOR PBSFOSUmO

tion may be poured into the jar, and then the jar shaken, so
as to permit the water to absorb the gas. The candle may be
simply stuck upon the end of a bent wire, but it is much
neater to have the tinsmith fit a little cup for its reception, as
shown in the figure.

2. The worn-out watch-springs which can be obtained
gratis of any jeweller, may be easily straightened by draw-
ing them between the fingers. If the end of each spring be
heated and then pounded with a hammer on any smooth
hard surface, the temper may be thoroughly drawn and the
edge sharpened. Make a slit with a knife in the side of a
match, into which insert the edge of the spring. Take a
piece of zinc or tin large enough to cover the mouth of the
jar containing the oxygen, and make a hole through it with
a nail. Pass the other end of the spring through thb hole,
and then through a thin cork. The spring is now ready for
burning. The metal cover will prevent the flame from coming
out of the jar and burning one's hand, and the cork will hold
the spring in its place. When the match is ignited, and then
lowered into the jar of oxygen, the spring should not reach
more than half-way to the bottom, and should be pushed
down as it bums. If a specie-jar be used, do not fill it quite
full of gas, as a little water left in the bottom will prevent the
melted globules of iron fi'om breaking the glass.

31 • I. If brimstone be used in this experiment, and it fails
to light readily, pour upon it a few drops of alcohol, and then
ignite it.

2. If you have not a deflagrating spoon to contain the phos-
phorus, one may be readily extemporized. Hollow a small
piece of chalk and attach it to a wire, which may then be se-
cured to a metal top, as in the case of the watch-spring.
This need not be pushed down into the jar as the burning
progresses. At the close of the experiment, test for the add
formed in the combustion. The fumes are very disagreeable,
and should not be inhaled or allowed to escape into the room.

3. If a piece of bark charcoal be ignited, and then lowered
into a jar of oxygen, it will deflagrate with bright scintilla'-
tions.

39* I. Put in an evaporating-dish a little starch; cover it

WCPBBIMBNT8 IN THIS CUEMiaTBT. 75

with water in which a few crystals of iodide of potassium have
been dissolved, and heat. Stir the liquid, to prevent lumps.
When cooked, immerse in the paste slips of blotting-paper.
Use while moist. Be careful not to heat the glass tube too
hot, lest the ether vapor may ignite. Keep the jar well filled
with vapor by frequently shaking it. Lower into the ozone a
bit of silver-leaf mobtened with water ; it will quickly crumble
into dust, the oxyd of silver.

32. I. To make the iodide of nitrogen, cover a few scales
of iodine with strong aqua ammonia. After standing for a
half-hour, pour off the liquid and place the brown sediment in
small pieces on bits of broken earthenware to dry. This will
require several hours. They may then be taken to the class-
room very carefully and exploded by a slight touch of a rod,
or even a feather.

87. I. For making NO, a special apparatus is necessary
for complete success. The Florence flask may, however, be
used, and the heat of the spirit-lamp will be sufficient. The
fumes may be caught in the evolution flask, which is kept
cool by a towel frequently wet. When the retort is partially
cooled, at the conclusion of the process, pour in a little warm
water, to dissolve the sulphate of potash, otherwise the retort
may break by the crystallization of the salt.

2. Mix equal parts of nitric acid and oil of vitriol (perhaps
a teaspoonful of each), and pour the mixture on hot finely-
powdered charcoal, or on a little oil of turpentine. It will
be oxydized with almost explosive violence. This should be
performed out of doors.

3. Bits of tin may be obtained of any tinsmith. Put them
in a tumbler and nearly cover them with the NO,. In using
copper, the apparatus shown on page 39 is excellent. The
acid may be turned in gradually through the funnel tube.
Before putting in the acid pour into the flask warm water to
cover the lower end of the funnel tube, which should nearly
reach the bottom of the flask. When a jar is filled with the
NO, it may be lifted out of the water and inverted, when the
NO^ will pass off in blood-red clouds. If the jar be left in
the cistern and one edge be lifted so as to admit a bubble of
air, red fumes will fill the jar. By standing a moment the

76 DIRECTIONS FOR PERFORMING

water will absorb the red vapor. This process can be re-
peated several times with the remaining gas.

40. I. The finely-powdered sal-ammoniac and lime may
be mixed in an evaporating-dish. The escaping ammonia
should be tested with a glass rod or tube wet with hydrochloric
acid.

2. Heat a little aqua ammonia in the Florence flask. Col-
lect the vapor in an inverted bottle, to which is fitted a cork
and tube, with the inner extremity drawn to a fine point over
the spirit-lamp. Insert the cork, and then plunge the bottle
into a vessel of water. The water which passes in first will
absorb the gas so quickly as to make a partial vacuum, into
which the water will rush so violently as to produce a minia-
ture fountain.

43. I. In making H, the directions given on pages 236-7
should be carefully observed. For purifying the gas a solu-
tion of potash should be placed in the flask d (page 42). If a
junk bottle be used the acid should be added slowly, as the
heat generated is liable to break the bottle. Pour the water
into the flask a until the lower end of the funnel is covered,
before adding the acid. The flow of gas may be regulated
by additions of acid, as may be wanted. One part of acid to
ten or twelve of water will liberate the gas very rapidly. If
it comes off very fast, the liquid is liable to froth over. The
philosopher's lamp, page 237, is very interesting. The jet
may be a straight glass tube drawn to a fine point over the
spirit-lamp. Large glass tubes or the beaks of broken re-
torts, held over this flame, will produce the singing tones,
though not as well as the apparatus figured in the book. The
tone may be regulated by the size of the flame, /. e. the rapid-
ity with which the gas comes off, the size of the jet as well as
the length and size of the tubes. The H can be collected
over the pneumatic cistern, or, since it is lighter than air, in
inverted bottles. As soon as the bottles are turned right side
up the gas will escape. To measure the H and O for the
** mixed gases," a receiver, with a stop-cock on top, which
may be connected by rubber tubing with the gas-bag, is very
useful. The oxygen may be passed directly into the gas-bag,
however, as on page 234, until it is about one-third full, when

SXPERIMENTS IN TWB CSEMBfTMT. ^^

the bag may be removed and attached to the hydrogen ap-
paratus to be filled.

50. I. In lieu of a small crucible, fill a common tobacco-
pipe with crystals of blue vitriol, and heat them over the
lamp or in a common fire until the water of crystallization is
expelled. Alum may be rendered anhydrous in the same
manner.

56. I. Small paste-diamonds may be obtained of a jew^
ler, to illustrate the forms of cutting the diamond.

00. I. Place a filtering paper in the glass funnel, and in it
a couple of ounces of bone-black or finely-powdered charcoaL
Filter through it water colored with ink, htmus, or any other
impurities. In pouring the liquid into the filter hold a glass
rod against the edge of the pouring vessel, so as to direct the
stream into the fiinneL The funnel may be placed in the
nozzle of a bottle, but must not fit closely. A bit of wood or
a thread inserted between the stem of the funnel and the
nozzle will leave an opening sufficient lor the egress of the air«

64* I. !6reak some marble into small bits ; place them care^
fully in the evolution-fiask, and, inserting the cork and tube,
pour in HCl slowly. The gas, on account of its weight, may
be passed directly into a bottle or jar.

2. Lower a lighted candle into a jar of the gas, or, lowering
the candle into an empty jar, pour the gas into the jar, as if it
were water. Test the acid with litmus paper.

3. Place a piece of lime as large as an egg in a pint oi wa-
ter; let it stand overnight; pour off the clear liquid — it is
lime-water. Place a little in a tumbler and breathe through it
by means of a tube, or pass a current d CO, from the evolu-
tion-flask until the liquid, at first milky, clears.

4. Breathe through a tube into an empty bottle. Lower
into it a lighted candle — it will be immediately extinguished*
Pour in some lime-water, shake it thoroughly and it will be-
come milky.

5. Twist a wire around the neck of a small wide-mouthed
vial, to answer as a bucket. Lower it by the wire into a jar
of COa, our ideal well foul with the gas. Raise it again, and
test for the CO, by means of a lighted match* The bucket
will be found to be full of the gas.

78 DIBSVTI0N8 FOB PERFOnMma

6. Fill a jar with hydrogen, and in a similar way dip the
gas downward and bum it over a lamp. This shows in a very
striking manner the difference between H and CO. in respect
to specific gravity. The one, we see, is dipped upward, the
other downward.

7. Balance a large paper bag or box on a delicate pair of
scales, or in any simple manner one's ingenuity may suggest.
Empty into the box a large jar of CO,, and the box will quickly
descend.

8. Arran«;e little wax-tapers in a wooden or pasteboard
trough, as on page 65. Light them, and then pour in at the
top a bottle of carbonic acid gas. If the proper slant is given
to the trough, all the candles will be extinguished.

73. I. Olefiant gas may be made by heating in the flask one
part, by measure, of alcohol and two parts of sulphuric acid.
Pass it through a solution of potash, as shown on page 88, and
then collect in the gas-bag. Fit a piece of glass tubing, drawn
to a fine point at one end, to the stop-cock of the gas-bag by
means of a bit of the rubber tubing. On turning the stop-
cock and forcing out the gas it may be ignited, when it will
burn with a clear white light.

2. Fill a tall jar one-third full of olefiant gas, and the re-
mainder with chlorine gas. On lighting, the mixture will
burn with a dense cloud of smoke. HCl is the product of the
combustion.

3. Mix with oxygen and explode in soap-bubbles. It pro-
duces a greater noise even than the " mixed gases." Great
care must be taken not to let the light approach the gad-bag
containing the mucture.

4. Fit a large test-tube with a cork and a- piece of glass*
tubing, drawn to a fine point at the outer end. Fill the tub
with fine dry pine-shavings. On heating, the gases from the
wood will pass off, and can be ignited at the jet- tube. The
test-tube can be held by a strip of twisted paper or wire.

5. At the close of the ist exp. perform Ae one figured on
page 79. A small piece of wire-gauze, 4 or 6 inches square,
for this purpose can be purchased of any tinsmith. If you do
not force the gas out too rapidly, you wiU be able to bum it
on either side of the gauze at pleasure.

SXPSSIMENTa m THE QHSKISTBY. 79

79. Place on top of the gauze a bit of camphor-gum. Ig-
nite it, and the flame will not pass through to the lower side.
Then ignite on the lower side, and- extinguish the flame on the
upper side.

77. The carbonic acid of a burning candle may be passed
through lime-water in the following manner. Take a bottle
arranged with tubes, as in the middle one shown in the figure
on page 87. From the tall tube at the left suspend a glass
funnel with the stein coupled to the tube by means, of a piece
of rubber tubing. Place under this funnel a burning candle.
Partly fill the bottle with lime-water. Then placing the mouth
to the right-hand tube, draw out the air from the bottle. This
makes a draft over the candle, and draws its iavisible smoke
through the funnel, down the long tube, and up through the
lime-water, which soon becomes milky.

SO. The compound biow-pipe with gasometers, as shown on
page 238, is the most serviceable. If gas-bags are used, the
one for hydrogen should be twice the size of the one for oxy-
gen. A board should be laid on each bag, upon which weights
may be placed, when ready for use, so as to force out the gas
steadily. Turn the stop-cock so that theH will pass out
twice as fast as the O. Always ignite the H first, and then
turn on the O slowly until the best eflect is produced. If gas-
ometers are used, press the inner receivers down to the bottom,
and then pour in water till it reaches nearly the top. The rub-
ber pipes may then be attached to the hydrogen or oxygen
apparatus, and the gases passed 4irectly into the gasometers.
Proper pressure is produced, when the jet is to be ignited, by
unloosing the strings from the inner receivers, and thus taking
off the '' lift" of the weights which equipoise them. Additional
pressure is secured by bearing down upon the receivers. All
the metals burn in the blow«pipe flame. with their character-
istic colors. Narrow slips should be prepared for this purpose.
A mirror, and a cup for holding >the x:halk, are necessary to
show the Ume-iight. A. piece of hard chalk or; lime, whittled
to about the size of a pencil, may. be held. in the £ame to illus-
trate the principle.

S7. Put in'^e flask two ounces of common salt and an
ounce and a. half of black o:^d of manganese. Pour on

8o DIRECTIONS FOR PERFORMING

enough water to reduce the mixture to a thin liquid. Shake
the flask until the whole interior is moistened. Insert the cork
and deliver>'-tube ; the middle bottle shown in the figure is not
necessary. Fill the pneumatic cistern with warm water, using
Just as small a quantity as possible, since water absorbs the gas.
Pour in an ounce of the oil of vitriol through the funnel-tube, or
directly at the nozzle, by removing the ground stopper, if a
kind of flask be used which has one. The gas will come off
at once, even before the heat is applied. Collect the gas in
bottles and use directly, if convenient, otherwise put corks in
them and rub the nozzles well with tallow. Pass the gas
through cold water, as shown on page 88, or more simply,
through a tumbler of water. This will form chlorine water,
which should be bottled and kept in a dark place.

2. Fill a test-tube nearly full of pure rain or snow water,
and let fall into it a drop or two of the nitrate of silver solu-
tion. A drop of HCl will form a cloudy white precipitate.

01. I. Place on a clean white dish a few scales of iodine
and a bit of phosphorus as large as a pea. It will soon ignite.

2. Fill three test-tubes nearly full of soft water. Pour in
one a few drops of a solution of bichloride of mercur}', into
the second of sugar of lead, into the third of subnitrate of
mercury (formed by pouring NO, on mercury). Add to each
of these a few drops of the solution of iodide of potassium.
The first especially will produce a brilliant color (iodide of
mercury) ; the rapid change from yellow to red is very marked.
On continuing to add the iodide of potassium, the red precip-
itate will be dissolved and disappear.

3. Make an additional quantity of the iodide of mercury,
as in the 2d exp. Let it settle. Pour off the liquid, and
then spread the sediment on a piece of heavy card-board,
making a red spot as large as a silver dollar. Dry it care-
fully. Then heat very strongly, when it will turn yellow.
Rub over the yellow spot the point of a knife several times,
bearing on very firmly, and a red mark can be seen. Lay away
the paper for a day or two, and the red color will spread over
the whole spot.

4. Dissolve a few scales of iodine in fifteen or twenty times
its bulk of alcohol. Pour a few drops of this solution on a

SXPEBIMENTS IN THE CHEMISTRY, 8l

freshly-cut potato or apple. Blue specks will show the pres-
ence of starch.

96. I. Melt a quantity of sulphur, either the flowers or
brimstone, in a test-tube. It is at first thick and dark-colored,
but after continued heating becomes thin and dark-colored.
Pour it now into water and it will form an elastic gum, which
can be moulded into any desired form.

2. Heat a piece of brimstone in a test-tube. After a little
the sulphur will sublime and collect in the upper part of the
tube as flowers of sulphur.

3. Fill a cup with brimstone and melt it with a gentle
heat. Set it aside to cool. When a crust has formed on
top, break it and pour out the liquid contents. If the cup
be broken, the bottom will be found covered with crystals of
sulphur.

100. Place in the evolution-flask half an ounce of sulphuret
of iron. Cover this with water, and then pour in oil of vitriol
through the funnel until the gas comes off freely. It may
be passed through a glass of cold water. This solution must
be bottled and closely corked. The gas may be tested di-
rectly ; see page 137.

102. I. Cover a stick of phosphorus with dry, fine-pow-
dered charcoal. It will soon ignite.

2. Put in a vial half an ounce of sulphuric ether and a half-
dozen pieces of phosphorus not larger than grains of wheat.
Thoroughly shake and then set away. Repeat the shaking
often. When the phosphorus is dissolved, pour a little of the
solution on the hands, and when briskly rubbed together in a
dark place they will glow with a ghostly light.

3. Pour some of the solution on a lump of loaf-sugar. Drop
this in hot water, when the ether will catch fire.

4. Place in a wine-glass a few crystals of chlorate of potash
and a small bit of phosphorus. Fill the glass nearly full of
water. By means of a funnel-tube, pour a little oil of vitriol
to the bottom of the glass. A violent deflagration will imme-
diately take place, and, in a dark room, flashes of green light
will be seen.

119. Cut off three or four inches of magnesium ribbon, and
holding one end with a pair of pincers, thrust the other into

^8 DISSCTWN8 FOR PESFOMMING, ETC.

IStkt flame of the spirit-lamp. The metal will almost instantly
ignite, when it may be removed and held up to the view of the
class until the Mg is consumed.

134. To make a saturated solution of alum, drop crystals
of the salt into boiling water, until a drop of the liquid taken
out on the end of a glass rod and put on a bit of glass will
crystallize as soon as it cools.

134. Fill a test-tube nearly full of water. Pour in it a few
drops of the solution of sulphate of copper. Add ammonia,
and a blue precipitate will be formed. Notice the change from
green to blue. The sulphate of copper may be readily made
for this experiment by covering a copper cent with dilute oil of
vitriol. This experiment may be made to show the divisibility
of matter by weighing the cent, then seeing what proportion of
the whole solution you use, and then experiment to find what
quantity of water can be taken and yet have the blue color
perceptible in the ammonia test.

1§5, Fill a test-tube one-sixth full of sweet pil, add a little
ammonia, and nearly fill with water. The constituents remain
separate. Shake thoroughly, and they will combine, forming
a thin, soapy liquid. Add an acid, and they will dissolve part-
nership at once.

SUGGESTIONS.

