------------------------+----+----+----+------+----+-----+ |JAN.|FEB.|MAR.|APRIL.|MAY.|JUNE.| +----+----+----+------+----+-----+ Gain by rain--inches |2.00|2.21|2.40| 2.93 |3.47|2.88 | Loss by evaporation--in.| .60| .70|1.00| 1.60 |2.90|3.40 | +----+----+----+------+----+-----+ Difference--Gain inches |1.40|1.51|1.40| 1.33 | .57| -- | Difference--Loss inches | -- | -- | -- | -- | -- | .52 | ========================+====+====+====+======+====+=====+ ------------------------+-----+----+-----+----+----+----+------ |JULY.|AUG.|SEPT.|OCT.|NOV.|DEC.|TOTAL. +-----+----+-----+----+----+----+------ Gain by rain--inches |2.99 |3.00|2.67 |2.53|2.48|2.24| 32. Loss by evaporation--in.|3.70 |4.00|2.90 |1.50|1.00| .70| 24. +-----+----+-----+----+----+----+------ Difference--Gain inches | -- | -- | -- |1.03|1.48|1.54| 8. Difference--Loss inches | .71 | .80| .23 | -- | -- | -- | -- ========================+=====+====+=====+====+====+====+====== SUMMARY OF FLOW OF RAIN-FALL IN CU. FT. PER MINUTE PER SQUARE MILE.--(_From Fanning._) AT LAKE AT CROTON COCHITUATE BASIN CU. FEET. CU FEET. January, 99.17 92.48 February, 150.42 147.69 March, 174.76 177.02 April, 169.80 132.63 May, 131.80 164.49 June, 44.27 115.12 July, 45.27 48.37 August, 49.15 70.22 September, 42.84 85.99 October, 62.45 81.08 November, 75.90 124.92 December, 78.94 106.23 AQUEDUCTS. The plan, as adopted by Mr. Hawskley at Liverpool, and Mr. Bateman at Glasgow, of subterranean pipes, is now universally followed by engineers. And there is no longer any excuse for incurring the outlay which must attend the erection of monumental structures, such as were necessary in the times of the ancient Romans. The engineer of Marseilles Conduit adopted the “Pont du Gard” plan for conducting the waters of the Durance, in preference to iron pipes, and constructed the splendid folly, “as Humber terms it,” of the aqueduct “Roquefavour.” The dimensions are: Length, 1,289 feet. Height, 266 feet. 1st tier of 12 arches each 49½ feet span. 2d tier of 15 arches each 52½ feet span. Upper tier of 54 arches each 16½ feet span. The cost was $750,000, while inverted syphon pipes could have been laid for one-third of this sum.