The chief drawback to type A is that the errors of the screw are liable to change by wear, otherwise the apparatus, as made and used at Potsdam, is, on the whole, a convenient and accurate one.
The early existence of an accurate system of dating is not surprising; it was necessitated by the fact that Babylonia was a great trading community, in which it was not only needful that commercial and legal documents should be dated, but also that it should be possible to refer easily to the dates of former business transactions.
Coincidently therewith, the hope of neutralizing infections by fortifying individual immunity has grown brighter, for it appears that immunity is not a very radical character, but one which, as in the case of vaccination, admits of modification and accurate adjustment in the individual, in no long time and by no very tedious methods.
From the first he appreciated the importance of accurate measurement, and all through his life the attainment of exact quantitative data was one of his chief considerations.
A survey sufficiently accurate as regards the maritime parts was also executed, under the orders of the British admiralty, by Captain Graves and Captain (afterwards Admiral) Spratt.
Foxe, who died in 1587, included a vast and generally accurate collection of documents in his Acts and Monuments, popularized as the Book of Martyrs, though his own contributions have to be discounted as much as those of Sanders, Parsons and other Roman Catholic controversialists.
The most accurate method for the determination of lead in ores is the gravimetric method, in which it is weighed as lead sulphate after the various impurities have been separated.
The French map on a scale of 1: 80,000 is clearer and more accurate than that on a scale of 1: 100,000.
The development of the compound microscope rendered possible the accurate study of their life-histories; and the publication in 1851 of the results of Wilhelm Hofmeister's researches on the comparative embryology of the higher Cryptogamia shed a flood of light on their relationships to each other and to the higher plants, and supplied the basis for the distinction of the great groups Thallophyta, Bryophyta, Pteridophyta and Phanerogamae, the last named including Gymnospermae and Angiospermae.
A wonderfully accurate register, or successive superposition of each block, is got mainly by the skill of the printer, who is assisted only by a mark defining one corner and another mark showing the opposite side limit.