Melted snow, or very clear rain-water*, will answer the place
of distilled water in making solutions, &c., for experiments.
Whenever corks leak gas they may be wrapped with thin strips
of wet paper to make them fit more tightly, or the entire
nozzle may be smeared with tallow, or covered with sealing-
wax, if heat is not used. In that case a little plaster of paris
may be wet up and quickly applied. The experimenter will
find a retort-stand for holding the retorts, a test-tube holder, a
set of tin cork-borers, several Florence flasks of different sizes,
the copper retort for making oxygen, and the gas-bag, with
its tubing and connectors, almost indispensable. After these,
the compound blow-pipe is of the greatest value. A few dropi
of a solution of magenta (\ dr. in a gill of HO) will color th^
water beautifully, and add to the effect of certain experiments;

EXPLAINING MIRRORS AND LENSES.

The author has met with the best success in explaining
mirrors and lenses to his pupils, by using the following
method.

A Concave Mirror, — Holding up before his eye the fore-
finger of each hand, he represents to the pupil how the rays
of light enter his eye converging / how he then sees the ob-
ject on diverging rays : thus the visual angle being increasedy
the apparent size of the object is correspondingly increased.
By crossing his two forefingers before his eye he represents
the focus, and shows how diverging rays then enter the eye ;
the object is seen on converging rays, the visual angle is de-
creased, and the apparent size of the object correspondingly
decreased.

A Convex Mirror, — Using the fingers in the same way, he
illustrates how diverging rays enter the eye, the object is seen
on converging rays, the visual angle is diminished, and the
apparent size of the object correspondingly diminished. The
rays of light are not brought to a focus, hence the second ef-
fect of a concave mirror cannot be seen.

The same illustration can be used in explaining lenses,
remembering that the effect of a convex lens is like that of a
concave mirror, and of a concave lens that of a convex mirror.

At the close of the explanation and illustration with the
fingers, the following formula is put on the blackboard, and
the pupil applies it to each class of mirrors and lenses :

Converging (diverging) rays enter the eye, the

OBJECT IS SEEN ON DIVERGING (converging) RAYS ; HENCE
THE VISUAL ANGLE IS INCREASED (decreased), AND THE
IMAGE IS LARGER (smaller) THAN LIFE.

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branch.

Foot ITotdS on every page afibrd all the incidental instruction which the
teacher is usually required to impart. Indices of words refer the pupil to the
place of their first use and definition. The Biograpliies of Authors and others
are in every sense excellent.

ScO&OSiy* Although the number of pages in each volume is fixed at the
minimum, for the purpose recited above, the utmost amount of matter available
without overcrowding is obtained in the space. The pages are much wider and
larger than those of any competitor and contain twenty per cent more matter than
any other series of the same type and number of pages.

All thd QrOftt FeaturOS. Besides the above all the popular fleatnres of the
National Readers are retained except the Word-Building system. The latter
gives place to an entirely new method of progressive development, based upon
aome of the best features of the Word System, Phonetics and Object Lessons.

3

The JV*ational Series of Sta^fdm^'d School-IBooks*

The National Eeaders and Spellers.

THEIB BECOBD.

These "books have been adopted by the School Boards, or official anfhority, of
tihe following important States, cities, and towns^in most cases for exdnsive use.

Tlie State of Mixmesota,

The State of MisaourL

The State of Alabama.

The State of North Carolina.
The State of Ijouisiana.

Kew York.

New York Citj.

Brooklyn.

BofflOo.

Albany.

Rochester.

Troy.

Syracuse.

Efanira.

Fenxisylvania.

Beading.
Lancaster.
Erie.
Scranton.
Carlisle.
Carbondal).
Ifeadville.
Schnylkill HaTen.
WilliamFport
Norrietown.
Bellefonte.
Altoona.
&c., &c.

New Jersey.

Newark.
Jersey City.
Faterson.
Trenton.
Camden.
Elizabeth.
New Branswick.
Phillipsbnrg.
Oraz^.
£c., &c

Delaware.

Wilmington.

D. C.

Washington.

The EaxusalUnMl IhiXUSin records periodically all new points gained.

4

Illinois.

Indiana.

Chicago.
Peoria.

New Albany.

Fort Wayne.

Alton.

Lafhyette.

Springfield.
Aarora.
Oalesbanr.
Bockforo.

lladition.

Logansport.

Lidianapolis.

Bock Island.

Iowa.

&c., &c.

Davenport.

^

Burlington.

'Wisconsin.

Mascatine.
Mount Pleasant.

Milwaukee.

&c.

Fond dn Lac.

Oshkoeh.

Nebraska*

Janesville.

Brownsville.

Bacinc.

Lincoln.

Watertown.

&c.

Sheboygan.

La Crosse.

Oregon.

Waukesha.
EenoBha.
&c., <fec.«

Portland.
Salem.
&c.

Michigan.

Virgrinia.
Bichmond.

Grand Bapids.

Norfolk.

Kalamazoo.

Petersburg.

Adrian,
tiackison.

Lynchburg.

MoLToe.

Lansing.
&c., &c

South Carolina.
Columbia.

Charleston.

Ohio.

Toledo

Georgia.

Sandusky.

Savannah.

Conneaut.
Chardon.

Louisiana.

Hudson.

New Orleans.

Canton.

Salem.

Tennessee.

&C., &C.

Memphis

21^ Mtiionat Series of Standard SchootSooks.

SCHOOL-ROOM CARDS,

To dicGompany the National Beaders,

^« ^» •^

50

Eureka Alphabet Tablet *i

Presents tlu alphabet upon tbe Word Method System, by which the
child vill leara the alphabet ia nine dayt^ and make uo amall prc^ireu ia
reading ani speUiiig ia the same tiae.

National School Tablets, lo Nos. . . . . .*8 oo

Embrace readloff and conrersational exercises, object and moral les*
sons, form, color, £c. A complete set of these large and elegantly illus-
trated Cards will ^'nTw"**'^ the sohool-room more than any otLer article
offuniitttre.

READING.

Fowle's Bible Reader- • $100

The narrative portions of the Bible, chronologically and topically ar-
ranged, Jadiciously combined with selections from the Psalms, Proverbs,
and other portions which inculcate Important moral lessons or the great
trutlis of Christianity. The embarrassment and difflculty of reading the
Bi »le itself, by course, as a class exercise, are obvLited, and its use made
fessibtot by tlUs means.

North Carolina First Beader ^o

North Carolina Second Reader • • • • . 65
North Carolina Third Reader i oo

Prepared expressly for the schools of this State, byC. H. Wiley, Snper-
Intendentof Coiunion Schools, and F. M. Hubbard, Professor of Litera-
ature ia the State University.

Parker's Rhetorical Reader i oo

Designed to familiarise Readers with the pauses and other marks in
general use, and lead them to the practice of modulation and inflection of
ue voice.

Introductory Lessons in Reading and Elo-
cution 75

Of similar character to the foregoing, for less advanced classes.

High School Literature l 50

Admirable selections from a long list of the world*s best writers, for ex-
ercise in reading, oratory, and composition. Speeebes, dialogues,
model letters represent the latter department

TJ^ JV*aiionat Series of Standard Schooi^SookSm

ORTHOGRAPHY.

►-♦i

SMITH'S SERIES

Bnpplifs a fipellfr for every clnn In gmded schools, and coiD\irtae8 the most ottm-
pl«te and excellent ' treatise on Knglish Orth<^imph/ and Its oompanion
brauclien extant.

1. Smith's Litile Speller • .......$ 20

First Round in the Ladder of Learning;

2. Smith's Juvenile Dedner 45

Lf'smns compomM) of fnniiliar vords srmiippd with refnrenoe to dmOar
ai^iiiticaiiion or u><«, and correctly s|i«llrMl, accente<l, and defined.

3. Smith's Grammar-School Speller .... 50

FamlPHr words in'onped with rnference to the namfni'SR of sonnd of syl-
lables dilTt'reutly K]H'lli>d. Also dpfliiitions, coinpli'te rulrs for spelling and
formation of dv rivativus, and exercises in false orthography.

4 Smith's Speller and Defmer's Manual • so

A conip|pt« School Dietiomiry containing 14,000 words, with rarioiu
otlier useful matter in the way of Kales aud Exercisea.

5. Smith's Etymology— Small, 75 ; Complete . 1 25

The firRt and only Fltyniolo^ to reRO|?n<xe the AngloSitcsnn onrmtMur
Ununie ; eontniniiig also full liitts of derivatives from the Latin, Greek,
Oanlic Swedish, Nonnan, dec., 6uc ; being, in faet, a complete etymology
of the language for schools.

Sherwood's Writing Speller 15

Sherwood's Speller and Defmer 15

Sherwood's Speller and Pronouncer ... 15

The Writing Sp<*ller consists of properly ruled and numbered blanks
to rHC«>ive the words dictated by the teacher, with space for remarks and
corivctions. The other volume? mAy be used for the dictation or ordinary
class exercisifs.

Price's English Speller *i5

A complete qielling-book for a!t grades, containing more matter thaa
** Webster,"" manufactured in superior style, and sold at a lower price—
Qonseqnently the cheapest speller extant

Northend's Dictation Exercises 63

Knibracing valualrie information on a thousand topics, eommunieated
in such a nuinner as at once to relieve the exercise of spelling of its usnal
tedium, and combine it with instruction of a general character calculated
to profit and amuse.

Wriaht's Analytical Orthography .... 25

'nils standard work is popular, because it teachefl the elementary soaods
In a plain and philosophical manner, and presents orthography and or-
thoepy in an easy, nniforni system of analysis or parsing.

Fowle's False Orthography 45

Exercises for correction.

Page's Normal Chart * ^ *3 75

The elementary sounds of the langusgo for the sehool-room walla

6

2yke Miiionai Series of Standard SchootSooJbs.

~ ENGLISH GRAMMART"

CLARK'S DIAGRAM SYSTEM.

Clark's First Lessons in Grammar ... 45

Clark's Normal Grammar (JNew), i oo

Clark's Key to English Grammar .... 75
Clark's Analysis of the English Language • ^
Clark's Grammatical Chart *3 75

The theory and practice of teaching grammar in American whools to
meeting vith a tboroii};h reTolutioii from the nae of this system. Whfle
the old niethodti off.T proficieticy to the pnpil only after much veaiy
plodding and dull m .'niorizing, this afiCords from the Inception the no*
vantage of ymetieal Object Teaching^ addressing the eye by means of il-
iQBtratiTo figures ; furnishes asaodadon to the memory, its most power-
fill aid, and diverts the pupil by taxing his ingenuity. Teachers who are
vsiug Clark's Grammar uniformly testify that they and their pupils find
it the roost interesting study of the school course.

Like all great and radical improrements, the system naturally met at
first with much unreasonable opposition. It has not only ontUved the
greater part of this oppodtion, but finds many of its warmc st admirers
among those who could not at first tolerate so radical an innovation. All
it wants in an impartial trial, to conrince the most skeptical of its merit.
Ko one who has fairly and intelligently tested it in the school-room has
ever been known to go back to the old method. A great success is al«
ready etitablishcd. and it is easy to prophecy that the day is not far dis-
tant wliea it will be the oniy sj^stem qf tettehing English Grammar. As
the STsrEM iH copyrighted, do ether text^books can appropriate this ob-
Tiuus aud great iuiprovbment.

Welch s Analysis of the English Sentence • 1 25

Remarkable for its new and simple classification, its method of treat-
ing eonnectiTus, its czplaaations of the idioms and constructive laws of
the language, iui.

ETYMOLOGY.

* 0m m

Smith's Complete Etymology, i 25

Smith's Condensed Etymology, "5

Containing the Anglo-Saxon, French, Dutch, German, Welsh, Danish,
Gothic, SwedlBh, Gaelic, Italian, LAtin, and Greek Roots, and the English
words derived therefrom accurately spelled, accented, and defined.

The Topical Lexicon, i 75

This work is a School Dictionary, an Etymology, a compilation of syn*
onyms, and a manual of general information. It difieiH from the ordinary
lexicon In being arranged by topics instead of the letters of the alphabet,
thus renliaing the apparent paradox of a ** Beadable Dictionary.** Aa
anusuaUy valuable school-book.

7

The J\raiionai Series of Standard School -Hooks.

Clark's Diagram English Grammar.

T£8TIMONIAIj8.
Frvm J. A. T. Duknix, Printtpid Dmbmamt R. C. Acad*mrf, fowc
In my opinion. It is well ealenlated bjrita syateni of analT^* to d«>velop thiiM) national
Ausuldes vhicli in the old syntema vere rather left to dpTiJop thauii«lv«ia, while Uiq
aiemory waa overtaxed, and the pupila diaenuragird.

From B. A. Cox, Sekool OommiuionBr, WarreH Commiyy IlUnoit.

I have examined 180 Utaehers in the bMt ynar, and thoae liaring studied or taiicrht
Clark^s System have nniveraallj stood fifty per oeuL beiUsr examinatioiia than ihoae
tiaving studied other authors^

From M. II. B. Busxr, Principal Mttmnuc IntUfU, Qtorgttown^ Tent^ntite.

I traveled two years amaring mjrself in instmctin^ (exrlnslvply) (irHmniar rl is<«e
with Clark's system. The first class I instrocted fifty dayt^ but found tiiat this w-ae
more time tlian was reqnired to impart a theoretical knowledge uf the 8rii>M<<!e.
During the two years thereafter I instructed chuaes only thiriif days ench. iiivMriably
I proposed that unless 1 prepared my classes for a mi>re thorough, miniito, hikI aecu*
rate knowledge of English Orammar than that obtained from the ordinary biHiks and
in the ordinary way iu from one to two years, I wiiuld make no cliar^e. i iit^ver
failed in a solitary case to far exceed the Lupvs of my classes, and made money and
character rapidly as an Instructor.

Frmn A. & Douai^ss, School Commiasloner^ Delaware Coumtp, Sew VurL

I have never known a clan pursue the study of it under a live teacher, that hai not
snoceeded ; I have never known it to have an opp«uient in an educated ti*arlier who
liad {/korou^M.v investigated it; I have never known an ifftytraut teacher tu examine
it ; I have never known a teacher who has used it, tu try any other.

Frorii J. A. Dudok, Tetfeheramd Lecture^ on Bnglith Gmmmnr^ Rmtnebti.
We are tempted to assort that it foretells the d-iwn of a bri};hter a^^e ti» out mother*
tongue. Both pupil and teacher can fare snmptuonsly upon its contenrs, hdwever
highly they may have prix*>d the manuals into which they may have been iuiiiated.
and by which their expressiais have been moulded.

FroTh. W. T. CiiAPMAN, Superintendent Pttblie SrhfHtlSt WfUinijtnn, Okin,
I regard (Mark's System of Grammar the Ijest published. For teachin*. the analysis
of the Englif h Language, it surpasses any I ever used.

Frtnn F. 8. Lvow, Prinnpttl South Snrwulk Union School, OnnnectimL
1 Miring ten years* experience iu teaching, I have UHed six difTerent authors on the
•nbject of rngli.^h Orammar. I- am fully convinced that Clark's (rrnnnuat is better
calculated to make thorough gramnmriaiis than any other that 1 have seeiL

From CATALoauK or Rohbkk*b CoMMEBinAL Collbuk, St. Ltmin, MiJtmftru
Wv do not hefdtate to assert, without fear of succesiifui contradiction, that a het^ter
knowledge of the English language can be obudned by this system ia ttix weeks than
by the ola methods in as many luoutlis.

From A. Piokictt, President of the State Teachers* Atutoeiation, IHscatuin.
A thorough experiment in the use of luaiiy approved authors upon the suhjert of
Euglish tirauDnar lias convinced me of (he superiority of Clnrk. \Vhe,o the pupil has
completed the course, he is left upon a foundation of principle^ and nut apou ihe c/to>
'HtH of the author.

Fi-om Gfx». F. McFarland, Prin. jVcAllisterviUe Aeademif^ Jutvkxta Co., Penn.

At the first examination of public-school teachers by the county superintendent,
when oiieof our student teachers commenced analysing a sentence acrordiiig to Clark,
the superintendent listened in mute astoniHhmeoc until he had !ini:<hed, tlien asked
what that meant, and finally, with a very knowhig look, said such work wouldn't do
toere, and asked the applicant to parse the sentence right, and gave the luwesi oertifl-
eates to all who barely mentioned Clark. Afterwards, 1 presented him with a copy,
«ud the next fall he permitted it to be partially used, while the third or last falU no
openly commended the syKteni, and appointed three of my best teachers to explain it
at the two inslitutea and one County Convention lutld since iiepteml>cr.

Fur further testimony of equal force, sue the Publishers' Special Uirculaft Of
dUTfat uiuuborv of the i^ucaUonal Bulletin.

8

2%e National Series of Standard SchootSookt.

GEOGRAPHY

<■■#■■ »

NATIONAL GEOGEAPHIOAL SYSTEM.

THE SERIES.

*! I. Monteith's First Lessons in Geography,
11. IMonteith*s New IManual of Geography,
II. IMcNally's System of Geography, ....

INTERMEDIATE OB ALTERNATE YOLinfES.

*". Monteith's Introduction to the IManual, .
2*. Monteith's Physical and Political Geography,

1 35
1 10
200

. 63

• 1 88

.•20 00

. 25

75

. *26

ACCESSORIES.
Monteith's Wall Maps (per set) ....
Monteith's Manual of Map- Drawing (Allen's System)
Monteith's Map-Drawing and Object-Lessons,
Monteith's Map-Drawing Scale, ....

