« НазадПродовжити »
ARANSAS PASS, TEXAS.
• THE WORK OF REMOVAL OF THE OBSTRUCTING GOVERNMENT JETTY FINALLY APPROVED AND Bids INVITED.—The last chapter in
this record is brief, for as yet nothing has been done on the work of removing the obstructing jetty. The act was passed at the close of the last session of Congress, March 4, and after careful and intelligent consideration the Government Engineer of the district, Col. C. S. Riché, son of Prof. George I. Riché, late member of this Society, recommended the letting of the work under the appropriation and provisions as made by Congress. It was authorized July 11, and advertised on September 25 for thirty days, when the bids are to be opened, which brings the chronology of events up to the 30th inst. Additional time will be consumed before the preliminaries are complied with. If there be no bidders, the work must be readvertised. In such case no contractor can transfer a plart to the site much before the winter storms begin which involve serious loss of time and increased cost for the Government, or loss to the contractor. Even after the removal of the old jetty time will be required for the currents to adjust themselves to the new regimen and demonstrate their ability to enlarge the channel. These delays therefore will doubtless retard greatly the development of the channel at this important entrance on the West Gulf coast.
THE PROGRESSIVE DEEPENING PRODUCED BY THE BREAKWATER Without DREDGING OR OTHER AID.-In conclusion it remains only to state that this half completed, single breakwater has so far controlled the ebb currents as to have removed from the channel by their own energy some 400,000 cubic yards of compact, sandy material, and to have produced a progressive improvement of depths, as follows:
August 28, 1896. After suspension of work on breakwater by company..
6.0 December 10, 1896. Before old jetty was breached the depth was.
6.5 February 2, 1897. During use of dynamite.
8.0 June 8, 1897. After work was suspended...
and added, “ The S. E. wind this summer did not fill
January 4, 1899. Telegram announced (on pilot's range). 13.3 February 11, 1899. Capt. Welker wired the Coast Survey office....
ECONOMY AND DEPTHS UNPRECEDENTED.-So that in two years there was a gain of eight feet produced by a half-finished structure in the face of serious obstructions at a cost of less than $30,000 per foot depth as compared with from $200,000 to nearly $900,000 at other places by the usual twin jetty system. It may therefore be safely stated, even without awaiting the completion of the breakwater and the removal of the obstructing jetty, that as our respected VicePresident, Mr. Coleman Sellers, remarked only last evening in referring to the progress of the Mechanic Arts : “ Two blades of grass have been made to grow where one grew before.” In fact the adage may be carried further, since in this case the half of a blade (jetty) has done what two complete blades (jetties) have never done before in the same time, without dredging, and the American Philosophical Society has evidently not made a mistake of judgment in awarding its highly prized Magellanic premium and medal for this "invention and discovery."
GENEALOGICAL TREES OF BUTTERFLIES.
BY A, RADCLIFFE GROTE, A.M.
(Read October 6, 1899.)
Previous to 1897 the butterflies were generally regarded as mono. phyletic, springing from a single stem, the family branches being variously arranged by different authors. In classification they were kept together as “Rhopalocera ;" and the only exception to this course was the more recently attempted exclusion of the Skippers, the family Hesperiadæ, under an analogous title, equally derived from the Greek, and having reference to the structure of the horns or antennæ. It must be admitted that the reasons given for this were inconclusive, where they were not wholly absent.
From studies of the neuration I was able to announce (February,