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Further statistical tests have been made on levelling data in the Lac St. Jean area of QuCbec. These tests confirm that relative to QuCbec City there is downward movement focussed about Stoneham at the rate of 45.7 cm per century with a 95% confidence limit of * 14.5 cm per century, and that there is uplift to the north and west with rates and 95% confidence limits of 58.8 12.5 cm per century at St. Fklicien and 83.5 k 22.8 cm per century at Senneterre. A test for correlation between elevation differences and movement rates showed no significant effect; this is interpreted as evidence there was no appreciable systematic error in the levelling, From these analyses the possibility that the results might be explained in terms of errors, either random or systematic, can be rejected without any reservations.Des tests statistiques ont CtC effectues ultCrieurement sur des relevCs de niveau dans la rCgion du Lac St-Jean au QuCbec. Ces tests confirment l'existence, en rapport avec la ville de QuCbec, d'un mouvement descendant, concretrk aux environs de Stoneham, ceci B raison de 45.7 cm par sikcle avec une limite de confiance B 95% de "14.5 cm par sikcle, et celle d'un mouvement ascendant vers le nord et l'ouest avec des taux et des limites de confiance B 95% de 58.8 t-12.5 cm par sihcle St-FClicien et de 8 3 3 2 22.8 cm par siecle B Senneterre.Un test de corrklation entre les differences d'klevation et les taux de mouvement nc donne pas d'effet significatif. Ceci peut &re interprCtC comme une preuve de l'absence d'erreur systematique appriciable dans les relevis de niveau. Ces analyses amenent a rejeter sans reserve toute interprktation des rksultats en terme d'erreurs, soit dies au hasard, soit systdmatiques.[Traduit par le journal]Canadian Journal of Earth Sciences, 9, 1139 (197%) Can. J. Earth Sci. Downloaded from www.nrcresearchpress.com by MCGILL UNIVERSITY on 12/13/14For personal use only.

Many hitherto unexplained erratic gravimeter measurements can be attributed to the effect of vibration on the gravimeters during transportation between gravity stations. Experiments with four LaCoste and Romberg land gravimeters on a vibrating platform showed that all are affected to some degree by forced vibrations at frequencies and peak accelerations that can occur on common carriers. Two effects were found: all four gravimeters when subjected to vibration in the 35‐ to 70‐cps range for 1 min or more at peak accelerations of about ±1 g drifted erratically in the ±0.1‐mgal range; at about 48 cps positive drift as rapid as 1 mgal/min sometimes occurred. The threshold of acceleration needed to produce this unidirectional drift varied from ±0.5 to ±2.0 g for the meters that were tested. As there is extensive documentation to show that vibration of these intensities may occur at frequencies in this range in aircraft or land vehicles, it is concluded that vibration is the major cause of the inconsistent performance that is occasionally observed on these instruments. In experiments with foam rubber and mechanical isolators to minimize the effect of the ambient vibration field, it was found that by using mechanical isolators to support the gravimeter within the carrying case it was possible to eliminate the unidirectional drift at accelerations of ±2 g.

Seisrnic regionalization is defined as a rnethod of establishing earthquake risk factors using seismicity analyses supplemented, in some cases, by tectonic information Definit1ve catalogues have been published of all earthquakes known to have occurred in historical time in eastern Canada. The se provide the basis for a statistical evaluation of the earthquake risk. Good progress has been made on compilation of a regionalization map prepared objectively by sound statistical methods. It is anticipated that intime, this map will, supersede the present provisional map as a basis for evaluating the earthquake factors to be used for design loading in the National Building Code. Information on recent tectonic activity in eastern Canada is summarized. Although preliminary analysis of geomorphological, tide-gauge, relevelling and gravity data indicate that postglacial crustal tilting has been, is, and should be occurring on a regional scale, much more data are needed before there is any possibility of using tectonic information to supplement seismicity analyses for the regionalization of eastern Canada.

This 1912 book by Angus Hamilton (1874–1913), a Fellow of the Royal Geographical Society, is an account of the British military expeditions to quell uprisings among remote tribes in north-eastern India in 1911–12. Famous for his earlier books on Afghanistan, the problems of the Middle East, and Somaliland, Hamilton gives a full account of the various phases of the 'Abor expedition' which resulted in a crushing defeat of the local tribes. The book begins with a survey of the geography of the area, and a description of the Abor people, explaining the turbulent background to the murder in March 1911 of two British officials. A highly detailed and illustrated account then follows of the murders, and of the punitive response of the government in Delhi, which sent an expedition both to bring the area back under control and also to carry out geographical surveys of a relatively unknown area.