1. PRAOTIOAL OBJECT TEAOHINO. The infent Bcholar is flrat introduced
to ajUtAwt whence he may derive notionB of the shape of the earth, the phenom-
ena of day and night, the distribution of land and water, and the great natnrai
diyidions, which mere words would fiiil entirely to convey to the untutored mind.
Other pictures follow on the same plan, and the child^s mind is called upon to grasp
no idea without the aid of a pictorial illustration. Carried on to the higher
books, this system culminates in Physical Geography, where such matters ae
climates, ocean currents, the winds, peculiarities of the earth's crust, clouds and
rain, are pictorially explainel and rendered apparent to the moBt obtuse. The
illustrations used for this purpose belong to the highest grade of art.

2. OLEAB, BEAUTIPUL, AKD ODBBEOT MAPS. In the lower numbers the
maps avoid unnecessary detail, while respectively progressive, and affording the
pupil new matter for a3q'ii3ition each time he approaches In the constantly en-
larging circle the point of coincidence with previous lessons in the more ele-
mentary books. lu the Physical and Political Geography the maps embrace many
new and striking features. One of the most effective of these is the new plan for
displaying on each map the relative sizes of countries not represented, thus obvl-
atiug much confhsion which has arisen from the necessity of prepenting maps in
th3 same atlas drawn on different scales. The maps of " McNally" have long been
celebrated for their superior beauty and completeness. This is the only school-
book In which the attempt to make a complete atlas aXm clear cmd distinct, has
been successful. The map edUyring throusrhout the series is also noticeable.
Delicate and subdued tints take the place of the startliug glare of Inharmonious
colors which too frequently in such treatises dazzle the eyes, distract the atten-
tion, and serve to overwhelm the names of towns and the natural features of the
landscape.

9

^ationai Series of Standard School' Sookt,

G EOG R AP H Y~Continu«d.

3, THE VAEEBTT OP MAP EZEBGI8E. Starting eacli time from a cllfferent
basis, the pupil in many Inutances approaches the itame fact no less tLan iix
titneSj thus indelibly impressing it npou his memory. At the same time this nyE-
tern is not allowed to become wearii^ome— the extent of exercise on each subject
being graduated by its relative importance or difficulty of acquisition.

4. THE OHABAOTEB ABD ABBASaEMEHT OF THE BESGBIPTIVE
TEXT. The cream of the Ecience has been carefully culled, unimportant matter
rejected, elaboration avoided, and a brief and concise manner of presentation cul-
tivated. The orderly consideration of topics has contributed greatly to simplicity.
Due attention is paid to the facts in history and astronomy which are Inseparally
connected with, anJ important to the proper understanding of geography— and
such only are admitted on any terms. In a word, the National System teaches
geography as a science, pure, simple, and exhaustive.

6. ALWAYS UP TO THE TIMES. The authors cf these books, editorially
speaking, never sleen. No change occurs in the boundaries of countries, or of
counties, no new discovery is made, or railroad built, that is not at once noted
and recorded, and the next edition of each volume carries to every school-rccm
the new order of things.

6. SUPEBIOB GBADATIOK. This is the only series which Itmishes an avail-
able volume for every possible class in graded schools. It is not contemplated
that a pupil must necessarily go through every volume in succession to attain
proficiency. On the contrary, itco will sufQce, but three are advised ; and if the
coarse will admit, the whole series should be pursued. At all events, the books
are at hand for selection, and every teacher, of every grade, can find among them
one exactly suited to his class. The beet combination for those who wi«h to
abridge the course consists of Nos. 1, 2, and 8, or where children are somewhat ad-
vanced in other studies when they commence geography, Nos. 1*, 2, and 8. WLere
but two books are admissible, Nos. l^and 2*, or Nos. 2 and 3, are recommended.

7. FOBM OP THE VOLUMES AND MECHANICAL E2ECUTI0H. The maps
and text are no longer unnaturally divorced in accordance with the time-honored
practice of making text-books on this subject as inconvenient and expensive as
possible. On the contrary, all map questions are to be found on the page opposite
the map itself, and each book is complete in one volume. The mechanical execu-
tion is unrivalled. Paper and printing are everything that could be desired, and

>e binding is— A. S. Barnes and Company^s.

8. MAP-DBAWIN&. In 1869 the system of Map-Drawing devised by Professor
Jebomb A11.XN was secured exdusitely for this series. It derives its claim \o
originality and usefhlness from the introduction of a Jlaed unit <if metuuremftit
applicable to every Map. The principles being so few, simple and comprehensive,
the subject of Map-Drawing is relieved of all practical difficulty, (fix Nos. 2, 2*,
and 8, and published separately.)

8. ANALOGOUS OUTLINES. At the same time with Map-Drawing was also in-
troduced (in No. 2), a new and ingenious variety of Object LesE^ons, consisting of a
comparison of the outlines of countriea with fhmiliar objects pictorially represented,

10

The J>raHonat Series of Standard SehooiSookf.

Monteith k McNally's National Geographies.

CRITICAI. OPINIONS.
From B. A. Adams, Membtrqf Board qf Edueatimi^ Kew Tork.

I hATe loand, by ezMnination of the Book of Supply of our Board, that coneid-
«raU|y the huqgest number oi any tBerica now naed in oar pabUc echools is th4
Nattonal, by Monteith and McNaQy.

From Bbo. Patbuk, CMrf PrmBkmdai qf flu Vast EOueaOonai SocUejfifaie
CmnsTiAX Bdothebs in the United SUUes.

HaTiBff been conrinced for aome time past that the aeries of Geographies in
nue in oar echoola were not glring Batisfection, and came ikr short of meeting
our most reasonable expectations, I hsTO felt it my imperative dnty to examine
into this matter, and eec if a remedy ocold not be found.

Copies of the different Geographies published in this country have been placed
at our command tor examjnation. On account of other pressing duties we have
not been able to give as much time to the Inyestigntian of all these dilTcrent eeries
as we could haTe desired ; yet we hare found enough to convince us that there are
many others better than those we are now using ; but we cheerftiDy give our most
decided preference, above all others, to the National Series, by Monteith & McNally.

Their ea^ gradation, their thorouglily practical and independent character,
their comprdiensive completeness as a ftUl and accurate system, the wise dis-
crimination shown in the adectionof the subject matter, the beantiftilaad copious
illustrations, the neat cut type, the general execution of the worte, and other es>
oeOendes, wiB commend them to the friends of education everywhere.

From the **Hoxb Mohthlt,** JToaAvUfe, Term,
MoJiTUTU*8 Aim McNaxxt^s GEooRAFXXiES.~Gcography is so closely con-
nected with Astronomy, History, Ethnology, and Geology, that it is difficult to
dellne its limit j in the construction of a text-book. If the author confines himself
etrictiy to a description of the earth^s surfiice, his book will be dry, meager, and
unintelligible to a chUd. If, on the other hand, he attempts to give information
on the cognate eciencee, ho enters a boundless field, and maj wander too fiur. It
seems to us that the authors of the series before us have hit on the happy medium
between too much and too little. 2%e First Leaaons^ by applying the system of
object-teaching, renders the subject so attractive that a child, just able to read,
may become deeply interested in it. The second book of the course enlarges the
% lew, but still keeps to the maps and simple descriptions. Then, in the third
book, we have Geography combined with History and Astitmomy. A general
view of tie solar system is presented, so that the pupil may understand the
earth^s position on the map of the heavens. The first part of the fourth book
treats of Physical Geography, and contains a vast amount of knowledge com-
pressed into a small space. It is made bright and attractive by beautiftil pictures
and suggestive illustrations, on the principle of object-teaching. The maps in
the second part of this volume are remarkably clear, and the map exercises are
copious and judicious. In the fifth and last volume of the series, the whole sub-
ject is reviewed and systematized. This is strictly a Geography. Its maps are
beautiftilly engraved and clearly printed. The map exercises are iUl and com-
prehensive. In aH these books the maps, questions and descriptions are given in
the same volume. In most geographies there are too many details and minnto
descriptions— more than auy child out of purgatory ought to be required to learn.
The power of memory is overstrained ; there is conftision— no clearly defined idea
is formed in the childTs mind. Bat in these books, in brief, pointed description?,
and constant nse of bright, accurate maps, the whole subject is photographed gp
the mind. 11

The National Series of Standard SckooiSat^Jbs.

^ ■ ^ ■ , — ■■ ■ ■ »-i. ■ ■ ■ ^i^»^» ■■»■■ ■-^— ■■ »■■■■■ ,. ^ »^

The National System of Geography,

By Mokteith & McNally.
its begobd.

These popular textrteokB bare been adopted, bj offlclal authority, for t3ie achoola
of the ftkUowlog States, cities, and assodatians— in moe^cases for ezchinTe and
naifonnase.

Caufokhia. states.

HissouBi. Ybbhoht. HnnnsoTA.

At.a»awa- Iowa. Kobth Cabouha.

Tkhhsbsbb. LoumAXA. Kajras.

MnSBSIFFL

CITIES.

Hew York CHy. Limiflillle. NashTiDe. Portland.

BoMklyn. Newaik. Utica. Savannah.

NewOrieana. HUwaokee. Wilmington. IndianapoUa.

BoiBdo. diarleston. Trenton. Springfield.

BicbmoDd. Bocbsster. Norfolk. Wheeling.

JersejClty. Mobile. Norwich. Toledo.

Hartfbrd. Syracose. Loclqiort. Bridgeport

Worcester. Ilempbia. Dabnqne. St. FauL

ASSOCIATIONS.

The Sodetj of the CHREsriAir ^bothsbs, representing 40,000 pnpfls.
The FBAXCiscAir Bbothkbs, 8,000 pupils.

AXEHCAX MUSIOHABT SOCIBTT, 60,000 piQlilS.

Montei&'s Physical & Litennediate Geography.

This is the most lecentlj pnblisbed of the Geographical Series, and as miglit
have been anticipated, was vexy wannly reoelTed.

TBBTIMONIAIiS IN BRTEF.

The more I examine the better I am pleased.— J. T. Goomrow, SaU Supt. JTom,
Has no superior as a text^Mwk.— K J. Thompsoh, Supt. FUbnore Cd., Mnn.
Brtet^ dear, soggestive, and admirably adapted.— E. Cokakt, PHn. VL Normal,
It is'a gem of a book.— E. A. Stboho, 8upt. PubUc Schools^ Grand BapUU^ iOdL
The best adapted we have seen.— O. Fatillb, 8taU 8upL, Iowa.
A book that has long been needed.— A J. Kinoxak, SupC, McSenry Co.^ IB.
Prepared with hOxir, care, and weD adapted.— C. B. HALBTSAD,SWp^.iV<no&«r^,i\r. T.
The best Geography ever published.— J. Hutchison, Prin. Boys'* 8ch. J^erson^ La.
I like it very much.— A J. Cbaio, l^ate Superintendent^ Wisconsin,
Cannot fon to awaken a new interest- Vermont School Journal. [ CoU.^ To,

A new field cultivated with great saccess.- T. C. Johnson, Pres. Randolph Macon.
Contains more common sense than any other.— J. Angsab, lYin. Madison AeJowCL

12

27ke MUionai Series of Standard SchoolSooki.

MAT HEMAT ICS.

■LATBU

ARITHMETIC.

1. Davies' Primary Arithmetic $25

2. Davles' Intellectual Arithmetic . 40

3. Davles' Elements of Written Arithmetic ... 50 $ Cd

4. Davies' Practical Arithmetic ........ 90 1 10

Key to Practical Arithmetic 90

5. Davles' University Arithmetic 1 40 1 CO

Key to University Arithmetic *1 40

ALGEBRA.

L Davles' New Elementary Algebra J 215 1 40

Key to Elementary Algebra 'l ^

2. Davles' University Algebra J ^ ^ ^^

Key to University Algebra •^ «»

8. Davles' Bourdon's Algebra ' ' J o«

Key to Bourdon's Algebra .....•» ^

GEOMETRY.

1. Davles' Elementary Geometry and Trigonometry 1 ^ 1 J

2. Davles' Legendre's Geometry •••;•• ^ !: « ^

3. Davles' Analytical Geometry and Calculus . . 2 50 3 TO

4. Davies' Descriptive Geometry » ^«> » ""

MENSTJRATrON.

1. Davles' Practical Mathematics and Mensuration 1 ^^ J

2. Davies' Surveying and Navigation ' \r ' ' Vl \Z^
S: Davies' Shades, Shadows, and Perspective . . 3 75 4 00

MATHEMATICAL SCIENCE.

Davies' Grammar of Arithmetic . • •

Davies' Outlines of Mathematical Science i w

Davies^ Logic and Utility of Mathematics -^i^^^^

Davles' Metric System • ^^ ^

Davies & Peck's Dictionary of Math^<haliCi| ..,,.. v w

la

. MiHonai Series of Standard Schoot-^ooks*

■Km-x% — -- - _ _ _ ■ ■ - ■ - _ , -- .

DAVIES' NATIONAL OOUESE of MATHEMATICS.

ITS RECORD.

In claiming for this series the first place among American text-books, of what-
ever class, the Pnblishers appeal to the magnificent record which Its volumes
have earned daring the thirty-fl'oe years of Br. Charles Davies^ mathematical
labors. The nnremitting exertions of a life-time have iJaced t/ie modem eeties on
the same proud eminence among competitors that each of its predecesEors has
successively enjoyed in a course of constantly improved editions, now rounded to
their perfect firuition— for it seems almost that this science is susceptible of no
ihrther demonstration.

During the period alluded to, many authors and editors in this department have
started into public notice, and by borrowing ideas and processes original with Br.
Bavies, have enjoyed a brief popularity, but are now almost unknown. Many of
Uie series of to-day, built upon a similar basis, and described as '* modem books,"
are destined to a similar Me ; while the most far-seeing eye will find it diClcult to
fix the time, on the basis of any data afforded by their past history, when these
books will cease to increase and prosper, and fix a still firmer hold on the afiiectiun
of every educated American.

One cause of this unparalleled popularity is found in the Diet that the enterprise
of the author did not cease with the original completion of his books. Always a
practical teacher, he has incorporated in his text-books ft-om time to time the ad-
vantages of every improvement in methods of teaching, and every advance in
science. Buring all the years in which he has been laboring, he constantly sub-
mitted his own theories and those of others to the practical test of the class-room
—approving, rejecting, or modifying them as the experience thus obtained«might
suggest In this way he has been able to produce an almost perfect series of
dass-books, in which every department of mathematics has received minute and
exhaustive attention.

Nor has he yet retired from the field. Still in the prime of life, and enjoying a
ripe experience which no other living mathematician or teacher C3n emulate, his
pen is ever ready to carry on the good work, as the progress of science may dc'
mand. Witness his recent exposition of the ** Metric System." which received
the official endorsement of Congress, by its Committee on Uniform Weights and
Measures.

Bavibs* Ststem is the acknowledgbd NatiokaIi Standabd fob thb
UmTBD States, for the foUowing reasons :-—

1st. It is the basis of Instruction in the great national schools at West Point
and Annapolis.

Sd. It has received the qun^ endorsement of the National Congress.

3d. It is exclusively used in the public schools of the National Capital.

4th. The officials of the Government use it as authority in all cases involving
mathematical questions.

6th. Our great soldiers and sailors commanding th'? national armies and navies
were educated in this system. So have been a majority of eminent scientists in
ttiis country. All theee refer to '* Bavies " as authority.

6th. A larger number of American citizens have received their education from
this than from Any other series.

7th. The series bap a larger circubtion throughout the whole country than any
Other, being esctensively used in every State in the Union.

14

9%e jyaiionai Series of Standard SehooiSooJbs.

■ — — I

MATHEMATICS-Continutd.

ARITHMETICAL EXAMPLES.

Reuck's Examples in Denominate Numbers $ -^o
Reuck's Examples in Arithmetic i oo

Theae Tolnmea differ from the ordinary arithinetle in their peealiarlr
pruotietd elamracter. They are oompoeed mainly of examples, and aff»ra
the moat aerere and thorough dladpliiie for the mind. While a boo^
which vhonld contain a complete treanse of theory and praetloe vould be
too eumberaoroe for erery-day aw, the insufficiency of praeUeal examples
baa been a aooree of complaint.

HIO-HER MATHEMATICS.

Church's Elements of Calculus 2 50

Church's Analytical Geometry 2 50

Church's Descriptive Geometry, with Shades,

Shadows, and PerB})ectiye 4 00

Theae Tolumea oonatttute the " West Point Coarse** in their aavwaS

departmentab

Courtenay's Elements of Calculus . . . • 3 oo

A work eapedally popolar at the Soath.

Hackley's Trigonometry 3 oo

With applications to naTigation and anrreylng, nautical and practical
geometry and geodesy, and lo|^thmic, trigonometrlcalf and nantieal

APPLIED MATHEMATICS.

Peck's Ganot's Popular Physics i 75

Peck's Elements of Mechanics i 75

Peck's Practical Calculus ....... ii^

Prof. \^ G. Peck, of Columbia College, has deBigned the iirst of theBe works for
the ordinary wants of schools in the aepartment of Natural Philosophy. The
work enjoys a high reputation.

The Mechanics and Calcnlns are the briefest treatises on those subjects now
published. Their methods are purely practical, and unembarrassed by the details
which rather confhse than simplify science.

