TABLES OF DIFFERENCES OF MEAN TEMPERATURES. 149 



Jan. 



Apr. 



May. 



June. 



July. 



Aug. 



Sept. 



Philadelphia, Girard College, Penn. Lat. 39° 58'. Long. 75° 10' W. of G. 



Alt. 114 feet. June, 1840, to June, 1S45, inclusive. 









Mdn't 



—1.42 



I 



—1-97 



2 



— 2.12 



3 



—2.40 



4 



— ^2.60 



S 



—2.82 



6 



—3.10 



7 



—3.22 



8 



—2.80 



9 



—1.52 



10 



0.00 



II 



+ 1-33 



Noon 



+2.56 



I 



+3-55 



2 



+4.21 



3 



+4. 28 



4 



+4-05 



5 



+2-73 



6 



+ 1.91 



7 



+ I.10 



8 



+0-43 



9 



— 0.15 



10 



—0.74 



II 



—1.20 



Comb's 





10, 10 



— 0-37 



6,2,9 



+0.32 



6, 2, 10 



-f-o. 12 



7>2,9 



+0.28 



7.2.9W3 



+0.17 



3.9.3.9 



+0.05 







^ 







— 2.69 



—3.16 —3. 



— 3 



II 



—3.81 —4. 



—3 



SI 



—4-36 



— S- 



—4 



05 



—4.66 



— 5- 



—4 



34 



-4-83 



— b. 



—4 



S6 



-S.63 



—6. 



—4 



84 



—5.64 



—6. 



—4 



70 



—4.99 



—4- 



— S 



16 



—3.01 



— 2. 



— I 



23 



— 1. 01 



— 0. 



+0 



81 



+0.84 



+ !• 



+2 



S4 



-1-2.86 



+3- 



+3 



91 



+4-34 



+4- 



+■; 



OS 



+ 5-39 



+0. 



4-^ 



68 



+6.14 +7- 



+ S 



9S 



+6.69 



+7- 



+s 



71 



+6.59 



+ 7- 



+4 



S7 



+5-44 



+6. 



+ 2 



91 



+3-57 



+ .S- 



+ 1 



72 



+2.44 



+2. 



+0 



44 



+ 1-39 



+0. 



— 



31 



— 1.06 



— 0. 



— I 



II 



—1.41 



— 2. 



—1.68 



—2.13 



—3- 



—0.15 

 +0.18 



— 0.09 

 +0.22 



+0.09 

 +0.09 



—0.28 



— 0.19 



— 0.30 



+0.03 



96 



— 0.29 



+0.08 



— 0-33 

 +0-59 



—0.24 +0.23 



O.OI +°°2 



—4.70 



—5-32 

 — 6.04 

 — 6.72 



-7.3S 



— 7.26 



-5.82 



—3-70 



— 1.42 



+0.78 

 +2.36 

 +3-84 

 +5.00 

 +6.04 

 +6.94 



+7-40 

 +7.60 

 + 7-14 

 +5-58 

 +3.00 

 +0.36 

 — 1.22 

 -2.58 

 —3.80 



— o. II 



— 0.03 

 —0.49 

 +0.67 

 +0.20 

 +0.06 



-S.28 



—5-99 

 -6.56 

 — 7.21 

 —7.68 

 — 7.21 

 -5-78 

 —3-36 

 . — 0.96 

 +0.97 

 + 2.64 

 +4.14 

 + S-S4 

 +6.56 

 + 7-44 

 +7-73 

 + 7.86 

 +6.96 

 +5.62 

 +3-12 

 +0.12 



—1-53 

 —2.88 

 —4.18 



— 0.12 

 +0.04 

 — 0.41 

 +0.85 

 +0.25 



— O.OI 



—4.1 

 — 5- 

 — 5- 

 —6.. 



—6.' 



— 5-' 



+0.; 



+ 2- 



+4-' 

 +5-: 

 +6.. 

 +6.: 

 +7-' 

 +7- 

 +6-, 

 +5-' 

 +2. 

 + 0.. 



— o. 10 

 — 0.09 

 —0.51 

 +0.6S 

 +0.15 

 +0.01 



.68 



— 4-. 



.42 



— 4.C 



.98 



— S-^ 



• 48 



— S- 



•92 



—6. 



.70 



—6. 



•64 



— .s- 



• 34 



-3. 



.OcS 



— I. 



).S8 



+0. 



■50 



+2. 



I..00 



+ 3- 



.22 



+ S- 



).o6 



+ s. 



).8o 



+6. 



.oS 



+7- 



.02 



+ 6. 



,.36 



+ S- 



.02 



+4- 



2.88 



+ 2- 



X30 



— 0. 



•42 



— I. 



2.70 



— 2. 



