the plural, three cases are alike in nouns ending in um. These three cases are the nominative, the accusative, and the vocative, which in the singular end in um, and in the plural in a.

I subjoin an instance of each of the four terminations, thus:hortus, a garden, has the first termination; puer, a boy, the second; vir, a man, the third; bellum, war, the fourth.

C'ses.

N.
G.

Ac.

Cu.cs.

N.

D.

Ac.

horti, O gardens!

hortis, by gardens.

V.

Atle Nue him, and through g the line hn; from f, with the
, draw the arc i; from 3, with the radius ga, draw the
rak; and from h, with the ralias hi, draw the arc ik;
i will be the arch required. It will be noticed that the
radiation of the joints of the stones composing these various
arches, is to the centres from which the arcs themselves are drawn.
We give these few instances of the principles upon which arches
are constructed, in order to assist the pupil when drawing a
building from the object, or from a copy where these facts are
not indicated by aditional lines, to understand at once how he
is to proceed in free-hand drawing, when placing his points of D.
rection or arrangement. We shall have frequent occasion to
sok for help in Geometrical Problems, as they so materially. V.
a-sist us in our explanations, and we hope the pupil also in Ab.
comprending them; we de-ire, therefore, that the pupil will
practically go through the few problems given, in order to fix
the principles of construction permanently in his mind. To, G.
draw an arch in perspective-that is, in a retiring position--the
points of the arch and the points which help us in the construc-
tion must all be used, as they are when the arch (like Figs. 51
to 55) is in a parallel position. We will first give an example
of a single retiring arch (Fig. 56), and then a group of them
under different arrangements. Draw the horizontal line H L, and
the line ab; from a draw a line to the V P; this will determine
the length of the line ed; these are the perpendicular heights
from which the arch springs. To find the centre, e, draw cb and
ad, draw eg, and mark f, the height of the arch. The difficulty
will be to find the point p in the curve fa, this curve not being
so straight as fe; throughf draw the line mk from the vani h-
ing point; continue de to m, and ba to k; draw the curve je,
observing its distance from the line (or chord) cf; draw mi,
cutting the curve fc in r, draw ik; through r from the VP draw
the line on, cutting ki in p; fpa will be then the course of the
curve to form the remainder of the arch; the outer edge of the
arch, t my kl, can be understood from the drawing; all the
joints of the arch will radiate, as in Fig. 54, those from a to g
in c, and those from c to g in ; the horizontal lines of the
wall will vanish, as previously explained, at the point v P. If
the arch had been a semi-circular one, the joints of the arch
would then have radiated in the perspective centre i. So the
pupil will see that to accomplish the difficulties of a retiring,
arch, he must first dot in that which may be termed the scaffold-
ing or perspective, and build his arch upon it.

Fig. 57 represents the interior of a tower having recesses crowned by pointed arches. After the instructions given for the single arches, it will not be difficult to understand the principles of drawing these.

LESSONS IN LATIN.-VII.

Plural. puer, los. puerum, of

pueris, to boys.
pueri, bos.
pueri, bos!
pueris, by bo s.

viri, men.
virorum, of

men.

viris, to men.
viros, men.
viri, O men!
viris, by men.

bellum, war.

belli, of icer. bello, to war. bellum, war. bellum, Owar! bello, by war.

bells, wars. bellorum, of

cars.

bellis, to wars. bella, vars.

bella, O wars!

bellis, by wars.

Ab.
In ager, o fiell, and some other nouns, the e is rejected in all
the cases except the nominative and vocative singular. Thus,
ager makes in the genitive singular agri :

:

Plural.
N. agri, fills.
G.

agrorum, of fields.
D. agris, to felds.
Ac. agros, fields.
V. agri, O Felds
Ab. agris, by fields.

NOUNS OF THE SECOND DECLENSION, ETC. THE second declension is known by the ending of the genitive singular in i. The terminations of the nominative are us, er, ir, and um; of these terminations us, er, ir, are masculine, and Discipulus, -i, m., a Magister, magistri, m., um is neuter; that is, nouns ending in us, er, ir, are of the masculine gender, and nouns ending in um are of the neuter gender.

is by, with or from. A few remarks will make the meaning of the above table clear. First, let us speak of the singular. In the nominative there are four terminations. The arrangement is meant to show that of all these four i is the genitive-ending, and othe dative-ending. In the nominative plural, there are two terminations. The arrangement is meant to show that of both these orum is the genitive-ending, and is the dative-ending. The dative-ending and the ablative-ending is the same, being in ngular o, and in the plural is. In both the singular and

Malum bellum.

Multi, many.

Peregrinus, -i, m., a
stranger.

Ripa, -æ, f., a river's
bank.
Reguum, -i, n., a king-
dom.

Schola, -æ, f., school.

EXERCISE 21.-LATIN-ENGLISH.