SLATED ARITHMETICS.

This consists of the application of an artificially slated Rur&ce to the inner cover
of a book, with flap of the same opening outward, so that students may refer to
the book and use tne slate at one and the same time, and as though the slate were
detached. When folded up, the slate preserves examples ana memoranda till
needed. The material used is as durable as the stone erne. The additional cost
of books thus improved is trifling.

15 •

^ationat Series of Standard Schoot^Sooks,

' - - I ■ ■ I 1 1 ■ < ^

Davies' National Course of Mathematics.

TSSTIMONIAIiS.
From L. Van Bokkelen, StaU Superintendent Public Instruction^ Maryland.

The series of Arithmetics edited by Prof. Daviea, and published by your flrm.
have been used for many years in the schools of several connties, and the city oi
Baltimore, and have been approved by teachers and commissioners.

Under the law of 1865, establishing a nniform system of Free Public Schools,
these Arithmetics were unanimous^ adopted by the State Boanl of Education,
after a carefhl examination, and are now used in all the Public Schools of Mary-
land.

These &cts evidence the high opinion entertained by the School Authorities of
the value of the series theoreacally and practically.

Fivm noBAox Websteb, President of the College of New York,

The undersigned has examined, with care and thon^^ht, peveral volumes of Ba-
vies* Mathematics, and is of the opinion that, as a whole, it is the most complete
and best course for Academic and Collegiate instruction, with which ho is ac-
quainted.

lYom David K. Casf, State Superintendent of Common Schools^ Connecticut.

I have examined Davies* Series of Arithmetics with some care. The language
is clear and precise ; each principle is thoroughly analyzed, and the whole so ar-
ranged as to liocilitate the work of instruction. Haviitg observed the patisihction
and^Buccess with wliich the different books have been used by eminent teachers,
it gives me pleasure to commend them to others.

From J. O. Wilson, Cliairman Committee on Text-Boolcs, Washington^ J>. C,

1 consider Davlc3* Arithmetics decidedly euperior xo any other series, end In
this opinion I am sustained, I believe, by the entire Eoard of Education and Corps
oT Teachers in this city, where thoy have been used i(fr several years past.

From JoHK L. Camfssell, Profeosor qf MatJiemativs^ Wahash College^ Indiana.

A proper combination of abstract reasoninf* and practical Illustration is the
chief excellence in Prof. Bavies* Mathematical works. I prefer his Arithmetics,
Algebras. Geometry and Trigonometry to all others now in use, and cordially re*
commend them to all who desire the advancement of sound learning.

From Majob J. H. Whittlbset, Government Inspector cf Military/ Schools.

Be assured, I regard the works of Prof. Davies, with which I am acquainted, as
by far the best text-books in print on the subjects which they treat. I shall cer-
tainly encourage their adoption wherever a word from me may be of any avail.

From T. McC. Ballantine, Prof. Ifathematics Cumberland CoUeje^ Kentuckf^,
I have long taught Prof. Bavies* Course of Mathematics, and I continue to like
their working.

From John McLean Bell, B. A., Prin, of Lower Canada College,

I have used Bavies* Arithmetical and Mathematical Series as text-books in the
schools under my charge for the last six years. These I have found of neat effi-
cacy in exciting, invi^rating, and concentrating the intellectual iaculties of the
young.

Each treatise serves as an introduction to the next higher, by the similarity of
its reasonings and methods; and the student is earned forward, by easy and
gradual steps, over the v/holo field cf mathematical Inquiry, nnd that, too, in a
shorter time than i3 usually occupied in mastering a single department. I rincerc-
ly and heartily recommend them to the attention of my fellow-teachers in Canada.

From B. W. Steele, Prin. Philekoian Academy^ Cold Springs^ Texas.

I have used Bavles' Arithmetics iV\ I know them nearly by heart. A better
series of school-books never were published. I have recommended them until
they are now used in all this region of country.

A large mass of similar " Opinions'* may be obtained by addressing the pub-
lishers ror special circular for J)avie8' Mathematics. New recommendations are
published in current numbers of the FducatUmal Bulletin.

' 16

«Mi

27ke Mitionai Series of Standard School^l^ooks^

HISTORY.

# ^ #

Honteith's Youth's History, $75

A IlistotT of the L'uite<l States for beginners. It is arranged npon tlie
oatechetictl pUu, with UlastratiTo maps and engraviugs, r«Tiew qaeetions,
dates in parentheaes (that their atadir may be optional with the younger
cl.isa of leamen), and intereating Jilographical Sketches of all persona
who haro been prominently iJenUfied with the hlntory of our countiy.

Willartfs United Slates, School edition, . . . i 40

Do. do. University edition, . 2 25

The plan of this standard work Is chronologically exhibited in front of
the title-page; tlie Maps and Sketches are found useful assistants to the
memory, and dates, usually so difflcnlt to remember, are so systematically
arranged as in a great degree to obviate the difhcalty. Candor, impar-
tiality, and accuracy, are the distinguiahiag features of the narratiye
portiou.

Willard's Universal History, 2 25

The most valuable features of the *" UnituU Btutcs** aro reproduced in
fhiSk The poeuliaritiea of the work are its gn^t oouciseuess and the
prominence given to the chronological order of events. The margin
marks each successive era with great distinctness, so tliat the pnpil re-
tuins not oily the event but its time, and tlms fixes the order of history
firmly and usefully in his mind. Mrs. TVillard's books are constantly
revised, and at all times written up to embrace important historiod
«veuts of reoeal date.

Berard's History of England, • i 75

Py an authoress well known for the success of her TTistory of the United
Btatra. Ttio social lite of the English people i» felicitously interwoven,
as in £ict| with the civil and militaiy trauftactious of tlie realm.

Ricord's History of Rome, i 60

Possesses the charm of an attractive romance. The Fables with which
this history abounds are introduced in such a way as not to deceive the
inexperienced, while adding materially to the value of the work as a rcll- .
able index to the character and institutions, as well as the history of the
Bomaa people.

Banna's Bible History, 12s

The onlv compendium of Bible narrative which affords a connected ard
chronological view of the important events there recorded, divested of uil
superfluous detaiL

Summary of History, Complete 60

American History, $0 40. French and Eng. Hist. 35

A well proportioned outline of leading events, condensing the substance of the
more extensive text-bouk in common use into a series of statements s^ brief, that
every word may be committed to memory, and yet. so comprehenrive that it
presents an accurate though general view of Uie whole continuous life of nations.

Marsh's Ecclesiastical History, . . . . . a oo

Questions to ditto, 75

Affording the History of the Church In all ages, with accounts of the
pagan world during Biblical periods, and the character, rise, and progress
of all Religions, as well as the various sects of the worshipers o/ Christ.
Thf work is entirely non-sectarian, thongh strictly catholic.

X *

2^e JVational Series of Standard Schoot'Sooks.

PENMANSHIP.

Beers' System of Progressive Penmanship.

Per dozen ... $1 68

This ** round hand'" system of FenmansMp in twelre nnmbers, com-
mendn ikself by its simplicity and thoroughness. The first foar numberi
are primary books. Kos. 6 to 7, advanced books for boys. Nos. 8 to 10,
advanced books for girls. Nos. 11 and 12, ornamental penmanship.
These books are printed from steel plates (engraved by McLees), and are
unezceiled in mechanical execution. Large quantities are annually mdMSu

Beers' Slated Copy Slips, per set ..... *50

All beginners should practice, for a few weeks, slate exercises, fikmiliar-
izing them with the form of the letters, the motions of the hand and arm,
&c., &c These copy slips, 82 in number, supply all the copies found in a
complete seiiee of writin^books, at a trifling cost

Payson,Dunton&Scribner's Copy-B'ks.P.doz.,1 80

The National System of Penmanship, in three distinct series— (1) Com-
mon School Series, comprising the first six numbers ; (2) Budness Series,
Nos. 8, 11, and 12 ; (3) Ladies' Series, Nos. 7, 9, and 10.

Fulton & Eastman's Chirographic Charts,*3 75

To embellish the school room walls, and furnish class exercise in the
elements of Penmanship.

Payson's Copy-Book Cover, per hundred .*4 oo

Protects every pugu except the one in use, and ftoiishes ** Unea** with propet
slope for tha. penman, under. Patented.

National Steel Pens, Card with all kinds . . . *15

Pronounced by .competent Judges the perfection of American-made pens, and
superior to any foreign article.

Index Pen, per gross . . . 7S

SCHOOL SERIES.
School Pen, per gross, . .$ 60
Academic Pen, do . . 63

Fine Pointed Pen, per gross 70

POPULAR SERIES.

Capitol Pen, per gross, . . 1 00

do do pr. box of 2 doz. 25

Bullion Pen (imit gold) pr. gr. 75

Ladies' Pen' do 63

BUSINESS SERIES.

Albata Pen, per gross, . . 40

Bank Pen, do . . 70

Empire Pen, do . . 70

Commercial Pen, per gross . 60

Express Pen, do . 75

Falcon Pen, do . 70

Elastic Pen, do . 75

Stimpson's Scientiflc Steel Pen, per gross .*2 oo

One forward and two backward arches, ensuring great strength, well-
balanced elasticity, evenness of point, and smootlmess of execution. One
gross .in twelve contains a Scientific Gold Pen.

Stimpson's Ink-Retaining Holder, per doz. .*2 oo

A simple apparatus, whic^ does not get out of order, withholds at a
single dip as much ink as the peo would otherwise realize from a dozen
trips to the inkstand, which it supplies with moderate and easy flow.

Stimpson's Gold Pen, $3 oo; with Ink Retainer** 50
Stimpson's Penman's Card, * 50

OuQ. dozen Steel Pens (assorted points) and Patent Ink-retaining Pea
luddar.

X8

TAe Mitionai Series of Standard School !Dook$m

BOOK-KEEPING

Smith & Martin's Book-keeping .... $i 25
Blanks to ditto *60

This work is by a praetleal teacher and a practical book-keeper. Tt Is
of a thoroughly popular daas, and trUl be welcomed by every one who
loTes to see theory and practice combined in an ea^r* eoneiae, and
methodical form.

Tlie Single Entry portion is well adapted to supply a want felt in nearly
all other treatises, which leem to be prepared mainly for the use of wholes
sale merehantSt leaving retailers, meefianics, farmers, &c^ who transact
the greater portion of the business of the country, without a guide. The
work is also commended, on this account, for general use in Young LRdie^
Bemiuaries, where a thorough grounding in the Biuipl4>r form of accounts
will be iuTaluable to thb future honsekeepers of the nation.

The treatise on Double Entry liook-keeping combines all the adTan-
tages of the most recent methods, with the utmost si aipUcity of applicarion,
thus affording the pupil all the advantages of actual cxperiencH tu> the
counting-hoiise, and giving a dear compreheosion of the entire SHb>
Ject through a judicious eonrse of mercantile transactions.

The shape of the book \% such that tlie transuctiuna fan be pnntented as
in actual practice ; and the simplified form of Wanks, three iu number,
adds greatiy to the ease experienced in acquiring the scienca

D RAWING .

The Little Artist's Portfolio *50

25 Drawing Cards (jn'ogressive patterns), 25 Blanks, and a fine Artlsf s
Pencil, all in one neat envelope.

Clark's Elements of Drawing *i oo

Containing full Instructions, with appropriate designs ani copies for a
complete course in this graceful art, from the first rudiments of outiiue to
the finifdied sketches of landscape and scenery.

Fowle's Linear and Perspective Drawing 'CO

For the coltivation of the eye and hand, with copious illustrations and
directions, whkdi win enable the unskilled teacher to learn the art himself
while Instro^ng his pupils.

Chapman's American Drawing Book • • .'^6 oo

The standard American text-book and authority in all branches of art.

Honk's Drawing Books— Six Numbers, per set ^2 25

Each iKKtk contains eleven large patterns with opposing blanks. No. 1 . —
Elementary Studies; No. 2. — Studies of Foliage; No. 3. — Landscapes;
No. 4.— Animals, I. ; No. 5— Animals, 11. ; No. 6.— Marine Yiews» dec.

Ripley's Map Drawing i 25

One of the most rtflicient aids to the acquirement of a knowledge of
geography is we practice of map drawing. It is useful for the same reason
that the best exercise in orthograi^y is the vn-iHng of difficult words^
Sight comes to the aid of hearing, and a double impression is produced
upon the memory. Knowledge becomes less mechanical and more intui«
tive. The student who has sketched the outlines of a country, and dotted
the important places, is little likely to forget either. The impression pro
dnced may be compared to thai of a traveler who has been over tht
ground, while more oomprehensive and acoorace in detalL

19

2Jke tATaiionai Series of Standa^xl iichool':8ook»^

NATURAL SCIENCE.

FAMILIAR SCIENCE
Norton & Porter's First Book of Science, • $i 75

By eminent Profetwors of Yale College. Oratains the principles of
Natural PhOoflophy, Astronomy, Chemistry, Pliysiology, and Geology.
Arranged on the Catechetical plan for primary classes and beginners.

Chambers' Treasury of Knowledge, ... i 25

Progressive lessons upon— /(r«^ common things which lie most irame- i

diately around us, and firat attract tlie atteotion of the young mind i
second, common objects from the Mineral, Animal, and Vegetable king-
doms, manufactured articles, and miscellaneous substances ; thirds a sys-
tematic TiRw of Nature under the tarious sciences. May be used as a
Reader or Text-Book.

NATURAL PHILOSOPHY.
Norton's First Book in Natural Pliilosophy, i oo

By Prof. NoBTON, of Yale College. Designed for beginners ; profusely
illustrated, and arranged on the Catechetical plan.

Peck's Ganot's Course of Nat. Philosophy, 1 75

The standard text-book of France, Americanised and popularised by
Prof. Pbck, of Columbia College. The most magnificent system of illns-
tration ever adopted in an American achool-book is here found. For
intermediate dassesi

Peck's Elements of Mechanics, 2 25

A suitable introduction to Bartletfs higher treatises on Mechanical
Philosophy, and adequate in itself for a complete academical oourso.

Bartlett's Synthetic MechanicSi 5 00

Barllett's Analytical Mechanics, • .... 5 00
Bartlett's Acoustics and Optics, 3 50

A system of Collegiate Philosophy, by Pro£ Bakelsxt, of West Point
Milittury Academy.

Steele's 14 Weeks Course in Philos. (seep.25.). 1 50

GEOLOGY.
Page's Elements of Geology, 1 25

A volume of Chambers* Edncation^l Course. Practical, simple, and
eminently calculated to make the study interesting.

Emmon's Manual of Geology, 1 25

.The first Oeologist of the country has here produced a work worthy of
bis reputation*

Steele's 14 Weeks Course (see p. 26) .... 1 so

20

The ^ationai iferres of seanaard SchoolSooks.

— ■ » »

Feck's Qaaot's Popular Physics.

TBBTIMONIAIjS.

JVwn F1K>7. Aunrao OoLLzar, CornOl CoOBge^ Jowa.
I am pleaaed with it I bave decided to introdace it as a text-book.

From H. F. Jobhsoh, PteriderU MaeHton OoOege^ 8h4mn^ Mitt.
I am pleaaed with Peck^s Oanot, and think it a magnificent t>ook.

JTrom PBor. Edward Bbooss, Pennsylvania State Sormal SehooL

So eminent are its merits, that it win bo introduced as the text-book npon d»
mentary physics in this insUtation.

From H. H. Lockwood, Prqfetoor Kahtral P/dloeophy U, S. Kaval Academy.

I am BO pleased with it that I wiH probably add it to a course of lectures given ta
the midshipmen of this school on physics.

From Geo. S. Maceib, Prqfettor Xaturai EMory VniverHty qf KashvUU^ Tenn,

I have decided on tbp introduction of Peck^e Oanot*s Philosophy, as I am satis>
fled that it \^ the bestbook for the purposes of mv pupils that I liave seen, com-
bining simplicity of explanation witu el^^ce of llmau»tion.

From W. S. McRab, Supsrintendent Vevay PubHe Schools^ Indiana.

Having carefhlly examined a number of text-books on natural philosophy, I do
not hesiUte to ex()re0s my decided opinion in favor of Peck^s Qanot The matter,
style, and illustration eminently aJapt the work to the popular wants.

From Rav. Samuel McKnnraT, D.D., PresH Austin CoUegey HantsviUe^ Texas,

It gives me pleasure to commend it to teachers. I have taught some classes with
It as onr text, and must say, for simplicity of stvie and clearness of illustration, I
have found nothing as yet published of equal value to the teacher and pupil.

From C. V. Sfeab, Principal Maplewood Institute^ PittsJUldy Mast,

I am much pleasel with Its ample illustrations by rlates, and its clearness and
Fimplicity of statement. It covers the ground usually gone over by our higher
classes, and contains man/ fresh illustratioDs from liie or daily occurrences, and
new applications of scientiflc principles to tjuch.

Fiwn J. A. Banfield, Superintendent Marshall PubUe Schools, Michigan.

I have used Peck's Ganot since 1863, and with increasing pleasure and satisfko-
tion each term. I consider it superior to any other work on physics in its adapta-
tion to our high schools and academies. Ita illustrations are superb^beiter
than three times their number of pages of fine print.

From A. Schxjtleu, Prof, qf Mathematics in Baldwin University, Berea, Ohio.