3.66 



—3- 



—0.18 

 —0.09 

 —0.47 



+0.53 



+0.04 



+0. II 



—4-32 



— 4-S8 

 — 4.9S 



—5-44 

 —5-76 

 -5-98 

 — 6.00 



+0.46 

 + 2.54 

 +4.22 

 +5.56 

 +6.48 

 + 7-30 

 +7.40 

 +7-32 

 +5-92 

 +3-72 

 + 1.52 

 —0.72 

 — 1.96 

 -3- 16 

 —3-74 



—0.31 



— 0.22 

 —0.62 

 +0.40 

 — o. 19 

 +0.11 



—3-54 

 —3-92 

 —4.50 

 —4.92 

 —5.40 

 -5.82 

 —6. 16 

 -4-78 

 —2.32 

 +0.10 

 + 2.26 

 +3-92 

 +5.42 

 +6.48 

 +7.26 

 +7.18 

 +6.92 

 + 5.06 

 +2.86 



+ I-20 

 —0.28 

 — 1.30 



2.46 



—3.22 



— o. 10 



0.07 



—0.45 



+0-39 

 —0.03 

 +0.26 



— 0.09 

 +0.18 

 +0.01 

 +0.28 

 +0.02 

 +0.16 



—1.49 

 —1. 91 



—2.27 

 —2.57 

 -2.8s 

 —3-17 

 —3-41 

 —3- 1 1 

 —2.61 

 —1.23 

 +°-3i 

 + 1-83 

 +2.91 

 +3-65 

 +4.25 

 +4-03 

 +3-65 

 +2.43 

 + 1-73 

 +0.99 



+0-37 

 — 0.03 

 —0,47 

 — 0-93 



—0.08 

 +0.27 

 +0.12 



+0-37 

 +0.27 

 +0.05 



+0.03 

 —0.28 

 +0.44 

 +0.0S 

 +0.08 



Washington City, Capitol Hill, D. C. Lat. 38° 53'. Long. 77° 01' W. of G. 



Alt. 80 feet. Lieut. J. M. Gilliss, U. S. N. Jan. 1841, to June, 1842, inclusive. 



0.2A.M. 



—2.73 



-2.83 



—3.60 



—4.40 



—5-25 



— 6.49 



—6.62 



— 5.20 



—5-37 



— 3-90 



—1-93 



— 2.20 



—4.21 



2.2 



— ^ 



GO 



—4.19 



-4.82 



—5-39 



—7. 1 1 



- 7.2S 



—7-31 



— 6.90 



—6 



17 



—5.10 



—3-03 



— 2 



S4 



— S-24 



4.2 



—3 



39 



—4.90 



—6.02 



— 6.19 



—8.03 



- 8.2,s 



—8.62 



-7-85 



—7 



07 



— 6.50 



—4-33 



— 3 



50 



6.22 



6.2 



—4 



36 



—5-23 



— 6.20 



-S.82 



—4-95 



— 5.06 



—4.76 



—6-33 



—6 



78 



—7.10 



—4-93 



—4 



10 



—5-47 



8.2 



— I 



97 



—3-97 



—3.80 



-2.38 



— 0-73 



+ °-3i 



— 0.21 



— 0.63 



2 



34 



-3.80 



—4-23 



—3 



82 



—2.30 



0.2 



+0 



28 



+ ■•31 



+ 1.98 



+ 1.71 



+ 2.78 



+ 4-05 



+ 2.98 



+4.07 



+ 2 



9S 



+2.81 



+0.37 



+0 



30 



+2.13 



0.2 P.M. 



+ ^ 



18 



+4.63 



+S-3I 



+ 5-37 



+5-93 



+ 6.01 



+5-73 



+6.68 



+ 6 



S9 



+6.50 



+4-27 



+3 



SO 



+ S.31 



2.2 



+ S 



7S 



+ 7.10 



+7-53 



+ 7.67 



+8.03 



+ 8.61 



+ 7-SS 



+8.71 



+8 



43 



+8.20 



+5-47 



+ S 



60 



+7-41 



4.2 



+ S 



08 



+6.87 



+ 7.20 



+ 7.89 



+S.24 



+ 10. II 



+9:36 



+8.07 



+8 



23 



+7-40 



+4-77 



+4 



90 



+7-34 



6.2 



+ 1 



S8 



+2.81 



+3.89 



+4-91 



+ S.48 



+ 3-57 



+5-93 



+3-91 



+4 



23 



+4.14 



+3-57 



+ 2 



2S 



+3.86 



8.2 



+0 



38 



— 0.03 



+0.12 



—0.13 



—0.62 



— 1.03 



—0.47 



—0.54 



+0 



52 



— 0.40 



+0.47 



+0 



56 



O.IO 



0.2 



— 



85 



—1-55 



—1. 71 



— 3-19 



—3-75 



— 4.62 



-3-84 



— 4.02 



—3 



17 



— 2.20 



—0.51 



— I 



00 



—2.53 



By means of interpolation we find the diurnal ordinates for the full hours of combination, as follows : — 



Comb's 

 10, 10 

 6,2,9 



6, 2, 10 

 7,2,9 



7, 2, 9 Ma 

 3.9,3.9 



-0.4 



—0-3 





—0.8 



—0-5 



— 0.3 



—0.4 



0.0 





+0.1 



— 0.2 



— o.S 



+0.4 



+0.4 



+0.2 



+0.1 



+0.3 



+ 0.2 



+0.3 



0.0 



+0.2 



0.0 



+0.2 



+0.4 



-1-0.2 



+0.1 



— O.I 



—0.4 



-0.3 



-0.4 



— 0-3 



— 0.5 





—0.3 



0.0 



+0.2 



+ 0.7 



+O.S 



+0.6 



+0.6 



+ 1.0 



+ I.O 



+ 1.0 



+0.9 



+0.8 



+O.S 



+0.3 



+O.S 



+0.5 



+0.3 



+0.3 



+0.2 



+0.3 



+ 0.2 



+0.3 



+0.2 



+0.4 



+0.1 



+0.3 



+0.3 



+ 0.2 



0.0 



0.0 



0.0 



— 0.1 



+ 0.2 



0.0 



+0.1 



+0.1 



0.0 



— 0.1 



+0.1 



—0.3 



+0.2 



0.2 



+ 0.7 



+ 0.3 



0.0 



