LKSSONS IN .,i:..|.K 



Increases with tho site of a convex leu, but doriCMo* In sharp- 

 ness ; for only the rays that fall in tho central part ol the IMS 



t<> a point ; those towards tho edge disperse M in a 

 ]>risiii, and make the image of the object confused. Hence the 

 Inn of the eje in covered with the iris, except at it* centre; 

 mi. I muling glasses hare their edges ground off or covered with 



iiorn. This defect is called the " aberration of sphericity." 

 It is, p< rliapa, difficult to say who made the first telescope. 

 Tho conception of sueh an optical instrument appears to belong 

 t<> 1'ri.ir liueon, OH it is asserted by Dr. Jebb, who edited the 

 famous work of Roger Baoon entitled " Opos Majos," that in 

 one of the passages of this work the friar states he actually 

 .: [.lied telescopes to astronomical purposes, and therefore so 

 long ago as the thirteenth century. Afterwards the names of 



a Porta, Diggos, and then J onsen and Galileo, were 

 connected with this important instrument. 



A very simple astronomical telescope can be mode with two 

 piiper, wooden, or brass tubes, sliding one within tho other. At 



I of the widest tube is fixed tho object-glass, a double 

 convex lens with a long focal distance, and called the object- 

 cause it is nearest tho object; while thn lens placed at 

 the other end of the smaller tube, through which tho observer 

 looks, is called the eye-glass, also a double convex lens, bat 

 bavin? a short focal distance. An inverted image is formed in 

 the focus of the object-glass, and this is magnified again by 

 the eye-glass. With this telescope all objects are inverted, 

 and therefore the one invented by Galileo (Fig. 10) is the more 

 convenient. It is constructed like the astronomical tele- 

 scope, only a double concave lens is substituted for the double 

 convex ono used as the eye-glass. It is, in fact, similar to on 

 ro-glass, and has this advantage, that tho object is seen 



opera 

 erect. 



Mr. Richard A. Proctor, in his excellent work entitled " Half 

 Hours with the Telescope," says : " There are few instruments 

 which yield more pleasure or instruction than tho telescope. 

 Even a small telescope only an inch and a half or two inches 

 perhaps in aperture will seem to supply profitable amusement 

 to those who know how to apply its powers. I have often seen 

 with pleasure the surprise with which the performance of an 

 opera-gloss, well steadied, and directed towards certain parts 

 of the heavens, has been witnessed by those who have snp- 

 icd that nothing but an expensive and colossal telescope 

 iuld afford any views of interest. But a well-constructed 

 romatic of two or throe inches in aperture will not merely 

 iply amusement or instruction it may be made to do useful 

 irk." The principles of the achromatic telescope will be 

 hereafter. 



LESSONS IN GREEK. XXXI. 



FUTURE AND FIRST AORIST MIDDLE AND THE PERFECT 

 FUTURE. 



The future middle is formed from the future active by chang- 

 the personal ending of the active that is, u> into the per- 

 ending of the middle that is, O/MU : as Au<r-o>, \\ia-oy.on. 



be o here may be considered as a connecting vowel, and the 

 be divided thus Xu-<r-o-^a<. Of each of these four parts 

 student should give an account. 



Tho first aorist middle is formed from the future middle by 

 prefixing the augment and changing opai into O^TJV thus, 

 \vff-onai, -Au<r-ojUT7i> ; or it may be formed from tho first aorist 

 active by simply adding /*TJI/ thus, tAixra, f\vffa-niiv 



Tho perfect future, or, as it is sometimes called, the third 

 future (also the paulo-post-futurum), is formed from the second 

 person singular of tho perfect passive by changing at into o/ueu, 

 as \t\vffat, AfAufT-ojuai where, again, o may be accounted a 

 connecting vowel as well as the model vowel, or vowel marking 

 the indicative mood. For the optative, o becomes 01, as A*Axr<n- 

 Uriv that is, i is added to o. 



The principal parts of irauo> are, irava>, iravota. -rrfiravKa, irtwavff- 

 ftai ; the future middle, iravtro/ia< ; first aorist middle, 

 perfect future, 



vairowo, I cause to 

 rest ; in the mid- 

 dle, I rest. 



VOCABULARY. 



wc, I let taste ; in 

 tho middle, I taste 

 (with genitive). 



nrrriSfiw, I attend 

 to, I prosecute, 

 practise. 