After a careftd examination of Peck's Ganot's Natural Philosophy, and an actual
test of its merits as a text-book, I can heartily recommend it as admirably adapted
to meet the wants of the grade of students for which it is intended. Its diagrams
and illustrations are unrivaled. We use it in the Baldwin University.

From D. C. Van Nobman, Principal Van Korman Institute^ Keto York,

The Natural Philosophy of M. Ganot, edited by Prof. Peck, Is, In my opinion,
the best work of its kind, for the use intended, ever published in this country.
Whether regarded in rekition to the natural order of the topics, the precision and
clearness of its definitions, or the fhllness and beauty of its illnatrations, it is cer-
tainly, I think, an advance.

t:^* For many similar testimonialB, see current numbera of the maatrated £d>
mcaUonal BpilAtm.

21

'2yke National Series of Standard School- ^ooJbSm ■

NATURAL SCIENCE-Continued.

CHEMISTRY.

Porter's First Book of Chemistry, . . . .|i oo
Porter's Principles of Chemistry, . . . . 2 oo

The above are widely known as the prodactions of one of the most
eminent scieQtiflc men of America. The extreme aimplioity in the method
of presenting the science, while exhaustiydy treated, has excited nni-
versal commendation. Apparatus adequate to the performance of every
experiment mentioned, may be had of the publishers for a triflinfi^ sura.
The effort to popularise the science is a great success. It is now withia
the reach of the poorest and least capable at onco.

Darby's Text-Book of Chemistry, .... i 75

Purely a Chemistry, divesting the subject of matters comparatively
foreign to it (such as heat, light, electricity, etc.), but usually allowed to
engross too much attention in ordinary schaol-books.

Gregory's Organic Chemistry, .... . 2 50
Gregory*s Inorganic Chemistry, 2 60

The science exhaustively treated. For colleges and medical students.

Steele's Fourteen Weeks' Course, i so

- A successful effort to reduce the study to the limits of a single term^
thereby making feasible its general introduction In institutions'of every
character The author's felicity of stylo and success in making the
science pre-eminently iiiteresUna are neculiarly noticeable features.

Chemical Apparatus, to accompany "Porter** 20 00
do do to accompany " Steele" 26 00

BOTANY.
Thinker's First Lessons in Botany, .... 40

For children. The technical terms are largely dispensed with in favor
of an ea^ and familiar style adapted to the smallest learner.

Wood's Object Lessons in Botany, . . . . i 50
Wood's American Botanist and Florist, . . 2 50
Wood's New Class-Book of Botany, . . . 3 50

The standard text-books of the United States in this department In
style they are rimple, popular, and lively ; in arrangement, easy and nat-
ural ; in description, graphic and strictly exact The Tables for Analysis
art! reduced to a perfect system. More are aonuaUy sold than of all others
comlnned.

Darby's Southern Botany, 2 oo

Embracing general Structural and Physiological Botany, with yegetable
products, and descriptiooa of Southern plants, and a oomplete flora of
tho Southern States ^^

27te National Series of Standard SchoolSookt.

NATURAL SCIENCE-Continued

PHTSIOLOGT.
Jarvis' Elements of Physiology, .....$ 75
Jarvis' Physiology and Laws of Health, • i 65

Tho only books extant irliich approach this subject with a proper Tiew /

of the true object of teaching Physiology in sctiools, viz., that scholars
may know how to take care of their own health. In bold eonfcrast with
the abstract Anai.€fm.ie%^ which children learn as they would Oreek or
Latin ^and foiiget as soon), to discipline the niindy arc these tezt-bookn,
using the acienee as s secondary consideration, and only so far as is
necessary for the comprehension of the laws 0/ health.

Hamilton's Vegetable & Animal Physiology, l 25

The two branches of the scienea combined in one mlnme lead tho stu^
do^t to A proper comprehensiou of tho Analogies of Nature.

ASTRONOMY.
Steele's Fourteen Weeks' Course i ^o

Ruilnced to a ringle term, and better adapted to school use than any
work heretofore published. Not written for the hiforraation of seientifie
men, but for the inspiration of youth, the pages are not burdened with a
multitude of figures which no memory could possibly retain. The whole
subject is presented in a dear and concise form.

VVillard's School Astronomy, i oo

By meant of dear and attractive illustrations, addressing tho eye in
many cases by analogies, careful definitions of all necessary technical
tcmLS, a cateful avoidance of rerbiage and unimportant matter, particular
nttention to analysis, and a general adoption of the simplest methods,
Mrs. Willard has made the best and most attractive etenientary Astron-*
omy extant

Mclntyre's Astronomy and the Globes, .-150

A complete treatise for iatermediate classes. Highly approved.

Bartlett's Spherical Astronomy, . • • • . 5 oo

The West Point course, for advanced classes, with applications to the
current wants of Navigation, Geography, and Chronology.

NATURAL HISTORY.
Carl's Child's Book of Natural History, . . 50

Illustrating the Animal, Vegetable, and Mineral Kingdoms, with appli-
cation to the Arts. For beginners. Beautifully and copiotisly illustrated,

ZOOLOG-Y.
Chambers' Elements of Zoology, l so

A complete and comprehensive system of Zoelogy, adapted for aca-
demic instruction, presenting a systematic view of the Animal Kingdom
as a portion of external Nature.

23

National Series of Standard School- ^0oJt$.

Jarvis' Physiology and Laws of Health.

TEBTIMONIAIiB.

From BAjron. B. MgLahi, SuperintendtrU Fublie SehooiU, Ktokut, Iowa.

I am glad to see a reallj good text-book on this much neglected iMiinch. Thli ii
dear, ooudse, accurate, and eminently adapted to the elauuhromn.

From William F. Wtkbs, Principal of Academih W«tt Cheattr^ Pmnat/lvania.
A thorough examination has aatisiled me of its superior claim* as a text-book to the
attention of teacher and taught I shall ind'oduce it at once.

From H. R. SAifPosn, PrindpcU of Ea^ Oeneme Conference Seminary^ N. Y.

** Jarrl^ Pbjrsiology*^ is received, and fuIlT^met our expectationa We Immediatdj
adopted it.

Frwn Ibaao T. Oooonow, State Superintendent of Kanaaa^-pubtiehed in cormeetion

with the '" 8ch4>ol Law."

** Jarrl^ Physiologj,** a common-sense, pmetical work, with just enough of anat-
omy to understand the physiolo^CHl portiotia The last six pages, ou Man's Kespon
Bibuity for his own healtli, are worth the print of the book.

From D. W. Stktknb, SiiperhUendetU Public Schools^ Fatt IHver^ Maea.
I hare examined Jarvi^ ** Physiology and Jaws of Health,** which you had the
kiednesB to send to me a short time ago. In my jiidguiont it is fur the best work of
the kiad within my knuwledg^e. It has bccu adopted as a text-lwok iii uur public
■clioola

From Hrnrt G. Denmt, Chaimutn Book Committee, Boston, Jfan.

The very excellent ** Physiology ** of D. Jarvis I had introduced into our High
School, where the stndv had been temporarily dropped, belieTtng it to be by far the
best work nf the kind tnat hatl come under my obaerration: indeed, the reintrodnc-
lion of the study was delayed for some months, because Dr. Jarvis' book could not t>«
had, and we were uuwilllug to take any other.

From Psor. A. P. Psabout, P.D., LL.D., Uarvard Univertdty,

* * I have been in the habit of examining school-books with great care, and 1
hesitate not to say that, of all the text-l>ooks on Physiology which havo been {^veti to
the public. Dr. Jarvis* deserves the first place on the score of accuracy, thoroughness,
method, simplicity of statement, and constant rtference to topics of practical intoresi
and utility.

From James N. Towaaawn, Superintendent PulHUi Sehoala, Hudson^ It. Y.

Every human being is appointed to take charge of his own liody ; and of all hooka
written upon this subject. I know of none which will so well prepare one to du thlM as
** Jarvis* Physiology'* — that is, in so small a compass of matter. It considers the
pure, simple tawa of hetUth paramount to science : and though tlie work is thoroughly
scientific, it is divested of all cumbrous technicalities, and presents the subject of phy-
sical life in a manner and style really chanuing. It is unquestionably the best text-
book on physiology I have ever seen. It is giving great satisfaction in the schools of
this city, where it has been adopted as the standard.

From L. J. Sahfobd, M.D., Prof. Anatomy and Phyeiolofpj in Yale CoUege

Books on human physiology, designed. for the use of schools, are more generally a
failure perhaps than are school-books, on most other subjects.

The great want in this department is met, we think, iu the well-written treatise of
Dr. Jarvis, entitled ^* Physiology and I^aws of Health.** • • The work is not too
detailed nor too expansive in any department, and is clear and coucise in all. It is
not burdened with an excess of anatomical description, nor rendered discursive by
many zoological references^ Anatomical stetements are made to the extent of qnali.
fying the student to attend, understandingly, to au exposition of those fimctional pro*
eesses which, collectively, make up health; thus the laws of iiealth are en undated,
and many suggestions are given which, if heeded, will tend to its preservation.

For ftirther testimony of similar character, see current numbers of the lUua
trated Rducational Bulletin.

24

7%e MiHonai Series^ of Standard Schoot'Sookt*

NATURAL SCIENCE.

"FOUBTEEN WEEKS" IN EACH BMNOH.

By J. DORMAN STEELE, A.M.

Steele's 14 Weeks Course in Chemistry • $i ao

Steele's 14 Weeks Course in Astronomy • i ^

Steele's 14 Weeks Course in Philosophy • i 50

Steele's 14 Weeks Course in Geology. • i 50

The nnpanUeled snccess of the first volnmc, " 14 Weela in Chetniitryy* enconr-
aged the pnbllshen to project a complete coarse npon a eixnilar plan, and designed
to make the Natoral Sciences popular.

Our Text-Books in these studies arc, as a |*eDeral thing, dun and uninteresting.
They contain fh>m 40O to 600 pages of diy fiicts and unconnected details. They
abound in that which the student cannot learn, much less remember. The pupil
commences the study, 13 conAised by the line print and coarse print, and neither
knowing exactly what to learn nor whet to hasten oyer, is crowded through the
eingple term genemUy assigned to each branch, and frequently comes to the close
without a deHnite and exact idea of a single scientific principle.

8tecle*8 Fourteen Weeks Courses contain only that which every well-informed
person should know, while all that which concerns only the professional scientist
is omitted. The language is clear, simple, and interesting, and the illustrations
bring the subject within the range of home life and daily experience. They give
such of the general principles and the prominent fiicta as a pupil can make famil-.
lar as honscholi words within a single term. The type is large and open ; there
is no fine print to annoy; the cuts are copies of genuine experiments or natural
phenomena, and are of fine execution.

In fine, by a system of condensation peculiarly his own, the author reduces each
branch to the limits of a single term of study, while sacrificing nottiing that is es-
sential, and nothing that is usually retained from the study of the larger manuals
in common use. Thus the student has rare opportunity to eooaomize his timet or
rather to employ tliat which he has to the best advantage.

A notable feature is the author's charming *^ style,*^ fortified by an enthusiasm
over his subject in which the student will not fiEtU to partake. Believing that
Natural Science is tvJl of fascination, he has moulded it into a form that attracts
the attention and kindles the enthusiasm of the pupil.

The recent editions contain the author's " Practical Questions^* on a plan never
before attempted in scientific text-books. These are questions as to the nature
and cause of common phenomena, and are not directly answered in the text, the
design being to test and promote an intelligent use ot the student's knowledge of
the foregoing principles.

Steele's General Key to his Works . • • • *i 50

This work is mainly composed of Answers to the Practical Questions and Solu-
tions of the Problems in the author's celebrated "Fourteen Weeks Courses " in
the several sciences, with -many hints to teachers, minor Tables, &c. Should be
on every teacher's desk.

25

. 2%e ^diionat Series of Standard School" SpoJbt^

-^ . rf

^ Steele's 14 Weeks in each Science.

TSSSTIMONIAIiS.

From L. A. Bibub, PnsidirU If. O, OoOegt,
X bave not been disappointed. Shall take pleasure in introdacing thi^ series.

From J. F. Coz, Frest. Southern Female College^ Oa.
I am mncli pleased with these boolu, and expect to introduce them.

lYom J. R. B&ANHAii, Frin. BrowneviUe Female Cottege^ Term,
They aro capital little books, and are now in use in our institution.

From W. H. Qoodaia, Fiqfeeeor Seadvlile Seminary^ La,
We are using your 14 Weeks Course, and are much pleased with tbem.

From W. A. BouEs, Supt, SMbyviOe Graded Schooly Ind.
They are as entertaining as a story book, and much more improving to the mind.

IVwn S. A. Snow, Principal c/ djh School^ UxMdge, Mass.
Bteele^s 11 Weeks Courses in the Sciences are a perfect success.

From John W. Doughtt, Nevotmrg Free Academy^ N. T.

I was prepared to find Prof. Steele's Course both attrsctive and instmctlTe. Hy
highest expectations have been fully realized.

I^rom J. S. Blackwell, Frest, GTient CoUege^ Ky.

Prof Steele^s unexampled success in'provldin^ for the wants of academic classes,
has led me to look forward with high anticipatu>na to his forthcoming issue.

From J. F. Cook, Frest. La Orange College, Mo.

I am pleased with the neatnefis of these books and the dclightftil diction. I have
been teaching for years, and have never seen a lovelier UtUe volume than the As-
tronomy.

From M. W. Smith, Prin. qfSijh School^ Morrison, n.

They seem to me to be admirably adapted to Ihe wants of a public school, con-
tsinins, as they do, a sufficiently comprehensive arrangement of elementary prin-
c^les to excite a healthy thirst for a more thorough knowledge of those sciences.

From J. D. Babtuet, Prin. qfBigh School, Concord, N. H.

They are just such books as I have looked for, viz., those of interesting style,
not ctmibersome and tilled up with things to be omitted by the pupil, and yet suf-
ficiently full of focts for the purpose of most scholars in these sciences in our hi^h
schools ; there is nothin;; but what a pupil of average ability can thoroughly
master..

From Alonzo Nobtow Lewis, Principal of Parker Academy, Conn.

I consider Steele's Fourteen Weeks Courses in PhUosophy, Chemistry, &c., the
best school-books that have been issued in this country.

As an introduction to the various branches of which they treat, and especially
for that numerous class of pupils who have not the time for a more extended
course, I consider them invatttable.

From Bdwabd Bbooks, Prin. State Normal School, MUersviUe, Pa.

At the meeting of Normal School PrincipalR, I presented the following resolu-
tion, which was unanimously adopted : " Refotved, That Steele's 14 W^eeks
Courses in Natural Philosophy and Astronomy, or an amount equivalent to what
is contained in them, be adopted for use in the State Normal Schools of Pennsvl*
▼ania.^' The works themselves will be adopted by at least three of the schools,
and, I presume, by them alL

26

3%€ J^^hiionai Series of Standard Sehoot^^ooks.

MODERN LANGUAGK

French and English Primer, 4 lo

German and English Primer, lo

Spanish and English Primer, 13

The naiDM of ooBunon ol)|eeto proj^ij llbiitemted and aiXHiged ia aa^
leaonii

Ledru's French Fables, 75

Ledru's French Grammar, i oo

Ledru's French Reader, . • • # i oo

The eathor*8 long experience hae enabled him to present the most flieiw
ttighlj praetleal tezt-booka extant, in this branch. The aystem of pro-
nuneUtion (bv pbonetlo Uloatration) la origioal with thia author, and will
commend Itacdf to all American teachera, as it e:uible8 their pupila to ae-
eure an abaolntely correct prononciation withoat the aaaistanoe of a nativo
mnater. This featore la peealiarly valoable also to *^ aelf-tau^t** atodeat^
The directions for aaoertainin<; the gender of French nouns— also a great
■tambllng-block— are peculiar to this work, and will be found lemarl&ibl/
competent to the end proposed. The criticism of tcushers and tha tost of
tl:a school-room is iaTited to thia ezcclleat aerioi, with coafideacai

Worman's French Echo, i 25

To teach conversational French by actual practice, on an entirely new
plan, which rceogniaes the importance of the student learning to think in
the language which he speaka It furnishes an excensiTe vocabulary of
words and expressions in common use, and suffices to free the leanier
from the embarrassmenta which the peculiarities of his own tongue are
likely to be to him, and to make him thorougtily familiar with the use
of proper idioms.

Worman's German Echo, i 26

On the same plan. See Worman*s German Series, page 29.

Pujol's Complete French Class-Dook, ... 2 25

Offera, in one volume, methodically arranged, a com:)leto French eonrse
•-nsualiy embraced in aeriea of from five to twelve books, incloding the
bulky and ezpenaive Lexicon. Hsre are Grammar, Conversation, and
cliolce Literature— selected from the best French aothorai Each branch
is thoroughly handled ; and the student, havi'ir? diligently completed the
course aa prescribed, may consider himself, without further appUcatioa,
au/aU in the moat polite and elegant language of inoderu timea.

Haurice-Poitevin's Grammaire Francaiss, • 1 00

American schools are at last supplied with an American edition of thfs
famous text-book. Many of our best institutions have for years been pro-
curing it from abroad rather than forego the advantages it offers. The
policy of putting students who have acquired some proficiency from the
ordinary text-books, into a Grammar written in the vernacular, can n^t
bo too highly commended. It affords an opportnnif y for finish and review
at once ; while embodying abundant practice of it» own rulea.

