RECREATIVE SCIENCE. 



A saplentibus vita in unA Tirtute poslta est 8. FoliciUtem pono iu 

 Dei amoro. 9. Entile tibi cupiditus verum iuveuitmJi ? 10. Natum 

 auiinid talem oupi<litatm ingenuit oinuibus. 11. Kt diritibn 

 peribus amor sui iugouitus oit 12. Fratro* tui iras luocubuerunt, <-t, 

 convert!* luanibui, pugnaveruut. 13. Puter mom progredletur urbuui 

 obcssurus. 14. Copue progress! luut domosque diripiuut. 



APPLICATIONS OF "COLO." 



1. Tbo steward has ben appointed for the sake, of tilling the land. 

 Not all fields which are tilled are fruit-bearing. 

 J. Inhabit the city, O my Rufus, and lire iu that light (dittinguiihed 



plttOi). 



3. Thou, Jupiter, who carest for and nourishest the raoe of men. 

 Let it bo your object to take care of your breast by noble means, 

 oultirated the study of philosophy from early j 



5. Now clearly I am ablo to pursue neither that diet nor that way 

 of life. 



6. I lore you, because you regard me. 



By whom we seem to be carefully regarded and esteemed. 



7. What is it you say why the gods should be worshipped by men, 

 when the gods not only do not look upon men, but, indeed, core 

 nothing about them ? 



We ought both to adore and worship these gods. 



EXERCISE 149. LATIN-ENGLISH. 



1. Regard for our body is implanted in us. 2. Where there is no 

 sowing, there is no reaping. 3. Everything which was gross and 

 corporeal, God made subject to the mind. 4. You have put down the 

 reproaches and hatred of ill-disposed persons by your way of living. 

 5. The governor, Frobus, planted the Golden mountain, near Mcesia, 

 with vines. 6. The battle having begun, all places far and wide were 

 strewn with weapons, armour, and dead bodies. 7. The consciousness 

 of despised virtue torments the wicked man. 8. Tell me why you have 

 despised my counsel. 9. Listen, boy, your mother asks you why you 

 have forgotten to eat the buttered bread. 10. Loveliness (vcnustaa) and 

 beauty of person are not separated from health. 1 1. Cato addressed 

 the people. 



EXERCISE 150. ENGLISH-LATIN. 



1. Insitus est pectore liberorum nostrorum amor. 2. Mcum con- 

 silium spreveruut. 3. Consilium meum ab illis spretum es.t. 4. Sper- 

 nam nullius consilium. 5. Mi puer, butyro obline panem. 6. So 

 oblinent mails moribus. 7. Boni a malis secernendi aunt. 8. Pueros 

 secrevi a puellis. 9. Cicero concionabitur. 10. Victoria regnante, 

 BrituimifD poteutia mirum in modum crevit. 11. Amicitia uostri 

 cum octato crescet. 



RECREATIVE SCIENCR II. 



ARTIFICIAL ILLUMINATION. 



THE imitative faculty of man has, no doubt, prompted many 

 notable discoveries which might probably never hare been con- 

 ceived if Nature had not first suggested the primary idea. The 

 great lamp, the sun, burning and shining continually in the 

 heavens during the day would, by its very absence at night, 

 even to the most ignorant of savages, suggest the thought of 

 making a substitute, an imitation in short, an artificial fire or 

 illumination. 



Thus the primary idea realised by a rude fire of wood would 

 be gradually worked out, the commencement being made with a 

 pine torch, and the light-giving agent elaborated, until the con- 

 struction of the most elegant and perfect lamp was attained. 



The ancients, according to Fortunio Liceti, do not appear to 

 have been satisfied with a mere lamp. Their ambition appears 

 to have led them to suppose that the sun could be more closely 

 imitated, and that lamps might be made perpetual. Liceti 

 contended vigorously for the possibility of constructing a 

 " perpetual lamp," and he quotes in support of his arguments 

 the famous lamp of Olybius, said to have been discovered in 

 the year 1500 at Atesta, near Padua. Some peasants digging 

 the earth to a considerable depth, came to a tomb, in which 

 they found two earthen urns, one within the other. The inner 

 vessel is said to have contained a burning lamp, placed between 

 two phials, one filled with liquid gold, and the other with liquid 

 silver. But, unfortunately, the rustics who found this inestim- 

 able treasure were not sufficiently careful, and so the lamp 

 was broken and extinguished. Liceti seems to have confounded 

 the myth of a perpetual lamp with the fact that lamps were 

 kept burning night and day in certain temples. There was the 

 lamp of Demosthenes in the temple of Minerva at Athens, and 

 the vestal fires at Rome, which were not self-supporting, but were 

 religiously watched by the vestal virgins, and supplied with con- 

 tinual aliment. 