1. Boni viri bonos pueros amant. 2. Boni pueri amantur a bonis 3. Bonus puer scholam amat. 4. Boni magistri bonorum puerorum amantur. 5. Estne tibi bonus magister? 6. Funestum est bellum. 7. Est mihi bona amica. 8. Pueri sunt in schola. 9. Nonne sunt pueri in schola ? 10. Peregrini multi in Britanniam navigant. 11. Aper amici mei est magnus. 12. Est Indus in rips. 13. Discipuli epistolas amant. 14. Ranæ sunt in ripis. 15. Caper est magnus. 16. Bella funesta sunt in insulà.

EXERCISE 22.-ENGLISH-LATIN.

1. I love good scholars. 2. Good scholars are loved by good men. 3. Dost thou love a friend? 4. I have a boar. 5. Thou hast a goat. 6. The goats are on the river's bank. 7. A great and deadly war is in the island. 8. Many fields are in Britain. 9. Boars are often deadly. 10. O men, do you love the boys? 11. My friends do Lot love strangers. 12. Boys love play. 13. Do boys love play? 14. Have you a female friend? 15. I have not a large boar. 16. The letter of my female friend is in the garden.

what are called three terminations; as, amplas, ampla, amplum, We are now in a condition to decline and study adjectives of large or spacious. Amplus, you see, is like hortus: ampla i like mensa; and amplam is like bellum. In fact, amplus is of

the masculine gender, and is declined like a noun masculine it is thus declined: N. dii, G. deorum, D. diis, Ac. deos, V. dii, of the second declension; ampla is of the feminine gender, | Ab. diis. and is declined like a noun feminine of the first declension; and amplum is of the neuter gender, and is declined like a noun neuter of the second declension. I subjoin the full deelension of amplus, a, um. Like it are declined all adjectives ending in us, a, um; which are said to have three terminations from the fact that such three terminations, us, a, um, etc., they really have.

ERRATUM. In the first Vocabulary, page 71, for Vincio, I con prer, read, Vincio, I bind.

X. amplus ampla

amplum

ample

ampli

D. ampl

ample

amplo

Ac ampla amplim

amplum

V. ample

ampla

amplum

M.

Plural.
F.

N.

ampli ample ampla amplorum amplirum amplorum amplis amplis amplis amplos amplas ampli ampli ample ampli Ab ampl amplis amplis amplis This form and other similar forms I advise you to learn by heart in three ways; first, vertically, that is, from top to ottom; you will thus see the identity in form of the adjective with the corresponding noun. Then learn it from the left hand to the right; thus, amplus, ampla, amplum; learning the ingular first, and then the plural. Finally, learn the caseedings in the same two ways; thus:-.

3. G. D. AC. V. AB. 43, i, 0, um, e, 0, You cannot bestow too much pains in making yourself perfly familiar with each declension, each example, each form, as you go forward. There is a good Latin maxim which says, festina lente," literally, hasten slowly, or as the English proTerb says, "slow, but sure." In grammatical studies the brvance of the proverb is very serviceable.

The adjective liber, free, is declined like the noun puer. The aljative pulcher, fair or beautiful, is declined like the noun ar. Liber in the feminine gender is libera, and libera is lined like mensa. In the neuter gender, it is liberum, and liberum is declined like bellum. I will give you the forms fall of both liber, libera, liberum, and pulcher, pulchra, pulchrum.

Colo, 3, I cultivate, I
honour, or, I worship.
Committo, 3, I intrust.
Curro, 3, I run.
Celeriter, swiftly.
Equus, -i, m., a horse.
Fecundus, -a, -um,
fruitful.

EXERCISE 23.-LATIN-ENGLISH.

1. Equus hinuit. 2. Juba equi est pulchra. 3. Muscæ sunt molesta. 4. Sunt ne muscæ moleste ? 5. Boni discipuli non sunt molesti. 6. Longa bella sunt molesta. 7. Equi celeriter currant. 8. Vir regit equum. 9. Equus regitur a viro. 10. Equo pulchro delector. 11. Agri sunt fecundi. 12. Herbæ agrorum sunt varice. 13. Agricola committit agris grana frumenti. 14. Agricola colit agros. 15. Quam pulchre virentur agri ? 16. In agris florent variæ herbæ. EXERCISE 24.-ENGLISH-LATIN.

1. The field is fruitful. 2. Are the fields fruitful? 3. Wars are not fruitful. 4. Fields are cultivated. 5. You honour (worship) the gods. 6. The gods are honoured by Tully (Tullius). 7. The horse and the mare are guided by the man. 8. Boars run swiftly. 9. Do goats run swiftly P 10. Flies are (there are flies) in the beautiful garden. 11. Thou intrustest the horse to the field. 12. Good scholars are honoured. 13. O my son, temples are intrusted to the gods and goddesses. 14. O Antony, the gods and goddesses are worshipped in temples. 15. O good God! thou art worshipped in the fruitful fields. 16. Good men are honoured by their sons and their daughters.

KEY TO EXERCISES IN LESSONS IN LATIN.-VI.
EXERCISE 15.-LATIN-ENGLISH.

1. The frog croaks. 2. The frog is often (sæpe) the prey of the stork. 3. A stork injures a frog; or, the stork injures the frog. 4. The stork devours the frog. 5. O frog, thou croakest. 6. The water is disturbed by the frog. 7. Plants (or the plants) flourish. 8. The earth is clothed with an abundance of plants. 9. Storms injure (nocent) plants. 10. The earth produces plants. 11. O plants, how beautifully you adorn the earth!

plants.