Willard's Historia da los Estados Unidos, • ^ oo

The History of the United States, translated by Professors Tolon and
Da ToBMos, will be found a yaluable, instractiv^ aud entertaiaiag raad*
lng*b90ltfor8pftBifihoUMeSi q-

The MMonai Series of Siandard ScMooi^lSookt.

Pujol's Complete French Glass-Book.

TISSTIMONIAIaS.
Wnm PB07. Eu&fl !*■■»■■■, Vwkm OaOtagg.

I take great pleasure in recommendiiig PiqoI and Yam Sormam^s Frendi CIas»*
Book, as there is no Fren«d& siammar <Mr dass-liook whkh can be compared with
it in completeness, system, cleanieaB, and general ntilit j.

jTVvMnEmrAKD Nona, TnMad cf BanmiUim OoBeg*.

I haye careftilly examined Piu<d and Tan Norman*s French Class-Book, and am
satijfieJ of its superiority, for coDege pnrpoees, over acy other hoetolore lI^cd.
We shall not Ml to use it tilth oar next class in French.

From A. Cmrns, Preset (f CimiiutaA IMerary tmd Seiem^/lc IhHUttte.

I am confident that it nay he riade an instramcnt in conTeyirgfo the Ftiic!ert,
in from six months t j a year, the art ot speaking and vritntg the French with
almost native flncncy and propriety.

JVom HiRAX QBcnTT, A. IL, iVm. G^awood and TVden Ladis$* Seminttrim.

I have nsed Floors French Grammar in my two seminaries, exclasively, for
more than a year, and have no hesitation in eaying that I r^jard it the test text>
book in this department extant And my opinion is confirmed by the te^ timoDy
of Prof. F. De Lamiay and UademciscUo llarindin. They assure me that the
book is eminently accmate and practica], as tested in the school-rooin.

lYom Pbov. Theo. F. !>■ Fusat, Bdfrew JSdyeational I/uOtute^ Memphit^ ^enn,

M. Pnjoi^s French Grammar is one of the best and most practical wotks. The
French lanjiiaTO is choeen and elesant in st^le— modem ard easy. It Is ftr su-
perior to the other French class-boolis in this country. The selection of the con-
versational part is very good, and wUl interest pupils ; and beins all ccmplett d in
only one veinme, it is especially desirable to hare it introduced In our schools.

I^vm Poor. Jabes H. Wobxah, BordetUown FemaiU OoiUgt^ N, X

The work is upon the same plan as the text-books for the study of French and
Bngliah published in Berlin, for tbe study cf those who have cot the aid of a
teacher, and these books are considered, by the firtrt authorities, the beet books.
In most of our institutions, Americans teach the modem laDgnaees, and hereto-
fore the trouble has been to give them a text-book that would dispose of the
difficulties of the French pronunciation. This diQculty is succeseftilly removed
by P. aud Van N., and I have every reason to believe it will soon make its way
hito most of our best 6cho<^.

IVwn PBor. CixAixES 8. Don, Ann Smith Academy^ Lexington^ Va.

I cannot do better than to recommend '* Pujol end Van Norman.'' For compre-
hensive and systematic arrann[umcnt, pro^ssivo and thorough devcIopmeLt of
all grammatical principles and idioms, v/itn a due edmixturc of tl^eoreticnl knowl-
edge and practical exercise, I regard it as superior to any (other) book of the kind.

JVw» A. A. FoBBTEB, Prin. Finehtirst School^ Toronto^ C. W.

I have great Batiofhction in bearin^j testinony to H. PujolV System of French
Instruction, as given in hia complcto cl?.BB-book. For clcarrerB and comprchcn-
eivcnesa, adapted for ell claeees cf punil?, I have found it superior to ory other
work of the kind, and have now ueed'it for some years in my establishment with
great sticc^s.

F^rom Pbof. Otto Feddeb, Maj^ewood I/utUtUe, Fitt^/Md^ Maa».
The conversational exercises will prove an immense saving of the hardest kind
of labor to teachers. There is scarcely any thing more tiylng in the way of
teachin'T languf^, than to rack your brain for short and easily intcllif ible Dlts
of conversanon, and to repeat them time and again with no better repult than
extorting at long intervals a doubting "oui," of a hesitating " non, monsieur."

^^ For fhrther testimony of a similar character, see special circular, and
current numbers of the Educational Bulletin.

28

The J\railonai Series of Standard SchootSooks.

GERMAN.

■^« ^ •<

A COMPLETE COUESE IN THE GEEMAII.

By JAMES H. WORMAN, A. M.

Worrflan-s Elementary German Grammar -ei 50
Worman's Complete German Grammar . 2 co

These volumes are designed for intermediate and advanced claeECs reepectivelj.
The bilterueae wiUi vLicU they have been attacked, and their extraordinary euc-
cesB in the lace ol an unpriiic^pled opposition, are iactB which have Btamped ihcm
as possessing nnpcraOcled merit.

Though foUowing the eime general method with "Otto'' (that of 'Oaspey'),
onr aailw«r dJTcrs csscnct'illy in its application. He Ifi more practical, more eyi*-
trmn tic, mere accnrate, and beaidea introduces a nmnber of invaluable features
which Iinvc nerer before teen combined fa; a Getinaii gnanmar.

As)piig other things, it may be claimed for Prof. Wonsan that he has been
fh* first to introduce in an American text-book for learning German, a system
of analogy and comparison with other languages. Our best teachers are also
enthusiastic about his methods of inculcating the art of speaking, of understanding
the spoken language, of correct pronunciation ; the sensible and convenient origi-
nal dassiflcation of nouns (in four declensions), and of irregular verBs, also de-
serves much praise. We also note the use of heavy type to indicate etymological
changes in the paradignuL ind, in the exercises, the parts which BpeciaUy illostrate
preceding rules.

Worman's German Reader ti 75

The finest compilation of classical and standard German literature ever offered
to American students. It embraces, progressively aiyanged, selections from the
masterpieces of Goethe, Schiller, Eomer, Seume, Uhland, Freiligrath, Heine,
ScLlegel, Holty, Lcnau, Wieland, Herder, Lessfaig, Kant, Fichte, Schelling, Win-
kclmann, Humboldt, Banke, Raumer, Henzel, Gervinus, &c., and contains com-
plete Goetbe^B '^ IpUgenie,^* Schiller's '' Jungfran;** also, for instruction in mod*
em conversational German, Benedix's ** Elgensinn."

There are besides. Biographical Sketches of each author contributing, Notes,
explanatory and phUoIogical (after the text). Grammatical Beferences to ail lead-
ing grammars, as well as the editor's own, and an adequate Vocabulary.

Worman's German Echo $1 25

Consists of exercises in colloquial style entirelj in the German, with an ade-
quate vocabulary, not only of words but of idioms. The object of the system de-
Tcloped in this work (and its companion volume in the French) is to break up the
laborious and tedious habit of translating the thougMa^ which is the student's
most effectual bar to fluent conversation, and to lead him to thitik in the language
in which he speaks. As the exercises illustrate scenes in actual life, a considera-
ble knowledge of the manners and customs of the Gterman people is also aoquirod
from the n;;e of this manual.

29

Jth^ ATiisHonai Series of Standard Schoot-^ofcs,

Worman's German Grammars.

T£bT]CMOVIAI.S.

From Prof. li. "W. Joxes, Peiertburff Female College^ Ya.

From irhaX I havaseea of tho vorkit is almost certaiB / aJiall introduce it into
Jiia institution.

From Prof. O. Caxpbku,, UnivertUy qfUinnemtta,

A valuable ctddition to oar Bchool*books, »jid vili find many friendii and do great
good.

From Prof. O. U P. Cobfekw, JlTary MUUary JniA , J/d.

I am better pleased with them tba? any I hatra CTcr taught I liare already ordered
through our. booksellers.

From Prof, E. 8. Krxdall, Ve>*Hon Academy^ Conn.

I at onoe put the Elementary Grammar iato thj hands of a class of beginners, and
hare used it wWi great ttatlMfacUon.

From Prof. D. E. IIolmks, Berlin Academy, Wis.

Worman's German works are superior. I shall uso them hereafter in my German
classes.

From Prof. Magnus BuciinoLxz, fliretm College^ Ohio.

I have examined the Complete Grammar, and find it tJScellenL You may rely that
it will be used here.

FroTti Pfin. Tho& W; Tobkt, Paducah Female Seminary, Ky.

The Completo Germm Grammar ii worthy of ai exteiuiire circulation. It is ad»
mirably aaapted to the class-room. I shall use it

J^rom Prof. Alrx. Bosexbpitz, Houston Academy, Texae.

Bearer will take and pay for 8 dozen copiea Mr. Worman deserves the approbation
and esteem of the teacher and tho thanks of the student

From Prof. G. Malmxxe, Augusta Seminary, Maiiie.

The Complete Grammar cannot fail to givs great sati^fiution by the simplicity
of its arraugement, and by its completeness.

From Prin, Oval Pirkkt, Chrietiain University, Mo.

Just such a series as is positivelv necessary. I do hope thw author will saoeeed •■
well in the French, &&, as he ha3 in tho German. ^

JProm Prof. S. D. IIillman, IHckinson CoUiye, Pa.

The class hav3 lately commenced, and my oxamination thus fnr warrants me in say^
ing that I regard it as the best grammar for iastruction in the German.

From Prin. Silas Ijvk&mokk, Bloomfield Seminai'y, Mo.

I hare fonnd a classically and scientifically educated Prussian gentleman whom I
propose to mak i Germ-in instructcr. I have shown him both your German grammars.
He has expressed his approbation of them generally.

From Prof. Z. Tasx, Ilowland School for Young Ladies, H. Y.

I shall introdnco the books. From a cnrsory examination I have no hesitation in
prononncing the Complete Grammar a decided improf>emeiit on the text-books at
present ia uso id this country.*

From Prof. Lewis Ki&tler, KortliwefUm University, TU.

Having looked through the Complete Grammar with some car«j I must say that yon
have produced a good book ; you may be awarded with this gratification — that your
grammar promotes the facility of learning the German language, and of becoming
acquaiated with its rich literature.

From Pres. J. P. Rous, StockweU CtiUegittte Tn*d., Ind.

I supplied a class wirh the Elementary Grammar, and it gives complete sattt/ar-
tion. The conversational and reading exercises are well calculated to i'.lnstrate the
prlncipUs, and lead the student on an easy yet thorsugh ooorse. I think the Com
plAto Grammar equally attractive.

30

JVaiionai Series of Standard SchootSooks*

THE CLASSICS.

LATIN.
Silber's Latin Course, $i 25

The book oonUins aa Epitome of Latia Grammar, followed b^ Heading Exerdaes,
with explanatory Notes and copious References to the leading Latin Grammars, and
also to the Epitome which precedes the work. Then follow a lAtin-EngUsh Vocabu-
larj and Exercises in Latin Prose Composition, being thus complete in itMll^ and a
very soitay e work to put la the hands of oue about to study the language.

Searing's Virgilis £neid, 2 25

It contains only fhe first six books of the .£neid. 3. A very carefully oonstmeted
Dictionary. 8. bnillciently copious Notes. 4. Grammatical references tofourlead«
Ing Grammars. 5. Numerous Illustrations of the h^est order, 6. A superb Map
of the Mediterranean and adjacent countries. 7. Dr. 8. H. Taylor's ** Questions on
the iEneid." 8. A Metrical Index, and an Essay on the Poetical Style. 9. A photo-
graphic /otf sifNifs of au earl^ Latin M.S. 10. The text according to Jahn, but panr
graphed according to Ladewig. 11. Superior mechanical execution.

Hanson's Latin Prose Book, 3 oo

Hanson's Latin Poetry, 3 oo

Andrews & Stoddard's Latin Grammar, *i 60

Andrews' Questions on the Grammar, • *o 15

Andrews' Latin Exercises, *i 25

Andrews' Viri RomaB, *i 25

Andrews' Sallust's Jugurthine War, &c. *i ^o

Andrews' Eclogues & Georgics of Virgil, *i 50

Andrews' Caesar's Commentaries, .... *i 60

Andrews' Ovid's Metamorphoses, . . . *i 25

G-REEK.

Crosby's Greek Grammar, 2 oo

Crosby's Xenophon's Anabasis, i 25

MYTHOLOO-T.
Dwight's Grecian and Roman Mythology.

School edition, $1 25; University edition, *3 00

A knowledge of the fkbles of antiquity, thus presented in a systematic form, Is as
Indispensable to the student ofgeneral literature as to him who would peruse intelli-
p-ently the classical antbors. T%e mythological allasiooa 6o frequent ia literature are
readily understood with sucb ft Key as this.

81

EL OCUTI ON.

Watson's Practical El ocutiwi - - . . . 4 a K
Zachos' Analytic Elocution i so

All depaitniidiU of d «ad«i
■entetiee. phonologj, rtiytlnB,
for iastmction in daaaea, iiliiitniad kj

Sherwood's Self Culture i 00

treatifle to thoae who wmOA pofwt ihiMiliia te tkew MMaqdM^MflML

S P E A K E R S.

Northend's LitUe Orator. *&3-€hild's Speaker*60

Two lifeUo works of the aune gs>kdi: tat difl:3-««t «»->>>? wzik c ot^JLia^
limple And attndivse p h r i a fior childrea wwhir twtrrc jts»r* «f

Northend's National Orator .^25

Aboat one hoadrvdAad e e »et j cfcoiee pieeee hepyily e n b m i j i I
deidgn of the aathor te aMkiac the eeleelie« hae heea %• CMliarate

Northend's Entertaining Dialogues • • . .n 25

Eztraele emiaealiyadeftod t» ealtirate the ^raawtir facaWee, as vidl
as entertaic aa

Swell's Common School Speaker ... .n 25

Seloctiooa tma raeest literatoie.

Raymond's Patriotic Speaker ^ oo

A supfro eomollaaoD el modem eloqncnoe aa4 fioetrj, with orfidnel
dramatic exeroaeh. Mearf 7 everj minipiat Vbiimg t^miait la npreatirti^
without diatiDction of plaee or party.

COMPOSITION, &c.

^••-

Brookfield's First Book in Composition • so

Making the caltiTrntioa of this important art feaaible for the saaHest
child. By a new method, to induce and atlronlate tfaoagbt

Boyd's Composition and Rhetoric . . . . i 50

1 his work fnmisbea all the aid that is needftil or can b» derirrd fai
the Tarious aepartments and styles of composition, both in pre ae and Torasi

Day's Art of Rhetoric 1 25

Noted for exaetnesa of definition, clear limitation, and phfloonphiesl
development of subject ; the large share of attention ^ren to InTBathm*
•■ a hnunch of Bhetoric, and the unequalled aoalyris of style

32

J\rationai Series of Standard SchootSoohs.

LITERATURE.

Cleveland's Compendiums ... - ea<jh, $*2 50

English Literatubb. Aicericak LrrERATUBB.

Eno. Lit. of XIX Century. Classical Literature.

In these four volamea are gathered the cream of the liteiatare of all ages fbr
the school room and the general reader. Their reputation is national. More
than 125,000 copies have b^n sold.

Boyd's English Classics each, ♦! 25

Milton's Paradise Lost. Thomson's Seasons.

Yo jng's Night Thoughts. Pollok's Course op Time.

Cowpbr's Task, Table Talk, &c. Lord Bacon's Essays.

This series of annotated editions of great English writers, in prose and poetry,
is desiCTcd for critical reading and partying in HchoolB. Prof. J. it Boyd proves
himself an editor of hi^h capacity, and the works themselves need no encomium.
As anjdUaty to Uie study of Belles Lettres, etc., these works have no equal.

Pop3's Essay on Man *20

Pope's Homer's Iliad *80

The metrical translation of the CTeat poet of antiquity, and the matchless
** E^say on the Natnre and State of Man," hy Albxattdbb Pops, afford superior
exercise in literature and parsing.

AESTHETICS.

Huntington's Manual of the Fine Arts • •*! 7S

A view of the rise and progress of Art in different countries, a brief
aooouc* of the most eminent masters of Art, and an analysis of the priB»
ciples of Art It is complete in itself, or may precede to advantage the
cntical irork of Lord Eames.

Boyd's Karnes' Elements of Criticism • •*! 76

The best edition of this standard work ; without the study of which
none may be considered proficient in the science of the Perceptions. Mo
other study can be pursued with so marked an effect upon the taste and
refinement of the pupiL

POLITICAL ECONOMY.

Champlin's Lessons on Political Economy i 25

An improvement on previous treatises, being shorter, yet containing
every thing esmntial, with a view of recent questions in finance, ets.,
which is not elsewhere found.

33

TJke JYaiionai Series of Standard School" Saoks. '

MENTAX. PHILOSOPHY.

Mahan's Intellectual Philosophy ... $1 75

The subject exhaustirely considered. The author has evinced leam-
hig,^ candor, aod independent thinking.

Mahan's Science of Logic 2 oo

A profound analysiaof the laws of thought The system possesses the
merit of being intelligible and self consistent. In addition to the author's
carefully elaborated views, it embraces results attained by the ablest
minds of Great Britain, Germany, and France, in this deparUnent.

Boyd's Elements of Logic i 25

A systematic and philosophic condetisation of the subject, fortified with
additions from Watts, Abercrombie, Whately, &c.

Watts on the Mind so

The improvement of the Mind, by Isaac Watts, is desitnied as a guide
for the attainment of useful knowledge. As a text-book it is unparalleled ;
and the discipline It affords cannot be too highly esteemed by the edu-
cator.