The ordinary materials which furnish artificial light during 



the act of combustion are oils, wax, tallow, spermaceti, parafio, 

 rock oil, and ga from coal, roan, wood, or oU*er suitable organio 

 matter. Too extraordinary light-giving agenU are oxygen and 

 hydrogen gases, burning and directed on to a ball of lime ; the 

 combustion of the metal magimeinm in air, or of phosphorus in 

 oxygen gas ; toe voltaic battery, in which xino U consumed and 

 incandescence is produced by the current of electricity ; the 

 magneto-electric machine, worked by steam power, and there- 

 fore consuming coal instead of zinc, to produce the electric light. 



The predominating elements in the ordinary light-giving Mb* 

 stances are carbon and hydrogen, and when any of them are 

 subjected to destructive distillation, these element* unite ~*"\ 

 form two important compounds, the one called defiant gas, and 

 the other light carburotted hydrogen ; and if coal is mod, a 

 number of other compounds are also produced. The -**-*fflit- 

 tion of coal is easily conducted on a small scale by placing 

 some roughly-powdered coal in an old pistol barrel, and having 

 plugged the touch-hole, and fitted a piece of pewter pipe with 

 some plaster of Paris to the muzzle of the barrel, the latter may 

 be thrust between the ban of an open grate in which a brisk 

 fire is burning. In the first instance, moisture only distils over ; 

 at a dull red-heat more water, a thick smoke, and but little or no 

 gas; and it is only when a full cherry red-heat is attained viz., 

 a temperature of 1500 that gas of high illuminating power 

 is evolved. The crude gas being very impure, and containing 

 many things useless for illuminating agents, is subjected at the 

 gas-works to purification, and even then does not consist only of 

 compounds of carbon and hydrogen, but of hydrogen and other 

 gaseous bodies. Dr. Letheby states, that coal gas may contain 

 from 25 to 50 per cent, of hydrogen gas, 35 to 52 per cent, of 

 light carburetted hydrogen and from 3 to 20 per cent, of 

 olefiant gas, and other hydro-carbons mixed with g&ses, such as 

 carbonic oxide, carbonic acid, cyanogen, ammonia, ULjgett, 

 nitrogen, some aqueous vapour, and sulphur compounds. 



The only gases required out of this complex mixture are the 

 compounds of carbon and hydrogen ; and hence tallow, oils, wax, 

 paraffine, turpentine, etc., used in candles and lamps, which are 

 miniature gas-works, yield a gas purer than the heterogeneous one 

 derived from the distillation of coal. That a burning candle 

 is a gas-maker is shown by blowing out a lighted composite 

 candle ; a column of smoky gas ascends from the wick, which 

 may be set on fire by holding a burning match at the top of 

 the column, when the flame runs down in a very curious !" 

 to the hot wick, and the candle is re-lighted. In a candle the 

 retort is the wick, and this when first lighted burns down unt ; i 

 the heat reaches that part which is saturated with the tallow, 

 composite, or wax : at this point destructive distillation com- 

 mences ; the heat from the increased combustion now melts more 

 of the solid material ; and this, being drawn up into the wick by 

 capillary attraction, is decomposed in its turn, and furnishes 

 fresh gas for combustion. In the above case the gas is 

 generated and burnt directly it is produced. With coal gas the 

 generating process is over, and the gas only is burnt. Capillary 

 attraction (from capillus, a hair), in allusion to the nature of 

 some of the bodies having this property, is an illustration of the 

 adhesion between solids and liquids. If a slice of salt is cut 

 out of the solid block, and placed upright in a plate containing 

 a little ink, the latter soon runs up the white salt, and first 

 attacking it by capillary attraction, the liquid is introduced into 

 the pores, the salt partly dissolves, and the remainder crumbier 

 down into the plate. 



A bit of cane, cut free from joints, and about six inches long, 

 placed upright in a bottle containing some turpentine, soon 

 draws up with its hair-like tubes the combustible fluid, and this 

 may be set on fire at the top of the cane, which acts, of course, 

 like the wick of a candle. The experiment is hastened by suck- 

 ing up the fluid with the mouth, or by reversing the cane after 

 one end has been immersed in the turpentine for some minutes. 



On examining the flame of a candle, it is found to consist of 

 three distinct portions. That nearest the wick is almost black, 

 the next is very bright and luminous, and the third emits so 

 feeble a light that it is hardly visible. A picture of the flame 

 of a candle is easily sketched on a wall or on a white sheet of 

 paper, by placing it between the wall and a lens condensing a 

 sunbeam passed through a hole in the shutter of a darkened 

 room. The shadow of the flame may be seen distinctly, and the 

 darkest part is actually the brightest, whilst the more distinct 

 portion of the shadow is that of the outer part emitting the very 