12. The earth is clothed with

EXERCISE 16.-ENGLISH-LATIN.

1. Plantæ florent. 2. Procella nocet plantæ. 3. Plante nocentur procella. 4. Ranæ devorantur a ciconià. 5. Terra gignit plantas. 6. Plantæ gignuntur terrà. 7. O plantæ, quam pulchre gignimini terrå! 8. Copiam aquæ laudo. 9. Procella movet aquas. 10. Aquæ procellâ moventur.

EXERCISE 17.-LATIN-ENGLISH.

1. I have a beautiful lark. 2. Hast thou (estne tibi) a beautiful lark ? 3. My lark is beautiful. 4. Is my lark beautiful? 5. Is not thy lark beautiful? 6. Thy pigeon is very beautiful. 7. I have a good maid-servant. 8. My maid-servant is beautiful. 9. Julia is sacred (augusta). 10. Sacred Julia is beautiful. 11. Is not sacred Julia beautiful P 12. The lark of my maid-servant is beautiful. 14. The island is great.

pulchrorum pulchrarum pulchrorum 13. Thy table is not square.

D. pulchro pulchra pulchro pulchris
Ac. pulchrum pulchram pulchrum pulchros
Vpicher pulchra pulchrum pulchri
Ab, palchro pulchra pulchro pulchris

pulchris pulchris
pulchras pulchra
pulchræ pulchra
pulchris pulchris.

EXERCISE 18.-ENGLISH-LATIN.

1. Est mihi columba. 2. Est tibi bona puella. 3. Estne tibi bona puella? 4. Non est mihi bona puella. 5. Alauda tua est pulchra.

OES.-The ch is pronounced like k, thus, pulker, pulkra, 6. Nonne magna est insula ? 7. Magna non est insula. 8. Est ne

1. I have a deserter of Jugurtha. 2. Thou hast a bad deserter. 3. I praise a good poet. 4. A good poet is praised. 5. The mare is praised by the charioteer. 6. The sailors sail to the island. sailors praise their country. 8. The eagle is often praised by poets. 9. Husbandmen greatly delight in plants. 19. Thou errest, O sailor!

a son, makes in the vocative singular fili, and meus in the vocative singular makes mi, as, O mi fili: O my son! 11. Do you not err, O charioteers ? 12. I have the sadness of good

but filia, a daughter, makes in the vocative singular filia, and
in the neuter makes meum, as, O mea filia! O my
Ighter! O meum officium! O my duty!
Proper names ending in ius have i in the vocative singular,
as Tullius, O Tulli; Virgilius, O Virgili; Mercurius, O Mercur?;
Antonus, O Antoni.

Deus, God, has in the vocative singular deus; in the plural

poets. 13. I greatly love the shades of the groves. 14. The husbandmen ride through the wood.

EXERCISE 20.-ENGLISH-LATIN. laudantur. 1. Estne tibi perfuga? 2. Malus estne perfuga? 3. Boni poetæ 4. Poetas bonos laudo. 5. Boni agricolæ patriam laudant. 6. Bonorum poetarum patria laudatur. 7. Per sylvam equitat pirata. S. Ad insulam navigat nauta. 9. Bona est equa aurige boni.

In Lostration of vent is een mining the advantage fang ze cu mare de wernerated in sir, a peculiar Tetion between te surth and be internally situated ur-tatter f cabe mentioned. In the carp,

senis & get a central cavity in the base of si ne me wo at sind end, all filled with De ay if bear & and from these a chain of three shes mms a theater In the ittle ish caled the loach. Vichs me of the irst acts led by the searcher of de inte pocs left y se dosting me, the air-bladder seems d be retained suein minister to the ear: and in the herring the latter teef senis processes to be applied to other proShames went to meet them to the vestibule.

In the ither par ier of ish-fistinguished from the foremeines by the general character of the skeleton, this being hot song, but y-om the fact that elastic cartilage is not 40 marchant & body and net so goed a conductor of sound, as none other appliances are given to bring the ear in closer relation to the extemal water, whence the sounds come. The Vice lacyrinth is closely surrounded by gristle, and in sharks from the gratie cavity a mnal runs to the top of the head, and a there closed by the skin. In the ray, a canal runs from the wion of the two semi-ren'ar canals to a similar orifice. Both of there cazals are of course filled, not with air, but with fluid, that of the shark being filled with what is called perilymph, or external fluid, and that of the ray with endolymph, or internal

So much has been conjectured, and so little is really known, about the organ of hearing in the invertebrate classes, that it publication. The great diversity of sounds produced by insects, is scarcely advisable to enter upon the subject in a popular some of which, like the cicada (which makes the Italian coppices ring perpetually with its loud, grating cry), have very elaborate contrivances for the production of noises, makes it almost certain hearing. On the other hand, the almost universal muteness of that this large order of the jointed animals have the sense of the mollusca might have led us to suppose that the organ of