action he was closely followed by all who served under him.

Is there any one then so blind or so unjust, as to praise the successful results of the combined and unwearied labours of so many able and conscientious men, and yet to withhold from the man in the track of whose example they had trodden, and by the fire of whose spirit they had been kindled into enthusiasm, that honour to which his memory is so justly entitled ?

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PART II.

HAVING followed General Colby to the last scene of exhibition of that personal energy which was so remarkable a feature in his character as a practical geodesist, the narrative must be retraced back to the epoch when Major Colby was required to extend the operations of the British Survey to Ireland: and in order to estimate correctly the magnitude and the difficulties of the task thus imposed upon him, it is necessary to compare together the objects of the previously existing and of the projected surveys, and to consider what means were then available for, or suitable to, the purposes of the prospective work.

It is not until civilization has made considerable progress, and the value both of time and labour has begun to be estimated with scrupulous precision, that the importance of good maps can be fully appreciated. Until then the bold huntsman or the hardy peasant pursues his way over rough and dangerous tracks, regardless both of the labour and of the difficulties of his journey; but when at last by the pressure of an increasing population and the multiplication of its wants, men are taught to economise every mo

ment of their own time, and of the labour of their horses and cattle, as being an element of production, the loss of which must be attended by a corresponding loss in the productive value of their property, they cannot long be blind to the importance of such maps as will guide them in laying out their roads and their canals, or assist them in studying the physical condition and the local peculiarities of the country they inhabit and the soil they cultivate. The successful execution however of extensive national maps depends on certain scientific principles which have been founded on an accurate knowledge of the figure of the earth, and it is not therefore surprising that the production of really good or accurate maps should have been reserved for an age of scientific excellence. In this country, indeed, as has been already shown, a great scientific operation, simple in its details but grand in its results; namely, the triangulation for determining the length of an arc of the meridian, as an element in estimating the figure of the earth, was the precursor of the national survey, and supplied the necessary data for combining together the surveys or plans of detached portions of the earth's surface, and for projecting them correctly as one whole in the map of an extensive country. This first survey, commenced as it was in detached fragments, had for its object a general representation only of the country, and though the field work was plotted on the scale of two inches to a mile, the map itself was engraved and published on a scale of one inch to a mile, which was manifestly in

sufficient for practical purposes; for though in a favourably situated district, such as Wales, a map on this scale, sketched and shaded with the skill of a Dawson, may have proved sufficient for the geologist in tracing out the great features of the ground, a similar map in a country of less marked reliefs would have proved inadequate even to so limited an object. Beautiful therefore as maps upon this scale have been, and can be made; and valuable as they are to the traveller, to the general student of a country, or even to the road maker, they are not sufficient for the wants which have grown out of the modern refinements in agriculture and the improved modes of general communication, or have been consequent on the pressure of an increasing population. Waste of time and waste of space can no longer be tolerated, and hence it is that the value of minutely detailed maps has at length been felt and acknowledged. Nor was it only in the object of the work, that the early survey differed from the survey as it now is; it differed from it also in the principle of its execution. The original survey having been grafted, as it were, upon an independent scientific work, was local, and detached in order of performance, and as the importance of a great national survey was at first only partly recognised, the annual parliamentary grant voted for it was small, and the work proceeded under all the disadvantages of a slowly protracted survey, an interrupted publication of unconnected maps, and a tone of shading and style of execution varying, though improving, in its progress.

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Subsequently, indeed, the work was viewed as a whole, and every care was taken after the publication of the map of Lincolnshire to revise the first published maps, to lower their depth of shade, and put them in harmony with the last; but still the defect of a system, in which every successive map represents a portion of the country in a different condition from the preceding one, must cling to this great work, until at a future period it shall undergo a general revision, undertaken simultaneously over the whole country, and be thus rendered a faithful record of the condition of the country at some one definite epoch.

The British Survey has just passed into the transition state between a collection of detached and not very harmonious works, and a work executed on uniform principles as one whole; and the maps had assumed, under the immediate superintendence of Lieut.-Colonel (then Captain) Mudge, R.E., and Lieut.-Colonel (then Lieutenant) Dawson, R.E., who were ably assisted by the intelligence and artistic skill of Mr. Baker, the chief engraver, that purity of style and just graduation of shade, which have raised them to the first rank amongst the most beautiful specimens of topography of the present age, when the attention of Government was powerfully directed to the wants of Ireland, hitherto overlooked as regarded the national survey. The object however of the Irish Members of Parliament was not to require the extension of the British survey and British map to Ireland, but to ask for a work which should serve as a basis for a general valuation and