I make to 



die, 1 oes*e or 

 top. 



rioAiTia,-af, ^ (from 

 woAu t nmioe oar 



poliei, j, 



ft i'i j i'i 



omutUaUon, go* 



nftym. I brin* 



Uiiijf for**.- . .:. 



tbmkldle,l go, 



n*A. -i, j, a door, 



EXEECISB 90. GBBEE-EMOLUHL 



3. ' 



5. 

 I1avrt 



woptufftrnt 



TOIOUTOf 



10. Car 



4. Oi 'I 



6. -O ** 

 ri/Aoi TIII rvrret *Ai*errst. 



SJBJBJ 



REMARKS ox THIS EXERCISE. 

 , the optative, beoaose it is preceded by en histonsn) 

 tense, and because the action depends on the words or doolntsv 



tion of the subject vcrrnp (obliqua oratio). 



A*airai;<rauKot, having re ltd; that in, u** kt hat rsslsd. 

 The force of the participle in Greek can often be given in Eng- 

 lish only with the aid of a conjunction or an adverb. 



TTJI rurroi, by niyht, the genitive of time. (Use the Syntax.) 



EXERCISE 91. ENGLISH-GREEK. 



1. 1 shall have been educated. 2. He will have been sdoeatsd. 

 3. We shall have been educated. 4. They will have been planted. 

 5. He will have been slain. 6. The general will march to the 

 city. 7. The general marched to the city. 8. The general may 

 have marched to the city. 9. The general might have msrehed 

 to the city. 10. Wo shall have consulted respecting tho safety 

 of our native land. 11. He will consult respecting thy safety. 

 12. He consulted respecting the safety of the eftisens. 13. 

 They ceased. 14. They will have ceased. 15. He will oesss, 

 16. The two men ceased. 17. We will cease, O Mends. 18. 

 The friends travel 19. The friends will travel 20. The friend* 

 travelled. 



THE FIRST AORIST AND THE FIRST FUTURE PAflSTTS. 



The first aorist passive is formed from the stem of the perfect 

 active by changing K into Oijx, and by changing the reduplication 

 into the syllabic augment, as AAi*r, *\u9i)i>. 



The first future passive is formed from the first aorist passxvo 

 by dropping the augment and changing into /**, as A**V> 



-as, 77, 

 democracy, the 

 government of the 

 STJ^O* or people 

 (that is, the popu- 

 lace). 



p, I bring up- 

 on, I introduce; 

 (Lat. 



VOCABULAKT. 

 oellum tn/ero), to 

 make war on. 

 Mi;, not, lest (Latin, 



M). 



IloAffuoT, -a, -of, hos- 

 tile, the enemy's. 

 (<rw and 

 , a conven- 

 tion, agreement, 



treaty; in thotext, 

 need in the plural, 



that is. th* treaty 

 considered a* con- 

 taining many 



, *, a, 



EXERCISE 92. GREEK-ENOLISH. 



1. 'Efcroip vro AxiAAfMf Kportv&r). 2. Tw ft5AO*i vro 

 55a<r>caAou *w(u8t^77T7)i'. 3. rioAAai 8yi<Mr/>T>< vro T 

 vuv icaTf\u(hiff<u>. 4. MTCU ^a^at rovf woAireu 

 0ilKai VTTO rttr iroAmiwr Av0<7ir. 5. Efl arrt 

 wcuStvOiitv. 6. ovfutfirri, mucoupT*. 7. O 

 TTJV iroAffiiav fi\v wopivQifreu A7Orra. 8. Of woAf 

 &TJKWV ) utinffvr, ^/ir woA^w tvtypovour. 9. *O 

 6i)<r<Tcu. 



REMARKS ON THIS EXERCISE. 



Tvparrof doee not oxactiy correspond with oar word 

 though the latter cornea from the former, bat denote* one who 

 has seized the helm of government in a free state. A tyrant. 

 therefore, in the Greek sense of the term, is not necessarily a 

 despot, and the Greek may often be rendered by oar urarpcr. 



Mi) after verbs expressive of fear may be rendered by i**, 

 and requires the subjunctive with a present, a perfect, or 

 future tense ; and is followed by the opUtive when the verb in 

 the principal sentence is in an historic tense. 



3Lvv9r,K* Ai4rwr. This is what is called "the genitive 

 absolute," and corresponds with "the ablative 

 Latin tht treaty being broken. 



