1888MNRAS..48..307P 1 44 named. Noreallydefiniteconclusionscanbedrawnfromthese, Begarding thesecuriousdoubledarkstreaks (orratherthe Butte County: Chico 1870-84 Cherokee ...1871-84 differ largelyfromtheprecipitationtheresetdownonaccountof bright streaksbetweenthemandthefainter streaksoneither Middletown ...1879-84 Oroville ...1880-82 Cherokee Reservoir...873-79 KonoTyee, nearLakeport1873-84 Bake County: Williams ...1876-84 moment indeterminingtherelativevalueofvarionsplaces for afewstationsnearthelineoftotalitymayhesomeslight when misthangsovertheriver-beds,asIsuggested fouryears Willows ...1878-84 Princeton...... 1873-84 local topographicalreasons. however, fortworeasons,first,becausetherainfallfromyear side ofthem),asthediffraction-imagesMartian riversattimes Punta Arenas...1875-84 Mendocino County: Colusa ...1871-84 duplication ofthecanals”asMartianautumn isapproached. April 1888. Orland ...1882-84 [From theReportofStateEngineeronPhysicalDataCalifornia(ifäd).] stations onlyalittledistancefromthosenamedinthetablemay since intheNewcastle WeeklyChronicle,wemayexpectthe Ukiah ...1876-84 phenomena tobeasnoticeable whenMartianautumnisapproach- Colusa County: to yearvariesenormously,andsecond,becausetherainfallat © Royal Astronomical Society•Provided bythe NASAAstrophysics Data System The followingstatisticsofthetotalmeanmonthlyrainfall Mars shouldbecarefullyobservedinJune andJulyfor Stations. Years. Note onMars.ByBichardA.Proctor. Monthly MeansofRainandMeltedSnow. Mr. Proctor,NoteonMars. Bainfall. Inches. Annual 43‘9 20*3 41-9 21*3 60-3 30-5 172 I2’2 14-9 147 18-9 32-5 I IS December. Bainfall, Inches. 608 0- 4 7 2*26 3- 2 5 3-55 577 867 2*18 4- 6 9 7-64 2- 3 1 1- 6 9 371 January, Bainfall, Inches, 8 2 I3’35 8-37 Ù JÔ 4-23 4-5 7*66 2- 8 3 646 3'4 7-07 513 2-09 1- 9 5 307 1888MNRAS..48..307P 8 3° being visibleonlywithtelescopesbetweencertainlimitsof far moresatisfactory,thoughsomeminutedetailsseenby the telescopesconstructedwithinlastquarterofacentury these carefulobservers. drawings ofDawes,Burton,Knobel,Denning,andGreenare that is,asoptical—wefindanexplanationatonceoftheir northern hemisphere,towhichthedonblecanalschieflybelong). ing asafterMartianspringhasbegnn(thereferenceistothe their workwillratherbeuniquethanspeciallyinteresting. by whichthisdiffractiontheorycanbeputtothetest. observed), oftheirsynchronisingwiththeseasons,and usually must,onalightgroundtheduplicationwouldnotbe variable appearance(sincewhentheriverslookdark,asthey optical illusions.Regardingthemasphenomenaofdiffraction— aperture. Thislastconsiderationsuggestsaneffectivemethod realities ;but,ontheotherhand,noonecanregardthemas hard andunnaturalconfigurationsdepictedbySchiaparelli.The who haseverseenMarsthroughagoodtelescopecanacceptthe of delineatingthemwithsomedegreeartisticskill.Noone could beseenanddelineatedbyobserverspossessingthepower the examinationofplanets’discsforfeaturesdetectedor will beappliedtoanyworksothoroughlywithintheirpoweras posed toaddamazinglyourknowledgeoftheuniverse,since Hyperion, orofexceedinglyminutedoublestars,mustbesup- instruments toworkwhichsmallertelescopescannotattempt, be thoughtsomuchmoresatisfactorytoapplythesesplendid Schiaparelli maynothavebeenwithinthetelescopicrangeof the largetelescopesaresodiligentlyturnedonsuchwork,and that micrometricalobservationsofthesatellitesMars, suspected underthescrutinyofweakertelescopes.Itseemsto begun bysmallerinstruments.Unfortunatelyallthemore so carefullykeptfromenteringonworkwhichhasalreadybeen work whichtheyandonlycanopen,wemustfearthat important linesofresearchhavebeenopenedwithtelescopes instruments requiresthattheyshallbeusedonlyonlinesof comparatively inferiorpower;sothatifthedignityoflarger Corona Lodge,OrangeLake,Fla.: © Royal Astronomical Society•Provided bythe NASAAstrophysics Data System It wouldbewelliftheappearancesseenbySchiaparelli I supposenooneregardsthedoublecanalsasobjective It is,Iimagine,hopelesstoexpectthatthemostpowerfulof 1888, March31. Mr. Proctor,NoteonMars. XLYIII. 6, 1888MNRAS..48..307P April 1888.GreenwichObservationsofCometa, 1 Royal Astronomical Society•Provided bythe NASAAstrophysics Data System •c* O r-SS CO 00 CO r^s P4 -O *tó lä -Ki £ o 1 <£> £ O <£> « O «o 'ï) 6 »o Ps -io § o § ?s r 0 % ö 0 1:8 • rH r^.2 H P rP P ■? J 0Q • »-H-». •"< 5 § fl rP vo O -4-3 rP ^ J§a ^ 03 -p . -s ^ pi to l'u m c5 01 G0 ' Ö ÖD Ö 2 >* s cö §•§ GG QQ o ® .SP § ^ 2 ^ SS 2