204 PHILOSOPHICAL TRANSACTIONS. [aNNO I766. 



viate 2 or 3 degrees from right angles with the meridian, at that end where it 

 cuts it most nearly at right angles, in case the situation and circumstances of 

 the country should make this more convenient, the errors, that would be occa- 

 sioned by such a deviation, being too small to affect the conclusion. And if this 

 deviation was still much greater, and the length of a degree of the meridian at 

 the same place was known, it would be very easy to make the necessary cor- 

 rections. 



It will perhaps be objected, that the method above proposed depends, in some 

 measure, on time, as well as others, the finding of the meridian not being to be 

 performed without it; but it must be observed, that the motion of the pole star, 

 by which it is proposed to find the meridian, being slower than that of a star at 

 the equator, nearly in the proportion of 30 to 1, this method will admit of an 

 exactness greater in the same proportion (except the reduction of the sin. to the 

 R. before-mentioned) than those observations, by which we endeavour to find the 

 difference of the longitude of two places, by the difference of the time of the sun 

 or a star's coming to their respective meridians. 



The method above proposed will also require different instruments from those 

 commonly in use; but admitting that instruments of equal radius are capable of 

 equal exactness, this method will admit of the same exactness with the observa- 

 tions of a degree of the meridian, except the before-mentioned limitation. Nor 

 would the instruments for this purpose, if well contrived, be either less portable, 

 or more expensive, than those for measuring a degree on the meridian ; the same 

 telescope which would be necessary for finding the meridian, would serve like- 

 wise for tracing the arc of a great circle. It may further be observed that by 

 means of the above-mentioned method, a country not too near the equator, nor 

 attended with any other unfavourable circumstances, might be laid down with 

 great exactness. By running a great circle nearly e. and w. through the midst 

 of it, we should get the longitude of all the places the great circle passed over; 

 and if, by means of the meridian telescope, we should trace meridians through 

 a few of these places, as far n. and s. as the survey was intended to be carried, 

 we should then have a number of stations, in several parts of the country, whose 

 longitudes, with respect to each other, would be very accurately determined, and 

 to which other places might easily be referred, when the length of a degree of 

 longitude in those situations was known. 



XFII. Observationes de Ascaridibus et Cucurbitinis, et potissimum de Taenia, 

 tarn humana quam leporina. p. 126. 

 In the present advanced state of knowledge respecting the different species of 

 worms found in the intestines of man and other animals, there is nothing in this 

 paper sufficiently interesting for republication. 