MOR ALS~

Alden's Text-Book of Ethics co

For young pupils. To aid in systematising the ethical teachings of
the Bible, and point out the coincidences between the instructions of the
■acred volume and the sound conclusions of reason.

Willard's Morals for the Young . . . . •ts

Lessons in conversational tyle to inculcate the elements of moral phi-
losophy. The study is made attractive by narratives and engravings.

GOV EJR IT ME NT.

Howe's Young Citizen's Catechism .... 75

Ezplaining the duties of District, Town, City, County, Btate, and
Uniteid States Officers, with rules for parliamentary and commercial busi-
ness—that which every future ** sovereign'* ought to know, and so few
are taught

Young's Lessons in Civil Government . . i 25

A comprehensive view of Government, and abstract of the laws show-
ing the rights, duties, and responsibilities of citizens.

Hansfleld's Political Manual i 25

This is a complete view of the theory and practice of the General and
State Governments of the United States, designed as a text-book. The
author is an esteemed and able professor of cons'titntiotial law, widely
known for his sagacious utterances in matters of statecraft through the
public press. Recent events teach with emphasis the vital necessity that
tha rising generation should comprehend the noble polity of the Amer-
ican government, tiiat they nay act intelligently when endowed with a
f^ioviait.

3i

2%e MMonai Series of Standard Schoot^^ooks.

TEACHERS* AIDS.

# ^ »

Brooks' School Manual of Devotion • • • 75

This ▼olnme contains daily devotional exercises, consisting of a hymn,
selectionB of ■cripture for alternate reading by teacher and pupils, and a
prayer. Its vaioe for opening and closing school is apparenL

Cleaveland's School Harmonist *70

Contains appropriate tetiM for ead& bymn in the ** Hannal of Devo-
Uou" described above.

The Boy Soldier 75

Complete infantry tacties for eehools, vith illastnitiona, for the use of
those who would introduce this pleasing relaz&iien from the confining
duties of the desk.

Welch's Object Lessons . • . • i oo

Invaluable for teachers of primary schools. Contains the best explana-
tion of the Pestaloscian sjrstem. By its aid the proficiency of pupils and
the general interest of the school may be increased one hundred per cent

Tracy's School Record . , . *75

To record attendance, deportment, and scholarship; contaiidng also
many useful tables and (snggestions to teachers, that are worth of them-
selves the price of the book.

Tracy's Pocket Record *65

A portable edition of the School Eecord, wHheut the tables, Aa

Brooks' Teacher's Register • *i oo

Presents at one view a record of attendance^ redtatlons, and deport-
ment lor the whole term.

Carter's Record and RoU-Book *2 60

For large graded schools.

• National School Diary, per dozen *i oo

A little book of blank forms for weekly report of the standing of each
MhoUr, from teaoher to parent. A great oonvenienGe.

85

2^ National 2eaehers^ I^ibraty*

THE

TEACHER'S LIBRARY.

"•-^

The Metric System— Davies $♦! 60

G<maidered with reference to its general IntnidnetiMi, mud embnMbkg the
Tieirs of John Qoinej- Adams and Sir John HerseheL

The Student— Phelps *! 50

The Educator— Phelps *i 50

The Discipline of Life— Phelps *i 75

The anthoreas of these works is one of the most disfcingiiished writers
on education 4 and they -cannot fail to prowe a valuable addition to tiie
School and Teadiers* Libraries, being in a high degree both interesting
and instructive.

A Scientific Basis of Education— Hecker - *3 50

Adaptation of stttdj and dassificatien by temperaments^

Olgect Lessons— Welch • *i oo

This to a comirtete exposition of the popalatr modem ^jatem of ^ol^Jeet*
teaching/* for teachers of primary *

Theory and Practice of Teaching— Page .*i so

This volume has, without doubt, been read by two hundred thousand
teachers, and its popularity remains nndiminidied— laxge editions being
ozhansted yearly. It was the pioneer, as it is now fho patriarch o^
professional works for teachers.

The Graded Scb jI— Wells .*i 25

The proper way to orgs Ice graded schools Is here fllnstrated. Tha
author has availed himse of uie best elements of Um several syokems
prevalent in Boston, New York, Pliiladelphia, CfiKrtnnatl, St. Louis, and
other dties.

The Normal— Holbrook *1 75

Carries a working school on its visit to teachers, showing the most ap-
proved methods of teaching all the common branches, including the tech-
nicalities, explanations, demonstrations, and definitioas introduotory and
peculiar to Mch branch.

The Teachers' Institute— Fowie *i 26

This is a volume of suegestions inspired by the author*s e^Mrience «l
institutes, in the instrucoon of young teachers. A thousand points of ia-
torest to this elass are most flatulhetorlly dealt with.

86

2%s JVaHonai Teachers^ Zibrafy.

The Teacher and the Parent— Northend . »*i so

A trsallM apon eommon-aehool edneatlon, designed to lead teachers to
Ti«w tholr ealung In its true light, and to stimnlate them to fldelitj.

The Teachers' Assistant— Northend . . .*i so

A natersl eontlBnatioD of tb« aQthor*8 previoas work, more dfareetly
esleolated for dail j use in the administration of school discipline and in-
■fcmctioQ.

School Government— Jewell *i so

Fun of adraneed ideas on the salject which its title indicates. The cri-
ticisms upon current theories of punishment and schemes of administra-
tion hare excited general attention and comment.

Grammatical Diagrams— Jewell *i oo

The diagram system <^ teaching grammar explained, defended, and
improved. The curious in Uteratnre, the searcher for truth, those inter-
ested in new inventions, as well as the disciples of PrtMT. Clark, who would
see their favorite theory fairly treated, all want this bodL. There are
many who would like to be made familiar with this system before risking
Its use in a elassi The opportunity is here afforded.

The Complete Examiner— Stone *i 25

Gonrists of a series of questions i>n every English branch of school and
aoademie instruction, with reference to a given page or article of leading
text-books where the answer may be found in full. Prepared to aid
■teachers in seearing certificates, pnpils in preparing for promotimi, and
teachers in selecting review questions.

School Amusements— Root ....... .*i so

To assist teachers in making the schonl interesting, with hints upon the
management of the school-room. Rules for military and gymnastic exer-
cises are Indnded. Illustrated by diagrams.

Institute Lectures on Mental and Moral
Culture— Bates *i so

These lectures, originally delivered before instituteB, are based upon
▼uious topics of interest to the teacher. The volume is calculated to
prepare the will, awaken the inquiry, and stimulate the thought of the
aeahms teacher.

Method of Teachers' Institutes— Bates . . * 76

Sets forth the best method of conducting institutes, with a detailed ae-
eonnt of the olUeet, organisation, plan of instruetiou, and tr«e theory of
education on which such instruction should be based.

History and Progress of Education . .*i so

The systems of education prevailing in all nations and ages, the gradual
advance to the present time, and the bearing of the past npon the present
in this regard, are worthy of the careful investigation of all concerned IB
the cause.

37

ne MaUomai TeaeMen' Xibnuy.

Ikmerican Education— lansfield |i

American Institutions— De Tocqueville • -^i ^

A YmteaUa iadez to fib

Universal Education— Hayhew .... .n 75

The ml^eek to u^n m ^kU with ttie ckw. keen perecptioB of
lus obaerred its Mimrity, and raOisad its feutbOitjmad
alike. The rwleeming aad aferattiiK power «£ iBprored eommoo
eooatitatea th« ionintioa of the toIi

Higher Christian Education— Dwight

. . .*l 60

A trwIiM on die m Iw i| iica and apirit, tte modea, diraeliona,
aalteof an true tea^liig: ahofwing thai ri^t edseatioD ahoold appeal te
erery ehyent <f miHiiiiIiim m. the

Oral Training Lessons— Barnard . . • . *i oo

The object of this reiy nsefiil woik is to fliniidi materiAl for instmc-
tore to impart orally to their dasees, in branchefl not nsnan^ taught in
common schools, embracing all departments of Natoral Sdenoe and
much general knowledge.

Lectures on Natural History— Chadbourne * 75

Aflbrdine many fliemea for oral tnatmetioD in thia Interaatlng adeoo*—
eipwfallyin ti'hOTto wliere it ia not porsoed as a daaa exerdae.

Outlines of Mathematical Science— Davies *i oo

A manual anggeattog the heat methods of preaenting mathematioJ in-
atmetlon on the part of the teacher, with that comprehenalTe view of the
▼hole which ia neoeaaary to the intelligent treatment of a part, in adenee.

Logic & Utility of Hath«natics— Davies • •*! 60

An elaborate and lucid exposition of the principles which lie at the
foundation of pure mathematics, witk a highly ingenious appUcation of
their results to the derelopment of the essential idea of the dilEerent
branches of the science.

Mathematical Dictionary-Davies & Peck .*5 oo

This cyclop«dia of mathematical Bclence defines with oompletoneia,
precision, andaccuracy, every technical term, thus constituting a popular
&eatise on each branch, and a general view of the whole sut^ect.

School Architecture-Barnard *2 26

Attention is here called to the vital connection l»tween a good sidiM^
house and a good school, with plans and specifications for securing tne
former in th^ most economical and satisfactory manner.

38

JV)aHonal School Librairy.

THE SCHOOL LIBRARY.

-♦-<

The tvo alements of iiwtnietlon and enterteiiunent were never more bapplij oom-
Uoed than In this oolleetion of standard books. Children and adulte aiike will here
And ample food for the mind, of the aort that la easily digsated^ while not degene-
ratlQg to the leTel of modem romanee.

LIBRARY OP LITERATURE.

Milton's Paradise Lost Boyd's lUustrated Ed.|l 60

Young's Night Thoughts . . ^ do. . . i 60

Cowper's Task, Table Talk, Ac. - do. . . i 60

Thomson's Seasons do. . . i 60

PoUok's Course of Time . ... do. . . i eo

These great moral poems are known whererer the English language Is
lead, and are regarded as models of the beat and purest literature. The
books are beautifully illustrated, and notes explain all doubtful mean*
ingSi and fhmish other matter of Interest to the general reader.

Lord Bacon's Essays, (Boyd's Edition.) . . . i 60

Another grand English elassle, aflbrding the highest example of parity
In language and style.

The Iliad of Homer. Translated by PoPB. . . 80

Those who are unable to read this greatest of anelent writers In the
original, should not faO to arail tiiemselTes of this metrical rersion by «o
eminent sebolar and poet

The Poets of Connecticut— Everest • • • . i 76

With the biographical sketches, this TolurBe forms a complete history
of the poetical Uterature of the State.

The Son of a Genius— Hofland 76

A Jurenlle elassle which nerer wears ont, and finds msny InteresteA
readers in every generation of yoatb.

Lady Willoughby i od

The diary of a wife and mother. An historical romanee of the seven-
teenth oentury. At once beautiful and pathetic, entertaining and in-
stmctlTe.

The Rhyming Dictionary— Walker . . . . i 2s

A senriceable manual to composers of rhythmical matter, behqg a eem-
plete Index of allowable rhymes^

JVational School Zibraty,

LITERATURE-Continued.

Compendium of Eng. Literature- Cleveland, 12 50
English Literature of XIX Century • • do . . 2 50
Compendium of American Literature do . . 2 50
Compendium of Classical Literature • do . . 2 50

Nearly one hundred and fifty thousand volumee of Prof. Cleveland's inim-
itable compendfums have been sold. Taken together they present a complete
▼lew of literature ** from Homer tu Holmes-— from the first Greek to the latest
American author." To the man who can afford but a few books these will Eup*
ply the place of an extensive library. From commendations of the very highest
anthoriues the following extracts will give some idea of the enthusiasm with
which the works are regarded by scholars :

With the Bible and your volumes one might leave libraries without very pain-
ftd regret. — The work cannot be foimd from which in the same limits so much
interesting and valuable information may be obtained.— Good taste, fine scholar-
ship, fiuniliar acquaintimce with literature, unwearied industry, tact acquired by
practice, an interest in the cidture of the young, and regard for truth, purity.
phUanthropy and religion are united in Mr. C^veland.— A judgment clear ana
impartial, a taste at once delicate and severe. — ^The biographies are Just and
discriminating.— An admirable bird's eye view.— Acquaints the reader with the
diaracteristlc method, tone, and quauW of each writer.— Snodnct, careAiUy
written, and wonderfhlly comprehensive m detail, etc., etc.

Milton's Poetical Works— Cleveland ... 2 so

Thia is the very best edition of the great Poek It includes a life of the author, >
notes, dissertations on each poem, a fiiultlesB text, and is £Ad ovdy edition of v
Hilton with a complete verbal Index.

LIBRARY OP REFERENCE.
Home CyclopaBdia of Chronology . . • • 8 oo

An index to the Bources of knowledge— a dictionary of dates.

Home CycIopaBdia of Geography 8 oo

A complete gazetteer of the world.

Home Cyclopaedia of UsefUl Arts . . . . 3 oo

Covering the principles and practice of modem scientific enterprise, with a
record of important inventions in agriculture, architecture, domestic economy,
ei^g^eeiing, machinery, manulhctures, mining, photogenic and telegraphic art,
^kc, Ac.

Home Cyclopaedia of Literature & Fine Arts 3 oo

A complete index to all terms employed in belles lettres, philosophy, theology,
law, mythology, painting, music, sculpture, architecture, and all kindred arts.

40

Mxtionai School Libi^ary.

LIBRARY OP TRAVEL.
Life in the Sandwich Islands— Cheever . .$i 50

•nie " heart of the Padfle, u it wu and Is/' shoira most rlrldly the
contrast between the depth of degradation and barbarism, and the light
and liberty of civilisation, so rapidly reaUzed in these islands under the
bsmanichi^ infloenoe of the Christian religion. lUostrated.

Peruvian Antiquities— Von Tschudi- . ► . i so
Travels in Peru— Von Tschudi i so

The first of these Tolnmes affords whatever Information has been at>
tained by trarelers and men of science concerning the extinct people who
onee inhabited Pern, and who have left behind them many relicaof a
vonderfol dvilisation. The "Travels" furnish valuable information
concerning the country and its inhabitants as they now are. Illustrated.

Ancient Monasteries of the East— Curzon • i so

The exploration of these ancient seats of learning has thrown much
light upon the researches of the historian, the phUologist, and the theo*
logian, as well as the general student of antiquity. Illustrated.

Discoveries in Babylon & Nineveh— Layard i 75

Yalnable alike for the information imparted with regard to these most
interesting ruins, and the pleaaait adventures and observations of the
author in regions that to most men seem like Fairyland. Illustrated.

A Run Through Europe— Benedict, . . . . 2 oo

A work replete with instruction and interest

St. Petersburgh— Jermann i oo

Americans are less familiar with the history and Bodal customs of ttie
Russian people than those of any other modem civilised nation. Oppor-
tunities such as this book aflfords are not, therefore, to be neglected.

The Poiar Regions— Osborn i 25

A thrilling and intensely interesting narrative of one of the famons ex-
peditions in search of Sir John Franklin— unsuccessful in its main oljeet,
rat adding many &cts to the repertoire of science.

Thirteen Months in the Confederate Army 75

The author, a northern man conscripted into the Confederate service,
and rising firom the ranks by soldierly conduct to positions of responsi-
bility, had remarkable opportunities for the acquiiation of facts, respect-
ing the conduct of the Southern armies, and the policy and deeds of their
leaders. He participated in many engagements, and his book is one of
the most exciting narratives of adventure ever published. Mr. Steven-
son takes no sround as a partisan, but views the whole subiect as with the
eye of a neutral — only interested in subserving the ends of hlitpry by tho
coatiibatiou of impartial facta ninstratod.

41

National School Zibrary

LIBRARY OP HISTORY.
History of Europe— Alison .$2 50

▲ reliable and standard work, vhieh covers with dear, connected, and
eomnlete namttive, the erentfttl occnrrences trangplriog from A. D< 1780
to 1815, being mainly a history of the career of Napoleon Bonaparte.

History of England— Berard i 75

Combining a history of the social life of the English people with that of
the civil and military transactions of the realm.

History of Rome— Ricord i 60

PosseRses all the charm ef an attractive romance. The fables witb
which this history abounds are introduced in sach away as net to deceive
thri inezperienoed reader, while adding vastly to the interest of the work
and afforiUng a pleasing index to the genius of the Boman people. Bins-
tiated.

The Republic of America— Willard . . . 2 25
Universal History in Perspective— Willard 2 25

From Ihese two comparatively brief treatiaes the intelligent mind may
obtidn a comprehensive knowledge of the history of the world In both
hemispheres. Mrs. Willard' s reputation as an historian la wide aa the
land. Illustrated.

Ecclesiastical History— Marsh 2 00

A history of the Church in all ages, with a comprehensive review of all
forms of r^igion fn^m the creation or the world. No otaer source affords,
In the same compass, the information here conveyed.

History of the Ancient Hebrews— Mills . • l 75

The record of ^*Ood*B people"** from the call of Abraham to the destruc-
tion of Jerusalem ; gathtfod from sources sacred and profane.

The Mexican War— Mansfield 1 50

A history of its origfai, and a detailed account of its victories; with
official dispatches, the ti eaty of peace, and valuable tables. Illustrated.

