Q.U A 
Tranf. 
Quab. A letter concerning an extraordinary fifh 
called in Rufiia, quab, and concerning the 
{lores called crabs eyes - Baker 
Quadrable. Letter concerning the fpaces in the 
cycloid, which are perfe&ly quadrable 
Wallis 
Quadrant. The defcription of a new quadrant 
for taking altitudes without an horizon, either 
at fea or land - Elton 
- ■ A fpirit level to be fixed to a quadrant for taking 
a meridional altitude at fea when the horizon 
is not vifible - - Hadley 
■ ■■ — An account of Mr. Thomas Godfrey’s improve- 
ment of Davh’s quadrant, transferred to the 
mariner’s bow - Logan 
A defcription of a water-level to be fixed to 
Davis’s quadrant, whereby an observation 
may be taken at fea in thick and hazy weather, 
without feeing the horizon - Leigh 
■■ ■ ■ A defcription of anaftronomical mural quadrant 
freed from many of the inconveniences it has 
hitherto laboured under - Gerfien 
— — - A recommendation of Hadley’s quadrant for 
furveyn g, Specially the furveying of harbours, 
together with a particular application of it in 
fome cafes of pilotage - Michell 
— — A letter defcribmg fome addi • ions and alterations 
made t> Hadley s quadrant, to render it more 
ferviceable at fea - Dollond 
— Remarks on the Hadlev’s quadrant, ‘ tending 
princip lly to remove the difficulties which 
have hitherto attended the ufe of the back-ob- 
fer atio , and to obviate the errors that rnigh 
arife from a want of parallelifin in the two 
furfaces of the index glafs Majkelym 
■ See Level 
Quadratrix. The conflru&ion and properties of 
a new quadratrix to the hyperbola Perky 
XLV 174 
XIX111 
XXXVII 27 3 
XXXVIII 
167 
441 
XL 413 
XLIV 50; 
LV 70 
LXII 95 
99 
XXV 2253 
403 
Abridg. 
X 876 
I 116 
VIII 357 
- 366 
— 360 
XI43 
IV 66 
Quadratic* 
