The Fall of Fort Ticonderoga

This chapter discusses Burgoyne’s successful seizure of Fort Ticonderoga, the vital American position that guarded southern Lake Champlain and Lake George approach to the Hudson River and, ultimately, Albany. The significant leadership failures by the American commanders, especially Major General Arthur St. Clair and Major General Philip Schuyler, is examined in some depth. A combination of American failures—in preparation, execution, and the retreat—and the competent British conduct of operations, including the establishing of artillery on Mount Defiance, something the Americans believed was impossible, is discussed. Improperly sited fortifications, failure to secure key terrain, and an incompetently planned and executed retreat, ensured American failure to hold the fortification.

The First Invasion

This chapter describes the first British invasion of New York via the historic Lake Champlain, Lake George, and Hudson River route in the autumn of 1776. It starts with General Sir Guy Carleton’s successful defense of Canada and repulse of the American attempt to seize Quebec. The increasingly fraught relationship between Carleton and Lord George Germain is also addressed as is the naval arms race between the Americans and the British. This race delayed Carleton’s offensive south on Lake Champlain more than the celebrated Battle of Valcour Island, and he was forced to abandon the offensive after he reached Crown Point, much to the dismay of his second-in-command, Lieutenant General John Burgoyne. This failed first invasion planted the seeds for a new plan created in part by Burgoyne.

Passive acoustic determination of wave breaking dissipation rate across the spectrum

<p>The ambient sound near the ocean surface is controlled by many processes, while wave breaking becomes the dominant factor once it occurs. Laboratory experiment shows that a severer breaker will result in a higher sound level and a larger mean bubble size. This relationship indicates a potential to extract information about wave breaking from acoustic records. Based on both laboratory and field experiments, a passive acoustic method has been developed to determine the wave breaking dissipation rate across the spectrum which had been extremely difficult to obtain in the open sea. The laboratory experiments were carried out in a flume at the University of Adelaide. Waves of different amplitudes and periods were generated and triggered to break by an underwater obstacle. The wave profiles before and after breaking were measured by two capacitance probes to calculate their breaking severities. The acoustic noise emitted by bubbles was recorded by a hydrophone located right under the breaking zone and the mean bubble sizes were computed on the basis of the relationship between bubble radius and acoustic frequency. A non-dimensional empirical formula between breaking severity and mean bubble size was established then applied to acoustic measurements in Lake George, New South Wales, Australia. Acoustic pulse amplitude, power spectral density of acoustic spectrum and the ratio between acoustic pulse amplitude and period were analyzed to identify the acoustic pulses truly produced by bubbles. The mean bubble sizes of each breaker were deduced from the acoustic records and further converted into their breaking severities. Combined with the wave scale information extracted from wave surface records, the spectral dissipation rates in Lake George were finally obtained. The acoustic based results are compared with various kinds of whitecapping dissipation source terms of WAVEWATCH III® and their differences are discussed.</p>

U-Pb, Ar-Ar, and Re-Os Geochronological Constraints on Multiple Magmatic–Hydrothermal Episodes at the Lake George Mine, Central New Brunswick

The Lake George antimony mine was at one time North America’s largest producer of antimony. Despite being widely known for the antimony mineralization, the deposit also hosts a range of styles of mineralization such as multiple generations of W-Mo bearing quartz veins as well as a system of As-Au bearing quartz–carbonate veins. In situ U-Pb zircon geochronology, using LA ICP-MS, of the Lake George granodiorite yielded a weighted mean 206Pb/238U age of 419.6 ± 3.0 Ma. Step heating of phlogopite separated from the lamprophyre dykes produced a 40Ar/39Ar plateau segment date of 419.4 ± 1.4 Ma. Single molybdenite crystal analysis for Re-Os geochronology was conducted on two W-Mo-bearing quartz veins, which cross-cut altered granodiorite and altered metasedimentary rocks and yielded two dates of 415.7 ± 1.7 Ma and 416.1 ± 1.7 Ma respectively. 40Ar/39Ar geochronology of muscovite from alteration associated with Au-bearing quartz–carbonate veins yielded one representative plateau segment date of 414.1 ± 1.3 Ma. The dates produced in this study revealed that the different magmatic–hydrothermal events at the Lake George mine occurred over approximately a 10-million-year period at the end of the Silurian and the start of the Devonian following the termination of the Acadian orogeny.