Early History of Michigan— Sheldon ... 1 75

A work of value and deep interest to the people of the West. Com-
piled under the snpervision of Hon. Lewis Cassi Embellished with poc-

42

J^*aHanai Schooi J^ibraty*

LIBRARY OP BIOGhRAPHY.
Lift of Dr. Sam. Johnson— Boswelt • • -13 ae

Tliii woxk bM been boAm fhepoMefor wreii^ jmn, wMi faMNMlBg
appiolMtkm. Bocwdl ii kDovn m ** the prinee or NogimphenL**

Henry Clay's Life and Speeches^Mallory

2 Yols. 4 50

Tlib gTMft Ameriam BlatMmum oeomuiidto the aduirattoii, md Mi
duurmeter and deeds eolicit the skadj of ererj petriot.

Life & Services of General Scott—Mansfield i 7S

Tkut hero of the Mexlean war, who was for iiuui« yaate the luoet promS-
nent flgmre In Ameriean mUltery drclee, ehoold not be forgotten In tha
whirl m more recent erenta than those bf vhidi he rignaMaed himeelt
lUnetrated.

Garibaldi's Autobiography i so

The Italian patrlot'areeord of bk own nib, tranahited and edited br bia
friend and admirer. A thrilling narratlre of a ronantie career, with
portrait

Lives of the Signers— Dwight i 50

The memory of the noble men who dedared onr eomitry flree at tlka
peril tti their own **liTeB, fortanea^aad sacred honor,** should be em-
balmed in every Ameriean^a heart

Life of Sir Joshua Reynolds— Cunningham i 50

A candid, tmthlnl, and appredatiye memoir of the great painter, with
a compilation of his disooarsea. The Tolame is a text-book for artists, aa
weU as those who would acquire the mdiments of art With a portmH.

Prison Life 75

Interesting biographies of celebrated priaeners and martyrs^ dedgnad
espedally for the instruction and cultivatfon of youth.

4a

J^aiionai Sekooi Zibrafy.

LIBRARY OP NATURAL SCIENCK
the Treasury of Knowledge .... -ti 25

A eydopasdia of ten fhoaaand eommon thinfa, Aiabnudas th« irileit
nuige of saliJect-mafcter. lUiwtrAted.

Ganot's Popular Physics i 75

The elements of natani pbiloeophy for both student and the general
reader. The Miginal work ts celebrated for the magnificent character ef
its illnstratlons, a^ of which are literally reproduced here.

Principles of Chemistry— Porter • • • . . 2 oo

A work which commends itself to tne amateur in science by its extreme
simplicity, and careful aroidanoe of unnecessary detalL Illustrated.

Class-Book of Botany— Wood . . ^ . . . 3 so

Indlq^nsable as a work of reference. Illustrated.

The Laws of Health— Jarvis i 6S

This Is not an abstract amalomy^ but all its teachings are directed to the
beet methods of presenring health, as inculcated by an intelligent kaow*
ledge of the strnetttre and needs ef the human body. Illustrated.

Vegetable & Animal Physiology— Hamilton i 25

An ezhanatlTe analyds of the conditions of life in all animate nature.
Illustrated.

Elements of Zoology— Chambers l ^o

A complete view of the animal kingdom as a porJon el external aetare.
Illustrated.

Astronography— Willard 10^

The elements of astronomy in a oompaot and readable form. lUue-
trated.

Elements of Geology— Page ...... 1 25

The SI
niustrat

The subjoct p r es e nted in .its two aspects of interesting and importsttt
ited.

Lectures on Natural History— Chadbourne 7S

The snl^eetle here ecnsidered Ui its reUtiou to Inlelleet, taste, health,
•Bdieliglea. . .

national School I^ibrafy.

VALUABLE LIBRARY BOOKS.
The Political Manual— Hansneld H 26

Etbtj Ameiiean youth Bhoold be familiar iriih the principles of the
gOTernment under which he Uree, especially as the policy of this ooantry
will one day call apon him to participate in it, at least to the extent of his
baUot

American Inslilutions— De Tocqueville . . l 50
Democracy in America— De Tocqueville • . 2 25

The views of this distint^ished foreigner on the genius of onr political
institutions are of unquestionable ralne, as proceeding from a standpoint
whence we seldom hare an opportunity to hear.

Constitutions of the United States ... 2 25

Contains the Ckinstitution of the General Goremment, and of the sere*
ral State GoTemmeuts, the Declaration of Independence, and other Im-
portant documents relating to American history. Indispensable as a
work of reference.

Public Economy of tlie United States • • . 2 25

A full discusnion of the relations of the United States with other na*
tions, especially the feasibility of a free-trade policy.

Grecian and Roman Mythology— Dwight • ^ ^

The presentation, in a systematic form, of the Fables of Antiquity,
afTords most entertaining reading, and is valuable to all as an index to tlie
mythological allusions to frequent in literature, as well as to students of
tlie clasMcs who would peruse intelligently the classical authors. Illus-
trated.

Modern Philology— Dwight l 75

The science of language is here placed, in the limits of a moderate
▼olume, within the reach of all.

General View of the Fine Arts— Huntington i 75

The preparation of this work was suggested by the interested inquiries
of a group of young people, concerning the productions and styles of the
great masterK of art, whose names only were lamiliar. This statement is
sufficient index of its character.

Morals for the Young— Willard 75

A series of moral stories, by one of the most experienced of Ameriean
educators, lllnstrated.

Improvement of the Mind— Isaac Watts • • 60

A classical staiidard. No young penon shonld grow np without having
perased IL

45

JitaHonat Series of Standard SehoolSoohi.

A. S. Barnes dc Company

[Fnm the If aw Tour PAmFnn>am, Ai^. 18M.]

This -w-eD-knomi txA long^estabUshed Book and Stationery Bonse has recently re-
moved firom the premises with which it has been identified for over twenty years, to
the fine buildings, Nosl 111 and 113 William Street, corner of John Street, ¥eir T<»4r,
one bloclc only from the old store. Here they have been enabled to oi^talze their ejt-
tensive business In all its departments more fhorongfaly than erer before, and enjoy
facilities possessed by no other house in New York, for handling in lafge quantities
and at satisfactory prices every thing in {heir line.

A visit to this large establishment will well repay the carioas. On entering, we find
the first floor occupied mainly by offices appertaining to the different departments of
the business. The first encountered is the ^ Salesman's Office/* where attentive young
men are always in waidng to supply the wants of cttstomers. Further on we come to
the Entry Department, where all invoices fh)m the several sales-rooms are collected and
recorded. Next comes the General Office of the firm. Then a modest sign indicates ibe
entrance to the ** Teachers* Beading-Boom** — a spadoos &nd inviting apartment set
apart fcMT the use of the many profesrional friends and visitors of this house. On the
table we noticed files of educational Journals and other periodical matter — ^while a
book-case contains a fine selection of popular publications as samples. The private
office of the senior partner, and the Book-keeper*8 and MaQing Olerk*s respeetlto
apartments, are next in order, and complete the. list of offices on this floor. The re«
midnder of the space is occupied by the departments of stock known as **Lato Publi-
cations** and " General School Books.**

Descending to the finely lighted and ventilated basement, we find the ** Exchange
Trade,** " Shipping,** and " Packing** departments. Here, also, is kept a heavy stock
of the publications of the house, while a series of vanltB nnder the sidewalk afford
accommodation for a variety of heavy goods. Stepping on the platform of the fine
Otii^ Steam-elevatOT, which runs ^m hottom to top of the building, the visitor
ascends to the

Second Story. — This floor is occupied by the Blank Book and Stationery Depart-
ment, where are carried on all the details of an entirely separate business, by clerks
especially' trained In this line. Here every thing in the way of imported and 4iomestio
stationery is kept in vast assortment and to suit the wants of every class of trade. The
system of orgamzation mentioned above enables this house to compete successfully
with those who make this branch a specialty, while the Oonvenience to Booksellers xA
making all their purchases at one place is indisputable.

On the third floor are found the following varieties of stock : Toy and Juvenile
Books, Bibles and Prayer Books, Standard Works, Photograph Albums, iScc. The
fourth and fifth stories are occupied as store-rooms for Standard School Stock.
During the snmmer, while all the manufacturing energies of the concern are devoted
to the preparation and accumulation of stock for the fall trade, upwards of half a
fnxUyon cf volumes are gathered in these capacious rooms at once.

The manufacturing department of this house is carried on in the old premises, No&
51, 63, and 65 John Street, and 2, 4. and 6 Dutch Street A large number of opera-
tives, with adequate presses and machinery, are constantly employed in turning out
tht popular pnblimtioos of tbo firm.

4S

J\ration<U S eries of Standard Schooi-:SooJts.

The Feabody Correspondence.

New Yok, April S9, 1807.
T6 nn BoABD or TkDSxns of thb Psabodt Eovoatioiial Fuhd :

GKi«TLKiim~IIaTing been for many Tears intimatelj ooimected with the ednoa-
ttonal interest! of the Booth, we are dadrons of ezpreadng our appreciation of th«
noble charity whidi jon represent The PeatxMly Fund, to eneonrBce and aid com-
mon schools In these war-desolated States, can not fail of accomplismnff a great aod
good work, the bene6oent results of whidi, as they will be exhibited in Uie future, not
only nf the stricken population of the South, but of the nation at large, seem almost
Incalcniiihle.

It iH probable that the use of mer t t er tous text-books wiH prove a most effeettre agency
totirard the thorough aoeompUshment of Mr. Peabody's benerolent design. As wo
publish many which are considered such, we liaye selected from our list some of the most
raluable, and ask the priTflege of placing them in your hands for gratuitous distribu-
tton in connection with the fond of which you have charge, among the teadbers and in
the schools of the destitnte South.

Obsenrfaig that the training of teadwra (tbrongh the agency of Norma* t^ehools and
otherwise) m to be a promineni- feature of yonr undertaking, we offer you for this pur-
pose 5,000 Tolumes of the ** Teachers* Library,** — a series of professional works de-
signed for tli6 eflleiakt self-edacation of those who are in their turn to teach otherb—
asfUlowa:—

■00 Page*a Theory and Fraetloe of Teach- 860 Bates* Method of Teachers' Institutes

inc. SCO De Tooaueyille's American Institut*niL

BOO Wdcfa^i Manna! of Obleet-Lessona. 250 Dwight^ Higher Christian Edncatioi^

BOO Darle^ Oottnes of Mathematifial S50 History of Education.

Sdenec S60 Mansfield on American BdacatloB.

880 Holbrook*s Normal Methods of 850 Mayhew on Uniyersai ISducatioa.

Teachhig. 860 Northend*s Teachers* Assistant.

fOO Wells on Graded Sdioola. 850 Northend's Teacher and Parent.

860 Jewell on School OeveramouL 850 Root on School Amusementsi

850 Fowle*B Teachers* InstitotSL 850 Stone*s Teachers' Examiner.

In addition to these we also adt that yoa will accept 85,000 yolumes of sdiool-booka
for intermediate chiiiBos, embracing^

6,000 The National Second Reader. 6,000 Beer^ Penmanshipi

6,000 Dayies* Written Arithmetie. 500 First Book of Sdenet.

6,000 Monteith's Second Book in Oeogra- 500 Jaryis* Physioloay and Healfia

phy. 600 Peck's Ganot's Natural PliiloaophT.

8,000 Mouteith's United States History. 600 Smith & Martinis Book-keqdng.

Should yonr Board oensent t» undertake the distribotion of these yolumes, we shall
hold ourseWea In readiness to pack and ship tlio same in soeh quantities and to audi
points as you may designate.

We fiirther propose ^Jiat, should yon find it adyisable to use a greater qnantt^ of
our pnblieatioi» In the prooeeution of yoar ohms, we will donate, for the benefit of
this cause, hMnty-Jbfe per ctnL of tlie nsnal wholesale price of the books needed.

Hoping that our reqnest will meet with your approval, and ttmt we may have the
pleasure of contributing In this way to wants with which we dewly sympathise, we
are, gentlemen^ very respectfully^ yours, A. S. BARNES A CO.

BO0VO1I, ifoyT, I86T
Mbssbs. a. & BAXNxs>d( Ca, PVBUiHm, Nmw* Yobk:

Gkntlsubw— Your communication of the 89th nit, addressed to the Trustees of the
Poabody Education. Fund, has been lianded to me by our general agent, the Rey. D«.
Sears. I shall' take the greatest pleasure In laying it liefore the l>oard at their earlfest
•neetkig. I am unwilHng, however, to postpone- Its acknowledgment so long, and
hasten to assure Tou of the high value which 1 place upon your gift Five thousand
volumes of your ** Teachers' Library,'* and twenty-five tlioutsand volumes of ** Schooi-
Books for intermediate classes,** make up a most munificent contribution to tlie cause
of Southern education in which we are engaged. Dr. Sears is well acquainted wkh the
books you have so generously offered vs, and unites with me in the highest appreda-
tion of the f^ You. will be glad to kntMr, too, that your letter reached ns in season
to be ^^mmunicated to Mr. Peabody,. before he embarked for England on the 1st In-
stant and Uiat he expressed' the greatest gratification and gratitude on hearing what
yon had oilaredt <»»

Believe me, gea'tonea, with kbe higheit respeet and rennd, yo w obliged and ol»»
dient aervaat* BOBT. G. WINTHROP, OhalmiMb

47

,*

*5"

I

^U W^tn, nU l^anu^ris, mil all Wmn.

MTMAL TTTQ'Pn'D V STANDARD
SERIES. XLLijiUJili TEIT-BOOKS.

^^ History is (Philosophy teaching by Examples/^

THE UNITED STATES i- Youths History of the

I III. Vlll I kl/ W I fl I i-W. UNITED STATES. By James

MoNTBiTR, author of the National Qeographical Series. An elementary work
upon the catechetical plan, with Maps, Engrayings, Memoriter Tables, etc. For
the yonngest pupils.

2. Wiilard's School History, for Grammar Schools and Academic classes.

Designed to cultivate the memory, the intellect, and the taste, and to sow Uie
seeds of virtue, by contemplation of the actions of the good and great.

3. Wiilard's Unabridged History, for higher classes pursuing a complete

course. Notable for its clear arrangement and devices addressed to the eye, with
a series of Progressive Maps.

4. Su m m ary of American Hi StO ry . A skeleton of events, with all the prom-

inent fiEicts and dates, in fifty-three pages. Hay be committed to memory ver-
batim^ used in review of larger volumes, or for reference simply. " A miniature
of American History."

PNHI ANn '• Berard's School History of England, combining

1-llUl.Hllli* an interesting history of the social life of the English

people, with that of the civil and military transactions of the realm. Beligion,
literature, science, art, and commerce are included.

2. Sunnmary of English and of French History. FRANPF

A series of brief statements, presenting more points of ■ UttilWt.
attachment for the pupiFs interest and memory than a chronological table. A
well-proportional outline and index to more extended reading.

ROME Ricord's History of Rome, a story-llke epitome of this Inter-
n U III t ■ esting and chivalrous history, proftisely illustrated, with the legends

and doubtfttl portions so introduced as not to deceive, while adding extended

charm to the subject

RFNERAI Wiilard's Universal History. A vast subject 93 arranged
UlBlllLllHlBa mid illustrated as to be less duflcult to acquire or retain. Its

whole substance, in foct, is summarized on one page, in a grand *' Temple of

Time, or Hcture of Nations.

2. General Summary of History. Being the Summaries of American, and
of English and French History, bound in one volume. The leading events in
the histories of these three nations epitomized in the briefest nuuiner.

S. BARNES & CO.,

1 IBIHW^-^— i

f - — ■ »— iiiiri

- , . ; S'

" A "WeU of EngUsh Undefiled,"

LITERATURE AND BELLES LETTRES.

PROFESSOR CLEVELAN D'S WORKS.

A. WHOI^X! LIBJRABT IX FOUJR VOZUMJES.

COMPElI lfil'LIT EBATllBE.

One Hundred and Twenty Thousand of these Volumes have been sold,

and they are the acknowledged Standard wherever

this refining study is pursued.

PROF. JAMES R. BOYD'S WORKS.

EMBBACINO

COMPOSITION, lOGTC, ZITERATURE, RHETORIC, CRITICISM,
BIOGRAPHY f— POETRY, AND PROSE.

BOYD'S COMPOSITION AND RHETORIC.

Remarkable for the space and attention given to grammatical principlee, to afford a
snbstantial groundwork ; alno for the admirable treatment of synonymB, figurative
language, and the sources of argument and illustration, with notable exercises for pre-
paring the way to poetic composition.

BOYD'S ELEMENTS OF LOGIC.

explains, first, the conditions and processes by which the mind receives ideas, and
then unfolds the art of reasoning, with clear directions for the establishment and con-
firmation of sound Judgment. A thoroughly practical treatise, being a systematic and
philosophical condensation of all that is known of the subject.

BOYD'S KAMES' CRITICISM.

This standard work, as is well known, treats of the focnlty of perception, and the
result of its exercise upon the tastes and emotions. It may therefore be termed a Com-
pendium of Aesthetics and Natural Hot'als ; and its use in refining the mind and heart
has made it a standard text-book.

BOYD'S ANNOTATED ENGLISH CLASSICS.

Tliomson's Seasons,
PolloJc's Course of Titne.
lord Bacon's Essays

Milton's Paradise lost.
Young's Night Tlioughts,
Cowper's Task, Table Talk, &e.

In six cheap volumes. The service done to literature, by Prof. Boyf
upon these standard writers, can with difficulty be estimated. Line f
presslons and ideas are analyzed and discussed, until the best comp
powerflil use of language is obtained by the learner.