146 



KNOWLEDGE. 



attendant bright moons and belt inarUinKs mi the phinefs disc 

 form interesting objects of observation. The smallest tele- 

 scope magnifying about 40 times, shows the planet of the same 

 apparent diameter as the Moon seen with the naked eye. and 

 the surface markings may readily be observed. 



The following table gives the satellite phenomena visible 

 before midnight : — 



0" Capricorni : he is in quadrature on the 

 the stationary point on the 4th May. 



April. 1011. 



20th April and at 



Neptune is on the meridian at 6.45 p.m. on April 1st and at 

 4.47 p.m. on May 1st, and sets at 2.46 a.m. and 0.49 a.m. 

 on these dates. The planet is situated in Gemini about 

 il degrees S.E. of the star 5 Geminorum. 



Meteor Showers: — 



" Oc. D." denotes the r^is.^ppea^.-lllce of the Saleilile behind the disc, an<I 

 ''Oc. R." its re.ippearance ; " Tr. 1." the ingress of a transit across the disc, and 

 "Tr. E." Its ei^ress ; " Sh. I." the ingress of a transit of the shadow across thf disc, 

 and ".Sh. E." its egress ; "' Ec. D." denotes disappearance nf Satellite liy Eclipse, 

 and " Ec. R." its reappearance 



Saturn : — 



Date. 



.■\pl. I 



Mav I 



Right Ascension. 



2 IS 



Declination. 



11° 2.S' 



12" b' 

 12" 43' 



Saturn is observable for a few ex'enings during the early 

 part of the month, when he appears in the W., between Venus 

 and the horizon. During the greater part of the month the 

 planet appears in too bright a portion of the sky to be observed. 

 On Mav Ist the planet is in conjunction with the Sun and 

 hence will be unobser\able for some weeks tdllnwiiig. 



UraN'US: — 



Uranus is visible in the mornings, rising at 3. IS on April 1st 

 and 1.21 on May 1st. The planet is situated about 2 S.E. of 



Algol mav be observed at minimum on the 3rd at 8.52 p.m. 

 and on the 23i-d at 10.35 p.m. Its period is 2" 20'' 49"", 

 fiiim which nthcr niiniiii.i ni.i\' lie drdiicrd. 



Telescopic Objects: — 



Double Stars.— 7 Virginis, .XIl,'' 37'", S. 54', mags. 

 3, 3 ; separation, 6"-0. Binary system; both components are 

 yellow, though one is of a deeper hue than the other. An 

 eyepiece of magnifying power of 30 or 40 is required on a 3-in. 

 to effect separation. 



IT Boiitis, XIV.'' 36"', N. 16" 53', mags. 4, 6; separation 6". 

 Requires a power of about 40. 



f Boiitis, XIV." 41"". N. 27'' 30', mags. 3, 6i ; separation 

 2" -6. Very pretty double, with good colour contrast, the 

 brighter component being yellow, the other blue-green. 



t Boiitis. XIV," 47'". N. 19° 31', mags. 5, 7; sep.aration 

 2" -4. Binary; one component being orange, the other purple. 



Clusters.— M 3 (Canei> Ycnatici) XIII." 38"', N. 28° 48'. 

 This object, though really a globular cluster of myriads of 

 small stars, appears more like a nebula in small telescopes. 

 It is situated between Cor Caroli and Arcturus, but rather 

 nearer the latter. 



NOTICES. 



PLASKITT'S SIMPLEX CALCULATOR.— We have 

 received from Mr. F. W. K. Flaskitt, F.R.M.S., a copy oi a 

 series of tables, printed on a handy card, for finding the day of 

 the week of any particular date. The tables are easy to work 

 with, the amount of calculation is small, and so far as the 

 results have been tested they have always been correct. 

 The price is 6jd. post free, from the .'Vuthor :it 12, Woodbeech 

 Street, E.C. 



APPARATUS FOR USE IN PLANT PHYSIOLOGY.— 

 Our botanical readers will be interested to know that Messrs. 

 Bausch and Lomb are now able to supply sixteen important 

 pieces of apparatus from among those which have been 

 designed by Professor Ganong. of Smith College. To a new 

 catalogue of these. Professor Ganong contributes an intro- 

 duction, in which he says that it diverts time and energy from 

 the phenomena of the plant to centre them on a somewhat 

 slovenly kind of mechanics, and a wholly wrong ideal is 

 inculcated of the nature of scientific work which is based on 

 precision, logic and quantation. What is there peculiar in 

 plant physiology, he asks, that in it alone of all the sciences it is 

 better to do imperfect work with self-made tools than to exact 

 work with good tools made expressly for the purpose. 



The apparatus includes a clinostat, a photosynthometer, 



light screens, potometers, and smaller but c(]uallv useful 

 contrivances. 



The list can be obtained on application to Messrs. Bausch 

 and Loinb's London address, 19, Thavies Inn, Holborn 

 Circus, E.C. 



MESSRS. NEWTON & CO.'S NEW CATALOGUE.— 

 We have received a copy of Messrs. Newton & Co.'s new 

 catalogue of X-Ray and Electro- Medical Apparatus which 

 runs into 167 pages. By an ingenious arrangement it is 

 possible to turn at once to any section of the catalogue, 

 w-hether it be that concerned with X-Ray work, or apparatus 

 dealing with medical electrical currents, light, or high 

 frequency. 



THE MICROSCOPE AND SOME HINTS ON HOW 

 TO USE IT.— Mr. E. Leit/i has issued a useful little 

 pamphlet under the title given in our side-heading. It should 

 be especially useful to beginners, as it describes the parts of a 

 microscope in detail and explains the terms such as aperture, 

 resolving power and so on, which are applied to it. There 

 are paragraphs on such topics as focussing, and the making of 

 measurements imder the microscope, while three pages are 

 devoted to general hints as to the treatment and care of 

 the instrmiK-nt. 



