HECUEATIVE SCIEN^CE. 



85 



of tlie screws on wHcL. tlie weight was sus- 

 pended (Fig. 2). Instead of falling, as might 

 have been expected, the entire mass preserves 

 the plane in which it is placed, although the 

 whole weight of the wheel and ring is on one 

 side of the point of suspension, and a revolu- 

 tion of the whole is commenced round this 

 point. 



These secondary revolutions seem to be 

 due to the law of composition of forces, for 

 the wheel is acted upon at the same mo- 

 ment by the gravity of the earth, and also 

 by the peculiar property of resisting attempts 

 to change the plane of its motion consequent 

 upon the state of rapid rotation in which it 

 has been put. 



The peculiar forces exhibited by the 

 gyroscope may be due to the property of 

 inertia which belongs to all matter, and by 

 virtue of which it cannot move itself when 

 at rest, or stop itself when in motion, or 

 when in motion change the plane in which it 

 is proceeding. 



Or they may be traced to the direct in- 

 fluence of the force communicated to the 

 wheel, all the particles of which, whUe ro- 

 tating, ha^-e a tendency to fly off in a direc- 

 tion tangential to the circle in which it is 

 moving, and in the same plane in which 

 the rotation is taking place. Any attempt, 

 therefore, to interfere with the direction of 

 this plane will have to contend with the 

 force with which, were they not restrained 

 by the law of cohesion, every particle com- 

 posing the wheel would fly off. 



E. G. Wood. 



Grand Prize Bird Show at SoaxHAMPxoN. — We 

 hear of a variety of provincial " bird-shows" in prepara- 

 tion, and among them an important one at South- 

 ampton, open to all Hampshire. It is announced as 

 being under the highest patronage, and we hope it will 

 fully realize the sanguine expectations of its projectors. 

 Tt will take place late in the autumn, and be under the 

 superintendence of Mr. \Vm. Kidd, of Hammersmith, 

 who is to give one of his popular " Gossipping" En- 

 tertainments on Song Birds each day of the exhibition. 



ASTEONOMICAL OBSERVATIONS 

 EOE AUGUST, 1859. 



A TOTAi eclipse of the moon will occur on the 13th 

 of August, but will be invisible in England. It will 

 be visible in latitudes 14° and 15° S., and in longitudes 

 67^° to 158' E. A partial eclipse of the sun will take 

 place on August 27th, which will also be invisible in 

 England. It will begin at 15h. 30m. G.M.T., in lati-' 

 tude 28° 3' S., and longitude 42° 57' E., and end at 

 18h, 31m. in latitude 77° 23' S., and longitude 

 121° 34' E. The greatest eclipse will occur in latitude 

 61° 40' S., and longitude 33" 51' E., at 17h. lm.,G.M.T., 

 when above half of the sun's limb will be obscured. 



Full moon on 13th, at 4h. 34m. p.m. 



New moon on 28th, at 6h, 14m. a.m. 



The moon is at her least distance from the earth 

 on 27th, and at the greatest on the 12th. 



The sun is in the constellation Leo until the 23rd, 

 and then in Virgo. 



Mercury is in Leo throughout the moon, and is 

 favourably situated for observation at the commence- 

 ment of August. It is in conjunction with the moon 

 on tlie 28th. 



Venus is small, and nearly circular. On the 

 morning of 21st she will be within 10' distance of 

 Saturn, and at midnight of the same day within 4' of 

 Mars, the three planets forming a cluster. 



Mars is invisible near the sun, and at its greatest 

 distance from the earth on August 1st. 



Jupiter is in Gemini, and is a morning star. 



Saturn is near the sun, and invisible. 



August is ; remarkable for the great "number of 

 meteors, which more especially take pjace about the 

 9th and XOth. 



On the 1st the sun rises' in London at 4h. 24m. 

 a.m., and sets at 7h. 47m. p.m. On the 31st he rises 

 at 5h. 11m., and sets at 6h. 48m. p.m. 



On the 1st twilight ends at lOh. 40m. p.m., and 

 day breaks at Ih. 32m. a.m. On the 23rd twilight ends 

 at 9h. 21m. p.m. On the 7th, length of day 15 hours. 

 . OccuLTATioN OF Stars BY THE MooN : — On the 

 13th in Capricomi, 5th magnitude, disappearance, 

 llh. 59m.; reappearance, 12h. 12m. meantime. On 

 14th, No. 67, Aquarii, 6th ijuignitude, disappearance, 

 16h. 40m. ; reappearance, 17h, 41m. On 18th, NoJlOl, 

 Piscium, 6th magnitude, disappearance, 13h. 31m.; 

 reappearance, 14h. 25m. meantime. E. J. Lowe, 



Highfield Observatory, Nottingham. 



OCCTJLTATION OF SaTURN BY THE MoON, MaY 8, aS 



observed at Cambridge Observatory, occurred earlier 

 than was expected. Professor Challis remarked that the 

 moon's limb, where it crossed the middle of Saturn and 

 his rings, appeared to be unusually curved, and that both 

 the ball and the ring were reduced before disappearance 

 to a very narrow strip of light, and also that a lingering 

 in disappearance took place. The colour of the planet 

 was in remarkable contrast with the whiteness of the; 

 moon's light. 



